Evaluation of press mud, vinasse powder and extraction sludge with ethanol in a pyrolysis process

The effluents of the sugar and bio-ethanol industry, mainly vinasse as well as lignocellulosic waste, are produced in high volumes. Therefore, their treatment and valorization would reduce the environmental impact and make this industry more productive and competitive. The purpose of this study was to determine the potential use of press mud (lignocellulosic waste), vinasse powder, and vinasse sludge from an extraction process with ethanol, as raw materials for conventional pyrolysis evaluating the physicochemical characteristics that affect this thermochemical process, such as calorific power, density, ash content, volatile material, moisture and nitrogen, sulfur, carbon and hydrogen content, thermogravimetric profile, and quantification of lignin cellulose and hemicellulose. The batch pyrolysis experiments showed that all three wastes could be converted successfully into more valuable products. The powder vinasse led to the formation of the lowest content of bio-char (42.7%), the highest production of volatiles (61.6 wt.%), and the lowest ash content (20.5 wt.%). Besides, it showed the high heating value of 15.63 MJ/kg. Meanwhile, the extraction sludge presented the highest liquid yield (32%) with the lowest gas formation (18.2 wt.%) and the lowest heating value of 8.57 MJ/kg. Thus, the sludge could be a good feedstock for production of bio-oil and bio-char.