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GreenField’s Cellulosic Ethanol Division

GreenField is broadening Canadians’ fuel choices by developing commercially viable methods of producing next generation biofuels from agricultural, forestry and municipal waste.

The company’s Cellulosic Ethanol Division was established in 2007 to pursue two parallel paths of research into the commercialization of cellulosic ethanol production: biochemical conversion of plant fibers and thermochemical conversion of municipal waste.

What is cellulosic ethanol?

This clean-burning, fully biodegradable, renewable fuel can be created from a variety of feedstocks that would otherwise be disposed of as waste materials.

The key ingredient is cellulose, a fibrous material that makes up most of the plant matter in biomass such as corn cobs, corn residue, wood chips, trees, municipal solid waste and pulp and paper industry wastes.

Enhanced Environmental Benefits

As well as reducing harmful emissions from vehicles, cellulosic ethanol enhances the many environmental benefits of traditional ethanol by:

• helping to solve environmental problems related to waste management by using residual materials that would have decomposed to produce methane, a greenhouse gas
• producing as much as eight times more energy than it consumes
• requiring minimal amounts of water. Depending on the feedstock, the production process can even become a net producer of water
• encouraging the cultivation of bioenergy crops that provide a better environment for wildlife. Their extensive root systems increase nutrient capture, improve soil quality, sequester carbon, and reduce erosion

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Biochemical Process

Strategy

Researchers at the Centre of Excellence are developing a commercially viable process for making cellulosic ethanol from the plant fibers in agricultural and forestry waste.

Benefits

• New Opportunities - The production of cellulosic ethanol from agricultural waste, such as corn cobs, could provide a new market for farmers.
• Optimized Resources - Forestry waste is often left to rot, releasing a harmful greenhouse gas called methane. Cellulosic ethanol production would harness untapped forestry resources for the purpose of lowering greenhouse gas emissions.
• Feedstock Flexibility - Ethanol producers will be able to choose from a variety of feedstocks that can either be grown on poor soil or salvaged from waste. This flexability will allow GreenField to continue meeting the demand for clean-burning renewable fuel.

Unique Approach

Most of the current methods for converting plant fibers into cellulosic ethanol call for the use of harsh chemicals. GreenField is developing a simplified mechanical system of pre-treatment to produce a non-toxic sugar solution, known as a wort, that will yeild high ethanol concentrations when integrated with new fermentation techniques and enzyme technologies.

Current Research

Laboratory trials are being conducted using corn cobs, corn residues and selected forms of treated wood pulp as feedstocks. A small-scale pilot facility has been built at the Centre of Excellence to run more advanced tests once the initial laboratory trials are completed.

The research team is specifically focused on four main stages of the conversion process:

• Corn cob pretreatment
• Hydrolysis
• Fermentation
• Corn cob storage

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Thermochemical Process

Strategy

GreenField and Enerkem have joined forces to commercialize the production of cellulosic ethanol from solid municipal waste. Enerkem specializes in a thermochemical process called gasification, which heats carbon into a gas that can be converted into ethanol.

Benefits

• Flexibility – Ethanol producers will be able to choose between a wide variety of local feedstocks that would otherwise have been disposed of as waste.
• Waste Management - Solid urban wastes that cannot be recycled, reused or otherwise recovered will be converted into ethanol instead of collecting in landfills.
• Optimized Resources – Gasification provides the means to fully utilize wood residues from construction, forest operations and end-of-lifecycle power poles.
• Greenhouse Gas Reductions - Enerkem's technology eliminates more than two tonnes of CO2 per tonne of residues.

Unique Approach

Many other gasification technologies are using their gas for the production of electricity. Enerkem’s synthetic gas is uniquely conditioned for manufacturing products such as cellulosic ethanol, other biofuels and biochemicals. These higher value-added products make current waste management practices sustainable and economical.

Current Research

GreenField and Enerkem are presently collaborating on Canada’s first commercially viable ethanol gasification plant. 100,000 dry tonnes of municipal sorted waste from the city of Edmonton will be turned into 40 million litres of biofuels each year.

There are four main steps to the production process:

• Pre-treatment of residues: sorting-recycling, drying and shredding
• Gasification: the process of converting carbon-rich residues into syngas
• Gas scrubbing and conditioning: gas clean-up system
• Conversion of the gas into liquid: catalytic conversion from synthesis gas into liquid alcohol (methanol, ethanol, butanol, etc.)

This process transforms one tonne of raw material (dry base) into 340-360 litres of cellulosic ethanol.

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