Biomass gasification and the resulting production of “biochar” were among the topics addressed at the Texas Animal Manure Management Issues Conference in Round Rock last week.
The conference was attended by about 175 beef, poultry and dairy industry producers, researchers, engineers, regulators and others involved in environmental, regulatory and energy related aspects of manure management.
During a technical session devoted to advanced manure conversion/bioenergy, Dr. Sergio Capareda with Texas AgriLife Research spoke about how animal manure and other biomass can be converted into useful energy. He also noted the commercial possibilities of the biochar which is produced from biomass gasification.
“On-site animal manure conversion into heat and energy is possible with the use of high-throughput fluidized-bed gasification system,” said Capareda, who works in the department of biological and agricultural engineering at the College of Agriculture and Life Sciences at Texas A&M University.
He said the gasifier can thermally convert relatively dry manure or other biomass into heat, synthesis gas or electrical power.
“The conversion process is endothermic �“ formed by the production of heat �“ so no external energy source is required, except during initial startup of the biomass gasifier,” Capareda said.
According to its proponents, gasification also is an environmentally sound process because it produces clean air emissions and no water discharge. It also allows for the efficient disposal of animal waste and helps reduce odors emanating from agricultural operations.
“Biomass, like fossil fuels, contains a lot of carbon and hydrogen and can be a good alternative energy source,” Capareda said. “But while biomass produces less energy, unlike fossil fuels this is a renewable resource, and enormous reserves exist.”
Capareda, who has more than 20 years experience in biomass, biofuels and alternative energy, said his research on biomass gasification and biochar includes analysis of the various biomass “feedstocks.” Some of the feedstock material he has tested includes wood chips, poultry litter, dairy manure, sorghum crop residue, switchgrass and cotton gin residue.
He said his tests have shown that the “synthesis gas” produced by gasification of poultry litter and wood chips has produced a high-heating value, HHV, of about 150 British thermal units per cubic foot. A somewhat lower energy value was produced by manure gasification.
“Generally speaking, if an operation could just obtain a 15 percent efficiency in energy conversion from biomass, it could produce enough to be self-sustaining,” he said. “And any extra energy produced, depending on what form it’s in, could be sold back and put on the grid.”
Capareda added that biomass gasification also produces biochar, a carbon-rich product that can be used for many commercial applications. In agriculture, biochar has been shown to have a significant impact on replenishing soil, improving the growth rate of crops and reducing agricultural greenhouse gas emissions.
Copyright © 2009 The Boerne Star
