Emission of greenhouse gases from controlled incineration of cattle manure

Abstract

Greenhouse gas emission is a potential limiting factor in livestock farming development. While incineration is one approach to minimize livestock manure, there are concerns about significant levels of nitrogen and organic compounds in manure as potential sources of greenhouse gas emissions (N 2O and CH 4). In this study, the effects of various incineration conditions, such as the furnace temperature and air ratio on N 2O and CH 4 formation behaviour, of cattle manure (as a representative livestock manure) were investigated in a pilot rotary kiln furnace. The results revealed that N 2O emissions decreased with increasing temperature and decreasing air ratio. In addition, CH 4 emissions tended to be high above 800 °C at a low air ratio. The emission factors for N 2O and CH 4 under the general conditions (combustion temperature of 800–850 °C and air ratio of 1.4) were determined to be 1.9–6.0% g-N 2O -N/g-N and 0.0046–0.26% g-CH 4/g -burning object, respectively. The emission factor for CH 4 differed slightly from the published values between 0.16 and 0.38% g-CH 4/g -burning object. However, the emission factor for N 2O was much higher than the currently accepted value of 0.7% g-N 2O -N/g-N and, therefore, it is necessary to revise the N 2O emission factor for the incineration of livestock manure.