Pyrolysis technologies for biochar production in waste management: a review

Abstract

Abstract Pyrolysis is a thermal conversion process in the absence of air to derive energy components from the residues. Renewable-energy technologies will play a major role in addressing future challenges related to environmental safety and energy security. One of the many easily available renewable energy sources is biomass—an organic material that is thought to be carbon-neutral. Pyrolysis technology is a thermochemical process that can be used to produce useful products from biomass, such as biochar, bio-oil and combustible pyrolysis gases. The structure and relative product yield are impacted by the pyrolysis method employed. This article evaluates different approaches for biomass pyrolysis. Fast, slow and advanced pyrolysis methods using various pyrolyser reactors have been studied in the literature and are provided to increase the variety and use of these methods in upcoming studies and research. Slow pyrolysis can lead to increased ecological well-being, as it increases the amount of biochar produced using auger and rotary-kiln reactors. Rapid pyrolysis, mainly in fluidized-bed reactors with bubbling and rotating circulation, can be used to obtain bio-oil. Advanced pyrolysis methods offer a good probability of yielding great prosperity for specific applications. The selection of a pyrolysis process is based on the required output in terms of solid, liquid and gaseous fuels, and the parameter plays a crucial role in the pyrolysis performance.