Microwave pyrolysis of rice straw to produce biochar as an adsorbent for CO 2 capture
Journal
Energy
Journal Volume
84
Pages
75-82
Date Issued
2015
Author(s)
Abstract
The CO2 adsorption on biochar produced by microwave pyrolysis of rice straw was investigated in this study. A microwave power level of 200W and a maximum temperature of approximately 300°C would be the optimal parameters to adsorb the most CO2. The CO2 adsorption capacity was up to 80mg/g at 20°C. The adsorption capacity decreased at higher power levels and temperatures possibly owing to the pore destruction. The CO2 adsorption capacity was highly correlated with the specific surface area of biochar. The conventional pyrolysis at 550°C was optimal to produce the biochar absorbing the most CO2 which, however, was still lower than that of the biochar produced by microwave pyrolysis by about 14%. Low activation energy implies that CO2 adsorption on the biochar is physisorption. The ratio of CO2 quantity versus solid product quantity can almost match the CO2 adsorption capacity of the biochar produced at 200W microwave power levels, so the microwave pyrolysis without further processes to meet the zero emission of CO2 should be workable. Compared with conventional pyrolysis, microwave pyrolysis could produce the biochar with lower time, cost, and energy consumptions. © 2015 Elsevier Ltd.
Other Subjects
Activation energy; Adsorption; Enzyme kinetics; Microwave generation; Microwave power transmission; Microwaves; Physisorption; Adsorption capacities; Bio chars; Low-activation energy; Maximum temperature; Microwave power levels; Microwave pyrolysis; Optimal parameter; Rice straws; Carbon dioxide; adsorption; biofuel; energy efficiency; pyrolysis; straw; surface area
Publisher
Elsevier Ltd
Type
journal article