(Picture credit: EMA)

With the increased energy demands of developing countries and reduced global energy supplies, the US is now making a concerted effort to develop alternative energy supplies. Corn ethanol is one such entry point into biomass-produced energy, cited Ms Kathleen Robbins from Jatrophe Pepinye at a Clean Energy Expo Asia session on renewable fuels.

She shared that a six-fold strategy at a US$3.08 billion budget has been adopted by the US, centred on balancing rising energy demands with equivalent sources of supply for both stationary use as well as transport fuels.

As coal comprises the largest proportion in the supply chain, with natural gas picking up, more supply sources would need to be explored. Stationary solutions could include deploying cleaner electricity, modernising the grid, as well as increasing building and industrial energy efficiencies. As for transportation, deployment of alternative hydrocarbon fuels would be a key development, with other potential solutions including electrification of vehicle fleets and improvement of vehicular fuel efficiency.

Large-scale waste-to-energy plants for commercialisation

At high operating temperatures, plasma gasification of waste and other organic material produces synthetic gas (syngas) can be used to produce electricity and heat, and through other processes, be transformed into liquid biofuels without polluting the environment, explained Mr Zdenek Sima, Export Director, Solena Group.

Such applications can produce from 5 to 100 tonnes of fuel per hour, with the smallest installations capable of at least 8MW of electricity and 16GJ of heat energy. Larger units can even convert syngas to liquid fuel, which is a potential cost-savings solution, with up to 30 million pounds per year saved through a reduction in landfill use.

Algae fuel the way forward

While first-generation biofuels have been around, they are seen as a competing source of food and thus not suitable as substitutes for fossil fuels. As second-generation biofuels are generally finite, third-generation algae biofuels are seen to have the greatest potential for future large-scale deployment, observed Dr  Lee Yuan Kun from the National University of Singapore.

In contrast to the first- and second-generation biofuels, which require significant land space for crop cultivation, third-generation algae biofuels would be more suited for space-constrained Singapore. And compared with oil palm, which would need an area at least 200 times Singapore's land size to completely satisfy the city-state's diesel requirements using biodiesel, algae biofuel developments are much more compact.

Algae also has a much higher growth rate and 30 times more yield over higher plants. Algae is also ideal for efficient production of bioenergy. However, cost will ultimately be the key consideration for deployment. Hence, test-bedding and further studies of third-generation algae biofuels should be conducted in the meantime.