T.R. EGE UNIVERSITY

DEPARTMENT OF CHEMICAL ENGINEERING KMY 401 CHEMICAL ENGINEERING DESIGN

08.10.2008

BORNOVA/IZMIR

Submitted to:

Prof. Dr. H. Ferhan ATALAY Prof. Dr. Firuz BALKA�

Assist. Dr. Zehra ÖZÇELĐK

PROJECT: FORMALIN

PRODUCTION REPORT: 1

Prepared by:

05057361 Günter KULEŞOĞLU 05057274 Duygu BAYRAKTAR

05057288 Sinem ARMAY 05057330 Ayça ATA

CONTENTS

SUMMARY i

1.01.01.01.0 INTRODUCTION 1111

2.02.02.02.0 RESULTS 3333 2.1 PHYSICAL PROPERTIES 5

2.2 CHEMICAL REACTIONS 7

2.1.1 DECOMPOSITION 7 2.1.2 POLYMERIZATION 7 2.1.3 REDUCTION AND OXIDATION 7 2.1.4 ADDITION REACTIONS 8 2.1.5 CONDENSATION REACTIONS 8 2.1.6 RESIN FORMATION 9

2.3 USAGE AREA 9

2.4 STORAGE AND TRANSPORTATION 11

2.5 TOXICOLOGY, OPERATIONAL HEALTH AND PROCESS SAFETY 13

2.5.1 ACUTE TOXICITY 14

2.5.2 CANCER EPIDEMIOLOGY 16

2.5.3 ANIMAL CANCER STUDIES 19

2.5.4 GENOTOXICITY 19

2.5.5 FIRE AND EXPLOSION HAZARD 20

2.5.6 REACTIVITY 20

2.5.7 EMERGENCY AND FIRST AID PROCEDURES 20

2.5.8 spıll, leak and dısposal procedures 21

2.5.9 monıtorıng and measurıng procedures 21

2.5.10 protectıve equıpment and clothıng 22

2.5.11 engıneerıng and controls 23

2.5.12 medıcal surveıllance 23

2.5.13 envıronmental ıssues 24

2.6 economıc aspects 25

2.7 dısposal 31

3.03.03.03.0 DISCUSSION & CONCLUSIONS 32

4.04.04.04.0 REFERENCES 37

5.05.05.05.0 apPendıCES 38-45

SUMMARY

Formalin is the aqueous form (37 wt%) of formaldeyhde produced mostly from

methanol by an oxidation process. Because formaldehyde is highly water soluble, it is usually

marketed as a liquid solution, typically at 37 weight percent formaldehyde solution, combined

with water and up to 16 percent methanol. Recently, the production volume of formaldehyde

has grown rapidly with increasing demand in manufacturing sector for resins including

phnolic, urea, melamin, acetal many additives. Other additional application areas of

formaldehyde include surface coating, leather tanning, bindery applications, laminates,

insulation materials, etc. Also, formaldehyde is a preservative disinfection of bacteria.

Formalin is mainly manufactured by methanol oxidation of which processes are “

excess methanol process” and “excess air process” and “combined cataylst process.” The

basic difference between them is the catalyst applied. The methanol excess process, called the

silver process, employs silver as the catalyst while the air excess process (molybdenum

process) uses metallic oxides of iron and molybdenum. In considering higher investment cost

and more complicated operation than the silver process, it is recommended to use the silver

process.

Uses of formalin can be summarized as follows:

Phenol resin and adhesives, urea and melamine adhesives

Urea resin, melamine resin, hexamethy lenetetramine

Pentaerythritol, paraformaldehyde

Medicines and agricultural chemicals

Polyacetal resin

Hemiformal

Moreover, use of formaldeyhde derivatives and formalin are explained comprehensively

in Results part. Manufacturing processes of formalin are studied and the flow sheets of the

processes are given in the Appendix part. Also, there are known effects of formaldehyde and

its derivatives, therefore the needed information about its toxicology, exposure even

occupatioanl health and environmental issues are given in the Results section.

1.0 INTRODUCTION

Since Blum’s proposal of formalin as a useful general biological fixative in 1893 it has

become an unsurpassed standard. For 119 years zoologists, botanists, histologists, and

pathologists have used formalin to preserve their materials for a detailed anatomical,

histological or cytological study. To pathologists it represents until now the only admissible

standard, in spite of the denounced toxicity of the product.

Formalin is an aqueous solution of formaldehyde. The typical concentration is 37 - 40

%. That is, it is expected that a commercial formalin has 370 - 400 g of formaldehyde in each

1000 g of commercial solution. The intended dilution is w/w, not vol/vol. Formaldehyde is a

nearly colorless gas with a pungent, irritating odor even at very low concentrations (below 1

ppm). Its vapors are flammable and explosive. Because the pure gas tends to polymerize, it is

commonly used and stored in solution. Formalin, the aqueous solution of formaldehyde (30%

to 50% formaldehyde), typically contains up to 15% methanol as a stabilizer. As

formaldehyde is self-reactive, and continues to oxidize in aqueous solution producing formic

acid, and in older solutions may even form a precipitate of paraformaldehyde (a solid

polymerized formaldehyde). Formalin solutions thus really contain formaldehyde,

paraformaldehyde, formic acid, and methanol.

Formaldehyde is used in the manufacture of plastics; urea-formaldehyde foam

insulation; and resins used to make construction materials (e.g., plywood), paper, carpets,

textiles, paint, and furniture.

The first industrial process for production of formalin, an aqueous solution of

formaldehyde, was based on oxidative dehydrogenation of methanol over a copper catalyst.

Improvements in catalyst technology resulted in substitution of the copper catalyst for an

unsupported silver catalyst, which is the formula still used today. In the 1950s a competing

process for production of formaldehyde was developed. This process was based on selective

(partial) oxidation of methanol over an Fe-Mo (molybdenum and iron) oxide catalyst. The

two processes, (Oxidation-dehydrogenation using a silver catalyst involving either the

complete or incomplete conversion of methanol; and the direct oxidation of methanol to

formaldehyde using metal oxide catalysts (Formox process)), referred to as silver and oxide

processes respectively, are used today for the production of formalin on the industrial scale.

Each process accounts for about 50% of the total production of formalin, which today

amounts to about 20Mton per annum, expressed as 37 wt% HCHO in water.

In the silver process, vapourised methanol with air and steam is passed over a thin bed

of silver-crystal catalyst at about 650oC. Formaldehyde is formed by the dehydrogenation of

methanol. The heat required for the endothermic reaction is obtained by burning hydrogen

contained in the off-gas produced from the dehydrogenation reaction. The other process,

oxide process, involves the oxidation of methanol over a catalyst of Fe-Mo oxide. A mixture

of air and methanol is vapourised and passed into catalyst-packed reactor tubes. The reaction

which takes place at 350oC is highly exothermic and generates heat to provide steam for

turbines and process heating. Yields from both processes are around 90% to 92% but the

oxide process has a lower reaction temperature and the metal catalyst is cheaper than silver.

However, the silver process is still the most prevalent.

A wide range of alternative feedstocks have been considered but not found to be

economic. For example, a tiny amount is produced from the non-catalytic oxidation of

propane-butane mixtures. Formaldehyde can be produced from methane but a mixture of

products needs to be separated. It is also a byproduct of the oxidation of naphtha to acetic

acid.

Formaldehyde can cause irritation of the eyes, nose, and throat, even at low levels for

short periods. Longer exposure or higher doses can cause coughing or choking. Severe

exposure can cause death from throat swelling or from chemical burns to the lungs. Direct

contact with the skin, eyes, or gastrointestinal tract can cause serious burns. Drinking as little

as 30 mL (about 2 tablespoons) of formalin can cause death. Formate, a formaldehyde

metabolite, can cause death or serious systemic effects. Generally, more serious the exposure

to formaldehyde is the more severe are the symptoms. Previously sensitized persons may

develop a skin rash or breathing problems from very small exposures.

Formaldehyde has low cost, high purity, and variety of chemical reactions, so it has

become one of the world’s most important industrial and reasearch chemicals. More than 50

branches of industry now use formaldehyde, mainly in the form of aqueous solutions and

formaldehyde-containing resins. Worldwide production of formaldehyde is at /103 6× .

2.0 RESULTS

Formaline process description information and other related information found in

literature during feasibility study is composed in a logical order. Firstly process description is

given as a result:

The direct synthesis of formaldehyde from hydrocarbons has not yet resulted in cost

reductions and because of the reactivity of formaldehyde, its handling and separation, as well

as its direct preparation from hydrocarbons, are difficult. These factors, in the past, have

exerted considerable influence on the pattern of formaldehyde growth.

Currently, the only and competing production technologies for formaldehyde of

commercial significance are based on the partial oxidation and dehydrogenation of methanol

using a silver catalyst, or partial oxidation of methanol using a metal oxide-based catalyst

since nearly all of the world's formaldehyde is made from methanol.

In the silver catalyst route, which is also known as Methanol Excess Process,

vaporized methanol with air and steam is passed over a thin bed of silvercrystal catalyst at

about 650°C. Formaldehyde is formed by the dehydrogenation of methanol. The heat required

for the endothermic reaction is obtained by burning hydrogen contained in the off-gas

produced from the dehydrogenation reaction.

The other route, which is also known as Air Excess Process, involves the oxidation of

methanol over a catalyst of molybdenum and iron oxide (Formox Process - developed and

licensed by Reichhold Chemicals). A mixture of air and methanol is vaporized and passed

into catalyst-packed reactor tubes. The reaction which takes place at 350ºC is highly

exothermic and generates heat to provide steam for turbines and process heating.

A high pressure version of the Formox Process called as Perstorp Process also exists,

which can be retrofitted to existing plants to boost capacity. The high conversion rate of the

process eliminates the need for methanol recovery via distillation, and it can produce

formaldehyde at concentrations up to 57%.

SILVER CATALYST PROCESS: The silver catalyst process employs two main reactions,

which are given below, to convert methanol to formaldehyde: Dehydrogenation and Partial

Oxidation.

