Valorisation of organic sidestreams by thermochemical conversion: production of biochars by pyrolysis

Abstract

There is a need to valorize various organic (heterogenous) sidestreams available in (chemical) industries. Several refinery schemes have been successful to extract single or multiple compounds with added-value but often a (post-extracted) residue is left behind with no direct economic value. The conversion of these heterogenous (postextracted) organic sidestreams by thermochemical conversion into biochars and/or activated carbons can solve part of this problem, which is critical to the development of a sustainable global circular economy. Thermochemical conversion processes include direct combustion, gasification, liquefaction and pyrolysis. Pyrolysis is thermal degradation and conversion in an oxygen deficient atmosphere to produce a char and a variety of gaseous and condensable (bio-oil) products. In recent years, microwave assisted pyrolysis was proven to be a promising alternative to conventional pyrolysis because of its accelerated reaction rates and higher energy efficiency. Biochar is the solid and carbon rich product obtained from the conversion of lignocellulosic materials by pyrolysis at moderate temperatures. This product has the potential to improve soil fertility and its physical properties as slow nutrient releaser, by increasing the soil water retention, increase soil pH and by in improve microbial activity. We are interested to collaborate with (industrial) stakeholders that provide an organic sidestream that is suitable as feedstock for biochar production and is willing to study its potential at pilot-scale.