Biofuels: Alternative fuels fail to live up to the hype
September 12 2010
In the search for new feedstocks to provide the fuels of the future, one of the latest ideas is to use dirty nappies. Amec, the UK-based engineering group, is developing a process to use discarded disposable nappies and other plastic materials that are not now recycled to make a synthetic diesel fuel.
The US Environmental Protection Agency has estimated that 3.8m tons of disposable nappies were discarded in 2008, representing about 1.5 per cent of the country’s total municipal waste.
If they could be used for fuel, that could make a useful contribution to what Amec calls “a future where trash is a thing of the past”, as well as helping meet demand for energy.
Unfortunately, the process is still at the testing stage, and the stories of other similar technologies show that demonstrating technical possibilities is very different from establishing commercial viability.
The technical difficulties of scaling up production are prodigious, leaving the hopes of the industry as yet unfulfilled.
There will be a need for liquid fuels, especially in transport, for many decades, and in a world of finite oil reserves and pressure to curb carbon dioxide emissions, a growing proportion of those are likely to be biofuels.
To play a central role in the energy system of the future, however, biofuels will need to be different from the varieties that are generally available today.
First generation biofuels, such as ethanol from corn and sugar, and biodiesel from vegetable oils, are now well established in many developed countries, often encouraged by generous subsidies and supportive regulations, but their drawbacks have become increasingly evident.
In spite of a recent study published by the World Bank that suggested that biofuels played only a small part in the surge in food prices of 2006-08, there have been persistent concerns about diverting agricultural resources towards fuel production.
As a result, there has been an increasingly intensive search for new feedstocks and processes, and in the past couple of years large international oil groups including ExxonMobil, Royal Dutch Shell and BP have stepped up their commitment to research and development of advanced biofuels.
Several of the companies developing second-generation biofuels, those not produced from food crops, claim to be close to commercial deployment, yet delivery of large volumes of their products is still many years away.
Confident-sounding predictions of commercial production have frequently turned out to be over-optimistic, and in a sign of how realism has set in, the US government has cut sharply its targets for the use of advanced biofuels.
Legislation in 2007 set a goal for consumption of cellulosic ethanol, made from plants such as switchgrass, straw or wood chips, of 100m gallons for 2010, and 250m gallons for 2011. This year those goals have been scaled back to just 6.5m gallons for 2010, and up to 17.1m gallons for 2011.
If reached, next year’s upper limit would still represent only about 0.1 per cent of total US biofuel consumption, which is expected to be just under 8 per cent of total transport fuel usage.
Only a handful of companies are expected to be delivering cellulosic ethanol in the US next year, of which the largest is set to be Maryland-based Fiberight, which started production in May at its Blairstown, Iowa, plant, initially using pulp wastes from a local paper factory.
The second-largest could be Indiana-based Agresti Biofuels, again producing ethanol from waste, and the next could be California-based AE Biofuels, which has a plant producing conventional corn ethanol, butt plans to use it to create a rising proportion of cellulosic ethanol from straw.
The preliminary and tentative nature of even these plans – the tattered remnants of the high hopes of three years ago – are a warning of how difficult the large-scale production of advanced biofuels is likely to be.
Shell and BP have continued to increase their research and development into advanced biofuels, but have also both formed large joint-ventures to produce conventional ethanol from sugar cane in Brazil, which is both the cheapest and probably the most environmentally friendly variety of first generation biofuels – in terms of carbon dioxide emissions.
While progress towards the second generation falters, the first generation industry in the US – mostly corn-based ethanol – has been through a bruising time, squeezed between the volatility of fuel prices and corn prices, which this summer hit their highest levels for more than a year.
Refiners such as Valero have used the weakness of the ethanol industry as an opportunity to buy plants for a fraction of what they cost to build.
The US biofuels industry still enjoys strong political support, but is facing two critical political decisions in the next few months: whether to lift the limit on ethanol content in standard petrol from its present maximum of 10 per cent – a controversial issue because of the potential adverse impact on engines, particularly of older cars – and whether to renew the 45 cents a gallon tax credit paid to ethanol blenders.
If those decisions go the way the industry wants, US biofuels consumption will continue to grow.
The new fuels that could replace corn-based ethanol and provide a long-term large-scale alternative to conventional petrol, diesel and jet fuel, however, remain a distant prospect.
Source: Financial Times
Engineering News Archive