Parametric studies on Pyrolysis of Jatropha oil cake in fluidized bed reactor

Abstract

Jatropha oil cake is rich in nitrogen, phosphorous and potassium. It can be used as organic manure. Jatropha oil cake is chosen for study because it is a non edible material and cannot be used as cattle feed. It contains valuable materials such as char, liquid, and non condensable gases. Pyrolysis is one of the thermo chemical conversion processes. Usually solid residue, liquid, and non condensable gases are the three products obtained from pyrolysis process. The preferred technology for production of oily products is fast or flash pyrolysis at high temperatures with very short residence time of vapours in the reactor.. To get maximum oil yield flash pyrolysis process was carried out. The oil content is 25-30 % in the jatropha seeds. Fluidized bed flash pyrolysis experiments have been conducted on a sample of jatropha oil cake to determine particularly the effects of particle size, pyrolysis temperature and nitrogen gas flow rate on the product yields. The particle size, pyrolysis temperature and nitrogen gas flow rate were varied from 0.3 to 1.4 mm, 400°C to 550°C and 1.25 m³/ h to 2.4 m³/ h. The maximum oil yield of 54.8 wt % was obtained at a nitrogen gas flow rate of 2.0 m³/ h, particle size of 1.0-1.18 mm and pyrolysis temperature of 500°C. The maximum gas yield of 46.0 wt % was obtained at particle size of 0.3-0.6 mm, nitrogen flow rate of 1.75 m³/ h and at a temperature of 500°C. The maximum char yield of 14.1 wt % was obtained at a temperature of 400°C, particle size of 1.18-1.4 mm, and at a nitrogen gas flow rate of 1.25 m³/ h. The gross calorific value of pyrolysis oil was found to be 19.66 MJ/kg. The calorific value of jatropha oil cake was found to be 13.6 MJ/kg. The gas fractions were obtained using gas chromatography. The pyrolysis gas fractions were found to contain hydrogen, methane, nitrogen, oxygen, carbon dioxide and carbon monoxide.