An overview of pyrolysis of de-oiled cakes for the production of biochar, bio-oil, and pyro-gas: Current status, challenges, and future perspective

De-oiled cakes/seed cakes are being increasingly explored for the production of bio-oil and biochar. In this study, analysis of reported investigations covering i) characterization of various de-oiled cakes in terms ultimate, proximate, bio-chemical, and higher heating value (HHV) analyses, ii) reactors employed along with operating parameters for pyrolysis of various de-oiled cakes, iii) kinetics and thermodynamic analysis of pyrolysis of various de-oiled cakes, iv) characterization of biochar obtained from pyrolysis of various de-oiled cakes and its relationship with prospective applications, is deliberated. Average activation energy for pyrolysis of various deoiled cakes was found to be in the range of 98 to 162 kJ/mol. Analyses revealed that biochar from de-oiled cakes have remarkable scope in a variety of emerging applications in view of plenty of surface functional groups and high specific surface area. It was also revealed that plasma reactors and microwave-based reactors hold tremendous potential and need be explored further.