Fruit bunch on naturalized tree of Jatropha curcas or "physic nut", a promising biofuel plant. Couple of weeks ago Jatropha oil was used by IndianOil in experimental co-processing in a petroleum refinery to produce biodiesel. (Credit: Flickr @ Ton Rulkens http://www.flickr.com/photos/47108884@N07/)
The Indian Oil Corporation Limited—an Indian state-owned oil and gas corporation—has successfully developed and commercialized a technology to co-process non-edible vegetable oil in the existing diesel hydrotreating (DHDT) units of a petroleum refinery to make biodiesel. This is the first time in India when jatropha oil has been used for co-processing in a petroleum refinery. This technology for co-processing of jatropha oil has been developed by the R&D Center of IndianOil located at Faridabad.
Jatropha curcas is a species of flowering plant in the genus Jatropha in spurge family, Euphorbiaceae, that is native to the American tropics, most likely Mexico and Central America. It is cultivated in tropical and subtropical regions around the world, becoming naturalized in some areas. Currently the oil from Jatropha curcas seeds is used for making biodiesel fuel in Philippines, Pakistan and in Brazil, where it grows naturally and in plantations in the southeast, north, and northeast of Brazil. Likewise, jatropha oil is being promoted as an easily grown biofuel crop in hundreds of projects throughout India and other developing countries.
During the development of this process technology, IndianOil has also developed a process for demetallation and degumming of vegetable oils. It should be noted that the demetallation of oils is a prerequisite for the сo-processing since metals have a negative effect on the catalyst in a DHDT unit.
A total quantity of 200 tonnes of Jatropha oil was supplied by CREDA Biofuels Limited (A JV of Indian Oil and Chhattisgarh Renewable Energy Development Authority). This oil was used for the demetallation and degumming using IOC—R&D developed process and subsequently co-processed in the Chennai Petroleum Corporation Limited (CPCL) refinery at Manali. Successful co-processing was demonstrated in the DHDT Unit of the refinery. Operating with a specific catalyst developed by the R&D Centre of IndianOil, the DHDT unit used up to 6.5% of jatropha oil along with refinery stream. During the trial, the diesel cetane number improved by 2 units and its sulfur content was reduced. Moreover, the inlet temperature of the reactor could also be reduced by 100°C, therefore increasing energy efficiency.
Conventionally, biodiesel is produced by the transesterification process which requires a separate plant to be set up. Biodiesel produced through transesterification route has inferior oxidation stability, lower energy content and causes more deposits in the engine. Because of that, such biodiesel is not accepted very well by the automotive industry.
However, the novel co-processing technology developed by IndianOil overcomes these disadvantages and produces biodiesel with higher cetane number, good oxidation stability and lower density. In addition, co-processing technology can be deployed in an existing petroleum refinery infrastructure with minor modifications and does not require a separate plant. This process also costs less as operating cost is reduced by ~50% in comparison to a conventional biodiesel plant.
