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Interview – Biodiesel Cars for Sustainable Transportation


Interviewee: Avinash Narayanaswamy

Energy Review, Vol 4. Issue 8. 2022

Energy Review: As a sustainable development practitioner, can you explain the various advantages of biofuel transportation over other energy-efficient and low-carbon transport vehicles? Mr. Narayanaswamy: The various advantages biofuel transportation has to offer include - most importantly - a cleaner environment owing to lesser harmful emissions, as well as energy security for the country, job opportunities for the local population, and mitigation of climate change. I may add that the advantage of biofuels over electric vehicles remains only as long as the operating costs are lower.

Biofuels can be used in existing infrastructure, such as engines, generators, pump sets etc., with hardly any modifications. But in the case of electric vehicles, though they are efficient in operations, the existing electrical grid cannot support a huge input of electric vehicles as the demand for electricity in our country is still greater than the supply. Also, as India is a coal-dependent country, majority of the electricity produced is heavily carbon intensive, thus, electric vehicles charged under such conditions is counter-productive as far as climate change mitigation is concerned

Mr Narayanaswamy uses a self-made bio-CNG based engine in his car

ER: Given your experience using cars powered by self-made biofuels, what do you think are the major technological impediments in fulfilling the well-to-wheel energy requirements of such vehicles? Mr. Narayanaswamy: In the majority of diesel automobiles today, rubber parts are mostly absent. Rubber parts, if there are any, can be replaced with silicone rubber parts, which are completely resistant to biodiesel, unlike ordinary rubber.

Biodiesel, owing to a higher cloud point, tends to gel at lower temperatures (typically less than 12℃), which is a major problem in cold countries or at places located at high altitudes. Cold start problems are another issue with biodiesel. Cold start problems concern the ability of a fuel to ignite in an engine at low temperatures. Since biodiesel is slightly more viscous compared to the conventional diesel, it may cause cold start problems. In colder conditions, biodiesel gains viscosity and may not flow well. In such cases, a supplementary fuel with low viscosity and lower ignition temperature may be introduced to start the engine, after which biodiesel would be introduced as a blend with conventional diesel. Further, glow plugs are provided to avoid or minimize the problem in such weather conditions.

Usage of biodiesel as it is in diesel engines is another problem since it can cause lower pickup and mileage drop. When combined with conventional diesel (up to 20%), one may not observe much difference from a vehicle that is fully based on conventional diesel. Apart from these, no major technological impediments have been observed in my experience. ER: Apart from bio-diesels, what other alternative fuels do you predict will drive the sustainable transportation sector towards low carbon development pathways in the near future? Mr. Narayanaswamy: Specifically, in India, ethanol derived from biomass (India is rich in biomass, being an agricultural economy) holds a lot of promise as outlined by the Government of India. Hydrogen and fuel cell-based technologies are also great options as their cost effectiveness is slowly but surely being proved. The Indian government also strongly advocates the use of biofuels, and not just bioethanol or biodiesel, but also biogas and bio-CNG. (Mr. Avinash Narayanaswamy is the CEO of Green Law, an eco-based partnership firm incubated at the Centre for Incubation, Innovation, Research & Consultancy (CIIRC), Bengaluru. He is also currently working as an Assistant Professor at CIIRC.) ■□■


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