Gasification of Turkey Litter for Farm Energy

Prepared for:

Charison’s Turkey Hatchery Manitoba Livestock Manure Management Initiative

Prepared by:

DGH Engineering Ltd. 12 Aviation Boulevard

St. Andrews, Manitoba R1A 3N5

Contact: Stephen Brogan, EIT, AIT

Dennis Hodgkinson, P. Eng.

26 April 2006

Abstract

With increased fuel prices and Canada’s commitment to the Kyoto protocol, there has

been a renewed interest in gasification, an old technology. Charison’s Turkey Hatchery,

of Gunton, Manitoba, produces approximately 705 kg of litter per hour, and has an

average electrical energy demand of 353 kW. A need was identified to create value

from this waste that may be able to offset energy costs. A survey of gasification

technologies in Manitoba showed that despite a large amount of activity, there is still no

off-the-shelf solution available to generate electricity from biomass. Litter samples were

collected from several barns and sent to the CANMET Energy Technology Centre in

Ottawa, Ontario where bench scale gasification tests were done. These tests showed

that the loose litter tended to plug up the system, and only a low quality gas was

produced. Further testing was preformed by Innovation Technologies (Ireland) Ltd. of

Ballycarry, Northern Ireland on similar litter sourced there. These tests determined that,

due to the high ash and water content of the fuel and its loose configuration, it would

best be gasified mixed with sawdust in pellet form. Should Charison’s install a gasifier

on site for the purposes of generating electricity, issues with respect to clinkering and

pelletisation would need to be addressed, likely though the development of a gasifier

designed specifically for turkey litter. Given this analysis, it is recommended that further

development of a gasifier at Charison’s be carried out in conjunction with an organisation

that has expertise in gasification for the purposes of electricity generation, through the

development of a functional on-site prototype.

Table of Contents

1.0 Introduction 2.0 Project Objectives 3.0 Energy Use and Litter Production at Charison’s 4.0 Gasification Background Review 5.0 Survey of Gasifier Manufacturers in Manitoba

5.1 Heat Innovations Inc. 5.2 Home Farms Technologies Inc. 5.3 RES/OP Technologies Inc. 5.4 Modern Organics Inc. 5.5 Vidir Machine Inc. 5.6 W2E Technologies Inc.

6.0 Feasibility of Gasifying Turkey Litter 6.1 NRC Testing 6.2 ITI Testing

6.2.1 Sampling of the Litter 6.2.2 Testing Objectives 6.2.3 Fuel Characterisation 6.2.4 Power Generation Potential 6.2.5 Pellet Manufacture 6.2.6 Testing of the Pellets

6.2.6.1 100% MDF Dust 6.2.6.2 100% Turkey Litter 6.2.6.3 Mixed MDF and Turkey Litter

6.2.7 Gasification Testing 6.2.7.1 100% Turkey Litter Pellets 6.2.7.2 40% Turkey Litter Pellets

6.2.8 Conclusions 6.2.8.1 Fuel Pellet Manufacture 6.2.8.2 Pellet Carbonisation 6.2.8.3 Pellet Clinkering 6.2.8.4 Energy Value

7.0 Recommendations 8.0 References 9.0 Acknowledgements

Appendix I – Manitoba Gasifier Contact Information

Appendix II – Turkey Litter Sampling Protocol

Appendix III – National Research Council Test Results

Appendix IV – Ash Content Testing

1.0 Introduction

Charison’s Turkey Hatchery Ltd. is a

modern turkey hatchery with several

commercial turkey production farms

located in Gunton, MB, (Figure 1). As

western Canada’s largest turkey

hatchery, the farm’s main product is

turkey poults, as well as breeding stock,

and some commercial meat turkeys.

In the wake of recent bird flu epidemics, Charison’s is very concerned with bio-security in

the handling of wastes and mortalities. Ideally, the farm would like to dispose of all the

waste streams on-farm in a way that minimises land application and maximises energy

use. With a cold climate and a total confinement production system, the farm has a

large annual energy demand. The concept of disposing of waste on-farm and producing

energy to offset electrical usage is very attractive to Charison’s.

Figure 1 - Charison's Turkey Hatchery Ltd.

2.0 Project Objectives

The purpose of this investigation was to analyse the potential opportunity and make

recommendations to Charison’s Hatchery with respect to the installation or development

of gasification technology suited for using turkey litter as a fuel for a gasifier to produce

useful energy. The report endeavours to do this by:

• Establishing the energy needs at Charison’s Hatchery, and quantifying the litter

production.

• Reviewing any previous studies and literature with respect to gasification of

turkey or poultry litter.

• Investigating the gasification industry and experience in Manitoba.

• Testing the litter to determine suitability for use as a gasifier fuel.

3.0 Energy Use and Litter Production at Charison’s

Charison’s Hatchery Ltd.’s operations include several barns spread out around a 4 mile

radius from the central hatchery. The separation of the barns allows for greater bio-

security and segregation of valuable breeding stock. Most of the barns are open floor

style. The floors are covered with a bedding mixture which consists of wood shavings,

sunflower hulls, and straw. Bedding is renewed on a regular basis to maintain a sanitary

and comfortable environment for the birds. At certain points during the production cycle,

the barns are cleaned and the resulting litter is stockpiled and later spread on

neighbouring fields.

From a bio-security standpoint, it would be most desirable to locate any waste

processing facility off the site of the central hatchery (where there is the most traffic and

possibility of transporting contaminants). However, it is also desirable to be close

enough to one of the production facilities so that waste heat from the gasification system

can be utilised, and electricity can offset use from the utility. A piece of property east of

one of the commercial barns and central hatchery was chosen as the most likely location

for any such developments (Figure 2).

Figure 2 - Possible Location for Gasification Plant in relation to Charison’s Barns

Table 1 shows electricity usage, at the buildings nearby this property, that would be

potential users of gasification energy.

