Biomass Gasification
Klaesi_anaerobic_digester.jpganaerobic_digester.gifdigester1.gif

a. Goal
b. Benefits of the specific technology to the community
  • Utilizes animal waste from livestock
  • Multiple benefits: fertilizer, energy, heat
  • Doesn't rely on weather patterns (solar, wind, hydro)
c. Local Availability
d. Regulatory or Industry Standards for Implementation of Technology
i. International Standards
ii. Local code enforcement

e. Description of Product (s) or Process (es) and its Functionality (Succinct but Detailed Enough)
f. Design parameters- a function of the number of livestock available and the length of containment time.
i. Sizing- for a digester that could provide service for roughly 50 cows, the digester would need to be roughly 100 cubic meters. Unlike solar tech, this requires a fair amount of space. The size depends on the number of livestock and time of containment.
ii. Materials needed for Fabrication/ Construction of Technology
1. Various Options

iii.Other resources Needed for Implementation/ Use
  1. Construction Equipment- large-scale construction, unlike solar panels. Is an entire building with multiple chambers.
  2. Labor- requires construction beyond the range of unskilled workers (students). This will mean construction with help from a trained professional or company. There will also be labor required daily for "feeding" the digester with waste and checking appropriate chemical levels. There will also be labor involved in removing fertilizer from the digester to use for crops.
  3. Technical Consultation- consultation will definitely be necessary when determining the exact system for use as well as the size of the unit. Some technical knowledge will be necessary for any individuals caring for the system on a daily basis, which could mean extended technical help.
  4. Transportation Requirements- This is too large to purchase in the US and ship. It will have to be purchased in Kenya if we can find a supplier and construction company.
  5. Energy Requirements- this requires some energy in order to heat the mixture and complete the process. Once the digester is in full swing, however, some of the heat it produces and some of the energy can be used to sustain itself.
  6. Space
  7. Spare Parts
  8. Time for Construction
iv. Technical Skills Required to Operate or Utilize
  1. Training Requirements
g. Associated Costs
i. Capital
ii. Operations & Maintenance
Change 0 of 0


Typically, biogas plants have a 50day capacity. To reduce space, some have begun to use a 10day capacity tank. The smaller tank requires a more delicate mix of materials and requires a basic knowledge of biochemistry.

For the 10day tank, for 50 cows' waste, the plant was about 100 m^3 and circular. Fewer cows, smaller tank.

The tank would be "fed" waste daily. This requires keeping animals in barns in order to collect waste.

Digester would be built roughly the same way a farmer builds a silo. Half the circle is fed manure every day and mixed with water and heated to about body temperature. This mix seeps through the barrier to the other half where it is stored. At the end of the process (10 days or 50) this mix can be used to fertilize fields. The methane produced would be run through a heat exchanger to produce electricity.

About 25% of the energy that the digester produces would be used to power the digestor. The rest can make heat or electricity.

Grad student from Kenya: OLUSEGUN OLUJIMI OGUNKUA ooo105@psu.edu environmental pollution control

USDA cost estimates,
US Fed gov't, UN, UK, "factsheets" anaerobic digesters

Tom- do you have drawings of the digesters in Jamaica? Ray said you do...

PSU dept of Ag/Bio engineering- extension programs, factsheets/programs, biogas

industrial waste treatment

food waste/ composting

"pollution prevention pays"


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