Anaerobic Digestion (Biogas) Technology

Climate Friendly Farming Topics, Anaerobic Digestion (Biogas) 

Small-Scale Biogas Technology

Biogas technology has been used globally for decades, with primary applications for large-scale, high-tech commercial systems in Europe (and limited penetration in the US) and small-scale, low-tech “house-hold” scale systems in Asia. The potential for application of biogas technology on small-scale farms in the US is great for providing alternative means for managing on-farm organic wastes (manure, on-farm food processing) and providing a clean, renewable source of energy for on-farm applications (thermal energy for water heating, food processing, etc.). Making biogas technology a viable option for small farms requires the development of reliable, effective biogas reactors that can be readily fabricated and maintained by farmers. With support from the USDA Western Sustainable Agriculture Research & Education Program (Western SARE), CSANR developed a project to explore options for developing improved biogas technology for applications in small-farm settings in the US. Resources developed in this project are available on this site.

Project Resources and Publications

Advanced Biogas Plant Design
Detailed CAD drawings for improved version of pilot biogas plant developed at WSU.
Advanced small-scale anaerobic digester design tailored for household user living in cold climate
WSU Invention Disclosure.
A Procedure to Estimate Proximate Analysis of Mixed Organic Wastes
Journal of Water Environment Research 81:4.
Biomass Inventory Technology and Economics Assessment
Wei Liao, Craig Frear and Shulin Chen, June 2007. This project compiled a literature search for biomass chemical characterization and conducted supplemental laboratory study of forty two feedstocks for 33 parameters such as dry matter, COD, carbohydrates, lipids, elemental and mineral matter, and standard properties such as protein, fiber, pH, etc. A follow-on report will group similar feedstocks, assess potential energy conversion technologies and conduct an economic analysis of feedstock collection and energy production.
Producing Energy and Fertilizer from Organic Municipal Solid Waste - Project Deliverable #1

Usama Zaher, Dae-Yeol Cheong, Binxin Wu, and Shulin Chen, June 2007. A literature review of current digester technologies formed the framework for designing a bench scale study of a high solids anaerobic digestion (HSAD) system. The study shows that significant improvements in methane production can be attained while decreasing capital costs for facilities.  A new digester design is proposed that will optimize methane from organic food and green waste digestion, while recovering nutrients from the digestate. 

Household Biogas Digester: An Underutilized Potential
A presentation on applications of small-scale biogas plants in India.
Biomass Inventory and Bioenergy Assessment
Craig Frear, Bingcheng Zhao, Guobin Fu, Michael Richardson, Shulin Chen, and Mark Fuchs, December 2005. A biomass inventory and bioenergy assessment of forty five organic resource types across Washington was completed, producing this report and a database with GIS maps (http://www.pacificbiomass.org). Annual production of over 16.4 million tons of underutilized bone dry biomass was found, capable of producing (either by combustion or anaerobic digestion) over 15.5 billion kWh of electrical energy.
Smale-Scale Biogas Plant Enterprise Assessment Tool
A worksheet to facilitate preliminary planning for a biogas plant on a small farm.

Images

Images of small-scale biogas plant.  The pilot plants developed for this project were fabricated from steel to facilitate mobility and durability as demonstration units.   Actual biogas plants could be fabricated from a number of different materials.





Source: http://csanr.wsu.edu/pages/Small-Scale_Biogas_Technology

Anaerobic Digestion

 Anaerobic Digestion for Developing Countries with Cold Climates 


Utilizing solar heat to address technical challenges and facilitating dissemination through the use of carbon finance

Summary

A large proportion of the rural poor in developing countries have no access to a secure source of
energy. The  rural poor  in developing  countries  rely  primarily on  traditional  biomasses,  such  as
wood  and  charcoal.  The  reliance  on  traditional  biomasses  and  solid  fuels  result  in  substantial
human, social and environmental cost. To  tackle  these costs a switch  to a clean  fuel  is required.
One  of  the  solutions  is  anaerobic digestion  (AD)  of  manure  or  other  biodegradable matter  to
produce a clean fuel: biogas.
The principle of AD has been known for 3-4 centuries and in 1920 the first digester was
designed  for  house  on  site  biogas  production.  A  digester  is  a  technology which  converts  the
commonly found wastes in rural areas, manures, in a controlled anaerobic environment to biogas
and  an  excellent  fertilizer.   Biogas  is  a  clean,  convenient,  versatile  and  environmentally  benign
fuel which  does  not  pollute  the  indoor  air.  Furthermore,  a  biogas  plant  has  several  additional
benefits, such as replacing bought or collected wood (time or revenue savings), provision of light
by biogas lamps, empowerment of women by relieving them of the drudgeries of  traditional fuel
gathering. A toilet is in most cases attached to a digester which improves sanitation, a significant
virtue  since  the majority  of  the  poor  lack  access  to  sanitation. The  effluent  from  the  digester,
digestate,  has  a  high  fertilizer  value  comparable  to  chemical  fertilizers.  Digestate  is  also  an
excellent fish feed and can enhance fish yields. The adoption of biogas digesters has considerable
spillovers to the local, national and even to a global level. For instance, at local level, employment
opportunities, skills development and reduced pressure on the forest. At  a national level, it leads
to  less health costs, more employment, and potential  foreign exchange earnings and  at a global
level: greenhouse gas emission mitigation. Consequently, the cumulative effects of these benefits
alleviate poverty and contribute to achieve the Millennium Development Goals.

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 Anaerobic Digestion for Developing Countries with Cold Climates