Jul 30 2008
This article has been adapted from a presentation titled "Biofuels: Curse or Cure for Climate Change?" given by Professor Jerry Vanclay at Southern Cross University, Lismore, Australia on 25th July 2008
Introduction
Biofuels have been attracting lot of attention and controversy in the worldwide media. Some of the attention has been fuelled by the steep rise in grain prices, especially for rice, the staple food for half the world’s population, but also for other grains including maize and wheat. This rise in grain price reflects the increase in global biofuel production. So are biofuels the answer to climate change problems or a food crisis curse?
Fuel was added to this controversy by World Bank economist Donald Mitchell, who published a draft paper arguing that biofuels were responsible for threequarters of the 140% increase in food prices during the last six years. Others have also added grist to the mill. Jeff McNeely, Chief Scientist at IUCN, observed that “biofuels could end up damaging the natural world rather than saving it from global warming. Better policies, better science … can contribute to a greener biofuels revolution”. Given this context, it is timely to review the biofuel situation.
Biofuels and Forests
Why am I – a forester - interested in Biofuels? Because biofuels will affect forests in many parts of the world. Here’s an example. I met a man in Sumatra in 1999. He’s largely responsible for the deforestation and degradation in the national park. He harvests timber illegally from the national park, saws boards, and sells the lumber to smugglers who take the wood to Malaysia. He does this because it is the only way that he can support his family. If the price of staple foods (like rice) increases, he’ll have to cut more wood, and there will be more poor people like him in the same situation. There will be other effects too. There will be pressure to clear land like this to plant oil palm and other energy crops, and there will be people displaced from other plantation activities. So bad biofuel policy is bad forest policy, and – partly because I teach natural resource policy – that’s a topic that I’m interested in, and try to influence.
Why Should You Be Interested in Biofuels?
There are at least two good reasons why you should be interestd in biofuels. You’ve probably heard of Al Gore’s campaign. More recently, economists Nicholas Stern in the UK, and Ross Garnaut here in Australia have offered critical reviews in which they have argued that the evidence for climate change is compelling, and that it will cost us more to do nothing than it will to take action. Biofuels (potentially) offer one way for us to reduce our fossil carbon emissions.
Transport Disruptions
Stern and Garnaut mentioned some consequences, but they didn’t dwell on transport. In Australia we’re quite vulnerable to transport disruptions, because most of our airports are close to sealevel, and a very small amount of flooding is sufficient to close airports (and sea ports). And airport closures will cause major chaos, so we should take climate change seriously.
Peak Oil
And if you don’t believe climate change, the other reason is peak oil. Former oilman Kenneth Deffeyes offers a compelling view about the impending oil shortage. There is good evidence that our oil reserves are being depleted faster than new discoveries, so the price of oil is going to continue to rise, and the supply will gradually become erratic. Biofuels may be the best way to provide fuel, transport and food security in future.
We’re so dependent on liquid fuels, that even temporary interruptions to supply can cause major chaos. Fortunately, there are viable alternatives. VW has a concept car that gets more than 100kms from every litre of fuel, and Tesla has a desirable all-electric sports car. However, the challenge may not be personal transport (cars), but goods transport and farm machinery that is heavily dependent on diesel. So I’m going to focus much of this talk on diesel.
Diesel and Biodiesel
Much of the recent news has concerned ethanol for cars, but the real issue is diesel. So let’s consider the options for making biodiesel.
Biofuel Production
Most biofuels production is ethanol in the USA and Brazil, made from maize and sugar. Biodiesel production lags behind, but Germany leads with biodiesel made from rapeseed (canola) oil. There are some indications that oil palm in the tropics (especially in Malaysia and Indonesia) may soon become a major supplied of vegetable oil for biofuel manufacture. In addition, there is interest in plantations of Jatropha and Pongramia for vegetable oils as feedstocks for biodiesel. Maize, sugar, and vegetable oils are not the most efficient ways to produce biofuels, because they utilize only a small part of the plant’s production. The bulk of most plants is cellulose, and remains unused when biofuels are made from seeds, oils or sugars.
Fermentation and Distillation, Transesterification or Fischer-Tropsch
There are many pathways for the production of biofuels. The most common is the production of ethanol through fermentation and distillation, a thousand-year-old technology (that is good for drink, but not for fuel). Another approach is to convert oils to diesel by transesterification, a rather simple process that can be done in your garden shed. CSIRO have devoted considerable attention to the furan pathway, which offers some promise. And I have an interest in the Fischer- Tropsch pathway, which I’ll discuss further.