Table 1 - Electricity Usage at Nearby Buildings, 2004

Month Hatchery

(kWh)

Hatchery Heat

(kWh)

Truck Wash (kWh)

Commercial Farm (kWh)

Totals (kWh)

January 123,520 52,036 38,400 27,520 241,476 February 97,280 45,380 36,600 21,280 200,540 March 100,160 123,107 52,200 20,720 296,187 April 96,320 147,781 55,200 18,240 317,541 May 87,040 74,094 48,000 18,880 228,014 June 88,960 87,480 48,000 17,600 242,040 July 85,120 66,770 48,000 17,360 217,250 August 81,440 48,965 46,200 16,240 192,845 September 92,800 96,904 54,600 17,680 261,984 October 79,520 123,359 46,200 21,360 270,439 November 103,680 94,096 39,600 27,600 264,976 December 91,200 192,942 46,200 25,360 355,702 Annual 1,127,040 1,152,914 559,200 249,840 3,088,994

Propane usage data was also obtained from Charison’s, as shown in Table 2. Table 2 - Annual Propane Usage, 2004

Hatchery (litres)

Shop (litres)

Grain Dryer (litres)

Truck Wash (litres)

Total (litres)

136064.7 16974.3 1225.2 21449.7 175731.9

Litter production from each of these barns has been quantified by truckload. Historical

records obtained from Charison’s (Charison, 2004) are summarised in Table 3. Table 3 - Annual Litter Production

Number of 14-ton Loads Annual Litter Production 2003 392 5488 tons 2004 490 6860 tons Average 441 6174 tons

Given an average litter production of 6174 tons per year, it amounts to about 16.9 tons

per day or 0.7 tons per hour. From a global prospective, this is a relatively small amount

of litter to process. However, there is a possibility that the litter can be mixed with other

locally available feedstock in the form of sawdust.

4.0 Gasification Background Review

Simply stated, gasification is a method of high temperature combustion that turns solids

into a low quality gas (often called producer gas or syngas). This gas may then be

burned in a boiler, internal combustion engine, or turbine. The quality and energy

content of this gas is greatly affected by the type of gasifier and the type and moisture

content of the fuel being used.

Gasification is an old technology and was used over 100 years ago to make fuel for gas

streetlights and more recently to generate fuel for automobiles during petroleum

shortages in WWII. The technology was abandoned after the war with the advent of

cheap electricity and fossil fuels. The energy crisis of the 1970s saw a new interest in

the gasification technology, but few commercial units have been successfully operated

and it is not in wide use.

Two basic types of gasification units exist, updraft and downdraft. Downdraft units are

characterized by their ability to produce a cleaner fuel, but require a solid or pelletized

fuel. Updraft gasifiers generally produce a “dirtier” gas, but have the ability to burn a

wide range of fuel formats.

Only high quality syngas can be burned directly in an internal combustion engine or gas

turbine. Compared to natural gas or propane, syngas is relatively low in energy. Some

syngas fuelled engines use other common fuels to supplement the syngas in order to

take full advantage of the engine’s power capacity. Lower quality syngases, such as

those produced by an updraft gasifier, will foul moving parts of an internal combustion

engine and result in excess wear and short lifespan. These lower quality gasses are

best used in external combustion processes such as steam or Sterling engines in the

generation of electricity or for the firing of heating systems.

5.0 Survey of Gasifier Manufacturers in Manitoba

Manitoba is a hotbed of gasifier manufacturers. A survey of these manufacturers and

their processes/products was done to assess the possibility of employing local

technology at Charison’s. Contact was made with all the manufacturers listed in

Appendix I. A short description of each of the companies and gasification units follows.

5.1 Heat Innovations Inc.

Heat Innovations is based in Winkler, Manitoba and currently manufactures a line of

outdoor style hydronic heating boilers and accessories. The outdoor boilers are popular

with people who burn biomass such as wood and straw, although they may also be fitted

with a coal stoker. Heat Innovations is currently working on a prototype gasifier, but do

not expect to have a unit ready to test until 2007 or 2008. It is likely that this gasifier

would be geared toward hydronic heating as opposed to electricity generation.

5.2 Home Farms Technologies Inc.

Home Farms Technologies is based in Brandon, Manitoba and use a proprietary

gasification technology from Asia. Home Farms was not able to divulge the details of

the gasification unit. Their primary market is agriculture and they also market a

flocculation and dewatering systems for swine manure.

Home Farms Technologies does not actually sell gasification units, but operate on a

unique business plan were they maintain ownership of the equipment and the producer

supplies the biomass in return for discounted electricity.

5.3 RES/OP Techologies Inc.

RES/OP Technologies, a subsidiary of MESH Technologies an electronics engineering

consulting firm based in Winnipeg, Manitoba, has developed the Orverter (Organics

Converter).

The Orverter is not a gasifier in the traditional sense, but may fall in to the category as

there are some similarities in the combustion process. The Orverter accepts feedstock

from above and draws combustion air down through a grate, in that sense it is much like

a downdraft gasifier. The difference is that the combustion air is preheated by the

exhaust air, via a heat exchanger, making for an extremely hot combustion chamber.

There is no syngas produced, only thermal energy. Steam or thermal engines may then

be used to generate electricity if so desired.

Currently, a demonstration prototype unit exists at Elie, MB which has been used for

some short term testing. The original prototype experienced a meltdown, in which the

steel combustion chamber melted. RES/OP Technologies claims that despite intense

internal temperatures, problems such as NOx gas production and thermal breakdown

will be addressed before the Orverter is publicly available. Plans are in the works to

install a commercialisation prototype in the near future.

5.4 Modern Organics Inc.

Modern Organics of Headingley, Manitoba specialises in chelation and crop

enhancement chemicals for agriculture. The president of the company, Edward Mayer,

has built several gasifiers of different sizes since 1987.

Currently, Mr. Mayer is working on a large scale gasification unit (the Mayer DownDraft

Gasifier or the Mayer Energy Generator) that he hopes to sell to a large biomass

producer. This gasifier is said to produce a high quality syngas that can be used in

boilers or internal combustion engines. A small prototype exists, but had never been

used to run an internal combustion engine. Only a flare has been operated on the

syngas.

