Production of bio-oil from de-oiled cakes by thermal pyrolysis

► To determine the optimum temperature at which sesame, mustard and neem de-oiled cake gives maximum liquid product yield. ► To find the influence of temperature on the yields of liquid, gas and char at heating rate of 25°Cmin−1. ► Characterization of liquid product for it physical properties and ultimate analysis. ► Chemical characterization of pyrolytic oil by FTIR, 1HNMR, GC–MS. In the present study, pyrolysis of sesame (Sesamum indicum), mustard (Brassica napus) and neem (Azadirachta indica) de-oiled cakes were performed in a semi-batch reactor to determine the characteristics and yields of liquid and solid products. Pyrolysis experiments were carried out at the temperatures between 350°C and 700°C and at a heating rate of 25°Cmin−1. The maximum liquid product yield of 58.5%, 53.2% and 40.2% (by weight) was obtained and has the calorific values 25.5, 25.1 and 30MJ/kg for sesame, mustard and neem de-oiled cake respectively. The thermal degradation of sesame, mustard and neem de-oiled cake was studied in inert atmosphere by TGA. The chemical composition of the bio-oil and bio-char was investigated using 1H NMR, FTIR, GC/MS and SEM–EDX. The chemical characterization showed that the bio-oil obtained from sesame, mustard and neem de-oiled cake can be potentially valued as a fuel and chemical feedstock.