By Dr.Hwa A. Lim

RENEWABLE ENERGIES

We shall provide four examples of renewable energies, each pertinent to Malaysia in a different way:1) corn and sugar ethanol because of existing sugar plantations and corn fields; 2) algae because of the ideal climatic condition; 3) gasifier technology because of existing oil palm and rubber plantations; and 4) genetic engineering and synthetic biology because of existing research institutes.

Not So New Biofuel Technology
Humankind has been turning grains into alcohol for eons. The corn is ground, mixed with water, and heated; added enzymes convert the starch into sugars. In a fermentation tank, yeast gradually turns the sugars into alcohol, which is separated from the water by distillation. The left over, known as distillers’ grain, is used as feed, and some of the wastewater—rich in nitrogen—is used as a fertilizer.

The process also gives off large amounts of carbon dioxide (CO2). Most ethanol plants burn natural gas or, increasingly, coal to create the steam that drives the distillation, adding fossil-fuel emissions to the CO2 emitted by the yeast. This is where ethanol’s green label starts to brown.

Growing the corn also requires nitrogen fertilizer, made with natural gas, and heavy use of diesel farm machinery. Some studies of the energy balance of corn ethanol—the amount of fossil energy needed to make ethanol versus the energy it produces—suggest that ethanol may be a loser’s game, requiring more carbon-emitting fossil fuel than it displaces; other studies give it a slight advantage.

While corn ethanol’s energy ratio hovers around breakeven, sugar cane ethanol gets about eight units of ethanol for every one unit of fossil fuel. Experts estimate that producing and burning cane ethanol generates anywhere from 55 to 90% less CO2 than gasoline.

A Scummy Solution
Virtually every scientist studying the biofuel issue agrees that there is no magic-bullet fuel crop that can solve our energy woes without harming the environment. But most say that algae—a single-cell pond scum—comes closer than any other plants because it grows in wastewater, even seawater, requiring little more than sunlight and CO2 to flourish.

A dozen start-up companies have been trying to convert the slimy green stuff into a viable fuel. Some of these companies have developed a process that uses algae in plastic bags to siphon CO2 from the smoke-stack emissions of power plants. The algae not only reduce a plant’s global warming gases (CO2), but also devour other pollutants. Some algae make starch, which can be processed into ethanol; others produce tiny droplets of oil that can be brewed into biodiesel or even jet fuel. Most advantageously, algae in the right conditions can double in mass within hours. By comparison, each acre of corn produces around 300 gallons (1,135 liters) of ethanol a year; an acre of soybeans around 60 gallons (227 liters) of biodiesel; while each acre of algae theoretically can churn out more than 5,000 gallons (19,000 liters) of biofuel each year! With corn or soybeans, one harvests once a year; with algae one harvests every day.

GasifierTechnology
Gasifier technology uses gases—hydrogen (H2), carbon monoxide (CO) and methane (CH4)—extracted from wood chips to heat a boiler. This process can generate 1.3 megawatts per hour.

Figure 1: The wood gasifier involves 1. Gas collection; 2. Ignition; 3. Steam; 4. Electricity generation.

Essentially, the technology involves four steps:

1. Gas collection: The gasifier heats the wood chips to 700 or 800 degrees, where they smolder, releasing H2,CO and CH4. Spent wood chips disintegrate to ash. Water vapor is the only major emission.
2. Ignition: The gases travel to an oxidizer, where oxygen is added and the gases burn.
3. Steam: Hot gases travel to a boiler which heats the water to steam.
4. Electricity generation: The steam powers a turbine to create electricity. The steam finally will be used as hot water and to heat buildings.

Genetic Engineering and Synthetic Biology
Some companies are using old-fashioned genetic engineering to develop a strain of standard industrial microorganism that can produce hydrocarbons from treated agricultural waste. The present strain is very close to meeting an economic threshold, and is being tested in pilot plants. The youthful microbe already produces an ethanol-like product, at 65% of the cost of corn-derived ethanol. The fuel meets the same diverse needs as petroleum does, can be transported in existing pipelines and be used in existing vehicles.

Figure 2: If researchers were able to create a synthetic genome, the transplantation process might be able to create synthetic cells. 1) A synthetic DNA is inserted into a species of bacteria. 2) When the cell divides, one of the daughter cells is a synthetic cell. 3) In theory, the synthetic cells could be designed to have useful properties such as the ability to efficiently convert carbon dioxide to methane.

Besides genetic engineering approaches, other approaches are using synthetic life forms. In the latter case, there are many hurdles to over come before the vision of “lifebydesign” is realized.

REFERENCES

• This work is based on a forthcoming book: Hwa A. Lim, Eco-friendlily Yours: Energy, biofuels, green and clean technologies, (World Scientific Publishing Co., Hackensack, New Jersey, USA,2008).
• Hwa A. Lim, Genetically Yours: Bioinforming, biopharming and biofarming, (World Scientific Publishing Co., River Edge, New Jersey, USA,2002).
• Hwa A. Lim, “Biotechnology—Past, present and future”, Symbiosis, October 2004, pp.31-34.
• Hwa A. Lim, “Agriculture—nature’s gift”, Symbiosis, August 2005, pp. 10-12.
• HwaA.Lim, “Biofuels—the fifth utility”, Symbiosis, October2006, pp.8-13.
• Tad W.Patzek, “A first-law thermodynamic analysis of the corn-ethanol cycle”, Natural Resources Research, 15(4), February 2007, pp.255 –270.
• Nicholas Wade, “Scientists transplanted genome of bacteria”, The New York Times, June 29, 2007.

Dr. Hwa A. Lim, Ph.D., and MBA, is credited with coining the neologism “Bioinformatics” in the 1980s, establishing and shaping the field, and initiating the world’s very first bioinformatics conference series. These credits earn him the title “The Father of Bioinformatics”. Dr. Lim currently resides in Silicon Valley, California, USA. He can be reached at hal@dtrends.com or hal_lim@yahoo.com.