Compositional characteristics and energy potential of Chinese animal manure by type and as a whole

In this study, 838 representative animal manure samples were collected from 552 sites across China. Chemical analyses of 19 parameters, including the proximate analysis, ultimate analysis, heating values and some essential mineral elements, were conducted on the samples. The energy potential of animal manure in China was quantified based on the chemical analysis. The results showed that the chemical characteristics of the different types of animal manure were highly variable. Principal component analysis results demonstrated that the closest compositional characteristics were between dairy manure and beef manure. Several strong and important associations, namely phosphorus-magnesium, phosphorus-copper, phosphorus-zinc, copper-zinc, calcium-potassium, fixed carbon-calcium, volatile matter-iron and ash-volatile matter-fixed carbon-carbon-hydrogen-higher heating value-lower heating value, were identified. The calculated outputs of total potential annual thermal energy, syngas and methane yields from the five types of animal manure in China were 4400.63 TJ, 983.40 × 109 m3 and 188.89 × 109 m3, respectively. The air gasifier energy conversion efficiency (t = 850 °C, equivalence ratio (ER) = 0.3) for different animal manures was in the range of 66.80-83.22%.