Saturday, March 19, 2005

Liquid fuel from waste plastic

The Hindu reports that a group of students from Velammal Engineering College, Chennai has discovered a process to convert waste polythene and polypropylene consisting mainly of discarded bags and biomedical waste into a kind of petrol and diesel through catalytic cracking.
Waste polythene and polypropylene — consisting mainly of discarded bags and biomedical waste — are subjected to `catalytic cracking' or breaking down the carbon chain. The correct ratio of the catalyst and the plastic materials are taken in the reaction flask to get greater yield.

When heated at 400 degrees Celsius, the plastic yields a distillate crude. Fractional re-distillation yields a type of petrol at between 100 to 120 degrees C and kerosene at between 150 to 180 degree C. Finally, the process leaves diesel as residue.

In about two hours, the students were able to generate around 2 litres of crude from 2.5 kg of plastic waste and through distillation one litre of petrol and half a litre each of kerosene and diesel. The cost works out to roughly Rs. 22 for petrol and Rs. 26 each for diesel and kerosene.

Sridhar says by heating plastic in the absence of oxygen, toxic dioxin emissions are also avoided, making the fuel eco-friendly. Even the left over paraffin mass (approximately 500 gm) can be made into candles.

In the recent months, the Engineering colleges in and around Chennai have been coming up with interesting gadgets, processes or concepts. The Hindu has been covering most of them in its City Column. There have been several interesting inventions in micro-machines, microprocessors etc. These inventions may probably qualify only as toy-gun stuff, but what is gratifying is to see the engineering students jumping in to develop such interesting things and choosing them as projects. When I studied in IIT Madras we did nothing of this kind. We worked on boring and useless theoretical topics as our B.Tech projects.

News coverage in The Hindu shows that these developments are in fact coming from self financing engineering colleges with no Government support. The teachers in these colleges must be quite average, and are probably paid low salaries. This shows that the students should be quite smart and tenacious in wanting to do something unique and challenging. Good luck to them.


  1. The internet has really made a big difference in the approach of the students. I agree with you that the students are trying lots of new things. In fact there are even a lot of "project consultant" companies. These companies give you everything from the project proposal to the report. I know lots of people who have taken their consultance. I am sure they must be having double digit growths.

  2. Badri,

    This is an interesting trend and should be encouraged. If this continues, it is likely that an important invention may happen, which in turn will fuel further research.

    In line with what you mentioned about your theoretical projects, research in medicine is virtually non-existant in India. Although Biotech and pharma companies have sprung up, their major work is on generating generic versions of molecules invented somewhere else. Barring a few rare instances, most work is just replicating someone else's prescription. In the western world, higher degrees in medicine are all research-oriented when our higher medical degrees are theoretical and clinical with no emphasis on research. No teaching medical institutions (including AIIMS) offer primarily research-led degrees. Newer molecules evolve by careful study of human disease and this can only happen in educational institutions. If we dont get our act together, our new-found enthusiasm in biotech may be just a passing cloud.

  3. hi badri

    u should check out what the hobbies club at IITM are starting out with.

    maybe u can help and provide support

  4. While it is gratifying to see inventions from these colleges, the trend among students to "outsource" or use consultancy services for their projects is disturbing. There is a huge business to do the projects completely, from the ideas to implementation, aimed at these engineering college students.

    I attended a self financing college and though we wanted to innovate, there was very little incentive to do so. Hardly companies hire from these colleges directly. I hope the companies value the students' creativity and hire them.