Pulping by-products from fiber crops

What to learn from forest industry?

FIBRA Summer school, Beijing, July 2015

Klaus Niemelä (klaus.niemela@vtt.fi)

VTT Technical Research Centre of Finland

2 30/7/2015

Cai Lun – inventor of papermaking

Cai Lun (Tsai Lun), inventor of papermaking c. 105 AD

(raw materials included hemp waste)

3 30/7/2015

Main topics to be addressed

Introduction to pulping processes

Role of pulping by-products, overview

Discussion on selected by-products from wood and non-wood

raw materials

Some trends

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Paper and paperboard demand

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World consumption of paper-making fibre

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Consumption of bleached hardwood kraft pulp

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Global non-wood pulp production

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Chemical pulping processes

The main objective is to remove (dissolve) lignin and recover

cellulosic fibers (pulp)

Removal of other non-carbohydrate materials (extractives)

also targeted

Due to the pulping conditions, varying amounts of

hemicelluloses are also lost (sometimes desired, usually not)

Some cellulose losses also take place

Roughly, pulp yield is c. 50% (40-60%) of raw material

Cooking chemicals are recovered for re-use (not in all very

small mills)

Most of pulp is bleached to obtain required brightness

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“Pulp mill biorefineries”: pulp, chemicals, biofuels

Pulping process

Harvesting residues

AgromaterialsRecovered paper

Process(es)

Integratedpower/energyproduction

Processstreams

Pulp, paper

Energy

Biofuels

Chemicals

Chips

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Sulphite pulping processes

Cooking chemicals are sodium, calcium or ammonium sulphites

The conditions are acidic

Lignin is sulphonated and dissolved (as water-soluble derivative)

Hemicelluloses are partially hydrolysed, to give sugars to the

pulping spent liquor (also furfural, sugar acids, etc)

The process is mainly used for hardwood and some softwood

Was the dominating pulping process in the past, now small (but

important) role. Now new sulphite pulp mills have been

constructed since early 1980s!

Also used for dissolving pulp (high cellulose content) production

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The recent end of the world’s latest new sulphite pulp mill

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Kraft (or sulphate) pulping processes

”Kraft” is a German word, meaning ”strength” (of pulp derived)

Sulphate refers to sodium sulphate, used as make-up chemical

Uses NaOH and Na2S as the pulping chemicals (alkaline)

Lignin is degraded and dissolved (Na2S needed) and will

contain some organic sulphur (bad smell)

Hemicelluloses are largely converted into hydroxy acids

Used for hardwood and softwood

Huge pulp mill capacities (up to 2 million tons) operate

Numerous huge new mills constructed recently

Special pre-hydrolysis kraft pulp mills use water-vapour

pretreatment step to remove most of the hemicelluloses

(required for the manufacture of dissolving pulp)

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Soda pulping processes

Uses NaOH and as the pulping chemicals (alkaline)

Soda refers to sodium carbonate, used as make-up chemical

Used typically for non-wood raw materials

Lignin is degraded and dissolved (without Na2S); does not

organic sulphur (no bad smell)

Hemicelluloses are largely converted into hydroxy acids

Very small mills do not recover sodium for re-use

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Sulphite vs. kraft summary table

Constituent Sulphite product(s) Kraft product(s)

Lignin Lignosulphonate Kraft lignin

(with 2-3% org. S)

Hemicelluloses Sugars, furfural, Hydroxy acids,

oligosaccharides some xylan polymer

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Organosolv processes

Based on the use of different organic solvents

Planned especially for hardwood and non-wood materials

Planned for selective fractionation of all major raw material

constituents

No industrial scale process currently in operation

Two companies especially aim for Asian straw pulping

markets:

CIMV from France

Chempolis from Finland

They use formic or acetic acids as the main solvents

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Pulp production by methods (190-200 Mt in total)

430

40

Plenty!

40

Number of pulp mills

(10 pre-

hydrolysis

mills)

No organosolv processes

industrially operating

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Industrial products from sulphite

pulp mill biorefineries

o Glucose (not isolated as pure)

o Xylose; xylose to xylitol

o Arabinose, galactose, mannose

o Ethanol o Baker’s yeast

o Torula yeast

o Pekilo protein

o Ribonucleic acids

o Acetic acid (from fermentation)

o Biogas

Current products shown on bold

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Industrial products from sulphite

pulp mill biorefineries

o Lignosulphonates

o Oxidation to vanillin

o Vanillin process by-products

o Acetic acid

o Furfural

o p-Cymene (”turpentine”) for

softwood only

o Glucose (not isolated as pure)

o Xylose; xylose to xylitol

o Arabinose, galactose, mannose

o Ethanol

o Baker’s yeast

o Torula yeast

o Pekilo protein

o Ribonucleic acids

o Acetic acid (from fermentation)

o Biogas

Current products shown on bold

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Ethanol from sulphite pulp mill biorefineries: the first

2nd generation ethanol plants

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Ethanol-producing sulphite pulp mill biorefineries in Sweden

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Ethanol-producing sulphite pulp mill biorefineries in Finland

Summary of the past mills:

- Sweden 30

- Finland 20

- World total 150-200??

