Quantification of compositional characteristics of rice straw from diversified varieties in china

To better understand of basic compositions of diversified rice straws, 271 rice straw samples featuring different subspecies (indica and japonica) were collected from Hainan Province in China. Totally 28 compositional characteristics were analyzed. Results showed that the lignocellulosic contents of rice straw were cellulose (39.96%±3.19%) > lignin (15.39%±1.57%) > hemicellulose (14.68%±1.96%), and the ultimate compositions were oxygen (O) (40.83%±1.38%) > carbon (C) (39.78%±1.03%) > hydrogen (H) (4.93%±0.31%) > nitrogen (N) (1.51%±0.25%) > sulfur (S) (0.38%±0.07%). Proximate compositions were moisture (5.62%±0.41%), volatile matter (VM) (71.77%±1.60%), ash (12.58%±1.92%), and the fixed carbon (FC) (10.04%±0.83%). Mineral elements were ranked as potassium (K) > Calcium (Ca) > phosphorus (P) > magnesium (Mg) > manganese (Mn) > sodium (Na) = iron (Fe) > zinc (Zn) > arsenic (As) > boron (B) > copper (Cu) > chromium (Cr) > nickel (Ni) > cadmium (Cd). The ranges of the higher heating value (HHV) and lower heating value (LHV) were 14.35-17.24 MJ/kg and 13.18-16.14 MJ/kg, respectively. There were significant differences in Lig, P, K, Ca, Mg, Cu, As, Cd, HHV, and LHV between the two subspecies with a significant level (P) 0.50, P © 2019, Asian Association for Agricultural Engineering. All rights reserved.