Assessment of combustion and emission behavior of corn straw biochar briquette fuels under different temperatures.

The 350 °C and 700 °C corn straw biochars were used to produce solid fuel briquettes. NovoGro (NG), an industrial by-product, were selected as a binder in the briquetting process. The ratios of the raw material to NG was assumed as 100:1 and 50:1 (denoted as 350NB, 350NB, 700NB and 700NB, respectively). The physicochemical and morphological properties, combustion characteristics and gas emissions of the four briquettes were investigated. The results revealed that the biochars and the NG binder performed a good combination. The low temperature biochar briquettes, especially 350NB, had excellent combustion characteristics, including low H/C and O/C ratios (0.17 and 0.82), low gas emissions (104.06 mg/m of CO, 157.25 mg/m of NO and 18.92 mg/m of SO), optimal resistance to mechanical shock (~90%) and high calorific values (21.48 MJ/kg). Thus, NG is a good binder for the briquetting of biochar. The low temperature biochar was a good feedstock for solid fuel production in the improvement of the combustion and emission quality.