Several times this question has been raised : How can we produce bio-diesel ? Which plants can provide bio-diesel ? What is bio-diesel ? Some of the quick answers are : 1. What is biomass which you want to use to produce bio-diesel: Generally there are three categories of biomass which could be used to produce bio-diesel: a. Biofuel plants, plant pellets, bio-waste etc can be converted in to bio-fuel which can be eventually converted into bio-diesel by using simple process of vaccum pyrolysis. b. Non edible seed oil plants : Jatropha, Pongamia or any other non edible oil producing plant which can grow well in "wasteland" and does not create food vs fuel crisis, is ideally suited. However one needs to develop agrotechnology for their mass propagation otherwise it will meet a failure. Many immature attempts have resulted in poor yields . We have been working in this area in University of Rajasthan system and Govt of India supports can claim to have technologies which still need perfection as climatic conditions , germ plasm , soil are major players and productivity shall vary from region to region. c. Hydrocarbon yielding plants : Laticiferous plants have triterpenoids which can be converted into petroleum , bio-diesel etc using Zeolite catalyst and hydro cracking technology. d. Any fatty material, tallow etc can be trans esterified as basically biodiesel is methyl ester of any fatty acid like rapeseed methyl ester ( RME) . e. Any use of oil plam or edible oils for bio-diesel production is not advisable in my opinion as feeding cars or feeding hungry people can not be done at the cost one another. Next generation biofuels are based on conversion technologies for conversion of ligno cellulose from Miscanthes or other plants . However these technologies are far from perfect and BP has invested more than 500 million US dollars. Results ?????, (I would like to know if there are any positive indications of commercial success). G biotechnology has a major role to play for future .