5.5 Vidir Machine Inc.

Vidir Machine Inc. of Arborg, Manitoba manufactures industrial and commercial racking

and flooring cutting equipment. They are currently the only company that sells a

functional, commercial scale gasifier designed and made in Manitoba.

The Vidir Biomass Gasifier is a rotating grate updraft gasifier that uses round baled

cereal or flax straw for feedstock. A large chopping mechanism feeds a metering

system that meters biomass in to the gasifer based on heat demand. The syngas is

then burnt in a secondary combustion chamber that is essentially a boiler. This system

does not produce a syngas that is clean enough to burn in an internal combustion

engine.

A functional system has heated the Vidir head office near Arborg, Manitoba for a number

of years. Another system is installed near at Landmark, Manitoba at a chicken farm.

5.6 W2E Technologies Inc.

W2E Technologies Inc., near La Salle, Manitoba has a gasification system designed by

Fluidyne New Zealand. The system is installed at a lumberyard where sawdust and

wood chips are available as a feedstock. A bank of Cadillac engines, converted to run

on syngas is connected to a large electrical generator. Various problems have caused

the project to be mothballed for several months.

Eventually W2E would like to market the generation technology as a system that can be

sold to biomass energy producers.

6.0 Feasibility of Gasifying Turkey Litter

Turkey litter is unlike most animal wastes as it is relatively dry, roughly 20% moisture

content and quite heterogeneous. Its appearance is very reminiscent of its constituents:

a dirty mass of straw and wood shavings. These properties make the litter less suitable

for intermediate processes such as anaerobic digestion and more suitable for a process

which involves direct combustion, such as gasification.

Many projects around the world have been developed with the intent of gasifying various

types of biomass waste products. One of the most common problems with them is that

they are not reliable from an operational standpoint. Quite often large gasification

projects are abandoned because of this inability to function properly over extended

periods of time, although it is accepted that any carbon based material can be gasified.

Before any recommendations on type or size of gasifier can be made, testing of the

actual litter is needed. Two organisations were contacted with respect to this testing.

Firstly, the National Research Council’s Energy Technology Centre in Ottawa, and later,

Innovation Technologies (Ireland) Ltd. or ITI, in Ballycarry, Northern Ireland. The results

of the research are summarised as follows.

6.1 NRC Testing

It was believed that the best way to assess the properties of the turkey litter produced

from Charison’s turkey farms was to collect samples that were representative of the litter

coming from each contributing barn. A sampling protocol was developed (Appendix II)

and samples were collected on February 2nd 2005. These samples were sent to Dr.

Fernando Preto, of the National Research Council in Ottawa, Ontario. Due to staff

shortages and scheduling issues in Ottawa, the samples were not tested until June and

the results were received on June 21st 2005. A synopsis of the results are as follows:

Two samples were taken for moisture content tests and were found to be 27.1 % and

30.4%. Dr. Preto felt that these numbers were a little high for optimal performance, as

fuels for gasification are generally recommended to be below 20%. Were such a fuel to

be used, a drier admixture material would have to be added and blended for normal

gasifier operation. The gasifier was operated for 43 minutes on the fuel (13 minutes for

warm up and 30 minutes producing gas).

The syngas produced had the follow makeup (Preto, 2005):

• Hydrogen: 7% to 7.5%

• Carbon Monoxide: 14.67% to 17%

• Methane: 0.11% to 0.08 %

• Oxygen 6.5% to 7 %

• 12 MJ/kg or 12.8 MJ/m3

Two factors affected the syngas production, resulting in lower calorific values: the high

moisture content, in excess of the recommended 20%, and straw bridging across the

bottom of the gasifier. This straw bridge prevented proper mixing thus yielding a lower

quality gas as excess air bypassed the fuel and entered the system. The syngas

analyses show that this was indeed the case as there was a relatively high oxygen

content (6.5% - 7%) and a relatively low hydrogen content (7% - 7.5%).

Dr. Preto suggested that under better conditions, no fuel bridging and a lower moisture

content, a syngas of at least 20 MJ/kg could be produced. From these results it was

apparent that a viable system would have to overcome the tendency for fuel to bridge

and that the moisture content of the litter would have to be reduced by some means.

The results of the NRC tests showed that the litter could be gasified in its native form,

but producing only a low quality gas, and causing severe bridging after only a very short

run. It was felt that further testing, on a commercial gasifier would yield more relevant

results.

6.2 ITI Testing

Mr. Doug Williams, of Fluidyne Gasification (New Zealand), an experienced gasification

manufacturer and consultant suggested that we contact Innovation Technologies

(Ireland) Ltd. After some correspondence, ITI was selected in August to pursue further

testing of the litter. ITI is an engineering research and development company based in

Northern Ireland, UK. For the last 6 to 7 years, ITI has been involved in the

development of wood gasification technology for power generation at the small-to-mid

scale, i.e. 5-500 kWe. They have worked with feasibility studies, equipment technical

assessments, and first-hand sub-contract work on demonstration installations of

gasifiers. More recently ITI has undertaken the commercial development of a range of

wood gasifier power generation systems incorporating Fluidyne gas-making philosophy

and expertise. The first of these systems has recently been installed at a factory in

Northern Ireland. It is this gasifier that was used for the experimental fuel trials. The

following sections (6.2.1 to 6.2.8.4) detail the work of Dr. Brian Russell, C. Eng. of ITI.

6.2.1 Sampling of the Litter

In the wake of BSE and the bird flu epidemic, it was not possible to ship turkey litter

overseas. ITI located a local turkey farm that had similar housing and bedding material

as Charison’s Hatchery. The turkey litter was obtained from a commercial breeding

house in County Antrim, Northern Ireland, where the bedding is composed of fine wood

shavings. At the time of sampling, the birds had been resident in the barn for around 8-

10 weeks, so the lower layer of bedding was still relatively clean and dry. In order to

best represent the litter that would be disposed of, the sample was taken primarily from

the upper layer. Any feathers found in the litter were removed before the pellets were

made, as the pelletising machinery was not designed to handle them.

