Porosity and pore size distribution of biochar from straw biomass - data for DOE

Biochar is produced by pyrolyzing biomass in the absence of oxygen and has considerable promise as a sorbent or carbon sequestration material. Despite several investigations on biochar properties, the biochar porosity and sorption properties achieved with varied pyrolysis settings remain mostly unknown. The goal of this work was to evaluate the interrelationships between temperature, material grain size, heating rate, and retention duration, as well as the effects of these interactions on the surface morphology of wheat straw biochar. Biochars made at various pyrolytic temperatures were tested for sorption, porosity, and pore size distribution. Elemental analysis, BET-N2 surface area analysis, ICP-OES, and Fourier transform infrared spectroscopy were used to evaluate 19 wheat straw biochars produced through pyrolysis at various temperatures (500 to 700 °C), heating rates (20 and 30 °C/min), and residence periods (5 and 15 min). The best settings for wheat straw pyrolysis and the variables that have a statistically significant effect on biochar quality were established using a full factorial design technique and variance analysis. At 700 °C, with a grain size of 0.5-1.0 mm and a heating rate of 20 °C/min and a residence period of 5 minutes, a high surface area of 400 m2/g and an average pore size of roughly 2.34 nm were produced.