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Biomass gasification, biochar show promise

October 9, 2009  By By Paul Schattenberg Texas A&M communications specialist

Oct. 9, 2009, Round Rock, Texas — Biomass gasification and the resulting
production of “biochar” were among the topics addressed at the Texas Animal
Manure Management Issues Conference Sept. 29-30 in Round Rock, north of Austin.

Oct. 9, 2009, Round Rock, Texas — Biomass gasification and the resulting
production of “biochar” were among the topics addressed at the Texas Animal
Manure Management Issues Conference Sept. 29-30 in Round Rock, north of Austin.


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 per cent
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.



“Biochar is already known to be a useful soil supplement, especially
around the Amazon rainforest, where its continued use creates what is called
‘terra preta’ or black earth,” he said. “This black earth allows crops to grow
or crop production to increase by making nutrients more available through a
type of carbon sequestration.”

Biochar from biomass gasification could be sold as fertilizer or soil
amendment, or used as an ingredient in garden soil, he said. Many other
possible commercial applications are still being analyzed and explored.

Much of the biochar being used today is the result of wood used as the
fuel source, said Michael McGolden, president and CEO of Coaltec Energy USA in
Carterville, Ill.

“Using animal manure in the gasification process will not only produce
the carbon needed for nutrient uptake, it will provide many of the nutrients
crops need as well,” he added.

McGolden said Coaltec has developed agriculture-based biomass
gasification projects for the past five years, and has built on-site systems at
poultry operations over the past two years.

“The main goal of these projects has been to make manure a valuable
resource to these operations, even a key component of generating revenues,”
McGolden said.

He added that different animal manures have been scientifically tested
and proven to be a good fuel source for gasification, providing sustainable

“Potential revenue from biomass gasification can be derived from energy
value, manure management cost reductions, mortality disposal, improved animal
performance, environmental benefits, labour and cost reduction and the value of
the biochar produced,” he said.

He also noted that while the marketing of biochar is still being fleshed
out, it likely will provide producers with a significantly greater commercial
potential than the value of the energy produced by biomass gasification.



“Along with other applications, biochar also has commercial possibility
as a water filtration medium because the phosphorus in it also increases the
ability to capture heavy metal particles,” he said.

McGolden added that other benefits of the gasification process may
include disease control and biosecurity improvement, the potential for energy
credits, and enhanced ability to increase operational capacity by improving
manure-management capabilities.

To help prove the commercial viability of biomass gasification, Capareda
is in the process of building a “mobile conversion system” at Texas A&M.
The system, a portable biomass gasification unit that can be hauled to
different locations, will be used to demonstrate the efficacy of
biomass-to-energy conversion.

Capareda also is investigating how the synthesis gas combustible material
can be removed from gasified biomass so the gas can be pumped through a
pipeline in a manner similar to natural gas.

“The gas is combustible and may be cleaned and used to run internal
combustion engines that are coupled with generators,” he said. “We’re also
looking into condensing the gas to make what’s known as bio-oil or black oil,
which looks similar to crude oil and can be used directly as fuel or converted
into other valuable chemicals.”

Capareda noted that while much research on biomass energy conversion
remains to be done, his research shows it holds significant direct and spin-off
commercial potential.

“Right now, we’ve just scratched the surface of the potential from the
entire biomass energy conversion process,” he said.




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