OHHCHOOOHCH

HHCHOOHCH

223

23

21 +→+

+→

The equilibrium conversion in the dehydrogenation reaction is highly temperature

dependent. The amount of process air controls the temperature by supplying oxygen to the

exothermic reactions, including oxidation of hydrogen. The addition of inert materials such as

water or nitrogen can also aid conversion by permitting the use of higher methanol

concentrations relative to oxygen without entering the explosive region. These techniques

permit variations in the process:

Incomplete conversion plus separation and recycle of unreacted methanol,

Complete conversion.

The usual commercial form of the silver catalyst process involves incomplete

conversion of methanol at lower temperatures, which minimizes byproducts, followed by

distillation to remove and recycle the methanol. This allows the fine-tuning of the amount of

methanol in the final product.

Formaldehyde product may be produced at concentrations of up to 52- 55% by

adjusting the amount of water added in formaldehyde absorption. Methanol concentrations

can be adjusted as required (normally less than 1%) by distillation. In some cases, an ion

exchange unit is needed to reduce the formic acid concentrations, but most commercial

processes claim a figure of 0.06% without ion exchange.

The methanol conversion per pass is typically 75- 85%, and overall process yield of

formaldehyde from methanol is 90- 92 mol percent.

Impurities, particularly iron, determine the catalyst life. The catalyst bed has a

tendency to become matted under conditions of high temperature and throughput. Catalyst life

is typically one year and it may be electrolytically regenerated.

Although steam is generated internally, with most designs there is a net steam import

requirement. At a temperature of around 700°C, methanol conversion is sufficiently high to

dispense with the final distillation column.

A complete conversion process plant is similar to that described for incomplete

conversion, described above, in most other respects.

METAL OXIDE CATALYST PROCESS: The basis of the metal oxide catalyst process is the

vapor-phase oxidation of methanol with excess oxygen (from air) at temperatures of 250-

400°C.

Metal oxides in the catalyst are typically molybdenum and iron at a molar ratio of 1.5

to 2.0 (Mo:Fe). Small amounts of oxides of vanadium, cobalt, phosphorus, chromium and

copper may also be included.

Further reactions can occur to some extent, depending on temperature. These include

the continued oxidation of formaldehyde to formic acid and carbon monoxide, and

dehydration of methanol to dimethyl ether.

A significant variation on this process is the absorption of the formaldehyde into a

urea solution to make urea-formaldehyde precondensate. This can be used for the production

of urea-formaldehyde resins, the largest single use of formaldehyde.

Recycle of inerts permits the use of relatively high methanol concentrations without

creating an explosive mixture. Oxygen concentration is kept to approximately 10%, whereas

methanol is around 6- 9%, both on a molar basis.

The Fe/Mo oxide catalyst is relatively insensitive to impurities such as iron carbonyls

in the methanol feedstock. In a typical design, the catalyst is supplied as rings, and a very

constant temperature profile is maintained by the use of a number of layers with different

catalytic activities. A typical catalyst life is 18 months.

Export steam from the process is around 0.5 pound per pound of product. Licensors

claim methanol conversion per pass of 92- 94%. Therefore, no distillation column is required

to recover and recycle methanol in the product stream. Maximum methanol content ranges

from between 0.5 and 1.0 percent for 37 weight percent product to 1.5 percent for 50 weight

percent product. The formaldehyde solution typically contains 0.02- 0.04 percent formic acid.

If required, the formic acid concentration can be further reduced in an ion exchangers.

2.1 PHYSICAL PROPERTIES

Formaldehyde, CH2O, formula weight 30.03 is the first member of the series of

aliphatic aldehydes, is a colorless gas at ambient temperature that has a pungent, suffocating

odor and an irritant action on the eyes and skin.

Formaldehyde gas is flammable, its ignition temperature is 430 °C; mixtures with air are

explosive. At ca. 20 °C the lower and upper explosive limits of formaldehyde are ca. 7 and

72vol% (87 and 910 g/m3), respectively. Flammability is particularly high at a formaldehyde

concentration of 65-70 vol %.

At a low temperature, liquid formaldehyde is miscible in all proportions with nonpolar

solvents such as toluene, ether, chloroform, or ethyl acetate. Polar solvents, such as alcohols,

amines or acids, either catalyze the polymerization of formaldehyde or react with it to form

methylol compounds or methylene derivatives.

Since pure formaldehyde is a gas at ordinary temperatures and cannot be readily

isolated or handled in this state, it is marketed chiefly in the form of its aqueous solutions.

Monomeric physically dissolved formaldehyde is only present in low concentrations

of up to 0.1 wt%. At ordinary temperatures, formaldehyde gas is readily soluble in water,

alcohols and other polar solvents. Dissolution of formaldehyde in water is exothermic, the

heat of solution (62 kJ/mol) being virtually independent of the solution concentration. Clear,

colorless solutions of formaldehyde in water can exist at a formaldehyde concentration up to

% wt 95, but the temperature must be raised to 120° C to obtain the highest concentrations.

Concentrated aqueous solutions containing more than 30 wt% formaldehyde becomes cloudy

on storage at room temperature, because larger poly glycols are formed which then precipitate

out. The partial pressure of formaldehyde in equilibrium with the solution is low, due to

solvation, and is a function of methylene glycol concentration rather than the total

formaldehyde content. Formaldehyde is apparently not appreciable associated in the gaseous

state, and its partial pressure may be regarded as the decomposition pressure of the dissolved

hydrate. These factors explain the fact that formaldehyde solutions may be concentrated by

vacuum evaporation at low temperatures, whereas pressure distillation at high temperatures

makes its possible to obtain concentrated distillates from dilute solutions. On distillation at

ordinary pressures without rectification, the still residue is always somewhat more

concentrated than the distillate solution. Fractional condensation of the vapors of boiling

solutions results in increasing ratio of formaldehyde to water in uncondensed vapors since

water is the least volatile constituent of the mixed vapor.

For more information on physical properties of formalin, see the MSDS given in

Appendix.

2.2 CHEMICAL REACTIONS

Formaldehyde is one of the most reactive organic compounds known and, thus, differs

greatly from its higher homologues and aliphatic ketones. Formaldehyde will combine

chemically with practically every type of organic chemical with the exception of paraffin. It can

be employed as in the form of monomer, solution or polymer with essentially equivalent result. In

general, the form used is of importance chiefly in its effect on the rate of reaction. Monomeric

and polymeric forms are of special value where the presence of water is undesirable. Solutions

and polymers are less reactive than the monomer, since they represent lower energy potentials in

which the aldehyde has already reacted with itself or water. The most important reactions are

treated as below:

2.2.1 DECOMPOSITION

At 150 °C, formaldehyde undergoes heterogeneous decomposition to form mainly

methanol and CO2. Above 350°C, however, it tends to decompose into CO and H2. Metals such

as platinum, copper, chromium, and aluminum catalyze the formation of methanol, methyl

formate, formic acid, CO 2, and methane.

2.2.2 POLYMERIZATION

Anhydrous monomeric formaldehyde cannot be handled commercially. Gaseous

formaldehyde polymerizes slowly at temperatures below 100 °C, polymerization being

accelerated by traces of polar impurities such as acids, alkalis, or water. Thus, in the presence of

steam and traces of other polar compounds, the gas is stable at ca. 20 °C only at a pressure of

0.25-0.4 kPa, or at a concentration of up to ca. 0.4 vol% at ca. 20 °C and atmospheric pressure.

Monomeric formaldehyde forms a hydrate with water; this hydrate reacts with further

formaldehyde to form polyoxymethylenes. Methanol or other stabilizers, such as guanamines or

melamines, are generally added to commercial aqueous formaldehyde solutions (37-55 wt%)

to inhibit polymerization.

2.2.3 REDUCTION AND OXIDATION

Formaldehyde is readily reduced to methanol with hydrogen over a nickel catalyst. For

example, formaldehyde is oxidized by nitric acid, potassium permanganate, potassium

dichromate, or oxygen to give formic acid or CO, and water,

In the presence of strong alkalis or when heated in the presence of acids, formaldehyde

undergoes a Cannizzaro reaction with formation of methanol and formic acid. In the presence

of aluminum or magnesium methylate, paraformaldehyde reacts to form methyl formate

(Tishchenko reaction).

2.2.4 ADDITION REACTIONS

The formation of sparingly water-soluble sodium formaldehyde bisul-fite is an

important addition reaction of formaldehyde. Hydrocyanic acid reacts with formaldehyde to

give glycolonitrile. Formaldehyde undergoes an acid-catalyzed Pnns reaction in which it forms

a-hydroxy-methylated adducts with olefms .Acetylene undergoes a Reppe addition reaction with

formaldehyde to form 2-butyne-l,4-diol. Strong alkalis or calcium hydroxide convert

formaldehyde to a mixture of sugars, in particular hexoses, by a multiple aldol condensation

which probably involves a glycolaldehyde intermediate. Mixed aldols are formed with other

aldehydes; the product depends on the reaction conditions. Acetaldehyde, for example, reacts

with formaldehyde to give pentaerythritol, C(CH,OH)4 .

2.2.5 CONDENSATION REACTIONS

Important condensation reactions are the reaction of formaldehyde with amino groups to

give Schiff s bases, as well as the Mannich reaction. Amines react with formaldehyde and

hydrogen to give methyl-amines. Formaldehyde reacts with ammonia to give

hexamethylenetetramine, and with ammonium chloride to give monomethylamine, dime-

thylamine, or trimethylamine and formic acid, depending on the reaction conditions. Reaction

of formaldehyde with diketones and ammonia yields imidazoles.

Formaldehyde reacts with many compounds to produce methylol (-CH2OH)

derivatives. It reacts with phenol to give methylolphenol, with urea to give mono-, di-, and

trimethylolurea, with melamine to give methylolmelamines, and with organometallic

compounds to give metal-substituted methylol compounds.

Aromatic compounds such as benzene, aniline, and toluidine combine with

formaldehyde to produce the corresponding diphenyl-methanes. In the presence of

hydrochloric acid and formaldehyde, benzene is chloromethylated to form benzyl chloride.

