Heat recovery from composting – A comprehensive literature review

Thumbnail Image
Issue Date
Smith, M.M.
Aber, J.D., Dr
Rynk, R.. Dr
Proceedings of the 2015 International Composting Conference
It has long been recognized that composting yields a large quantity of thermal energy, which is normally lost to the surrounding environment as heat. Efforts to recover this heat using compost heat recovery systems (CHRSs) have been sporadic. Literature on the subject is also disjunct. To summarize the research that has been conducted, the authors performed an extensive literature review, covering publications in scien-tific journals, trade magazines, books, theses, and published reports. A focus on CHRS design and heat recov-ery rates is presented. The review covers 44 CHRSs in 16 different countries, ranging from simple hotbeds used in China 2000 years ago, to advanced super-thermal conductor heat pipe systems in 2014. Heat recovery rates varied significantly, with no predictable trend among the 44 systems. Recovery rates averaged 1895 kJ/hr (1159 kJ/kg DM) for lab systems, 20,035 kJ/hr (3899 kJ/kg DM) for pilot systems, and 189,822 kJ/hr (7084 kJ/kg DM) for commercial systems.
Presented at the 2015 International Composting Conference. October 22nd-25th, 2015. Beijing, China. Organized by China Agricultural University and China Composting Network.