Effect of process conditions on the removal of phospholipids from Jatropha curcas oil during the degumming process

Abstract

This work aims to study the removal of phospholipids from Jatropha oil through a conventional degumming process combined with ultrafiltration membrane separation in a small-scale batch system. The effect of temperature, amount of acid solution added, and speed of centrifugation during the conventional degumming process were analyzed using response surface methodology (RSM). The optimum operating condition was determined to be at 65°C, with 4wt% acid solution added and a centrifugation speed of 1600rpm. After the degumming process, the phospholipid content of Jatropha oil was reduced from 1200ppm to 60ppm. This was further reduced to less than 20ppm by subjecting the oil to ultrafiltration membrane separation. It was found that the entire process not only decreased the phospholipid content of the oil but also improved its fuel properties, especially its kinematic viscosity and carbon residue. The kinematic viscosity was decreased from 30.02cSt (mm2/s) to 27.20cSt, while the carbon residue was decreased from 7.8% to 4.0%. Aside from the phospholipid content, the other two properties mentioned above were also considered to be important in the use of pure plant oil as a fuel in diesel engines. Future research could investigate the integration and optimization of the conventional degumming process combined with a membrane separation process.