Formaldehyde reacts with hydroxylamine, hydrazines, or semicarbazide to produce

formaldehyde oxime (which is spontaneously converted to triformoxime), the corresponding

hydrazones, and semicarbazone, respectively. Double bonds are also produced when

formaldehyde is reacted with malonates or with primary aldehydes or ketones possessing a CH2

group adjacent to carbonyl group.

2.2.6 RESIN FORMATION

Formaldehyde condenses with urea, melamine, urethanes, cyanamide, aromatic

sulfonamides and amines and phenols to give a wide range of resins.

2.3 USAGE AREA

Formalin is an aqueous solution of formaldehyde. Formaldehyde has been used for

many years in consumer goods to deter spoilage caused by microbial contamiantion. It has

been used as a preservative in household cleaning agents, dishwashing liquids, fabric

softeners, shoe-care agents, car shampoos and waxes, and carpet cleaning agents. Generally

the formaldehyde content in these products is less than 1%.

Formaldehyde is commercially offered as a 37 wt% to 50 wt% aqueous solution, with

37 wt% (known as formalin or formol) being the most widely used grade which may also

contain 0-15 wt% methanol and a polymerisation inhibitor. As formaldehyde is self-reactive,

and continues to oxidize in aqueous solution producing formic acid, and in older solutions

may even form a precipitate of paraformaldehyde (a solid polymerized formaldehyde).

Formalin solutions thus really contain formaldehyde, paraformaldehyde, formic acid, and

methanol.

Formaldehyde is used as a chemical intermediate in the manufacture of a large variety

of organic compounds, ranging from amino and phenolic resins to slow release fertilizers.

Products manufactured using organic compounds, where formaldehyde is used as a chemical

intermediate in their production, include: plywood adhesives, abrasive materials, insulation,

foundry binders, and brake linings made from phenolic resins, surface coatings, molding

compounds, laminates and wood adhesives made from melamine resins; phenolic

thermosetting, resins curing agents and explosives made from hexamethylenetetramine;

urethanes, lubricants, alkyd resins and multifunctional acrylates made from

trimethylolpropane; plumbing components from polyacetal resins; and controlled-release

fertilizers made from urea formaldehyde concentrates. Polyacetal plastics produced by

polymerization of formaldehyde are incorporated into automobiles to reduce weight and fuel

consumption. They are also used in the manufacture of functional components of audio and

video electronics equipment.

Formaldehyde solutions have also been used for disinfecting dwellings, ships, storage

houses, utensils, and clothing. Solutions containing 28% formaldehyde have been used as

germicides to disinfect inanimate objects. Formaldehyde is used as a tissue preservative and

disinfectant in embalming fluids.

In agricultural industry, formaldehyde has been used as a fumigant, as a preventative

for mildew and spelt in wheat, and for rot in oats. It has been used as a preplanting soil

sterilant in mushroom houses. Formaldehyde has been used as a germicide and a fungicide for

plants and vegetables; as an insecticide for destroying flies and other insects; and in the

manufacture of slow-release fertilizers. Approximately 80% of the slow-release fertilizer

market is based on urea-formaldehyde-containing products.

Formaldehyde continues to be used in the manufacture of glass mirrors, explosives,

artificial silk and dyes; for waterproofing fabrics; for preserving and coagulating rubber latex;

and for tanning and preserving animal hides. In photography industry, formaldehyde has been

used for hardening gelatin plates and papers, toning gelatin-chloride papers, and for chrome

printing and developing.

Formaldehyde is used as an antimicrobial agent in many cosmetic products, including

soaps, shampoos, hair preparations, deodorants, lotions, make-up, mouthwashes, and nail

products. Formaldehyde is incompatible with ammonia; alkalies; tannin; iron preparations;

and salts of copper, iron, silver, potassium permanganate, iodine, and peroxide. When it is

used as a preservative in shampoos, formaldehyde may interact unfavorably with both

fragrance components and color additives. Some cosmetics have reportedly contained 0.6%

formaldehyde, while concentrations as high as 4.5% have been detected in nail hardeners.

Formaldehyde concentrations in dry-skin lotions, creme rinses, and bubble bath oils have

reportedly ranged from 0.4 to 0.5%. Formaldehyde has also been found in sun-tan lotion and

hand cream, bath products, mascara and eye make-up, cuticle softeners, nail creams, vaginal

deodorants, and shaving creams. Trace amounts of formaldehyde found in cosmetic products

could also result from its use as a disinfectant of the manufacturing equipment.

Compared to its use in product manufacturing, the use of formaldehyde in the medical

fields is relatively small. Consumption in this area averages approximately 1.5% of the total

production volume. Some of the earlier, minor, medicinal applications for formaldehyde

included its use during vasectomies, as a foot antiperspirant or as a preservative in such

products, as a treatment for athlete’s foot, and as a sterilant for echinococcus cysts prior to

their surgical removal. In veterinary medicine, formaldehyde has been used therapeutically as

an antiseptic and as a fumigant. It has also been used to treat tympany, diarrhea, mastitis,

pneumonia, and internal bleeding in animals. In animal nutrition, formaldehyde is used to

protect dietary protein in ruminants. It is used as a food additive to improve the handling

characteristics of animal fat and oilseed cattle food mixtures.

Other industries using formaldehyde in their processes include the sugar industry

where formaldehyde is used as an infection inhibitor in producing juices; the rubber industry

where it is used as a biocide for latex, an adhesive additive, and an anti-oxidizer additive for

synthetic rubber; and the food industry where it is used for preserving dried foods,

disinfecting containers, preserving fish and certain oils and fats, and modifying starch for cold

swelling. It has been use as a bacteriostatic agent in some foods, such as cheese. In the

petroleum industry, formaldehyde is used as a biocide in oil well-drilling fluids and as an

auxiliary agent in refining. Formaldehyde has been used as an anti- corrosive agent for

metals. In the plastics industry, for the preparations of phenol, urea, and melamine resins,

where the presence of water could interfere with the production process, paraformaldehyde

may be used in place of aqueous formaldehyde solutions. In addition to its use in selected

pesticide applications, paraformaldehyde has also been used in making varnish resins,

thermosets, and foundry resins, the synthesis of chemical and pharmaceutical products, the

preparation of disinfectants and deodorants, and the production of textile products.

Formaldehyde was used in the textile industry as early as the 1950s when formaldehyde-based

resins were initially used to produce crease-resistant fabrics. Postproduction analysis

indicated that these early resins contained a substantial amount of extractable formaldehyde

(more than 0.4% by weight of the fabric. With the introduction of new resins and other

process modifications in the 1970s, the level of extractable formaldehyde in crease-resistant

fabrics gradually decreased to 0.01–0.02%.

2.4 STORAGE AND TRANSPORTATION

With a decrease in temperature and/or an increase in concentration, aqueous

formaldehyde solutions tend to precipitate paraformaldehyde. On the other hand, as the

temperature increases, so does the tendency to form formic acid. Therefore, an appropriate

storage temperature must be maintained.

Table 2.1: Storage temperatures for commercial formaldehyde solutions.

Formaldehyde content, wt%

Methanol content, wt% Storage Temperature, °C

30 ≤1 7-10

37 <1 35

37 7 21

37 10-12 6-7

50 1-2 45*

50 1-2 60-65

*Stabilized with 200 mg/kg of isophthalobisguanamine.

The addition of stabilizers is also advisable (e.g., methanol, ethanol, propanol, or

butanol). However, these alcohols can be used only if they do not interfere with further

processing, of if they can be separated off; otherwise, effluent problems may be encountered.

The many compounds used for stabilizing formaldehyde solutions include urea,

melamine, hydrazine hydrate, methylcellulose, guanamines, and bismelamines. For example,

by adding as little as 100 mg of isophthalobisguanamine per kg of solution, a 40 wt%

formaldehyde solution can be stored for at least 100 days at 17 °C without precipitation of

paraformaldehyde, and a 50 wt% formaldehyde solution can be stored for at least 100 days at

40 °C.

Formaldehyde can be stored and transported in containers made of stainless steel,

aliminum, enamel, or polyester resin. Iron container lined with epoxide resin or plastic may

also be used, although stainless steel containers are preferred, particularly for higher

formaldehyde concentrations. Unprotected vessels of iron, copper, nickel, and zinc alloys

must not be used.

The flash point of formaldehyde solution is in the range 55-85 °C, depending on their

concentrations and methanol content. According to German regulations for hazardous

substances (Gefahrstoffverordnung, Appendix 6) and Appendix 1 of the EEC (European

Economic Community) guidelines for hazardous substances, aqueous formaldehyde solutions

used as working materials that contain ≥1 wt% of formaldehyde must be appropriately

labeled.

Formaldehyde should be stored in a cool, dry, well-ventilated area and properly

labeled. Formaldehyde should never be stored in vehicles except to transport to and from

field during sampling operations. Used formaldehyde, either from spill clean-up or from

activities generated from the process of change-out of sample containers must be stored in a

properly labeled hazardous waste container and made available for recycling under Resources

Conservation Recovery Act (RCRA) protocols. Storage of waste formaldehyde should be in

an area not frequented by the general population or duty workers and should be in an area not

subject to heat cycles and well ventilated.

Formaldehyde should be transported only in original container, fully labeled and

stored properly within the vehicle to prevent shifting, spillage or breakage. Formaldehyde

should never be opened, mixed or transferred to sample vials at any time inside a closed

vehicle. A Materials Safety Data Sheet (MSDS) should be in the possession of the user and

made available to those working with this chemical.

During operational use and/or during transportation where an accidental spill is likely

to occur, each field unit should have as part of their required emergency equipment, sufficient

absorbent material to handle small spills. Clean, 1 gallon plastic Nalgene containers with

Teflon screw caps, or equivalent, clearly labeled, should be available for small spills and for

transporting used formalin from the field to the laboratory for proper disposal. Care should be

exercised during clean-up that no person becomes dermally exposed to formaldehyde. If,

during the emergency, the spill occurs where there is insufficient ventilation to proceed with

clean-up, the area should be vacated immediately and others should be prevented from

entering the spill area unless properly suited and with a self- contained air supply. Proper

authorities should be notified if the spill occurs on a roadway or has potential to do harm by

entering a water supply or other bodies of water where there is a greater exposure potential to

humans and/or an aquatic ecosystem. A record of how much of the chemical was spilled and

the method of clean-up and proper disposal should be under-taken once the spill has been

contained and dealt with, not during the emergency. If exposed to formaldehyde, flush

exposed skin with copious amounts of water and remove contaminated clothing as quickly as

possible to prevent continued exposure.

