ALTERNATIVE ENERGY POSER

Janaka Perera makes a case for alternative fuels in the transportation sector

The energy implications of the war in Ukraine illustrate the many costs of oil reliance. Increasing air pollution and rising global temperatures make transformative changes in transportation – especially urban transport – vital.

One approach that’s underway is electric mobility and hydrogen-powered propulsion systems that can complement this technology. In this case, hydrogen is used either to power a combustion engine or converted into electricity using a fuel cell.

Hydrogen variants have several advantages over electric vehicles (EV). For example, they have an operating range of between 400 and 750 kilometres – greater than any current EV – and only need three to four minutes to refuel.

The necessity for alternative energy sources to meet Sri Lanka’s transport needs has been long felt. With the advancement of science and technology, many countries are seeking fuels that can replace petrol and diesel.

While the continued rise of EVs represents the most visible effort in the public’s mind, vehicle manufacturers are not alone in their plans to bring low or zero emission transport options to market.

Some of the fuel substitutes under consideration are biogas, hydrogen and vegetable oil. The question is this: which of these will be available in sufficient quantities to meet our transport needs?

Bioethanol is a good substitute for petrol. Experts claim that spark ignition engines can utilise bioethanol well because of its characteristics. Its flammability limits are broader, flame speeds are faster and the octane number is higher.

These characteristics enable shorter burn times and higher compression ratios that are ideal for internal-combustion engines of petrol vehicles. However, ethanol has lower energy density and a higher evaporation rate. So it’s best to mix ethanol with petrol (blends of various ratios) to harness its benefits and reduce or eliminate disadvantages such as lower energy density.

Experiments have proved that fuel grade ethanol sources such as sugarcane can be cultivated locally for at least the partial replacement of petrol by using blends. Local sugar production will also increase as a result of this – and this will reduce foreign exchange outflows for the importation of petrol and sugar.

Brazil is already using various blends of ethanol that have been sourced from its large-scale sugar industry and the product is being sold under the brand Gasohol. The US uses ethanol derived from its large corn (maize) industry for biofuel blends.

Large-scale cultivation and extensive production of oil-bearing crops are needed to partially replace diesel or make biodiesel blends.

Sri Lanka is a densely populated country with limited land for cultivation of non-food crops. The only potential non-edible oil feedstock currently available for the manufacture of biodiesel on a reasonable scale is rubber seed oil (RSO) due to a vibrant rubber industry.

To this end, the Department of Chemical and Process Engineering at the University of Moratuwa carried out research on biodiesel production using coconut; rubber, Jatropha and neem seed; and waste cooking oils.

Studies need to be undertaken to assess the economic feasibility of bioethanol and biodiesel production. This calls for a knowledge base and capital investment, which is beneficial in the long run.

R&D must be carried out to ascertain the feasibility of biofuels in Sri Lanka for energy security. The Sri Lanka Institute of Nanotechnology (SLINTEC) states that the production of bioethanol or biodiesel on a large scale could be a key solution to the global energy crisis.

Meanwhile, the National Engineering Research and Development Centre (NERDC) has tested vehicles with blends of coconut oil (straight oil) and petro-diesel.

In Roadmap Gas, a project on behalf of the German Environment Agency (UBA), the Fraunhofer Institute for Systems and Innovation Research revealed that hydrogen is of importance principally in areas where it’s difficult to use electricity directly.

While battery-powered vehicles are preferable for short trips and urban driving, hydrogen vehicles perform better over distances that range between 250 and 300 kilometres.

Proper infrastructure must be established if hydrogen vehicles are to make their mark in this country. When hydrogen is used directly in fuel cell vehicles, the three major considerations are efficiency, safety and reliability.

Investing in mass transport, walking and cycling should be on the agenda of every government – not only because these are the cleanest, least expensive and most inclusive modes of transport; but also because of less traffic congestion and noise, cleaner air, and healthier and more active citizens.

Active mobility and mass transport can enhance the quality of life of Sri Lankans, by helping turn cities into more liveable and equitable places. Cutting the transport sector’s ties with fossil fuels permanently should be the ultimate goal.