Bio-refining of plant biomass offers hope of new outlet for crops

By Andy Doyle

Plant bio-refineries have the potential to create a new outlet for farm crops. Grass, potatoes, etc. and even by-products like straw and beet tops could be converted via this process into compounds that are considerably more valuable than the raw material.

One such example is ethyl lactate where one tonne of straw can generate about 350 litres of the substance which is currently valued at about €875. And this is just one of many products that could be produced from the process.

A four-nation development group consisting of Ireland, Iceland Germany and France are seeking to build a pilot plant here in Ireland to test the theory of bio refining. BELTRA is the Irish company involved in the project and is working in conjunction with the Galway Mayo Institute of Technology to spearhead the project here.

€6m investment

The pilot bio-refinery plant suggested would have capacity to process about 5,000t of biomass and the initial investment is put at about six million euro. If the pilot plant proves successful, as expected, then the plan is to build a 45,000t discovery plant for commercial production.

The piolt plant would be used to test the current theories of bio refining and assess the range of raw material available. It would also seek to develop methods for the isolation of high value alkaloids from 'green' or 'ripened' biomass materials. Other products from the refining process might also need to be identified. There is also a need to assess raw material production and delivery potential in local rural areas where such a commercial plant might be located.

The refinery

The process seeks to develop new methods for processing herbaceous biomass (grasses, legumes and/or grains) into high value bio-refinery products. Such examples include plant protein, ethyl lactate and sparteine derivatives from lupine. More conventional products like bio ethanol and fibres will also be manufactured.

Using plants as the initial source of raw materials helps CO2 emissions. The crops used will depend on the location and country. Lupine/Lucerne are preferred by some of the participants such as Iceland as the perennial Alaskan lupin is available locally. In Ireland grass might be the major raw material.

Many raw materials can be used in the process. These include the high cellulose materials such as grass and straw but other raw materials can also be used, either at certain times of the year or when price permits.

These include grains, potatoes, beet, beet tops, etc. This means that a second source of raw material can be used if one is limiting or becomes too expensive for exceptional market reasons.

The process

The basic process converts cellulose (or starch) to glucose. This is done using enzymatic hydrolysis provided by microbes so there are no reactive chemicals involved. Acid hydrolysis is being used for this process in parts of the world but residue disposal is a big problem. The project is also looking at thermophylic bacteria to break down biomass under heat as this may better suit certain types of raw material.

Raw materials do not have to be dried before use as it is just tipped into a liquid biological solution to be broken down. This is then fermented and depending on the process used can produce a range of products, including either ethanol or lactate.

Both of these products are well known. Lactate is a feed industry additive while ethanol can be used as a fuel supplement. The value of ethanol is heavily influenced by oil prices and production of this material alone is hardly economic. But the bio-refinery can combine both of these ingredients to produce ethyl lactate which is much more valuable and is required in very large quantities as a raw materials for the chemical and bio-plastics industries. One tonne of straw is expected to yield 350 litres of ethyl lactate with an estimated current value of e875.

Pure products

The fermentation process seeks to strip out the individual components contained in the raw material. These basic ingredients are generally much more valuable when they exist in their pure form rather than as a component of another material.

As an example Professor Michael Wink of Heidelberg University told me if a tonne of lupins (worth say €250 per tonne) was refined to produce pure protein plus other components the protein alone (nearly half a tonne) would be worth €4000-€4500. And the protein is just one of the valuable by-products from the bio-refinery process.

Flexibility

The bio-refinery process is quite flexible in that it has the capacity to process a range of materials interchangeably. It is also flexible in that it can produce a number of different end products depending on what the market requires and can react to price trends quite easily.

Go for it

This project represents an exciting possibility for the future of farming and industry. It can use existing crops or their by-products to add value to farm-gate produce. And because our climate is very good for producing biomass we may be particularly suited for its exploitation. It could well provide a realistic option via the biotechnology platform that Tanaiste Mary Harney spoke of a few years ago when she described biotechnological projects as the necessary platform to sustain the Celtic Tiger into the future.

It is a clean technology in that all of the ingredients involved are from a natural and biological base and the final residue can be recycled through agriculture. It has many other environmental benefits also.

It can decrease our dependence on hydrocarbon energy sources and thus contribute greatly towards decreasing carbon dioxide build up in the atmosphere. And the end products produced, such as bio-plastic, would prove to be far more biodegradable than current sources.

Speaking at a Galway press conference to announce the initiative earlier this year Minister Frank Fahy stated that a breakthrough in the success of this project would be of great benefit to the country as a whole.

The benefits of a successful bio-refinery industry could well prove to be a lifeline to our depressed agriculture and a realistic non-food option for land use. The time for talking is over.

It is now time to test the theoretical principles and to be one of the first into this promising technology.

No doubt there will be risks as well as benefits but seldom do you get one without the other.

Design plans to build a bio-refining plant are shortly to be drawn up in Ireland, Iceland and Germany. These will then be compared and contrasted based on the raw materials to be used in an effort to optimise the design of the pilot plant, which hopefully will go ahead here.

So long, fossil fuel!

One German company involved in this technology uses the slogan "Petroleum was yesterday". It is time for the Government to put rural development into practice via a sound sustainable industry and to give agriculture a reason to believe it has a future again.