2.5 TOXICOLOGY, OCCUPATIONAL HEALTH AND PROCESS SAFETY

Formaldehyde is a colorless, pungent gas which polymerizes slowly at room

temperature. The four basic uses for formaldehyde include use as a bactericide or fungicide,

in the production of resins, as intermediates in the production of chemicals, and as a

component of end-use consumer items. Formaldehyde is also used as embalming fluid and in

textile treating to impart wrinkle-resistance to clothing.

Facilities reporting the highest exposures (0.1 to above 1.0 ppm) to formaldehyde

include those producing hardwood plywood, particle board, fiberboard and resins as well as

foundries, laboratories and funeral services. Industries in textile finishing, apparel

manufacturing, formaldehyde production and plastic molding have the next highest exposures

ranging from 0.1 to 1.0 ppm. A long list of facilities have exposures to low concentrations

(0.1 - 0.5 ppm), among them being pulp, paper and paperboard mills , softwood plywood

manufacturers, manufacturers of various cardboard and paper products, paint, pigment and

dye manufacturers, photo finishing labs, hemodialysis units, biology and veterinary labs, and

various facilities dealing with electrical devices.

Formaldehyde is an essential intermediate in cell metabolism in mammals and

humans. All tissues contain measurable amounts of formaldehyde, e.g., human blood 2-3

ppm.

Formaldehyde does not accumulate in the environment or in the human body because

it is rapidly oxidized or biodegraded. In the body, exogeneous formaldehyde is metabolized

with a half-life of 1.5 minutes into formic acid and carbon dioxide.

2.5.1 ACUTE TOXICITY

Formalin (aqueous formaldehyde) is highly acutely toxic with deaths occurring with as

little as 30 milliliters (ml, about one once) ingested. The inhalation of high concentrations of

formaldehyde is also extremely dangerous, with the IDLH (Immediately Dangerous to Life

and Health) concentration being 100 ppm. Accidental splash exposures into the eyes may

cause blindness especially in cases where immediate flushing of the eyes with water does not

occur.

Irritation of eyes, nose, throat and chest is an acute response to formaldehyde that

diminishes rapidly upon removal from exposure. OSHA (Occupational Safety and Health

Administration) reports that irritation complaints occur from employees manufacturing

particle board and molded plastics at levels of 0.4 to 1.0 ppm, by foundry care room workers

exposed to more than 1 ppm, by dialysis nurses exposed to 0.26 to 0.4 ppm, by embalmers

exposed to 0.25 to 1.39 ppm, by carpenters exposed to formaldehyde treated wood at 0.35

ppm, by textile finishers exposed at 0.16 to 1.2 ppm, and by garment workers with exposures

of 0.42 to 0.50 ppm. In an independent clinical study, irritation at concentrations up to 0.04

ppm in 2% to 4% of those tested was reported.

A major effect of formaldehyde on the skin is dermatitis, both irritant dermatitis and

"allergic" contact dermatitis which results in a small percentage of the population.

Formaldehyde had also been reported to cause hives. Although there is some absorption of

formaldehyde through the skin, it is not considered significant.

Formaldehyde has also been reported to cause asthma which may develop within

minutes of exposure or several hours after the exposure, either during the latter part of the

work day or after returning home. The development of asthma may be influenced by

continuous or intermittent exposures. Exposures to high concentrations for a short period

may be more hazardous in causing asthma than exposure to low concentrations over an

extended period.

Ingestion (Swallowing): Liquids containing 10 to 40% formaldehyde cause severe irritation

and inflammation to the mouth, throat, and stomach. Severe stomach pains will follow

ingestion with possible loss of consciousness and death. Ingestion of dilute formaldehyde

solutions (0.03-0.04%) may cause discomfort in the stomach and pharynx.

Inhalation (Breathing): Formaldehyde is highly irritating to the upper respiratory tract and

eyes. Concentrations of 0.5 to 2.0 ppm may irritate the eyes, nose, and throat of some

individuals. Concentrations of 3 to 5 ppm also cause tearing of the eyes and are intolerable to

some persons. Concentrations of 10 to 20 ppm cause difficulty in breathing, burning of the

nose and throat, cough, and heavy tearing of the eyes; 25 to 30 ppm causes severe respiratory

tract injury leading to pulmonary edema and pneumonitis. A concentration of 100 ppm is

immediately dangerous to life and health. Deaths from accidental exposure to high

concentrations of formaldehyde have been reported.

Skin (Dermal): Formalin is a severe skin irritant and a sensitizer. Contact with formalin

causes white discoloration, smarting, drying, cracking, and scaling. Prolonged and repeated

contact can cause numbness and a hardening or tanning of the skin. Previously exposed

persons may react to future exposure with an allergic eczematous and dermatitis or hives.

Eye Contact: Formaldehyde solutions splashed in the eye can cause injuries ranging from

transient discomfort to severe, permanent corneal clouding and loss of vision. The severity of

the effect depends on the concentration of formaldehyde in the solution and whether or not the

eyes are flushed with water immediately after the accident.

Note: The perception of formaldehyde by odor and eye irritation becomes less sensitive with

time as one adapts to formaldehyde. This can lead to overexposure if a worker is relying on

formaldehyde's warning properties to alert him or her to the potential for exposure.

2.5.2 CANCER EPIDEMIOLOGY

Lung Cancer:

Several recently published epidemiological studies have been instrumental in the

development of the new formaldehyde regulations. Perhaps the most important as well as

controversial study was conducted and published by the National Cancer Institute (NCI). In

one of the largest cohort mortality analyses, 26561 workers employed prior to January 1, 1966

were studies for excess lung cancer. Investigators compared the mortality of formaldehyde-

exposed workers with that of the United States population, the local population and non-

exposed workers.

Although a significant increase in lung cancer was observed in the worker population,

the investigators (Blair, et al.) concluded that "these data provide little evidence that mortality

from cancer is associated with formaldehyde exposures at levels experienced by workers in

this study" primarily due to a lack of correlation between increased cancer risk and increased

dose (as measured by cumulative exposure). The investigators' comments were met with

much criticism from other scientists who reviewed the raw data from the study.

A five member Advisory Panel to the study concluded that, "The finding of a

significant increase in the risk for lung cancer...makes up particularly hesitant to characterize

this as a study with evidence to exonerate formaldehyde as a carcinogen." Likewise, the

National Institute for Occupational Safety and Health (NIOSH -- the research branch

affiliated with OSHA) concluded that, "Sufficient evidence exists...to conclude that there are

significant excesses of lung cancer...The absence of anexposure-response trend is not

sufficient cause to discount the observed lung cancer excesses..."

Federal OSHA agreed with both the Advisory Panel and NIOSH stating that a

significant increase in lung cancer can determine carcinogenicity even if the study failed to

establish a dose-response curve.

Two independent researchers (Sterling and Weikam) proceeded to statistically

reexamine the data from the NCI study. The researchers reconfirmed a significant lung

cancer excess. Among the criticisms submitted primarily by the Formaldehyde Institute and

Dupont, their analyses failed to correct for cigarette smoking as well as other items. OSHA

defined their analyses by noting that the percentages of deaths resulting from lung cancer in

formaldehyde-exposed workers were excessively high and significant.

Another independent researcher (Sielken) took the raw data from the NCI study and

correlated the formaldehyde exposure data with the likelihood of dying from cancer of the

respiratory system and lung cancer.

The United Auto Workers (UAW) reanalyzed a section of the NCI study and

concluded an increasing likelihood of death due to lung cancer. They also discovered that

persons exposed at the highest cumulative doses were less likely to smoke because of

formaldehyde's irritant effects.

In summary, OSHA's position was that there was no dose-response relationship in the

NCI study due to exposure misclassifications and due to the fact that cigarette smoking was

not evident in workers with the highest cumulative doses. OSHA supported the study's

finding that there was a significant increase in lung cancer in workers with 20 or more years

of latency. They also noted the probability of a trend of an increased risk of lung cancer with

an increase in the average level of formaldehyde exposure.

OSHA also noted a British study of lung cancer which concluded a significant excess

of lung cancer among workers at the highest exposure level (greater than 2.0 ppm) after

comparison with national rates of lung cancer. A significant increase in risk of death from

chronic bronchitis was also observed. A possible dose-response relationship was noted.

Although the authors downplayed the validity of their cancer results due to the high national

rates of lung cancer, OSHA discounted their downplay and supported the study's findings.

Nasopharyngeal Cancer:

The NCI study also noted an "increased risk of death from cancer of nasopharynx with

an increased cumulative exposure to formaldehyde (however) a not statistically significant

(but) a striking dose-response gradient was observed by the authors." OSHA supported the

importance of the study in relating formaldehyde concentration to nasopharyngeal cancer.

Excursions to levels exceeding 4 ppm were noted. Cancer was also observed in workers

exposed to high concentration for less than 1 year. The Formaldehyde Institute and Cyanamid

Company criticized the study stating that the formaldehyde exposure was mixed with a

particulate exposure, that there were only 3 cancer cases of the 7 total who were exposed for

less than 1 year and that there were no cases observed in workers with the highest cumulative

exposure. OSHA regarded the criticisms as insignificant.

In another study conducted by an independent researcher (Vaughan et al.) in the state

of Washington, residents living in mobile homes exposed to formaldehyde through

formaldehyde-treated building materials, as well as occupations dealing with resin and glue

work (i.e., carpenters with less than a 0.5 ppm exposure, and furniture assemblers, cabinet

makers and sewing machine operators having exposures greater than 0.5 ppm) were studied.

Due to the extremely low exposure potential and cancer risk observed in most of the workers,

OSHA concluded that is was inappropriate to conclude that the occupational study was

negative even though excess cancer was not observed.