1. Grain - malt - Sugar - ferment - distil - Ethanol
2. Biomass - hydrolysis - Sugar - enzymes - Ethanol
1. Oilseed - press - Oil - transesterification - Diesel
2. Biomass - gassify - Syngas - FT-synthesis - Diesel
The top line above shows the traditional way to make ethanol, considered to be a ‘first generation’ technology. Fermentation makes the process show, and hampers the ability to scale-up. A second generation approach hydrolyses the whole plant biomass for form sugars, and uses enzymes to convert sugars into alcohols chemically. Such an approach should be faster, easier to scale-up, and should result in higher yields. The second line summarizes the transesterification of oil into diesel (a first generation technology), and contrasts it with the second generation Fischer- Tropsch approach which gassifies biomass, and then condenses the syngas over a catalyst to create diesel. The 2nd-generation FT Biodiesel delivers much higher yield than the 1st generation alternatives.
Syngas
Syngas, the central step of the biomass-to-liquid process, is a useful commodity that can be turned into many products. Fischer-Tropsch synthesis can turn syngas into diesel or into petrol, depending on the temperature, pressure and catalyst (usually iron, cobalt or ruthenium). Syngas can also be fed directly into a gas turbine to generate electricity. Syngas can be made from natural gas (as is done in the Shell plant at Bintulu, Malaysia), from coal (the Sasol process in South Africa), from biomass (the Choren plant in Germany) or from other sources. As an brief aside, this is why I don’t believe in ‘clean coal’ or in hydrogen cars. Liquid fuel, especially diesel, is just so useful that it makes sense to use FT conversion to convert hydrogen gas into diesel. And if we can separate pure carbon dioxide in a cost-effective way, we wouldn’t want to bury it; we’d use a solar kiln (or waste heat) to reduce CO2 to carbon monoxide, and then use the FT process to make conventional diesel.
FT or Fischer-Tropsch
The FT-process joins forms carbon chains into longer chains. With an iron catalyst, FT yields a high proportion of chains with length 10-18, that comprise diesel. Shorter and longer chains can be fed back into the process, or are saleable as petrol, and waxes.
There are about 4 steps in the biomass-to-liquid process. Biomass is chipped or chopped into small pieces. These are then turned into syngas, often in a circulating fluidised-bed gassifier. Suitable gassifiers are available off-the-shelf, for example from BEST Energy here in NSW. The gas then needs to be scrubbed to remove particles and impurities. Finally, a pressure chamber and catalyst is used to achieve FT-synthesis. This final step is an area of active research, building on 70-uear-old German technology. The background is a simulation of the process that occurs on the FT-catalyst as carbon molecules grow into longer chains.
Commercial FT plants are large and complicated, but the technology is established and can work at small scales. This war-time Mercedes car has a gassifier in the boot to make syngas, a graphic illustration that this can be done at small scales. This FT chamber at right is a research facility in Gussing, Austria. This chamber can produce 200 litres of diesel per ton of biomass, in contrast to 220 litres obtained from the larger, commercial Choren plant in Freiberg, Germany.
One of the good things about the FT technology is that it is carbon-friendly and energy-efficient. Compare wood-derived diesel with Cereal-based ethanol; there is an order of magnitude improvement in energy efficiency. (RTF = renewable transport fuels).
The Gallagher Review
The UK Government recently commissioned ‘The Gallagher Review of the indirect effects of biofuels production’. In this report, Ed Gallagher argues that Governments should proceed more slowly and carefully with biofuel incentives, should remove mandatory minimums, and should have specific incentives for the use of residues, and for the development of second-generation technologies such as the FT-process. His report, shows how FT-biodiesel is much more greenhouse efficient than alternatives, and how some alternatives don’t help, but hinder the battle against greenhouse gasses.
FT-Biodiesel is Financially Viable
A study from Imperial College London shows how Wood-based diesel compares with petroleum (and other fuels). Even with figures from 2003, before oil reached $100/barrel, FT-biodiesel was shown to be financially viable.
We have the resources to feed a FT-plant based on residues. Wood residues are ideal for a pilot plant, because they are uniform and free of contaminants. There are several sawmills in Grafton, and some are large enough to support a production-scale biodiesel facility, and could produce a semitrailer load of diesel every day, from wood residues that are currently underutilized.
FT is a proven technology. The Choren plant in Freiberg Germany is now operational. This plant makes 220 litres of diesel from every ton of wood residue. Other plants exist in South Africa (SASOL, making diesel from coal) and Malaysia (Shell, making diesel from natural gas).