An ash content and calorific value analysis were not undertaken on the litter sample as it

was believed to be reasonably representative of the litter found in any similar modern

turkey house located elsewhere and using similar bedding. The ash content was

therefore likely to lie within the region of 10-15% (Actual results from Charison’s

indicated an ash content of 9.51%, see Appendix IV).

An estimate of calorific value for the dry turkey litter would be around 90-95% of that of

wood, which would equate to a mixture of wood and sewage. This would give a

maximum value of around 16MJ/kg, a figure that would need to be adjusted downwards

to account for moisture content.

6.2.2 Testing Objectives

The objectives of the testing were as follows:

1. Investigate feasibility of making pelletised fuel of appropriate scale from the

turkey litter on its own (loose litter cannot be fed into the gasifier, only feedstock

in solid form, to allow proper air mixing in the combustion chamber).

2. Test a small number of pellets in the existing wood fuel gasifier.

3. Test the feasibility of making fuel pellets with increasing percentages of a

convenient fuel-mixing agent, if 100% turkey litter pellets were not viable.

4. Where viable pellets can be manufactured, test a small number of pellets in the

gasifier.

6.2.3 Fuel Characterisation

A technique for making experimental fuel pellets was developed previously by ITI when

investigating the use of sewage sludge as a potential gasifier fuel. It proved possible at

that time to make pellets using a combination of pressure and elevated temperature to

levels, determined by experimentation. The technique is highly labour intensive, but

nonetheless of considerable value since it facilitates provisional practical gasifier testing.

The following characteristics are of central importance for any fuel to be used in down-

draft wood gasifier:

• Carbonisation to a solid bonded pellet in the high-temperature, pre-combustion

zone of the gasifier.

• Combustion and gasification through the hearth of the gasifier without formation

of a solid clinker. Clinkers are lumps of silica formed at high temperatures from

the “ash” portion of the fuel. These clinkers will eventually plug the grate and

interfere with proper air mixing and combustion.

As was the case in the previous tests involving sewage sludge, the mixing agent used by

ITI for the combined fuel pellets was medium density fibreboard (MDF) dust. Fine dry

sawdust could equally have been used as a mixing agent if it had been conveniently

available.

As with sewage sludge, the prime-determining factor for fuel suitability is likely to be the

behaviour of the inorganic (ash) element of the fuel within the high temperature zone of

the gasifier. Where high ash content is present in an organic fuel, standard practice is to

control combustion temperatures to a level at which the formation of clinker can be kept

within acceptable limitations. How this is achieved is dependant on fuel, the ash

percentage of that fuel, and the mineral make-up of the ash. Upper limits of no more

than 650°C may be necessary in some cases (e.g. some sewage sludge incinerator

systems). However, a down-draft wood gasifier coupled with an internal combustion

engine, for electricity generation, should ensure that all fuel gas passes through a very

high temperature zone to crack the tar molecules that would otherwise damage the

engine. Temperatures as high as 1300°C are not uncommon as peak values. Without

some experimentation, it is difficult to predict with any certainly how a particular fuel or

fuel mixture will behave in terms of clinkers and tars within a given configuration of

gasifier. This most accessible first point of reference is therefore to see how a fuel

source can be prepared or adjusted to suit the characteristics of an existing wood

gasifier connected to a power generation system.

6.2.4 Power Generation Potential

In terms of potential power generation using a downdraft wood gasifier and a spark

ignition internal combustion engine, the rule-of-thumb for a typical wood-based fuel is

that around 1.4 kg/hr is required to generate 1 kW of constant electrical power. This

assumes that the moisture content in the wood is around 15%. Assuming that the

calorific value of a turkey litter fuel would be 10% lower than wood, and that the litter

would be dried to roughly 15% moisture, then approximately 1.55 kg/hr of turkey litter

fuel would be needed to produce 1 kW of electrical output. A 100kWe system would

therefore require around 155kg/hr of dried litter fuel, and a 500kWe system would need

around 780kg/hr of dried litter fuel. This assumes that the fuel is compatible with the

gasifier as described above.

6.2.5 Pellet Manufacture

The pellets were manufactured using a 20 kN hydraulic ram to exert pressure on a multi-

head die-and-piston assembly. Each die has an internal diameter of 30mm, and after

some experimentation it was found that five dies could be used in each press cycle. The

average pressure exerted on the die contents was therefore 5.7 MPa.

The pellets were also heated to about 120oC core temperature using a propane torch

directed on the die housings. The temperature was confirmed using a fire-proof

thermocouple after a successful technique of heating had been established.

Fresh turkey litter exhibited strong unpleasant odours, elevated static temperatures, and

intermittent gas releases under pressure. These characteristics were found to have

reduced when the same batch of litter was used to make more pellets a few weeks later.

This suggested that the process of pelletisation might be best undertaken a few weeks

after the turkey litter is removed from the turkey houses.

Once formed, the pellets looked essentially the same as those illustrated below in Figure

3. The pure turkey litter pellets were somewhat darker and denser than those

incorporating high percentages of MDF dust.

Figure 3 - 100% MDF Dust Pellets

6.2.6 Testing of the Pellets

6.2.6.1 100% MDF Dust

Pellets formed as shown in Figure 3, using MDF dust only, have a density of around 800

kg/m3, i.e. around the same density as the MDF board itself. They are also as stable in

water as the original solid board, maintaining their shape and integrity extremely well for

periods up to several days immersed in water. This simple cold-water immersion test

has been a good way to confirm their suitability as a fuel source for ITI-Fluidyne

gasifiers.

6.2.6.2 100% Turkey Litter

Pellets made from turkey litter only did not perform well when immersed in cold water.

