Converting Waste Agricultural Biomass into a Resource - UNEP

Operations and Maintenance Requirements:
Physical reduction of particle size (10mm) of the rice straw resides prior to
hydrolysis is needed. Urea and molasses are added in the bioreactor along
with rice straw residues and inoculated with 1% strained rumen fluid. Carbon
dioxide gas was bubbled in for 5 minutes to render the solution anaerobic and
stable at 6.8 to 7 pH. Latex balloons were placed on top of the narrow mouth
of the bioreactor to allow emitted gases to go in and out of the balloon through
the incubation period. The bioreactors were mechanically agitated for ten
minutes, twice a day.
Social Considerations:
This novel process could make possible the biomass ethanol conversion of 13
million metric tons of rice straw from 4,046,318 hectares of land devoted to
rice farming in the Philippines each harvest season. It has been estimated
that burning rice straw and sugar cane produces atmospheric pollution
equivalent to burning 13 million barrels of oil annually. This new process of
biomass ethanol production can provide farmers with a source of income and
stop the practice of burning crop residues.
Advantages to Developing Countries
Information of microbial growth patterns using CLSU model will be useful in
determining the optimum duration of fermentation. Although microbial
organisms can grow prodigiously, they reach a certain point at which they
cannibalize each other or start consuming desirable end products such as
sugars and ethanol at a greater rate than they produce from the substrate. It
is therefore essential that the process can be terminated at a pre-determined
peak population density consistent with maximum sugar and ethanol
production.
Examples of Real Life Applications
Philippine Institute of Graduate Studies
Central Luzon State University
Science City of Munoz, Nueva Ecija
Nutrition Laboratory
Philippine Carabao Center
Science City of Munoz, Nueva Ecija
Country: Philippines
Level of Use: Research
Sources:
P.C. Florendo and F.B. Abenes, Institute of Graduate Studies, Central Luzon
State University.
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