On the other hand, the residential exposures were greater than the workplace

exposures from the standpoint of cumulative dose. Exposures lasting up to 168 hours

(compared to typical 40 hour a week work exposures) were observed with concentrations in

new mobile homes of years ago averaging as much as 0.5 ppm. OSHA determined that

formaldehyde exposure is probably associated with the development of nasopharyngeal

cancer in humans. Although rare, nasopharyngeal cancer existed with a background rate of

approximately half of that seen in home residents.

Oral Cancer:

The National Institute of Occupational Safety and Health (NIOSH) conducted a study

on workers exposed to formaldehyde in the garment industry manufacturing permanent press

garments. Workers were exposed for at least 3 months to concentrations of o.14 to 0.17 ppm.

The investigators reported excess oral cancer. OSHA, however, severely criticized the study

stating that "some evidence of an association between formaldehyde exposure and oral cancer

(existed) but not necessarily a causal relationship." OSHA criticized the study for limited

latency periods, a middle-aged female population and a low percentage (5.5%) of deaths from

cancer.

Brain Cancer:

Brain cancer has been reported in pathologists, anatomists, morticians, embalmers and

funeral directors exposed to embalming fluid or other tissue preservatives containing

formalin. Exposure concentrations were not given. OSHA stated that the exposure

"probably" contributed to the excess risk of brain cancer observed in professional workers but

was unable to reach a determination that brain cancer is caused by exposure to formaldehyde.

Other Cancers:

Leukemia has been reported in embalmers. OSHA's position was similar to that stated

above for reports of brain cancer.

2.5.3 ANIMAL CANCER STUDIES

Several laboratories have studied cancer in animals. The one of greatest interest was

conducted by Battelle Columbus Laboratories for the Chemical Industry Institute of

Toxicology (CIIT). 120 male and female animals of each of two species, one rat and one

mouse, were exposed for 6 hours/day, 5 days a week at concentrations averaging 2.0, 5.6, and

14.3 ppm in an inhalation experiment for 24 months (the average lifespan of a rodent). In the

rats, there was a significant increase in nasal cancers at the highest concentration. The

numbers of nasal cancers in mice was insufficient to show statistical significance, but were

considered formaldehyde related due to pathological examination. No increases in leukemia,

lymphomas, or brain cancer were observed.

Other studies support their finding of nasal cancer. New York University conducted

studies in which formaldehyde was administered in a strain of rats different from that used in

the CIIT study. OSHA concluded that the NYU studies confirmed that exposure to

formaldehyde can cause cancer in animals. An independent inhalation animal study (Tobe et

al.) also reported nasal cancer after formaldehyde exposure even though only a small number

of animals were used in the experiment. An inhalation hamster study conducted by yet

another independent laboratory reported no tumors, but due to the many scientific flaws in the

study (decreased rodent survival time, limited experience at detecting tumors) OSHA

discounted the study.

Other studies have been conducted demonstrating that formaldehyde applied topically

to the skin of laboratory animals does not cause cancer.

OSHA concluded that the finding of nasal cancer in two strains of rats in three

independent studies on formaldehyde alone to be extremely strong and reproducible evidence

that formaldehyde is an animal carcinogen. Evidence of a dose-response relationship, finding

cancers of identical cell-type and location in two species and evidence that formaldehyde is

genotoxic strengthens the scientific relationship of formaldehyde exposure causing cancer.

2.5.4 GENOTOXITY

Formaldehyde appears to be capable of binding to DNA, a well known mechanism by which

chemicals cause cancer. Formaldehyde appears to be both an initiator and a late stage cancer

causing chemical.

2.5.5 FIRE AND EXPLOSION HAZARD

Moderate fire and explosion hazard when exposed to heat or flame. The flash point of

37% formaldehyde solutions is above normal room temperature, but the explosion range is

very wide, from 7 to 73% by volume in air. Reaction of formaldehyde with nitrogen dioxide,

nitromethane, perchloric acid and aniline or peroxyformic acid yields explosive compounds.

Extinguishing Media: Use dry chemical "alcohol foam", carbon dioxide, or water in

flooding amounts as fog. Solid streams may not be effective.

2.5.6 REACTIVITY

Stability: Formaldehyde solutions may self-polymerize to form white precipitates.

Incompatibility (Materials to Avoid): Strong oxidizing agents, caustics, strong alkalis,

isocyanates, anhydrides, oxides, and inorganic acids. Formaldehyde reacts with hydrochloric

acid to form the potent carcinogen, bis-chloromethyl ether. Formaldehyde reacts with nitrogen

dioxide, nitromethane, perchloric acid and aniline, or peroxyformic acid to yield explosive

compounds. A violent reaction occurs when formaldehyde is mixed with strong oxidizers.

Hazardous Combustion or Decomposition Products: Oxygen from the air can oxidize

formaldehyde to formic acid, especial when heated. Formic acid is corrosive.

2.5.7 EMERGENCY AND FIRST AID PROCEDURES

Employees and students must notify their immediate supervisor or instructor of all

illness and injuries related to exposure to hazardous chemicals. Contact your supervisor if you

have any questions regarding the procedure for treating a non-serious injury or illness.

Ingestion (Swallowing): If the victim is conscious, dilute, inactivate, or absorb the ingested

formaldehyde by giving milk, activated charcoal, or water. Any organic material will

inactivate the formaldehyde. Keep affected person warm and at rest. Get medical attention

immediately. If vomiting occurs, keep head lower than hips.

Inhalation (Breathing): Remove the victim from the exposure area to fresh air

immediately. Do not enter areas with high levels of formaldehyde. Wait for rescuers with

appropriate respiratory protection equipment. If breathing has stopped, give artificial

respiration. Keep the affected person warm and at rest until ambulance arrives.

Skin Contact: Remove contaminated clothing (including shoes) immediately. Wash the

affected area of your body with soap or mild detergent and large amounts of water until no

evidence of the chemical remains (at least 15 to 20 minutes). Get medical attention after

washing affected area.

Eye Contact: Wash the eyes immediately with large amounts of water occasionally lifting

lower and upper lids, until no evidence of chemical remains (at least 15 to 20 minutes). Get

medical attention immediately. If you have experienced appreciable eye irritation from a

splash or excessive exposure, you should be referred promptly to an ophthalmologist for

evaluation.

2.5.8 SPILL, LEAK, AND DISPOSAL PROCEDURES

Occupational Spill: Take up small spills with absorbent material and place the waste

into properly labeled containers for later disposal. In the event of a large spill, alert personnel

in the area that a spill has occurred. Do not attempt to handle a large spill of formaldehyde.

Vacate the laboratory immediately and call for assistance.

2.5.9 MONITORIG AND MEASUREMENT PROCEDURES

Monitoring Requirements: If the exposure to formaldehyde exceeds 0.5 ppm action level

or the 2 ppm STEL, employer must monitor the exposure. Employer need not measure every

exposure if a "high exposure" employee can be identified. This person usually spends the

greatest amount of time nearest the process equipment. If you are a "representative

employee", you will be asked to wear a sampling device to collect formaldehyde. This device

may be a passive badge, a sorbent tube attached to a pump, or an impinger containing liquid.

You should perform your work as usual, but inform the person who is conducting the

monitoring of any difficulties you are having wearing the device.

Evaluation of 8-hour Exposure: Measurements taken for the purpose of determining time-

weighted average (TWA) exposures are best taken with samples covering the full shift.

Samples collected must be taken from the employee's breathing zone air.

Short-term Exposure Evaluation: If there are tasks that involve brief but intense exposure

to formaldehyde, employee exposure must be measured to assure compliance with the STEL.

Sample collections are for brief periods, only 15 minutes, but several samples may be needed

to identify the peak exposure.

Monitoring Techniques: OSHA's only requirement for selecting a method for sampling and

analysis is that the methods used accurately evaluate the concentration of formaldehyde in

employees' breathing zones. Sampling and analysis may be performed by collection of

formaldehyde on liquid or solid sorbents with chemical analysis. Sampling and analysis may

also be performed by passive diffusion monitors and short-term exposure may be measured by

instruments such as real-time continuous monitoring systems and portable direct reading

instruments.

Notification of Results: Your employer must inform you of the results of exposure

monitoring representative of your job. You may be informed in writing, but posting the results

where you have ready access to them constitutes compliance with the standard.

2.5.10 PROTECTIE EQUIMENT AND CLOTHING

Clothing: Material impervious to formaldehyde is needed if the employee handles

formaldehyde solutions of 1% or more. Other employees may also require protective clothing

or equipment to prevent dermatitis.

Respiratory Protection: Contact Supervision if you believe respirators are required.

Protective Gloves: Wear protective (impervious) gloves provided by your employer, at no

cost, to prevent contact with formalin. Y our employer should select these gloves based on the

results of permeation testing and in accordance with the ACGIH Guidelines for Selection of

Chemical Protective Clothing.

Eye protection: If you might be splashed in the eyes with formalin, it is essential that you

wear goggles or some other type of complete protection for the eye. You may also need a face

shield if your face is likely to be splashed with formalin, but you must not substitute face

shields for eye protection. (This section pertains to formaldehyde solutions of 1% or more.)

Other Protective Equipment: You must wear protective (impervious) clothing and

equipment provided by your employer at no cost to prevent repeated or prolonged contact

with formaldehyde liquids. If you are required to change into whole-body chemical protective

clothing, your employer must provide a change room for your privacy and for storage of your

street clothing. If you are splashed with formaldehyde, use the emergency showers and

eyewash fountains provided by your employer immediately to prevent serious injury. Report

the incident to your supervisor and obtain necessary medical support.

2.5.11 ENGINEERING CONTROLS

Ventilation is the most widely applied engineering control method of reducing the

concentration of airborne substances in the breathing zones of workers. There are two distinct

types of ventilation.

Local Exhaust: Local ventilation is designed to capture airborne contaminants as near to the

point of generation as possible. To protect you, the direction of contaminant flow must always

be toward the local exhaust system inlet and away from you.

