Damned If You Do, Damned If You Don't:Whither Bioethanol?

On the TV screen, a fuel pump is held like a gun to an orangutan's head. "Tell the government to choose the right biofuel or the orangutan gets it!" This ad, sponsored by several environmental groups, was aired in the UK in May 2007, warning the public to be wary of biofuels that can damage the environment.

Currently there are two major types of biofuel. One is bioethanol, made from such crops as sugarcane, corn, sugar beet and wheat; the other is biodiesel, synthesized from seeds of plants such as rape, sunflowers, soybeans and palm. Since these alternative sources of energy come from crops, the amount of carbon dioxide released by burning them is the same as is absorbed from the atmosphere during photosynthesis. No excess carbon is produced or released, so it's considered a clean, environmentally friendly energy source for a low-carbon era.

Given this fact, how can it be that these promising energy sources have become targets of scorn?

Not long ago, the countries of the world hammered out targets and schedules for renewable energy and biofuels. The EU was to replace 5.75% of its fuel with alternative energy sources by 2010; the US planned a 25% renewable energy target by 2025. The vast "green gold" market led to rapid growth in the biofuels industry, and the supply of energy crops outstripped demand.

For the biofuel treaty the Bush Administration signed with Brazil in 2007, it was estimated that some 150 million hectares of trees (over 41 times the total area of Taiwan) would have to be felled in Brazil to plant enough sugarcane to meet the demand for ethanol in the US. In neighboring Paraguay, to satisfy Europe's eager need for biodiesel, forests were razed to plant soybeans, and in Southeast Asia vast swaths of forest were clear-cut to grow oil palms.

Excessive deforestation not only destroys the habitats of wild animals like orangutans; even worse, as the ravaged lands are used for planting single crops, crop disease resistance is weakened from lack of biodiversity, requiring massive use of chemical fertilizers and pesticides, leading to soil and water pollution and a chain of ecological devastation.

Problem 1: More global warming

Bio-energy is accused of being environmentally unfriendly, the irony being that while it can replace gasoline, it also accelerates global warming. In late 2006, former World Bank chief economist Nicholas Stern pointed out in the Stern Review on the Economics of Climate Change that while about two thirds of greenhouse emissions come from fossil fuels like coal and petroleum, the remaining third are the result of agriculture and deforestation, given that forests are the natural world's greatest "carbon sink."

A study published in the journal Atmospheric Chemistry and Physics points out that biofuels made from rapeseed and corn, currently the international rage, emit greenhouse gases exceeding those from gasoline by 70% and 50% respectively. British and German scientists have found that nitrous oxide, 296 times more powerful than CO₂ in its greenhouse effects, is released during planting, massively offsetting the volume of greenhouse gases that the process should reduce.

Also, how much gasoline and electricity is consumed in the process from planting biofuel crops to making fuel? How much greenhouse gas is emitted? Will it be so wasteful and environmentally harmful as to be a vain effort? These issues need to be considered in the development of biofuels, and they have led to huge studies by international academics into the life cycle of fuel crops.

Problem 2: Net energy values

To determine the net value of energy in the production of, say, a gallon of corn ethanol according to the energy efficiency analysis principles used in life cycle theory, it is necessary to evaluate the amount of energy consumed in planting, fertilizing, applying pesticides and harvesting, plus shipping to processing plants, the fermentation and distillation processes, and finally shipping to fuel stations. A comparison is then made between output and input, with higher ratios being better. (See Table, next page.)

"There are large variations in the energy efficiencies and CO₂ reduction efficiencies of biofuels stemming from different raw material sources and manufacturing processes," says Lee Chien-ming, assistant professor at National Taipei University's Institute of Natural Resource Management. Current figures show that of the four main kinds of bioethanol, the energy return on energy invested (EROEI) of sugarcane alcohol is 8:1 with a high CO₂ reduction efficiency (90%), with corn alcohol doing worst on both counts (1.5:1 and 15%-25%).

Problem 3: Elusive social benefits

Oddly enough, despite its questionable net energy value and CO₂ reduction efficiency, corn alcohol is receiving official encouragement and massive subsidies. US agricultural laws encouraging the planting of vast acreages of corn lead to the disqualification and effective exclusion of small farmers who need subsidies, and encourage monopolization by multinational conglomerates and mass production of corn, which is dumped all over the world for processing and conversion. In turn, this narrows the scope for agricultural development in developing countries. As these so-called "environmentally friendly" biofuels harm poor people and poor countries while at the same time feeding the auto industry and those who lead wasteful ways of life, cries of injustice are certain to flare up.

