For centuries, alchemists searched for a way to convert base metals into gold, only to be disappointed time and again. Sometimes it seems that the search for an economical method for converting biomass — cellulosic waste products as they are more commonly described — into ethanol has proven just as elusive.

Almost a decade ago, the U.S. Energy Department predicted that by 2009 cellulosic-derived ethanol would command as big a share of the market as conventional ethanol. But that hasn’t happened — yet, at least, according to the New York Times’ Mathew L. Walk and Alexei Barrionuevo.

Nevertheless, researchers and venture capitalists are still confident they eventually will turn the corner. However, the issue is resolved, one alternative fuels expert says now is not the time for Americans to become discouraged.

“Policymakers and Americans in general always need to bear in mind that renewable fuels make up a very big and complicated picture,” says Mark Hall, an Alabama Cooperative Extension System agent specializing in renewable energy who also serves on Governor Bob Riley’s renewable energy task force.

Hall says it may even be that current biofuel research and development represent only the first step toward energy independence.

“This picture really is so complicated, and it may be that the current types of renewable fuels represent only bridge technologies that will help us acquire a measure of energy self-sufficiency until more lucrative technologies can be developed further down the road,” he says.

Indeed, Hall says feedstocks such as corn and biomass crops may turn out to be long-term energy sources or they may end up serving comparatively short-term solutions until more efficient technologies prevail.

For his part, Hall is intrigued with the potential for algae, which can be bred and developed specifically for energy needs. While the concept is still largely in the drawing board stage, algae, conceivably at least, offers the potential to produce more in a smaller area than many other biofuel sources, he says.

For now, the biggest factor stymieing the development of cellulosic-derived ethanol is the cellulose — that is, finding a cost-effective way to break down the cellulose commonly found in stems, stalks and wood chips into sugars. Cellulose is comprised partly of sugars, though these are tightly linked in a more complicated chain. Breaking them up so they ultimately can be converted into ethanol requires several enzymes.

Last year, Honda announced it may have discovered a more efficient way to do this using a microorganism developed in a Japanese lab. The process results in a “significant increase in production of bio-ethanol,” according to a press release issued by Honda’s Tokyo facility. The new process conceivably will allow large volumes of ethanol to be produced from widely available waste wood, leaves and other sources typically described as soft biomass.

Hall stresses there are also other technologies on the horizon that bode well for cellulosic ethanol. For example, last year, scientists announced they had completed genome mapping of a poplar tree, black cottonwood or Populus trichocarpa, which offers huge potential as a biofuels source. The poplars, which grow 12 feet a year, mature in as little as four years and can reach 100 feet.

Scientists are hopeful the knowledge they’ve gained through gene mapping will enable them to undertake dramatic improvements in plantation productivity associated with the tree, possibly even rivaling the strides made from the green revolution in agriculture.

Still, the challenge remains of finding an economically feasible way to convert cellulose into sugar — one that venture capitalists and researchers have every incentive for overcoming.

The New York Times reports the Department of Energy has allocated $760 million for renewable fuel projects this year, including wind and solar energy. It recently awarded grants totaling $385 million over the next four years to six companies establishing cellulosic ethanol plants.