The pellets sank, indicating a density somewhat higher than 1,000 kg/m3. They also

began to break up directly upon impact with the water, exhibiting no water-resistant

bonding characteristic whatsoever. This poor result led the investigators to feel that the

pellets would have very little chance of performing effectively in the atmosphere of a

gasifier hopper. Sufficient pellets were nonetheless made to conduct a representative

trial in the ITI-Fluidyne gasifier.

6.2.6.3 Mixed MDF and Turkey Litter

Pellets were made using various proportions of MDF dust and turkey litter to determine

where a cross-over in performance might occur with respect to the cold water immersion

test. Pellets made using 50% dust and 50% turkey litter (by weight) still behaved very

much like turkey litter, not exhibiting good bonding. It was not until the dust proportion

was increased to 60% that the characteristics improved to the point where the pellets

were reasonably stable for several minutes when immersed. This ratio was therefore

chosen as the most appropriate setting for mixed fuel pellet gasification trials.

6.2.7 Gasification Testing

Meaningful gasification trials on experimental fuels can be difficult and expensive to

achieve. Operational wood gasifiers remain few in number, and gasifier operators often

tend to be secretive and protective of what they do. Any working wood gasifier will be

set up (either deliberately or accidentally) for a particular variety and format of fuel.

Having managed to set up a system to work with a particular fuel stream, few operators

will be willing to introduce different fuels unless cajoled with the incentive of a very hefty

fee. Successful tests results for the experimental fuels cannot of course be guaranteed

even in these circumstances.

On top of this, an experimenter will face the problem of preparing fuel samples for the

gasification trial. Most down-draft wood gasifiers work best with clean and evenly sized

small block-wood fuel, about 60mm square. Wood chips are not ideal unless they are

relatively coarse and three-dimensional (low fines, smooth chip surfaces, and good

characteristics under gravity flow). Any experimental fuel will need to be prepared to

mimic or match these criteria. If suitable fuel preparation equipment is not easily

available, then the fuel preparation is likely to be manual, and very slow.

For this reason, ITI has developed a method of preliminary testing where a small token

sample of the experimental fuel is added into the fuel flow of a gasifier running normally

on a wood-based fuel. After introduction of the experimental fuel sample, the gasifier is

allowed to run for a further pre-set time until the main body of the experimental fuel is

judged to be within hearth zone of the gasifier. The gasifier is then shut down, allowed

to cool, and opened for inspection to observe what remains of the experimental fuel

sample in the system. This technique was adopted for the trials undertaken on the

turkey litter and mixed pellets.

This technique should be seen as indicative rather than absolute. Negative results

cannot be presented as absolutely conclusive of unsuitable fuel, since an adjustment of

the gasification parameters might provide some improvement in performance. Poor

results do nonetheless indicate that the fuel will require an alternative approach to that

used for the standard wood-based fuel. This in itself is problematic, since any further

development of the gasifier system would require substantial quantities of experimental

fuel and possibly numerous tests with different gasifier hearth configurations. Even then,

a successful conclusion may still not be possible.

MDF fuel usage in the ITI-Fluidyne Atlantic Class gasifier, pictures above, is around 80-

90 kg/hr at full engine power output, so the introduction of small numbers of pellets can

be seen as very modest as compared to the standard flow rate of the fuel.

6.2.7.1 100% Turkey Litter Pellets

Twelve turkey litter pellets were made and introduced as a small batch to the gasifier

fuel feeding system during a standard power generation run. The gasifier system was

then operated for a further 40 minutes before shutting down. The system was then

opened and inspected the following morning.

One full pellet was found in the fuel zone a few inches above the nozzles. This pellet

was still in a solid cylindrical shape, and yet carbonised to a high degree. This was

taken as a sign that the fuel in this format might be able to maintain a good structure in

the distillation and combustion zone.

Further through the fuel towards the throat of the gasifier, the remains of a second pellet

were also found. The cylindrical shape was still apparent, but the pellet had lost its

strength and had broken into fragile pieces. The deterioration in strength did not seem

to be significantly greater than for the bulk of the fuel, i.e. the MDF blocks. In terms of

carbonisation and fuel hopper flow, it therefore appeared that the pelletised fuel might

Figure 4 - ITI-Fluidyne Gasifier Used in Testing

work as a gasifier fuel, provided that the fuel was kept dry before introduction to the

gasifier and that the fuel was not too severely handled. It might also be necessary to

ensure that the gasifier was auto-fed with a system of similar characteristics to the ITI

system, so that the fuel would not generally lie within the hopper too long.

The Figure 5 below shows the pellets extracted from the hearth of the gasifier. Note the

white residue on the remains of the second pellet, indicating the presence of a high

percentage ash.

Figure 5 - Results of 100% Turkey Litter Gasification

Progressing further through the system to the grate, the main problem with the

experimental fuel pellets became apparent. A significant build-up of clinker was found

on the grate bars, whereas with 100% MDF fuel the build-up of clinker expected would

be next-to-nil. This clinker was interpreted as the remains of the ash content in the 10

further pellets that had not yet been identified. Given further fuelling of the gasifier with a

fuel of this nature, the grate could be expected to block completely.

Given this rate of formation of clinker with so few fuel pellets, it would appear that the

grate might suffer substantial deterioration of performance within a period significantly

less than 2 hours. This can be taken as indicative evidence that fuel made from 100%

turkey litter will not be of use for a standard downdraft wood gasifier system. This is

similar to the result obtained in previous studies by ITI for sewage sludge.

Carbonised pellets (100% Turkey Litter) Clinker build-up on the grate (100% Turkey Litter)

6.2.7.2 40% Turkey Litter and 60% MDF Dust Pellets

The procedure above was repeated with another 24 pellets made from turkey litter and

MDF dust. In this trial, the gasifier was run a little longer after the introduction of the

pellets so that virtually all of the pellet material would pass through the system. The

main result from the test was therefore found at the grate.

Again on this occasion, a significant, though smaller, deposit of clinker was found on the

grate bars of the gasifier hearth. Some of this at least appeared to have come from the

pellets. It was noted nonetheless that a proportion of this clinker was definitely not from

the experimental pellets but from a sealant used to seal the hearth components during

system re-builds. This raised the possibility that the initial charcoal fuel charge had

somehow become contaminated on this occasion with some extraneous clinker

residues. It was therefore decided to repeat the tests.

