Short Paper
Exergy analysis and the dissipation function of the composting process
2016 年 72 巻 1 号 p. 37-42
詳細
2016 年 72 巻 1 号 p. 37-42
By regarding exergy as a fundamental driving force of composting, the exergy balance equation for composting is derived and its applicability is discussed. In composting, the available energy (termed exergy) is released from decomposition of the substrate by microbial reactions. Some of the released exergy is consumed by microbial growth and its movement, some is temporarily accumulated in the compost bed as a temperature increase, and the remainder is irreversibly dissipated and changed to anergy (non-available energy). There are two types of dissipation functions: bound and external dissipation functions. The external dissipation function governs the composting system. By considering the bound dissipation function as positive, the maximum value of microbial cell yield Y is theoretically formulated. Using the previously obtained experimental results, the proportion of the dissipation function of the entire amount of released exergy is confirmed to be as large as 90%. It is further shown that the application of the exergy analysis to the functional analysis of the composting process will be promising.