General (Mechanical): General dilution ventilation involves continuous introduction of

fresh air into the workroom to mix with the contaminated air and lower your breathing zone

concentration of formaldehyde. Effectiveness depends on the number of air changes per hour.

Where devices emitting formaldehyde are spread out over a large area, general dilution

ventilation may be the only practical method of control.

Work Practices: Work practices are an important part of a control system. If you are asked

to perform a task in a certain manner to limit your exposure to formaldehyde, it is extremely

important that you follow these procedures.

2.5.12 MEDICAL SURVEILLANCE

Medical surveillance helps to protect employees' health. Your employer must make a

medical surveillance program available at no expense to you and at a reasonable time and

place if you are exposed to formaldehyde at concentrations above 0.5 ppm as an 8-hour

average or 2 ppm over any 15 minute period. You will be offered medical surveillance at the

time of your initial assignment and once a year afterward as long as your exposure is at least

0.5 ppm (TWA) or 2 ppm (STEL). Even if your exposure is below these levels, you should

inform your employer if you have signs and symptoms that you suspect, through your

training, are related to your formaldehyde exposure because you may need medical

surveillance to determine if your health is being impaired by your exposure.

The surveillance plan includes: (a) A medical disease questionnaire. (b) A physical

examination if the physician determines this is necessary. If you are required to wear a

respirator, your employer must offer you a physical examination and a pulmonary function

test every year. The physician must collect all information needed to determine if you are at

increased risk from your exposure to formaldehyde. At the physician's discretion, the medical

examination may include other tests, such as a chest x-ray, to make this determination. After a

medical examination the physician will provide your employer with a written opinion which

includes any special protective measures recommended and any restrictions on your exposure.

The physician must inform you of any medical conditions you have which would be

aggravated by exposure to formaldehyde. All records from your medical examinations,

including disease surveys, must be retained at your employer's expense.

2.5.13 ENVIRONMENTAL ISSUES

Formaldehyde is a naturally occurring substance in the environment made of carbon,

hydrogen and oxygen. According to the U.S. Environmental Protection Agency, natural

processes in the upper atmosphere may contribute up to 90 percent of the total formaldehyde

in the environment (WHO, International Programme on Chemical Safety, Concise

International Chemical Assessment Document: Formaldehyde). Since formaldehyde is a by-

product of combustion, cars and trucks emit formaldehyde, as does burning wood.

Formaldehyde does not accumulate in the environment, because it is broken down within a

few hours by sunlight or by bacteria present in soil or water. Humans metabolize

formaldehyde quickly, so it does not accumulate in the body.

Formaldehyde manufacture and use represent only a partial source of formaldehyde in

the environment. Formaldehyde in the atmosphere results primarily from incomplete

combustion of hydrocarbons, as well as photochemical oxidation of unconverted

hydrocarbons from combustion sources.

Table 2.2 - Contribution to atmospheric formaldehyde

Emission Source Percent

Motor vehicle and aircraft exhausts

53-63

Photochemical reactions (largely from hydrocarbons in exhausts)

19-32

Combustion plants, incinerators

13-15

Petrochemical refineries

1-2

Formaldehyde production plants

1

Indoor formaldehyde levels are also of concern. It is known that formaldehyde-based

products such as resins and UF foam insulations contribute small amounts of formaldehyde to

the air. Some representative products include carpeting, floor and ceiling tiles, pressed wood

products, and linedair ducts. With time, formaldehyde decomposes in both the atmosphere

and normal nonsterile water. The initial oxidation product, formic acid, is a component of

acid rain. Because of its high solubility there will be efficient transfer into rain and surface

water which may be an important sink. Additional quantities are removed by dry deposition or

by dissolving in the ocean and other surface waters.

Although discharges to watercourses are strictly limited in most countries,

formaldehyde is not subject to the stringent controls that apply to bioaccumulating substances.

Specific concerns about formaldehyde are largely focused on the health impact on humans of

atmospheric formaldehyde in the workplace or home.

The International Agency for Research on Cancer (IARC), part of the World Health

Organization, recently has reclassified formaldehyde from group 2A “probably carcinogenic

to humans” to group 1 “carcinogenic to humans”. This move was made based on a finding of

“sufficient evidence that formaldehyde causes nasopharyngeal cancer in humans”, affecting

the nasal cavity and paranasal inuses.

As a result of health concerns, most countries in the developed world classify

formaldehyde as a toxic compound and require strict handling procedures and labeling of

products. Many countries have imposed stringent limits on the concentration of

formaldehyde, both in the workplace and home, and have also imposed standards on products

such as particle board. The product standards may be expressed as a direct limit on the

formaldehyde concentration, or as a maximum emission value for the product.

2.6 ECONOMIC ASPECTS:

Formaldehyde is one of the most important basic chemicals and is required for the

manufacture of thousands of industrial and consumer products. It is the most important

industrially produced aldehyde.

The formaldehyde industry provides thousands of jobs where workers are employed

directly in producing the chemical and managing its marketing, sale and distribution. These

workers operate and maintain the formaldehyde production facilities, and have responsibility

for management, research and development, sales and marketing. Beyond these jobs derived

direcly from formaldehyde, hundreds of thousands of workers are supported indirectly

through formaldehyde.

Formaldehyde’s chemistry makes it an extremely versatile contributor to the

production of hundreds of items that improve everday life. Some studies have made and the

results shows that, in the United States, production of formaldehyde and formaldehyde-

containing goods accounts for more than five percent of the yearly U.S. Gross National

Product (GNP) –or about $500 billion out of a GNP exceeding $10 trillion. Formaldehyde’s

wide-ranging use makes it essential to operations of nearly 50,000 U.S. facilities in 17 major

industries, and it serves as a basic raw material in another 70 industries. Annual U.S.

formaldehyde production exceeds five million metric tons.

Formaldehyde is the most important commercially aldehyde (class of highly reactive

organic chemical compounds obtained by oxidation of primary alcohol), according to the

most recent CEH Marketing Research Report on Formaldehyde from SRI International. More

than half of all formaldehyde is used primarily to make urea-, phenol-, melamine-

formaldehyde (UF, PF and MF) resins and polyacetal resins- altogether a business valued at

nearly $ 10 billion. If urea formaldehyde resins were not available to the industries that use

them, the additional cost to consumers in the United States and Canada would approach $3.5

billion annually.

If phenol formaldehyde resins were not available to the building, construction,

automotive and other industries that use them, the additional cost to consumers in the United

States and Canada would approach $4.65 billion annually.

If melamine formaldehyde resins were not available to the textile, surface coatings and

other industries that use them, the additional cost to consumers in the United States and

Canada would approach $365 million annually.

If polyacetal resins were not available to the numerous industries that use them, the

additional cost to consumers in the United States and Canada would approach $220 million

annually.

Manufacturing Regions of Formalin:

• China (mainland),

• Iran,

• India,

• South Korea,

• Taiwan,

• United Arab Emirates,

• Vietnam,

• Philippines,

• Indonesia,

• Japan,

• Pakistan,

• Russian Federation,

• Turkey,

• Ukraine,

• Egpyt

• Germany,

• Hungary,

• Myanmar

• Netherlands,

• Singapore

Main Export MarMain Export MarMain Export MarMain Export Markekekeketstststs:

• Western Europe,

• North America,

• Africa,

• South America,

• Mid East,

• Southeast Asia,

• Eastern Asia,

• Eastern Europe,

• Ocenia

Some formaldehyde manufacturers in the U.S. are:

� Borden Chemical,

� Georgia-Pacific Resins, Inc.,

� Capital Resin Corporation,

� GEO Specialty Chemicals, Inc.,

� Celenase Ltd. Chemicals Division,

� Hercules Incorporated,

� Perstorp Polyols,

� D.B. Western, Inc.,

� Praxair, Inc.,

� Dupont Chemical Solutions Enterprise,

� Solutia Inc.,

� Dynea USA, Inc.,

� Wright Chemical Corporation.

Table 2.3 - Producers and their capacities

PRODUCER CAPACITY*

Borden Chemical, (18 sites) 4,600

Capital Resin, Columbus, OH 100

Celanese, Bishop, TX; Rock Hill, SC 1,730

D.B. Western, Virginia, MN 40

Degussa, Theodore, AL 215

DuPont, LaPorte, TX; Parkersburg, WV 900

Geo Specialty Chemicals, (Trimet) Allentown, PA 135

Georgia-Pacific (14 sites) 2,510

Hercules (Aqualon), Louisiana, MO 170

ISP, Calvert City, Ky.; Texas City, TX 200

Neste Resins (5 sites) 900

New Mexico Adhesives, Las Vegas, NM 50

Perstorp, Toledo, OH 450

Praxair, Geismar, LA 140

Solutia, Alvin, TX 200

Wright Chemical, Riegelwood, NC 160

Total 12,500

*Millions of pounds per year on a 37 percent basis. Commercial production is from methanol

either by silver catalyst or metal oxide catalyst processes. 70 to 80 percent of formaldehyde

output is used captively.

In 1998 Geo Specialty Chemicals purchased Trimet from Mallinckrodt and Borden

Chemical acquired Spurlock Industries and its plants in Waverly, VA, and Malvern, AR,

adding another 275 million pounds of capacity. In 2000, Borden Chemicals and Plastics sold

its formaldehyde business, including the recently upgraded, 1,470 million pound Geismar, LA

facility, to Borden Chemical.

In 1999, International Specialty Products ended formaldehyde production in Calvert

City, KY, and closed the Texas City, TX plant the next year, eliminating 200 million pounds

per year in total.

Perstorp expanded its Toledo plant by 140 million pounds, increasing capacity at the

site to 450 million pounds in 1999.

In 2000, Georgia-Pacific acquired the formaldehyde of Celanese, but not the

production facility at Rock Hill, SC According to a long-term manufacturing agreement,

Georgia-Pacific will utilize the formaldehyde output of the Rock Hill plant to supply third

parties including former customers of Celanese.

Subsequent to the formaldehyde acquisition from Celanese, Georgia-Pacific

announced it is divesting its chemicals division and intends to sell the division as a single

unit. The business includes formaldehyde and its derivative resins. No buyer has thus far been

identified.