A second trial with the mixed experimental fuel was conducted. On this occasion, 24

pellets were once again introduced. During the subsequent strip-down, a number of

pellets and various pellet residues were found through the system, from 100mm above

the nozzles right down to the level of the throat. This represented around half of the

original pellet sample. Again, the carbonisation of the pellets seemed to have been

achieved very successfully, with the pellets holding together to maintain a good porosity

in char bed – at least as good as for the solid MDF block fuel.

Further down through the system, there was again some solid clinker residue formed

over the bars of the grate, again suggesting a problem with fuel ash levels. This

unfortunately appears to confirm the initial conclusion from the previous test, namely that

the pelletised fuels would still be problematic in a standard wood gasifier set-up even

with only 40% of turkey litter in the pellet. Only considerably more extensive trials with

100% experimental fuel would be able to confirm whether or not the gasifier set-up could

be altered to work with the fuel successfully. Otherwise, the percentage of litter would

have to be further reduced.

Figure 6 - Results of 60:40 Gasification

6.2.8 Conclusions

6.2.8.1 Fuel Pellet Manufacture

The results of the study would indicate that loose turkey litter cannot be used as a fuel

for a traditional downdraft wood gasifier unless presented in the format of a solid pellet.

For a gasifier of 70kWe scale, the pellet should be around 30mm diameter by 40mm

long. Turkey litter can be made into pellets of the required scale and density however,

the pellets are not very strong or resistant to water. Very careful handling would

therefore be required. The pellet manufacturing process requires application of pressure

to around 6 N/mm2 and heat to at least 120-150oC. The turkey litter can also be mixed

with sawdust or MDF dust to make a solid pellet that will carbonise properly. Tests have

been conducted with MDF dust using 50% and 60% dust by weight. So far this has only

been tested with the litter at a laboratory scale (i.e. involving manufacture of less than

100 pellets). It is nonetheless most likely that commercial equipment could be sourced

to achieve the same objective.

Pelletised 60 :40 fuel sample remnants recovered from the gasifier (above the throat).

Clinker material discovered on the grate – material probably originating from the

60 :40 fuel pellets

6.2.8.2 Pellet Carbonisation

Turkey litter fuel pellets from 100% litter have been shown to carbonise quite effectively

into solid blocks in a down-draft wood gasifier fuel hopper. This result was obtained with

small numbers of pellets, therefore the there is a proviso that the weakness of the pellets

could still be a problem if the wood gasifier were fuelled with 100% litter pellets only. A

more confident result was obtained when the pellets were manufactured using 40% litter

and 60% MDF dust. This is supported by the superior performance of such pellets in the

tests involving immersion of some pellets in cold water.

6.2.8.3 Pellet Clinkering

Use of fuel pellets made from 100% turkey litter appeared to create a very significant

operational problem in the hearth of the gasifier due to the formation of a solid clinker on

the grate. This was apparent when even as few as 12 pellets were introduced into the

standard fuel. This suggests that turkey litter would not be suitable on its own as a fuel

for a gasifier of this design. Fuel pellets were also manufactured and tested using 40%

litter and 60% wood dust. These pellets also appeared to cause a problem at the grate

following each of 2 fuel tests, albeit to a lesser extent than for the 100% turkey litter

pellets. This suggests that the percentage of litter in the fuel would need to be kept

below 40% to have any prospect of operational success in a standard wood gasifier set

up for wood. The precise percentages required for success are likely to be depended

primarily on the ash content of the litter. The recent tests suggest it is likely that the

overall ash content of the composite fuel would need to be less than 6%. It is unclear at

this stage how much less than 6% would be required. Some margin of improvement on

these latter results may be possible if the gasifier geometry were to be adjusted. The

specification for such adjustments would require extended tests on the target fuel only.

6.2.8.4 Energy Value

Assuming that the animal-derived element of the litter is similar in energy terms to

sewage sludge, then the calorific value of the composite fuel is likely to be around 90%

of that of standard wood fuel. Assuming that the fuel can be set-up to gasify on a

clinker-free basis, the fuel requirements of the system can therefore be predicted as

around 1.55kg/hr per kW of electrical output from an internal combustion engine

generator system. This assumes that the composite fuel contains 15% or less moisture

content.

7.0 Recommendations

Given a manure production rate of approximately 705 kg/hr, at 1.55 kg/hr/kWe, a

gasifier/internal combustion engine combination sized at 450 kWe could be installed.

Electrical energy demand at Charison’s, averaged over a year is approximately 353

kWe. Actual peak demands are greater, especially in the winter months, but overall,

more kilowatt hours of electricity per year would be produced than is consumed at the

hatchery, truck wash, and commercial barn. Given a value of $0.04 per kWh, and an

annual production of 3.94M kWh of electricity, $157,680 worth of electricity could be

diverted or sold to the utility.

A by-product of the electricity production is heat. The actual quantity of heat produced

would be dependant on the specifics of the generation system employed. A safe

assumption is that an equal amount of heat could be produced as electricity. While this

heat would be of little use in the warmer months, in the winter it could be used to as

supplemental for the hatchery or grain drying. The extent to which this would be

possible is dependant on the capital cost of installing glycol lines from the gasifier to the

hatchery.

Despite a great deal of activity associated with gasification in Manitoba in recent years,

there is no “off-the-shelf” systems suited for electricity generation via gasification. The

gasifier built by Vidir Machine in Arborg is likely the most viable gasifier produced in the

province at this time, from a proven reliability perspective, however, it is designed only

for heating, as the gas produced by it contains too many particulates for use in an

internal combustion engine. It is likely that this machine could be retrofitted to produce

steam that could then be used in power a generation turbine. However, the loss in

efficiency, and high cost of 24 hour supervision would render this option un-economical.