40% of embodied energy is realized as biodiesel, plus there’s some electricity and naptha. The only waste is dust and slag, and it is a very small proportion (0.5%)
FT Biodiesel seems to have been overlooked in Australia. In the last year or two, there have been a whole series of government reports on biofuel, but Fischer- Tropsch has not been mentioned, not once. These reports focus on diesel from plant oils, not on second-generation technologies like biofuel. Disturbingly, the government’s recent green paper makes no recognition of biomass-to-liquid processes (though it does mention vegetable-oil-based diesel), and the draft Garnaut report mentions 2nd generation biofuels only in passing. In contrast, the European literature is enthusiastic about FT technology; why is it overlooked in Australia?
Australia is not alone in ignoring the 2nd generation biofuels. Worldwide, most plants are large 1st generation plants that will have negligible environmental benefit. In this chart, only Choren and Syntrolium are BTL (biomass to liquids) from plant residues; the other 2nd generation plants will process oil and fat residues. Evidently, there is a failure of government policy, and the various US and EU incentives and mandates are promoting old technology (and easy profits) rather than environmentally-friendly technology.
Indirect Effects of Biofuel Production
In view of this policy failure, it is interesting to look at the Gallagher recommendations in ‘The Gallagher Review of the indirect effects of biofuels production’ published 2 weeks ago. This is a 100-page report, so the following short summary is somewhat selective, but reflects the main thrust of his report.
- The Government should amend but not abandon its biofuel policy to ensure its biofuels policy delivers net GHG benefits.
- Biofuels policies require feedstock that does not cause net additional pressure on current agricultural land.
- There should be a specific obligation on transport fuel suppliers to supply biofuels achieving a high level of GHG saving (possibly greater than 75%) from appropriate wastes and residues.
- Basing incentives and targets for biofuels on thei r GHG savings remains the optimum policy approach but should only proceed once the implications of indirect effects have been fully explored and adequately incorporated into calculation methodologies.
- Urgent further work is needed to enable incentives and targets for biofuels to be based upon lifecycle greenhouse gas emissions.
- Biofuels targets and policies should be constructed to ensure long term impacts on food prices do not significantly disadvantage the poor.
- The current RTF target should be amended to require feedstock from appropriate residues and production on marginal land.
- Biofuel targets should not be mandates but obligations with an appropriate “buy-out” price set.
Despite Gallagher’s urging, and a recent Parliamentary Research Paper advocating otherwise, NSW still has mandates for ethanol and biodiesel. Given the market distortions that other researchers have warned about, and the near monopoly on ethanol in NSW, this seems an unwise policy. Australian governments would do well to heed the Gallagher recommendations.
In concluding, I should point out that SCU is establishing a Biofuels Research Centre, and initiative led by the Centre for Plant Conservation and Genetics.
Biofuel Research Required
Research needed to make biofuels more readily available include:
- Technology, new enzymes and catalysts, to improve yields and simplify processes. The EU and US are investing heavily in these areas, and it will hard for us to compete, so our strategy will be to be a partner in centres like C2B2 (Colorado Center for Biorefining and Biofuels, which has a $200m/yr budget).
- Plants have been bred for a long time for foods, but not for biofuels or greenhouse efficiency, so plant breeding should be part of our strategy. Sugar and maize are grasses that amongst the plants most efficient at fixing carbon. Australia as 10% of the world’s grass species, so bioprospecting amongst our grasses may reveal some interesting opportunities.
- Much of Australia’s ecology is adapted to regular fires, but fire is problematic in fragmented and urbanised landscapes. Can we harvest biofuels in a way that replicates the ecological function of fires, providing an ecological service and biofuel harvest?
- Australia is unique in having large areas that are sparsely populated and far from the coast, yet depend on diesel fuel for farming and transport. We need to devise small-scale biofuel facilities for on-farm biofuel production.
Conclusion
The verdict? No unequivocal answer: some biofuels are good, some are bad. Ask your suppliers about the source of their biofuels…
- Food-friendly only if from crop residues or waste stream
- Environment-friendly only if second generation biofuel
- Lobby (your local member, local industries) for investment in 2nd generation biofuel research & development
- A review of the biofuel mandate Biofuels are just part of the solution…
- Also need to drive less, drive frugally, and drive a small car
Primary Author: Prof. Jerry Vanclay
Source: School of Environmental Science and Management, SCU