While biofuels can create a variety of problems, as we look beyond the end of the petroleum era to a time when we can no longer depend on a single energy source, then unless we are to be forced back to nuclear energy for our electricity, we will need to find distributed, diverse energy sources, and the search for the most appropriate biofuels will continue.

If, during the coming automobile revolution, we give up gasoline- and diesel-powered internal combustion systems in favor of solar- or hydrogen-fueled cars, the prospects for biofuel would be dim. In that case, should Taiwan develop technologies and manufacturing in this area? And how should it be developed?

Some believe that massive funding of research and development is not as good as directly importing proven new fuels developed in other countries. Others advocate re-setting the development targets for bio-energy. Still others stress accelerating technical innovation and striving to keep pace with the rest of the world. Amid the morass of conflicting opinions, there is an issue that is less contentious: refining alcohol from cellulose.

Solution 1: Cellulose alcohol

Dubbed a "second-generation biofuel," cellulosic ethanol is derived from agricultural wastes such as straw, sawdust, weeds and sugarcane residue. Because the fuel source comes from waste, there's no need to develop new land for planting crops. Thus it is far more energy efficient and environmentally friendly than first-generation biofuels that are mostly based on food crops. Furthermore, biological agents such as enzymes and microorganisms are used to break down cellulose and carbohydrates in the manufacturing process, eliminating the need for fossil-fuel-driven machinery, thereby reducing CO₂ emissions.

"Though the cost of cellulosic ethanol is now around US$1 a liter, three to four times that of sugarcane alcohol, we predict it will halve in a decade due to technological advances and mass production. There's a great deal of development potential," says Lee. This is a current development trend internationally.

However, fuel extraction poses considerable technical difficulties due to the sheer amount of cellulose in the raw material. The makeup of plants' protective cell walls is complex, with a tough network-like structure that is hard to break down. Countries are investing massively in R&D to find solutions. For instance, Japanese scientists have discovered an enzyme produced by microorganisms in the gut of termites that not only can break down wood cellulose ultra-efficiently, but can do so with no prior chemical processing, easily breaking down carbohydrates into alcohol.

Biofuel bigwig Brazil, with over 30 years of experience in sugarcane ethanol, recently developed new technology to convert sugarcane residue into alcohol. Once mass production starts, alcohol production per hectare is expected to increase threefold, driving down costs and achieving an EROEI of 10:1.

In Taiwan, a cellulosic ethanol research project is underway at Academia Sinica's Institute of Molecular Biology, aimed at improving cellulose pre-processing and breakdown technologies and alcohol fermentation methods, and identifying new microorganisms and enzymes to solve the technological impasse.

Academia Sinica vice president Andrew H. J. Wang, who heads up the project, states that the key technologies are currently in the experimental stage, but will become ready for commercial use by 2009. With the recent rise in oil prices and high market demand, it's possible it may be ready earlier.

Solution 2: Local research

Yet cellulose alcohol development is not without its uncertainties. As it's currently dependent on techniques such as gene transfer to cultivate special strains of organisms to break down cellulose, critics worry whether certain tree species could fall victim to artificially bred organisms if they are released into nature, due to a lack of immunity. For example, a biotech expert at North Carolina State University has developed a "transgenic tree" with half the lignin of its natural counterpart, allowing more efficient conversion of cellulose into biofuel. But whether this may trigger another ecological crisis has yet to be assessed.

Looking back at the biofuel saga of recent years, humanity has constantly corrected its course from its errors. As we face a future without petroleum, the road to finding alternative energies to continue advancing human civilization is one on which there is no turning back.

"Both traditional fuels and new biofuels need to be assessed for environmental and social impact, and given cost-benefit analyses," Shaw Daigee, president of the Chung-Hua Institution for Economic Research, reminds us. In Taiwan there is at present no local fuel crop life cycle research underway; all policy is decided based on overseas studies. However, results can differ widely due to differences in countries' natural environments, technological levels and social conditions. Taiwan should quickly establish a recording system for agricultural production and processing so that EROEI ratios and greenhouse gas reduction effects of different crops can be objectively calculated. In this way, Taiwan can avoid choosing the wrong objectives and losing direction in the coming energy revolution.