At this time, the only option it to look outside of Manitoba for this technology or to

embark on a detailed and intensive program of gasifier development.

A survey of gasification installations around the world shows a history of grand failures,

especially when projects are launched on a large scale, with little attention to simple

details, such as materials handling and gasification chamber plugging and clinkering. As

mentioned earlier in the report, such details, if not resolved, will result in a very

expensive failure. Turkey litter is a complex fuel comprised of many elements. A

gasifier would have to be developed specifically for this fuel. Were a gasifier to be

considered at Charison’s, a long term research and development with an organisation

that already has experience in the area of gasification would be greatly advantageous

and highly recommended, to develop a unit specific to turkey litter. Success would most

likely be achieved by adjusting an existing gasifier design to allow for a higher ash

content fuel. A small prototype could be installed at Charison’s and monitored for

performance over the long term. A larger unit could be constructed once the prototype

was proved functional. Once a functional gasifier is developed for use with turkey litter,

the possibility exists to market such a system to other poultry producers, especially in

areas where spreading land is limited.

8.0 References

Buffinga, G., H. Knoef. 2001. Implementation and demonstation of an embedded small-

scale poultry manure CHP process. Enschede, Netherlands: BTG Biomass Technology

Group.

Charison, C. 2004. [Personal Communication Re: Litter Production, 29 Mar 2004]

Charison, C. 2005. [Personal Communication Re: Energy Usage, 8 Jul 2005]

Cicek, N., S. Zubriski, C. Evans, D. Fraser, Q. Zhang, D. Tuhtar. 2003. Industrial scale

evaluation of a gasification process for the treatment of municipal biosolids. Winnipeg,

Canada: Biosystems Engineering, University of Manitoba.

Preto, F. 2005. [Letter Re: Testing of Samples, 21 Jun 2005]

Knoef, H. 2003. Gasification of biomass & waste – practical experience. International

Bratislava, Slovakia: Slovak Biomass Forum 2003.

Reardon, J., A. Lilley, Browne, K., and Beard, K. 2001. Demonstration of a small

modular BioPower system using poultry litter. Washington, USA: United States

Department of Energy.

Russell, B. 2005. Investigation of the production of wood gasifier fuel using turkey litter.

Ballycarry, Northern Ireland: Innovation Technologies (Ireland) Ltd.

Williams, D. 2005. [Various Personal Communications, Feb-July 2005]

9.0 Acknowledgements

Curtis Charison, Charison’s Turkey Hatchery Ltd.

Dr. Fernando Preto, National Research Council of Canada

Dr. Brian Russell, C. Eng., Innovation Technologies (Ireland) Ltd.

Bruce Watt, Charison’s Turkey Hatchery Ltd.

Doug Williams, Fluidyne New Zealand

Appendix I – Manitoba Gasifier Contact Information

Manitoba Gasifier Manufacturer Contact List Heat Innovations Inc. 499 Manitoba Road (Box 989) Winkler, MB R6W 4B1 Tel: (204) 325-4253 Fax: (204) 325-0628 Email: sales@heatinn.com Website: www.heatinn.com Contact: Blair Groening Home Farms Technologies Inc. 20 18th Street Brandon, MB R7A 5A3 Tel: (204) 725-0008 or (877) 464-7667 Fax: (204) 725-0785 Email: info@homefarmstech.com Website: www.homefarmstech.com MESH Technologies Inc. Suite 15-395 Berry Street Winnipeg, MB R3J 1N6 Tel: (204) 831-0351 Fax: (204) 888-8702 Email: mesh@meshtech.ca Website: www.meshtech.ca Contact: Ron Giercke Modern Organics Inc. 1150 Harris Road Headingley, MB R4H 1C2 Tel: (204) 896-7200 Fax: (204) 896-8240 Email: davecrumb@mb.sympatico.ca Website: www.modernorganics.com Contact: David Crumb/Edward Mayer Vidir Machine Inc. Box 700 Arborg, MB Canada R0C 0A0 Tel: 204-364-2442 or 1-800-210-0141 Fax: 204-364-2454 Email: roger@vidir.com Website: www.vidir.com Contact: Roger Friesen

W2E Technologies Inc. (Perimeter Lumber Site) Hwy 330 La Salle, Manitoba (204) 479-4720 Email: jude_sanson@shaw.ca Website: www.w2etechnologies.com Contact: Jude Sanson

Appendix II – Turkey Litter Sampling Protocol

Sampling Protocol A sample will be taken from each barn in the following manner:

1. The area of the barn floor will be divided up such that there are 4 evenly spaced horizontal lines that intersect 4 evenly spaced vertical lines giving 16 points of intersection.

2. One sample consisting of an evenly filled scoop (about 1 quart) will be collected from each sampling point.

3. All 16 samples will be placed in a 5-gallon bucket and evenly mixed to form a composite sample representative of the barn from where it was collected.

4. All 5 gallon buckets will be sealed to prevent any change in moisture content. 5. Turkey Litter Sample Worksheet will be filed with the sample.

Turkey Litter Sample Worksheet Bucket #:___ Barn:____________________ Date:______________/Time:__________ Collected by:__________________________ Time Since Last Clean Out (Days):______ Type of Bedding Used:________________________________ Description of Flock in Barn: _____________________________________________________________________________________________________________________________________________________________________ Notes: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Appendix III – National Research Council Test Results

Steve Brogan, EITDGH Engineering Ltd.

Fernando PretoCANMET Energy Technology Centre June 21,20005

Observations on Turkey Litter Gasification

Four pails of turkey litter were received with a total weight of 16.4 kg. This volume of turkeylittle represents approximately one third of the volume of the downdraft gasifier. This wasdeemed to be enough for one test but probably not enough to allow for optimization of thegasifier operation.

Two samples were taken for moisture determination: 27.1 % and 30.4%. This is a little high asfuels for gasification are generally recommended to be below 20% but should still produceacceptable results.

The turkey littler was placed in the gasifier and packed slightly (visual appearance indicatedapprox. half of litter is straw).

