| Greenhouse gas emissions from world energy generation in 2010 were the highest in history, according to the latest estimates from the International Energy Agency, released on May 30th, 2011. In addition, the demand for food, feed, fiber and fuel increases to meet the needs of a growing global population, making soil fertility management increasingly important. In this context Biochar has proved itself to be a potential and practical solution in combating these issues. In this present study, influence of various process parameters on the pyrolysis of the five different types of ligno cellulosic biomasses into biochar was investigated. The operational parameters for pyrolysis were optimized using response surface methodology individually based on the temperature of operation and the time of residence.;The independent process parameters for pyrolysis such as operational time and residence time were evaluated using a central composite design to access their effects and their interactions on the yield of biochar from lignocellulosic biomass. Optimal temperatures for a desirability function of 0.5 for maple, balsa, bamboo, pine and ebony are 345°C, 334°C, 326.7°C, 325.8°C and 340.8°C respectively with the corresponding residence times of 22, 43.75, 28, 24.8 and 21.75 minutes respectively. All the biomass data fitted the proposed model very well. The least fit was observed in balsa wood biomass. Temperature was the major influential factor compared to time. Density analysis was done to compare the changes in density before and after pyrolysis. It was observed that the density of biochar was 0.8 times the density of the wood from which it was originally made. Proximate analysis was performed to compare the fuel and optimal biochar properties.;Characterization of biochar revealed important details: Hyperspectral imaging analysis which measured the mean reflectances of the biochar disclosed that porosity which is inversely proportional to the porosity decreased as the temperature increased. Thus higher temperature indicated greater porosity compared to average and low temperatures. Pycnometry analysis suggested that the severity of the pyrolysis hiked the degree of porosity as well. This result was further substantiated with the scanning electron microscope images which showed larger sized pores at greater temperatures. |
