Pyrolysis of Waste Castor Seed Cake: A Thermo-Kinetics Study

Abstract

Biomass pyrolysis is a thermo-chemical conversion process that is of both industrial and ecological importance. The efficient chemical transformation of waste biomass to numerous products via pyrolysis reactions depends on process kinetic rates; hence the need for kinetic models to best design and operate the pyrolysis. Also, for an efficient design of an environmentally sustainable pyrolysis process of a specific lignocellulosic waste, a proper understanding of its thermo-kinetic behavior is imperative. Thus, pyrolysis kinetics of castor seed de-oiled cake (Ricinus communis) using thermogravimetric technique was studied. The decomposition of the cake was carried out in a nitrogen atmosphere with a flow rate of 100mL min-1 from ambient temperature to 900 °C. The results of the thermal profile showed moisture removal and devolatilization stages, and maximum decomposition of the cake occurred at a temperature of 200-400 °C. The kinetic parameters such as apparent activation energy, pre-exponential factor, and order of reaction were determined using Friedman (FD), Kissinger-Akahira-Sunose (KAS), and Flynn-Wall-Ozawa (FWO) kinetic models. The average apparent activation energy values of 124.61, 126.95 and 129.80 kJmol-1 were calculated from the slopes of the respective models. The apparent activation energy values obtained depends on conversion, which is an evidence of multi-step kinetic process during the pyrolytic decomposition of the cake. The kinetic data would be of immense benefit to model, design and develop a suitable thermo-chemical system for the conversion of waste de-oil cake to energy carrier.

Kinetic studies on the pyrolysis of plastic waste using a combination of model-fitting and model-free methods

“…Pérez et al (2012), reported that E α values from the KAS method became larger than those from the Friedman method for α >0.65. In other literature (Sokoto and Bhaskar, 2018), the activation energy calculated using the Friedman method decreased with increasing α in the range 0.1-0.6, while the values derived from the KAS method were stable for α values of 0.1-0.15 and 0.2-0.4. A decrease in E α values was observed for α values of 0.4-0.6.…”

Bioenergy value of seed waste from the Mexican date (Phoenix dactylifera L.) industry

“…This temperature range is characterized by a large release of low molecular weight volatile matter. This is the most active region of pyrolysis, where thermal decomposition of hemicellulose, cellulose, extractive substances, and part of lignin occur (Ceylan & Topçu, 2014;Sokoto & Bhaskar, 2018). The loss of mass in the pyrolysis region was lower in the PDS sample, because the oil and other substances soluble in non-polar solvents were removed during the oil extraction process (White, 1987).…”