The gasifier was started and a flame was produced after 13 minutes. Gasification continued forapproximately 30 minutes for a total run time of 43 minutes. Syngas samples were taken at 20minutes and 37 minutes. The results are attached.

During clean-up it was noted that the straw bridged across the bottom of the gasifier preventingthe fuel from dropping down. This would normally affect gasification by preventing propermixing and yielding lower quality gas. Based on the results of the syngas analyses, this wasindeed the case as the syngas had a relatively high oxygen content (6.5 - 7 %) and a relativelylow hydrogen content (7 - 7.5 %). The bridging resulted in excess air entering the system andbypassing the fuel hence the lower quality gas.

In terms of the syngas quality, the significant results are

Hydrogen: 7 - 7.5 %Carbon Monoxide: 14.67 to 17 %Methane: 0.11 to 0.08 %Oxygen 6.5 - 7 %

The calorific value of the syngas was found to be 12. MJ/kg or 12.8 MJ/m3. Two factors affected the syngas production resulting in lower calorific values: the moisture

content of the turkey litter reduces the quality of the syngas (as shown in the attached graph forgasification of wood chips). The carbon monoxide level is on par for what would be expected forthe moisture content found in the turkey litter. The hydrogen level is however much lower (i.e.up to 20 % expected) which results in the low calorific value. The operation of the gasifier withthe bridging of the fuel allowed excess air to bypass the gasification zone and had a negativeeffect on syngas quality.

In summary, the turkey litter was successfully gasified and a syngas with a calorific value ofapproximately 12 MJ/kg was produced. Owing to the high moisture content of the fuel andoperational difficulties this value was lower than would normally be expected and I expect thatunder better conditions a syngas of at least 20 MJ/kg could be produced.

I hope this preliminary analysis of turkey litter gasification is of use to you. We could of coursecarry out a more detailed evaluation however that level of work would require a formalagreement between our organizations.

Regards,

Fernando Preto

NATURAL RESOURCES CANADA 2005 CANMET ENERGY TECHNOLOGY CENTRE Page 1 Characterization Laboratory - General Report

Normalized Percent Report Sample Name: 0505xxxx13_1 Data file : C:\HPCHEM\1\DATA\PRETO\SIG12571.D Acq Operator : pmm Acq. Method : RG050330.M Analysis Method : C:\HPCHEM\1\METHODS\RG050330.M

========================================== | RT | Compound Name | Amount | | (min) | | % | ------------------------------------------- | 1.154|hydrogen | 7.54 | | 0.000|C7+ | 0.00 | | 2.451|carbon dioxide | 6.66 | | 3.208|methane | 0.11 | | 3.348|ethane | 0.00 | | 3.478|ethylene | 0.00 | | 0.000|propane | 0.00 | | 0.000|cyclopropane | 0.00 | | 4.567|propylene | 0.00 | | 0.000|acetylene | 0.00 | | 0.000|isobutane | 0.00 | | 0.000|propadiene | 0.00 | | 0.000|n-butane | 0.00 | | 0.000|hydrogen sulfide | 0.00 | | 0.000|t-2 butene | 0.00 | | 0.000|1-butene | 0.00 | | 0.000|isobutylene | 0.00 | | 0.000|c-2-butene | 0.00 | | 0.000|isopentane | 0.00 | | 0.000|n-pentane | 0.00 | | 0.000|1,3 butadiene | 0.00 | | 7.820|argon-oxygen | 7.07 | | 0.000|3-methyl-1-butene | 0.00 | | 0.000|t-2-pentene | 0.00 | | 8.204|nitrogen | 63.95 | | 0.000|2-methyl-2-butene | 0.00 | | 0.000|1-pentene | 0.00 | | 0.000|2-methyl-1-butene | 0.00 | | 0.000|c-2-pentene | 0.00 | | 9.679|C6+ | 0.01 | | 10.070|carbon monoxide | 14.67 | Total 100.00 ==========================================

NATURAL RESOURCES CANADA 2005 CANMET ENERGY TECHNOLOGY CENTRE Page 1 Characterization Laboratory - General Report

Normalized Percent Report Sample Name: SAMPLE 2 0505_4 11:54 Data file : C:\HPCHEM\1\DATA\PRETO\SIG12574.D Acq Operator : pmm Acq. Method : RG050330.M Analysis Method : C:\HPCHEM\1\METHODS\RG050330.M

========================================== | RT | Compound Name | Amount | | (min) | | % | ------------------------------------------- | 1.153|hydrogen | 6.94 | | 0.000|C7+ | 0.00 | | 2.452|carbon dioxide | 5.68 | | 3.207|methane | 0.08 | | 0.000|ethane | 0.00 | | 3.477|ethylene | 0.00 | | 0.000|propane | 0.00 | | 0.000|cyclopropane | 0.00 | | 0.000|propylene | 0.00 | | 0.000|acetylene | 0.00 | | 0.000|isobutane | 0.00 | | 0.000|propadiene | 0.00 | | 0.000|n-butane | 0.00 | | 0.000|hydrogen sulfide | 0.00 | | 0.000|t-2 butene | 0.00 | | 0.000|1-butene | 0.00 | | 0.000|isobutylene | 0.00 | | 0.000|c-2-butene | 0.00 | | 0.000|isopentane | 0.00 | | 0.000|n-pentane | 0.00 | | 0.000|1,3 butadiene | 0.00 | | 7.818|argon-oxygen | 6.45 | | 0.000|3-methyl-1-butene | 0.00 | | 0.000|t-2-pentene | 0.00 | | 8.200|nitrogen | 63.87 | | 0.000|2-methyl-2-butene | 0.00 | | 0.000|1-pentene | 0.00 | | 0.000|2-methyl-1-butene | 0.00 | | 0.000|c-2-pentene | 0.00 | | 10.036|carbon monoxide | 16.98 | | 12.008|C6+ | 0.00 | Total 100.00 ==========================================

Effect of moisture on syngas production from wood chips

Appendix IV – Ash Content Testing