- Now only 4 sulphite ethanol

plants (next slide)

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Current ethanol-producing sulphite pulp mill biorefineries

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Torula yeast and pekilo protein

• Pekilo protein produced only at two plants in Finland (1970s-1980s)

• Torula yeast currently produced in Japan, Russia and Czech Rep.

• Process utilises also pentoses, aldonic acids, uronic acids, acetic acid

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Ribonucleic acids

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26 30/7/2015

Danisco Sweeteners

Thomson

Lenzing

Anyang co., Ltd

Flambeau River

Paper, US

Lenzing AG,

Austria

Thomson

Kantvik

Vigo

(Kotka)

Tolling Manufacturers

Spent

Liquor

D-Xylose

Xylitol

D-Xylose

Side Stream

L-Rhamnose

L-Arabinose

L-Fucose

D-Mannose

D-Galactose

Suryps

L-Xylose

L-Ribose

ATBR

LTAR

XMAFlavour- / Food Industry

Feed Industry

Pharma Companies

R&D Institutes

Dietary Supplement Companies

Bio Companies

Cosmetics

Raw Material

Suppliers Danisco Sweeteners Customers

Sugars from sulphite spent liquors

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Isolation of acetic acid and furfural at Lenzing

sulphite pulp mill biorefinery, Austria

Production 25,000 t

Food-grade product!

Furfural isolated at the

same time, 4,000 t

(the only sulphite pulp mill)

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Lenzing pulping mill biorefinery, Austria

The net calorific value corresponds to

abt. 220 kg fuel oil per t of pulp produced!

Dissolving

pulp

Acetic acid

Spent liquor Excess

energy

Beech wood

50%

Pulp

mill

39% Furfural

Xylose

11%

Source: H. Harms, FTP Conf. 2005

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Sulphite pulp mill biorefinery in Finland in the 1980s

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Borregaard sulphite pulp mill biorefinery, Norway

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Lignosulphonates from sulphite processes - production

Annual "production" over 4-5 million tons.

Used as a chemical/material: 1.2-1.8 million tons.

Production in Europe, Asia, North America, Africa.

Several companies operating, LignoTech Borregaard dominating.

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Lignosulphonate functionality & substitutes

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Lignosulphonate uses 2008

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Current lignosulphonate producers (some figures are indicative)

Just announced: Borregaard and Rayonier will construct a new 150,000-ton capacity LS plant in Florida

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Where do Chinese lignosulphonates come from?

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Chinese lignosulphonate capacity steadily increasing

There is very little sulphite pulp industry in China to explain the volume of lignosulphonates.

Possibly mainly based on post-sulphonation of non-wood soda lignins?

In China, high demand for construction and agriculture

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Vanillin from lignosulphonates

Today, 15% of global vanillin production is based on oxidation of

lignosulphonates (yield is c. 10%)

Two producers: Borregaard (Norway), Bailu Papermaking (China)

In the past, also produced in the US, Canada, Japan, USSR, Poland

(and other Chinese plants). Many plants closed 1980-2000.

Isolated by-products include dehydrodivanillin, acetovanillone, and

oxalic acid.

Vanillin Acetovanillone

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Latest new lignin vanillin plant operated only for some time

LignoTech Kaishantun, China (joint venture with Borregaard,

Norway)

Planned vanillin capacity 300 tons

Started 1995, closed 1996

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Industrial products from kraft

pulp mill biorefineries

Prehydrolysis kraft pulping

o Xylose

o Furfural

o Ethanol

o Fodder yeast

Normal kraft pulping

o Turpentine

o Tall oil (”pine oil”)

o Palmitic acid

o Lignin

o Methanol

o Ammonia

o Dimethyl sulphide

o Dimethyl sulfone and sulfoxide

o Acetone, 2-butanone

o Light and heavy oils

o Biogas

Current products shown on bold

Pre-extraction kraft pulping

o Arabinogalactan (Stractan)

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Bratsk prehydrolysis-kraft pulp mill biorefinery in the 1970s Products included yeast 20,000 t/a

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By-product potential from kraft pulping

Chips

240 million tons

Kraft pulp (wood)

120 million tons Spent liquor organics

120 million tons

Current by-products

<2 million tons

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Main hydroxy monocarboxylic acids in all kraft

pulping spent liquors – potential future by-products

Not yet isolated commercially (not now discussed in more detail)

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Indicative turpentine production (1000 tons)

(From softwood resin or softwood pulping)

CST, crude sulphate

turpentine

Collecting resin for

gum turpentine and rosin

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Tall oil (“pine oil”)

”Tall” is Swedish meaning pine.

