As part of an ambitious farm waste-to-energy program, the Chinese government provides rural households with an anaerobic digester as a way to provide inexpensive cooking biogas and heat while also removing farm animal and human waste, according to Dr. Xiujin Li of Beijing University of Chemical Technology, who visited UC Davis today with a Chinese delegation.
China began a program for anaerobic digesters in 1975, but many suffered leaks and were of poor quality and were phased out. Today, some 35 MM of these rural digesters many made from newer durable materials now exist, up from 10 MM in 2000. Many are the size of a couple of refrigerators and buried underground on a farm. The price is $400, beyond reach of most Chinese farmers but paid for under the government program. Dr. Li mentioned that Americans have asked him where to purchase.
In larger Chinese communities or larger farms, such as a commercial chicken farm, the Chinese government has offered since 2005 a second program for much larger anaerobic digesters to convert the waste into biogas, fuel for electricity or natural gas for vehicle fuel. The government provides just over $700 MM annually for the equipment and the maintenance of these larger, more complex biodigesters, in which Dr. Li said support is “only a phone call away.” Local governments must then commit an equal amount of the funding. [update: Here is an excellent video by Amy Zeng about biogas production in Kunming]
China also a problem with dry, crop residue. Annually, China produces 700 MM tons of dry rice, wheat, corn waste (the stalks), half of which is burned in open fields. This dry waste has a high lignocelluloisic component, making it difficult to biodigrade. Dr. Li described several university research efforts in China to improve the biogas yields and reduce the time to produce. One promising approach is pre-treating with sodium hydroxide, other research effort range from fungus to various reactor designs.
What works in the lab, of course, may not work in the fields. This is true everywhere, but it is particularly important to realize that in a developing country, like China, development is uneven. The best features of a modern society can often be juxtaposed with the face of a poor, less developed society. In other words, Dr. Li stressed technologies used in anaerobic digestors must not only be low capital, cost-effective but also reliable and must scale easily.
Still, some lingering questions remain, do the small biodigesters leak and contaminate underground water? Who decides which villages and farmers have access to the government’s financial programs?
One way answer is to encourage collaboration with foreign scientists and this was just one purpose of Dr. Li visit, who had obtained his Ph.D from UC Davis.
(Remark: Dr. Li’s talk was about biogas. China limits the use of food crops for ethanol, but is working with jatropha )
Additional information:
http://www.methanetomarkets.org/expo_china07/docs/postexpo/ag_li.pdf
http://www.physorg.com/news131028348.html
http://www.pciaonline.org/beijing-university-chemical-technology-buct
Biogas in developing countries background
China began a program for anaerobic digesters in 1975, but many suffered leaks and were of poor quality and were phased out. Today, some 35 MM of these rural digesters many made from newer durable materials now exist, up from 10 MM in 2000. Many are the size of a couple of refrigerators and buried underground on a farm. The price is $400, beyond reach of most Chinese farmers but paid for under the government program. Dr. Li mentioned that Americans have asked him where to purchase.
In larger Chinese communities or larger farms, such as a commercial chicken farm, the Chinese government has offered since 2005 a second program for much larger anaerobic digesters to convert the waste into biogas, fuel for electricity or natural gas for vehicle fuel. The government provides just over $700 MM annually for the equipment and the maintenance of these larger, more complex biodigesters, in which Dr. Li said support is “only a phone call away.” Local governments must then commit an equal amount of the funding. [update: Here is an excellent video by Amy Zeng about biogas production in Kunming]
China also a problem with dry, crop residue. Annually, China produces 700 MM tons of dry rice, wheat, corn waste (the stalks), half of which is burned in open fields. This dry waste has a high lignocelluloisic component, making it difficult to biodigrade. Dr. Li described several university research efforts in China to improve the biogas yields and reduce the time to produce. One promising approach is pre-treating with sodium hydroxide, other research effort range from fungus to various reactor designs.
What works in the lab, of course, may not work in the fields. This is true everywhere, but it is particularly important to realize that in a developing country, like China, development is uneven. The best features of a modern society can often be juxtaposed with the face of a poor, less developed society. In other words, Dr. Li stressed technologies used in anaerobic digestors must not only be low capital, cost-effective but also reliable and must scale easily.
Still, some lingering questions remain, do the small biodigesters leak and contaminate underground water? Who decides which villages and farmers have access to the government’s financial programs?
One way answer is to encourage collaboration with foreign scientists and this was just one purpose of Dr. Li visit, who had obtained his Ph.D from UC Davis.
(Remark: Dr. Li’s talk was about biogas. China limits the use of food crops for ethanol, but is working with jatropha )
Additional information:
http://www.methanetomarkets.org/expo_china07/docs/postexpo/ag_li.pdf
http://www.physorg.com/news131028348.html
http://www.pciaonline.org/beijing-university-chemical-technology-buct
Biogas in developing countries background
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