Seven producers in Canada have combined total capacity for about 1,800 million

pounds per year of formaldehyde; Mexico's capacity totals about 510 million pounds from

eleven producers.

Demand in 1999: 9,623 million pounds; 2000: 9,702 million pounds; 2004: 10,096 million

pounds, projected. Demand equals production plus imports (1999: 82 million pounds; 2000:

62 million pounds) less exports (1999: 21 million pounds; 2000: 18 million pounds).

GROWGROWGROWGROWTH TH TH TH Historical (1995 - 2000): 1.8 percent per year; 1.0 percent per year through 2004.

PRICE PRICE PRICE PRICE Historical (1995 - 2000): High, $0.24 per pound, 37 percent methanol-free

(uninhibited) tanks, f.o.b. Gulf; low, $0.13, same basis. Current: $0.21, same basis.

STRSTRSTRSTRENGTHENGTHENGTHENGTH: Formaldehyde use in production of acetylenic chemicals (butanediol), MDI and

acetal resins continues growing at about 5 percent. These uses currently account for one-third

of formaldehyde demand.

WEAKNESS:WEAKNESS:WEAKNESS:WEAKNESS: In March, housing starts fell another 1.3%, to an annual rate of 1.61 million

units. In 2000, the rate stood approximately at 1.70 million units. This decrease depresses

demand for formaldehyde in urea- and phenol-formaldehyde resins used in particleboard and

plywood, respectively. These two classes of thermosetting resins consume more than one-

third of formaldehyde demand.

OUTLOOK:OUTLOOK:OUTLOOK:OUTLOOK: Formaldehyde demand is softening as housing and construction have declined.

Most large-volume formaldehyde contracts are tied to methanol and natural gas pricing, so

major customers are generally paying twice what they did a year ago, even though list pricing

for 37 percent material is $0.21 per pound. Natural gas remains around $5.25 to $5.50 per

million BTUs, down substantially from its high of $9 to $10 winter in 2000, but still around

twice its traditional value. Some analysts expect gas prices to continue falling, but others warn

that a summer surge in electricity demand could send gas back up around $7. Formaldehyde

capacity has always exceeded demand by a substantial margin, and this situation will continue

Prices of formaldehyde are closely linked to and generally track its methanol

feedstock. In Europe, formaldehyde is usually traded regionally over small distances and so

prices vary according to country and are unofficially set on a quarterly contract basis. In the

US, most large volume formaldehyde contracts are tied to methanol and natural gas pricing,

sometimes leading to a large delta between contract and spot prices. Companies in

formaldehyde sector in Turkey are:

� Çağlayan Kimya San.Tic.LTD.ŞTĐ.,

� Topçu Kimya Nak. ve Tic.,

� Saf Su Oya Kimya,

� Turca Kimyevi Maddeler Tic. LTD.,

� Mars Kimya,

� Kur Kimya,

� Söz Kimya LTD.ŞTĐ.,

� Joco Kimya,

But, for production of formaldehyde there are totally 6 registered companies in

Turkey: 1 in Bursa, Hatay, Đstanbul, Kastamonu and 2 producers in Kocaeli. Datas from

TOBB;

Workers Area (m2) Production

Capacity City

Registered

Producer E T F W AD Total

Closed

Area

Open

Area TO%S

BURSA 1 16 12 6 73 13 120 17,157 104,980 *

HATAY 1 2 0 4 32 9 47 2,000 24,743 *

ISTANBUL 1 4 0 0 23 3 30 2,805 7,148 *

KASTAMONU 1 1 2 2 9 2 16 1,673 7,779 *

KOCAELI 2 17 16 13 388 82 516 122,444 335,222 *

TOTAL 6 40 30 25 525 109 729 146,079 479,872 292,765

E: Engineer; T: Technician; F: Foreman;W: Worker; AD: Administrative;

2.7 DISPOSAL

The Resource Conservation and Recovery Act (RCRA) identifies formaldehyde as a

toxic waste if it discarded as a commercial product, manufacturing intermediate, or off-

spicification commercial chemical product. Formaldehyde is identified as the hazardous

constituent in waste assigned the hazardous wate number U122 under RCRA.

Spilled or used formaldehyde is considered a hazardous waste and must be handled as

a solid waste under RCRA. The generator-be it in the field office or the district office-must

contact a hazardous waste contractor for appropriate disposal under RCRA regulations. An

Environmental Protection Agency (EPA) identification number must be obtained for each site

from which disposal of a regulated material or waste will be made and records must be

maintained on the amounts of waste formaldehyde, storage time, and the contractor involved

in the hazardous waste recycling.

3.0 DISCUSSION & CONCLUSIONS

At ambient temperatures, formaldehyde exists in a gaseous state, emitting a familiar

sharp odor, irritating the eyes and skin. This gas is relatively stable at temperatures between

80°C and 100°C, but slowly polymerizes at lower temperatures, and is not sold commercially.

Because formaldehyde is highly water soluble, it is usually marketed as a liquid solution,

typically at 37 weight percent formaldehyde solution, combined with water and up to 16

percent methanol. Besides, pure formaldehyde is a gas at ordinary temperatures and cannot be

readily isolated or handled in this state, it is marketed chiefly in the form of its aqueous

solutions. Therefore, and all production comparisons shown in this report are made on a 37

percent basis.

However, higher concentrations are sold and are required for the production of some

derivative products such as polyacetal resins. The market trend is to sell solutions at higher

concentrations to reduce shipping costs. Stabilizers are usually required when shipping higher

concentrations of formaldehyde solutions. Unreacted methanol in solution helps inhibit

formaldehyde polymerization; however, this is highly time and temperature dependent. Other

product impurities include formic acid (less than 0.03 percent) and iron compounds (less than

0.5 ppm) in a 37 percent solution.

For the manufacture of formaldehyde; a wide range of alternative feed stocks have

been considered but not found to be economic. For example, a tiny amount of formaldehyde is

produced from the non-catalytic oxidation of propane butane mixtures. Formaldehyde can be

produced from methane but a mixture of products needs to be separated. It is also a byproduct

of the oxidation of naphtha to acetic acid.

Yields for both processes (Oxidation-dehydrogenation using a silver catalyst involving

either the complete or incomplete conversion of methanol; and the direct oxidation of

methanol to formaldehyde using metal oxide catalysts (Formox process)) are around 90 to 92

percent but the oxidation route has a lower reaction temperature and the metal catalyst is

cheaper than silver. However, the partial oxidation dehydrogenation route is still the most

prevalent.

The basic difference between them is the catalyst applied. The methanol excess

process, called the silver process, employs silver as the catalyst while the air excess

process (molybdenum process) uses metallic oxides of iron and molybdenum. In considering

higher investment cost and more complicated operation than the silver process, we

recommend that our clients use the silver process But, in considering higher investment

cost and more complicated operation than the silver process, it is recommend to use the silver

process.

Recent improvements in the metal oxide catalyst process have aimed at process

simplification, more extensive use of carbon steel equipment to reduce capital investment, and

modifications of the catalyst to increase catalyst life.

The most radical improvements in the silver catalyst process have been made by

BASF and are now used commercially. A different form of the catalyst, a higher reaction

temperature, and changes in reactor feed composition have made possible a high methanol

conversion; thus, it is no longer necessary to recover unreacted methanol. Maximum size of a

production unit has also been increased by these changes.

Silver-catalyzed processes for making formaldehyde from methanol can be

characterized according to the number of catalytic stages used to effect the conversion. Single

stage operation is quite widely used but suffers from the disadvantage that rather high

amounts of unconverted methanol are contained in the product emerging from the catalyst

bed. This phenomenon is customarily referred to as methanol leakage. Since for many

applications methanol is an undesirable contaminant, it must be separated from the

formaldehyde solution. This entails a substantial investment in distillation facilities and

energy to carry out such separations.

Because of the nature of the process, methanol and air concentrations are strictly

controlled to avoid potential explosions. An excess of methanol is used in production to

maintain concentration levels above the explosive limits.

A concentrated aqueous solution of formaldehyde can only be used for certain

applications, since it can neither be stored, nor transported, for extended periods. The most

usual concentration is of the order of magnitude of from 30 to 37% by weight, especially the

latter figure, since this represents a solution of optimum concentration which proves stable

over extended periods, without precipitation of paraformaldehyde. Such solutions are required

for the manufacture of phenolic resins.

On the other hand, solutions of maximum concentration have advantages for other

applications, e.g. to save transport costs, if the time for transport is relatively long and to save

Figure 3.1 - Formaldehyde production cost comparison, 37% basis, U.S. Gulf Coast, 1st Qtr 2005 (120 million pounds per year capacity)

evaporation costs in subsequent processes, e.g. the manufacture of urea-formaldehyde

condensation resins or the manufacture of butynediol by reaction with acetylene.

There has been significant research activity to develop new processes for producing

formaldehyde. Even though this work has been extensive, no commercial units are known to

exist based on the technologies discussed in the following.

One possible route is to make formaldehyde directly from methane by partial oxidation.

This process has been extensively studied. The incentive for such a process is reduction of raw

material costs by avoiding the capital and expense of producing the methanol from methane.

Another possible route for producing formaldehyde is by the dehydrogenation of

methanol which would produce anhydrous or highly concentrated formaldehyde solutions.

For some formaldehyde users, minimization of the water in the feed reduces energy costs,

effluent generation, and losses while providing more desirable reaction conditions.

A third possible route is to produce formaldehyde from methylal that is produced from

methanol and formaldehyde. The incentive for such a process is twofold. First, a higher

concentrated formaldehyde product of 70% could be made by methylal oxidation as opposed

to methanol oxidation, which makes a 55% product .This higher concentration is desirable for

some formaldehyde users. Secondly, formaldehyde in aqueous recycle streams from other units

could be recovered by reacting with methanol to produce methylal as opposed to recovery by

other more costly means, eg. distillation and evaporation. Development of this process is

complete.

ECONOMICS AND COMPARISON OF THE PROCESSES: The production costs of 37%

aqueous formaldehyde solution by the production processes (metal oxide catalyst process, the

silver catalyst process) are summarized in the following figure.