Isolated at numerous softwood kraft pulp mills worldwide

Distilled at c. 20 distilleries to different fatty and resin acid fractions

(and residues). Phytosterols also isolated in many countries

Production figure steady: 1.4-1.5 million tonnes

The main fractions are valuable products

Recent interest also for the manufacture of biodiesel

Softwood (tall oil and gum rosin) are the only sources of pine rosin

Forchem, Rauma (2002) Resitac, Brazil (2009)

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Tall oil rosin competitor: gum rosin

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Phytosterol producers

Total capacity c. 22,000 tons

More than 50% from tall oil

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DMSO – Dimethyl sulphoxide (via DMS)

More valuable product from black liquor processing

Pilot-scale production in Finland from

black liquor in the 1940s

Knowledge transferred to the USA,

where production from the 1960s to

2010 (by Gaylord Chemical). During

the recent years, c. 1/3 of global

DMSO was from black liquor.

Also, dimethyl sulphone (MSM) was

produced.

DMSO also produced in the Soviet

Union (1974-1990s)

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Kraft (sulfate) lignins

Annual "production" over 60-70 million tons.

Used as a chemical/material: under 150,000 tons.

Soda lignin isolation status unclear (Chinese lignosulphonates?)

Isolated in the US, Canada, Sweden, Japan, Finland

New capacity under planning or negotiations

All current isolation processes based on CO2-H2SO4 precipitation

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Kraft (and soda) lignin uses

Modified for dispersants and related uses

Phenol formaldehyde resins

Increading interest for commercialisation in polyurethanes,

carbon fibers, and different composites or plastic blends

Post-sulphonated kraft lignins are on the markets; uses are

similar to those of proper lignosulphonates

Uncertain future availability of lignosulphonates has strongly

increased attention to post-sulphonate alkali lignin, and also

to recovery of sulphonated lignins from pretreatment

processes in bioethanol production

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Flax pulp mill

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The lignin plant of ALM India in Punjab receives raw

material (soda lignin) from Kuantum Papers pulp mill

(in Punjab). Also markets post-sulphonated products.

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Borregaard is planning to ensure lignosulphonate supply

by a novel pretreatment process (BALI)

Sulphite-based pretreatment yields lignin as water-soluble lignosulphonates,

to ensure sufficient supply.

Commercial plant(s) can be expected in a few years time.

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BALI process – indicative mass balances

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About some future pulp mill biorefinery concepts

Pre-extraction of hemicelluloses (1)

Heavily studied, aiming at polymeric or mono-/oligomeric products

Sugars usually to ethanol, butanol, succinic acid, etc.

Pilot-demostration project operated several years at a kraft pulp mill

in Maine, USA

Mill recently closed, now new owner (future?)

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About some future pulp mill biorefinery concepts

Pre-extraction of hemicelluloses (2)

Industrial project recently announced at Cascades Canada’s Norampac-

Cabano plant

Sodium carbonate process will be changed and hemicellulose extraction starts

Hardwood process, little details on the target products given (xylose, xylitol?)

Options for xylan extraction from hardwood or non-wood processing

Alkaline or hot-water pre-extraction

Alkaline post-extraction from the bleached pulp

Isolation at an initial pulping stage

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Organosolv pulp mill biorefineries

Only one mill-scale production (Organocell) tested so far (1991)

Demonstration run of Alcell process in Canada (1989-1996)

Based on ethanol

Lignin production (marketed) 3,700 tons

Some furfural also isolated

Hardwood raw material

Technology later acquired by Lignol (now finacial problems)

Organic acid based processes close to commercialisation for straw

Chempolis, Finland

CIMV, France

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Conclusions

If more economical and environmentally sound solution for the utilization of

non-wood raw materials can be developed, it would be possible to raise the

world non-wood pulp production significantly from the present level.

There are promising future potential markets for non-wood soda lignins (as

they have many good properties and lack of smelling sulphur). A growing

area is the production of synthetic lignosulphonates.

An important requirement is secured supply of constant quality pulping raw

material.

The isolation of hydroxy acids will depend on the development techno-

economically feasible recovery and purification methods.

Sugar-based pre-extraction or pre-hydrolysis products also have potential

markets; the feasible recovery process needs to be optimised

The first mill-scale organosolv non-wood pulp mill is possible in near future.

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Semichemical (NSSC) pulping: developed in the US for tannin-

extracted chestnut trees before the attack of chestnut blight

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NSSC pulp mills

High-yield pulp mills (hardwood) for corrugated board, NSSC

process originally developed in the US in the 1920s to pulp wood

from tannin extraction

Pioneering acetic and formic acid separation processes developed

in the USA and Finland

Sonoco 1958-1970s

Savon Sellu 1979-1991,

chlorinated product used

for the manufacture of

CMC at Äänekoski.

Other products:

lignosulphonates

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Chestnut extraction-pulping mill operated in Italy 1957-2009

NSSC

pulping

Hot water

extraction

Tannin

Chips

Pulp