|A Texas A&M researcher working with a high-biomass variant of sorghum. Click to enlarge. Source: Texas A&M|
Gulf Ethanol Corp., a Houston, Texas-based ethanol company, is pursuing the use of sorghum as a feed stock for the production of cellulosic ethanol. Gulf Ethanol, which began as an importer of sugarcane ethanol from South America and the Caribbean Islands, now plans to produce, distribute, and blend biofuels.
Sorghum is a genus comprising numerous grass species, some of which are used for grain, fodder and forage (grain sorghum) and some of which are used for syrup production (sweet sorghum). Sorghum thus offers multiple pathways to ethanol:
Starch-to-ethanol from grain sorghum. About 15% of the US grain sorghum crop currently goes into ethanol production with one bushel of grain sorghum producing the same amount of ethanol as one bushel of corn, according to the National Sorghum Producers.
Sugar-to-ethanol from sweet sorghum; and
Cellulosic ethanol from:
- Residue/regrowth on grain sorghum
- Forage sorghums
- Bagasse from sweet sorghum
- Dedicated biomass sorghums
Sorghum plants tend to be water-efficient, drought- and heat-tolerant, and grow in warmer climates. Texas is thus interested in exploring the potential use of sorghum as a potential biofuel feedstock.
As an example, a Regional Water Plan prepared for the Texas Panhandle Water Planning Group in Amarillo, Texas, found that the water savings over 50 years for 524,243 acres spread over 21 counties in the Texas Panhandle would amount to 7,360,000 acre-feet of water if irrigated corn acreage were converted to irrigated sorghum.
That’s on average, 147,200 acre-feet saved per year—about 48 billion gallons US (182 billion liters) per year.
Texas A&M University is working on optimizing varieties of sorghum for biomass-based ethanol production.
Corn is a viable way to produce ethanol from starch, but that’s not the only option for Texas and the southern part of the country. Based upon our analyses, we find it’s efficient to take something like our new sorghum varieties or sugar cane that produces large volumes of biomass, rather than producing grain and then converting grain-starch to ethanol.—Dr. Elsa Murano, Vice Chancellor of Agriculture and Life Sciences for the A&M System and Director of the Texas Agricultural Experiment Station
One of Texas A&M’s initiatives is to develop a high biomass sorghum for use in cellulosic ethanol production. The goal of the development is high biomass accumulation—about 20 tons/acre.
In May, Chevron Corporation and the Texas A&M Agriculture and Engineering BioEnergy Alliance (Texas A&M BioEnergy Alliance) announced that they had entered into a strategic research agreement to accelerate the production and conversion of crops for manufacturing ethanol and other biofuels from cellulose. (Earlier post.)
An Economic Examination of Potential Ethanol Production in Texas (Abbreviated Version)
Texas Agricultural Experiment Station Bioenergy Initiatives