The higher capital cost of the metal oxide catalyst plant is compensated for by better

process yields from methanol. The silver catalyst process without recycle has the next lowest

estimated cost plus return on capital employed (ROCE); however, the product has a higher

methanol content than the product resulting from the metal oxide and silver catalyst with

recycle processes.

The price of methanol has a dramatic effect on formaldehyde economics, since cost for

methanol feedstock represents 80 to 86 percent of cash cost and 67 to 72 percent of cost plus

ROCE for the commercial processes studied. Sensitivities show the effect of methanol price

over the range 45 to 125 cents per gallon.

Concentration of the formaldehyde solution is an important consideration for three

reasons: downstream derivative requirements, shipping costs, and energy requirements to

remove excess water. Polyacetal resins, for example, are direct polymers of formaldehyde,

and require as concentrated a solution as possible to achieve polymerization. Resins are

usually supplied as a solution of 60 percent solids or more, for which formaldehyde feedstock

at more than 50 percent concentration is desirable.

Where concentrated formaldehyde is required, the metal oxide process has the

advantage. Conversely, in some cases, such as the highly exothermic production of phenol

formaldehyde resins, a more dilute solution is actually desirable.

The silver process with distillation offers a certain amount of flexibility which is

appropriate for a plant supplying a complex and varied market. On the other hand, the metal

oxide process has an advantage in serving the single largest formaldehyde market in its ability

to form urea-formaldehyde precondensate directly in the absorption column. Existing

production capacity is dominated by the silver catalyst process, whereas the majority of new

plants being built employ the metal oxide process. This is due to the higher formaldehyde

yields on methanol and higher product concentration achieved.

DEMANDDEMANDDEMANDDEMAND: The current consumption of formaldehyde stands at around 20 million metric tons

per year (37 wt. percent basis), representing the largest use of methanol globally. The

substantial costs associated with movement of formaldehyde over larger distances have

caused almost all of the formaldehyde plants globally to be integrated with appropriate

downstream plants. This has been possible owing to the versatility of formaldehyde end uses.

As can be seen in Figure 3.2, amino resins, which include mainly urea- and melamine-

formaldehyde resins, currently constitute slightly more than one-third of the total global

formaldehyde consumption. Phenolic resins are the second largest area of consumption.

Figure 3.2 - Breakdown of Global Formaldehyde End Uses (2005).

Global consumption growth is estimated for nine end use categories through 2015.

SUPPLYSUPPLYSUPPLYSUPPLY: Figure 3.3 shows the dominance of Western Europe in formaldehyde capacity. The

producers in the developed countries tend to have larger capacities distributed over a number

of production lines.

The producers in developing

countries tend to have much smaller

production capacities, and the

production tends to be

opportunistic. When margins are

good the plants operate flat out, but

when margins are poor, the plants

operate only to support the

consumption in the downstream

plants.

Figure 3.3 - Share of Key Regions in Overall Formaldehyde Capacity (2005).

SUPPLYSUPPLYSUPPLYSUPPLY----DEMAND BALANCEDEMAND BALANCEDEMAND BALANCEDEMAND BALANCE: The overall operating rate of the plants globally is expected

to increase from the upper 70s in 2005 to the lower 90s by 2015. Fragmentation in the

market that has led to poor margins in the past is expected to reduce with the closure of

some of the small, relatively uneconomical facilities.

Individual supply/demand balances are also provided for North America, Western

Europe, China, Japan, and Rest of the World.

In Turkey, just 6 companies produce totally, 292765 tons of formaldehyde in a year.

These values are too small when compared with the formaldehyde production in Canada and

United States. Also, there are many distributors in Turkey, so it can be understood that

formaldehyde production in Turkey does not meet the all requirements.

4.0 REFERENCES

[1] Ullmann, Ullmann’s Encyclopedia of Industrial Chemistry, Fifth Completely Revised

Edition, Volume A11, page 619-647.

[2] Othmer K., Kirk Othmer Encyclopedia of Chemical Technology, Fourth Edition, Vol

11, page 929-947.

[3] www.formaldehyde.org

[4] www.the-innovation-group.com

[5] http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-

uk.org.uk/mag/artoct02/toptips12.html

[6] http://www.sefsc.noaa.gov/HTMLdocs/appendix-I.htm

[7] http://cameochemicals.noaa.gov/chemical/17291

[8] http://www.sriconsulting.com/PEP/Reports/Phase_77/RP023A/RP023A.html [9] http://www.freepatentsonline.com/4119673.html [10] http://www.dsir.gov.in/reports/techreps/tsr137.pdf [11] http://www.mechatropia.or.kr/bbs/jck99/sp_3_034.pdf

APPENDIX A – SILVER CATALYST PROCESS IN DETAIL

5.0 APPENDICES

The following process produces 50000 tons/year of formalin from methanol

using the Silver Catalyst Process given in Figure A.1.

Formaldehyde and water required for the production are formed in the following

reaction:

molkcalHOHHCHOOOHCH rxn /3.3721

223 −=∆+→+

Reaction rate expression can be simplified to:

[ ]m

mm pk

pkhourcatalystgrmoler

2

1

1/

+=−

where where p is a partial pressure in atm, and m refers to methanol. The rate expression is

only valid when oxygen is present in excess. The catalyst bulk density is 100 lb/ft3 and the

above constants are defined as:

Tk

Tk

704079.10log

381043.11log 21 −=−=

where T is in Kelvin.

Fresh methanol, Stream 2, at 30°C and 14.7 psia mixes with recycled methanol,

Stream 15, at 68.3°C and 16 psia. Stream 3 (recycled and fresh methanol) is at 35.4°C and

14.7 psia. Pump, P-101, raises the pressure up to 35 psia. Stream 4 enters a heat exchanger

where the methanol is vaporized. Stream 5 is then at 150°C and 29 psia. Fresh air is available

at 25°C and 14.7 psia in Stream 1. Compressor, C-101, raises the pressure to 35 psia in

Stream 5. This stream is then heated by medium-pressure steam. The temperature is raised to

150°C in Stream 7. Stream 6 and Stream 7 mix at a pressure of 29 psia. The combined

mixture is at 149.6°C and 28 psia in Stream 8. The reactor converts 87.4% of the methanol.

The exit reactor temperature is 343°C. Heat is removed by making high-pressure steam from

boiler feed water. The outlet, Stream 9, is at 343°C and 25 psia. A valve drops the pressure of

this stream to 5 psia before it enters the absorber, T-101. Fresh water is sent through the T-

101 at 30°C and 20 psia. T-101 is set to absorb 99% of the formaldehyde that enters. Stream

13 is then heated to 102°C before entering T-102, the formalin distillation column. T-101

recovers a 37 wt% solution of formaldehyde in water. Most of the methanol is recovered in

the distillate. Stream 15, the distillate, is recycled back to the inlet of fresh methanol at 68.3°C

Table A.1 – Stream table for the production of formalin

and 16 psia. The bottoms, Stream 16 is pumped, by P- 103, up to 38.5 psia for storage.

Deionized water at 30°C in Stream 18 is added to achieve the 37 wt% solution of

formaldehyde in water. Storage of formalin is tricky. At high temperatures, undesirable

polymerization of formaldehyde is inhibited, but formic acid formation is favored. At low

temperatures, acid formation is inhibited, but polymerization is favored. With ≤ 2 wt%

methanol, the storage tank contents must be maintained between 35°C and 45°C.

Equipment description for the process described in Figure A.1 can be made as: P-101:

Methanol Pump, E-101: Methanol Vaporizer, C-101: Air Compressor, E-102: Air Heater

R-101: Fluid Bed Reactor, T-101: Formalin Absorber, E-103: Heater, T-102: Formalin

Distillation Column, E-104: Methanol Condenser, E-105: Formalin Reboiler, P-102: Reflux

Pump, V-101: Reflux Drum, P-103: Formalin Pump, E-106: Formalin Cooler.

Table A.1 (Continued) – Stream table for the production of formalin

Process flowsheet of the diagram is given in the following page:

F

igu

re A

.1 –

Pro

du

ctio

n o

f fo

rma

lin

fro

m m

eth

an

ol u

sin

g s

ilv

er c

ata

lyst

pro

cess

Fig

ure

B.1

– P

roce

ss f

low

dia

gra

m f

or

a s

am

ple

fo

rma

lin

pro

du

ctio

n p

lan

t w

ith

a p

rod

uct

ion

ca

pa

city

of

40

00

m3 f

orm

ali

n/d

ay

APPENDIX B –A SAM

PLE FORMALIN PRODUCTION PLANT

C

hara

cter

isti

c pr

oper

ties

for

a f

orm

alin

pro

duct

ion

plan

t ar

e ga

ther

ed t

oget

her

and

give

n in

thi

s se

ctio

n. F

or t

he p

roce

ss f

low

dia

gram

of

the

plan

t se

e Figure B.1

fir

st.

Table B.1 – Raw material and utility consumption

Typical equipments that will be needed for such a plant are listed below:

Reactor, Absorber, Air Filter, Suction Filter, Gas Mixer,

Gas-Water Separator, FML Filter, Drain Separator,

Evaporator, Mixed Gas Filter, M.V. Preheater, Air Preheater,

Formalin Cooler, Start-Up Heater, Flame Arrester, Air Blower,

Air Compressori RG Blower, RG Preheater, Cooling Tower,

Various Tanks for Raw Feed Materials and Products,

Various Pumps.

Production capacity of the plant is 4000 m3/day and working condition is 12

hours/day. Raw material and utility consumption for the plant and for the production of one

tone of 37% formalin is given in the following table:

Assuming that no unexpected complications are faced, such a plant is built in 18

months after the beginning of the construction scheadule. Required land area for a plant of the

given capacity is 3000 m2 and 1000 m2 of that area is covered by facilities and buildings

requred for manufacturing.

Plant layout for the sample formalin production plant is given in Figure B.2 in the

following page:

Fig

ure

B.2

– P

lan

t la

yo

ut

Table B.2 – Raw material and utility consumption

Operation manpower for the sample plant is also estimated and given to be such as in

the following table: