DIGESTERS and

SRS RENDERING

WASTE MANAGEMENT

For the treatment of: Stable manure, Organic waste, Flotation

sludges, Slaughterhouse waste, Intestines, Blood, Meat, Fat etc.

Technic for quality and performance

Tel. +32(0)14 65 66 67 E-mail: info@euroindustries.be

Hof ten Bergestraat 7 2381 Weelde - Belgium

WASTE MANAGEMENT

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Euro Industries bvba in Belgium has extensive

experience of treatment of a wide variety of organic

wastes with a view to controlling and managing

pollution, conforming to legislation regarding use,

disposal and utilising by-products.

For the treatment of organic wastes from

slaughterhouses Euro Industries bvba offers two

possible solutions, presented in this information

brochure.

The Basic Design

Type and quantity of wastes and sludge’s coming

from a slaughterhouse can be treated or by

rendering or by anaerobe digestion (biogas).

Both systems are in our delivery program, however

the two systems are totally different from approach.

In a few words:

A rendering system treats all the waste materials

in order to be used as a fertilizer or for incineration

(Category 2 and 1) or as an animal or for pet food

(Category 3).

The fat and oil coming from the rendering process

can be used as a bio-fuel, so the complete process

is a low energy cost process.

A digester system treats all the waste materials in

an air closed system with sufficient retention time in

order to degree the organic materials and to

produce interesting quantities of methane gas for

heating system and steam boiler or also co-

generation and to produce electricity. The treated

organic waste materials in the digester can be used

after dewatering for composting and as a fertilizer.

ANAEROB DIGESTION (biogas) of

slaughterhouse waste

Our design utilises well-established mechanical

principles proven in over a hundred digester

systems, and has a number of advantages over

other designs.

The Euro Industries bvba digester system is

suitable for treatment of a wide range of organic

wastes including:

Stable Manure

All meat waste (intestines, red offal’s,

white offal’s etc.)

Stomach contents

Blood

Sludge from the waste water treatment

Bones and hairs are not treatable in a digester.

In the Euro Industries anaerobe digester all

materials can be treated up to an average dry

substance of 15%. This is a special and unique

advantage of our system.

Due to the high possible dry substance, the system

can be build as a compact equipment.

Feeding the digester is never a problem. Holiday

periods or periods in which it is not able to feed the

digester do not disturb the process. In times of low

feeding the digester, only the gas production is

lower.

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General description

An anaerobic digester is a system which creates

optimum conditions for the growth and action of

anaerobic bacteria. These organisms occur naturally

in habitats where air is absent such as the stomachs

of animals, cesspits, swamps, and the mud’s of

rivers, lakes and oceans, where they play a vital

role in the decomposition of wastes and recycling of

nutrients in the environment.

By maintaining an optimum temperature and by

regular feeding and mixing of wastes, a digester

system speeds up the action of these bacteria

enabling them to process wastes far more rapidly

than would be possible in the often still and cold

conditions where they are normally found.

The digester tank comprises a sealed and insulated

vessel which is sized to process as much waste as

possible within the time required by the bacteria to

decompose the wastes.

The system contains a mechanical systems for

heating, mixing, loading and unloading of wastes,

together with an electrical system for operating,

monitoring and controlling the process.

The pasteurisation process for the total waste

volume is included to be conform to the European

legislation. The pasteurisation process is a closed

system, working at a temperature of minimum 75

ºC

Digester mixing

The digester is mixed by gas re-circulation.

Gas produced by the digesting wastes is routed

from the gas outlet to a condensation trap which

collects moisture from the cooling moist gas, and to

a gas holder.

The mixing system is the most important

mechanical system in the short term.

Digester system

The digesting wastes are maintained at an operating

temperature of 36-38 °C by the combustion of some

of the biogas produced by the digesting wastes. At

this temperature a Mesophilic process takes place

inside the digester.

An alternative digesting process is the Thermophilic

process which takes place at 55°C.

The disadvantage of the Thermophilic process

is the instability and high maintenance and

operation cost.

Gas pressure sensing system

A gas pressure manometer responds to variation in

gas pressure in the gas system. This signal is used

to control gas use and heating systems.

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Digester heating

A gas boiler heats water which is circulated to heat

exchangers suspended from the roof of the

digester. This design allows the heat exchangers to

be removed in the unlikely event they should

require repair or maintenance, and allows total

access to all parts of the heating circuit.

The Heating system contains a thermostat which

controls the maximum temperature of the hot water

circuit.

The temperature of the heating circuit water should

not exceed 60 °C due to the high probability of

caking of the heat exchangers above this

temperature.

The temperature of the digesting wastes is

measured by a probe mounted in flanges on the

digester roof, and is indicated by the digital

temperature gauge on the control panel.

Features of the Euro Industries bvba Digester

System

• Low profile rectangular tank which may be

partially or fully buried and is sympathetic

to planning requirements.

• Durable well-proven materials for digester

construction.

• Effective low-power gas mixing system

proven on high solids wastes.

• Removable inox heat-exchangers without

process decommissioning.

• Reduced pumping duty.

• Modular design.

• Low cost multi-stage option for process

flexibility.

The Euro Industries digesters are made with

isolated polyester roof elements for easy

access, mounting of all equipment and

complete gas closed for a pressure of 20 mbar.

The Euro Industries Digester System is a cost

effective method of waste treatment that can

produce valuable by-products

• Recycling of organic wastes reduces depend on

artificial fertilisers and reduces the consumption

of non renewable resources.

• Production and sale of by-products from

digested waste can make a significant

contribution to the economic viability of a

waste treatment system.

• Co-generation of electricity and hot water.

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SRS CONTINUOUS RENDERING SYSTEM

The Euro Industries Continuous Rendering System

is designed for processing organic waste from

slaughterhouses.

The SRS Rendering System is a key component and

build as a compact unit.

It is manufactured in three sizes with capacities of

500, 1.000 and 2.000 kilograms per hours.

The organic wastes are fed continuously to

shredders, sterilisation and Pentra Dryer where they

are reduced in particle size, heated and transported

to the sterilisation and Pentra Dryer in order to

ensure the highest possible product quality conform

to the legislation concerning sterilisation time,

pressure and temperature.

The problem

In most cases, at this moment the blood, flotation

sludge’s soft offal’s, hairs and other waste material

from a slaughterhouse are collected for “central

treatment or rendering” at high cost.

The circumstances to treat the waste materials at

site are changed.

We offer the possibility to treat the waste at

site at low cost, no smell and no noise.

The result is to obtain a serious volume

reduction and valuable material that can

be used as pet food or as fertilizer direct after the

treatment in the SRS unit.

How does the SRS unit work ?

The equipment for the treatment of blood,

single or together with other organic waste is

based on the idea that a complete closed

system can not produce any smell during the

treatment.

An industrial process that recovers a product within

the new legislation of the EU for pet food or

fertilizer.

The idea of our engineers was to develop an

equipment that could treat the waste materials at

an acceptable price in a continuous process and at a

very low level of cost for maintenance and

operation.

The SRS unit can work in a continuously automatic

operation, during 24 hours per day.

For the complete equipment a minimum of space

is required. The complete equipment does fit in

two 40 feet containers.

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Comparison of different rendering processes

The conditions of each different rendering system

have a considerable effect on the materials and

energy requirements and also on the properties of

the final product.

Batch versus continuous systems

Batch and continuous rendering systems each have

advantages and disadvantages. A batch rendering

system cooks, pressurizes, and sterilizes in the

same vessel.

The following major disadvantages of batch systems

are:

PENTA DRYER

The organic waste, coagulated and pre-dewatered,

blood, offal’s, sludge, hairs, feathers and other

solids are pressed into the step of sterilisation. The

sterilisation is a continuous sterilisation type, with a

guaranteed sufficient retention time of minimum 20

minutes, at a minimum pressure of 3 bar and a

minimum temperature of 133,3 ºC. This means that

the system is completely conform to the minimum

levels of the new EC legislation.

After the coagulation and sterilisation the product

will be treated in the next step by a centrifuge, this

means that the materials are almost dry when they

come out of the centrifuge. The dry substance after

the centrifuge is around 40 %.

The warm liquids coming from the centrifuge are

collected in the waste warm liquids tank and are

used for pre-warming the incoming organic waste.

All energy is almost completely re-used.

After the continues treatment in the centrifuge the

materials are collected in a closed hopper before the

final drying steps.

The condensates returning of the Penta Dryer

system is approx. 90 ºC. and returned to the steam

boiler.

The last part of the installation is the cooling screw

conveyor, to cool down the meal coming from the

Penta Dryer.

The vapours from the Penta Dryer are send to an air

condensers. This condenser collects all the vapours

and after cooling the condensate the water is

returned to the waste water treatment system.

• Fat is darker.

• The high cooking and pressing temperature

produces fines which pass into fat.

• Carcass materials must be cut and washed

otherwise it generates a loss of fat and

protein and adds water to the raw material.

• Since batch rendering processes are not

contained in enclosed vessels, there is

increased potential for re-contaminated of

cooked products, and plant sanitation is

more difficult.

• It is difficult to control the end point of the

cooking process.

• There is a high consumption of steam if

vent steam is not recovered as hot water.

• Finally it is a labor-intensive process.

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Continuous system – advantages

• Continuous systems consist of a single cooker.

• Continuous systems usually have a higher

capacity than batch systems.

• Continuous systems occupy considerably less

space than batch cooker systems of equivalent

capacity, thus saving construction costs.

• Single-cooker units are inherently more efficient

than multiple-cooker units in terms of steam

consumption. Thus, continuous systems achieve

a significant savings in fuel usage by the boilers.

Likewise, less electric power is consumed for

agitation in the single continuous cooker units.

• They are labor-efficient

• Continuous systems are more conductive to

computerized control through centers located

inside environmentally controlled rooms. Such

control centers feature process control panels,

which provide a schematic flow diagram of the

entire process; indicator lights show. Whether

individual equipment components are on or off.

Process microcomputers control all start/stop

operations in an interlocking sequence, adjust

the speeds of computerized control through

centers located inside environmentally controlled

rooms. Such

the key equipment parts, and control various

process elements to optimize plant operation.

General

Compared a conventional batch dry rendering

method using screw press defatting to a

continuous wet rendering method using

centrifugal defatting for processing inedible raw

material (76,5% soft offal, 15 % industrial bones,

and 8.5% swine cadavers) there are several

features.

Features of the Euro Industries SRS Rendering

System

• Less space required.

• Durable well-proven materials for SRS

construction.

• Effective low-power and energy consumption.

• Fully automatic operation, saving on main-

tenance and operation cost.

• Containerised Modular design.

• Production of tallow and meal of high quality

• The meal fat is about 5 - 8%

• Approximately 40% less steam is used com-

pared with batch rendering

The SRS unit answers completely to the recent

developments and legislation in the field of

treatment of organic waste, more specific the new

classification and the hygienic demands versus the

destination of the product.

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Technic for quality and performance

WASTE MANAGEMENT

Hof ten Bergestraat 72381 Weelde - Belgium

Tel . +32(0)14 65 66 67E-mail: info@euroindustries.be