By Rathindra Kuruwita

Hydrogen an important clean energy source of the future, Sri Lanka can produce 10 tonnes of it a day from municipal solid waste, Eng. Ruwan Nagahawatte, head of the mechanical engineering sectional committee of the Institution of Engineers Sri Lanka (IESL) said.

Nagahawatte said hydrogen is a clean alternative to methane, also known as natural gas. Hydrogen is the most abundant chemical element, estimated to contribute 75% of the mass of the universe. According to a 2023 McKinsey analysis, hydrogen could contribute to more than 20 percent of annual global emissions reductions by 2050.

As of mid-2023, over 1,000 large-scale hydrogen projects have been announced worldwide, totaling $320 billion in direct investments. In Europe alone, $117 billion has been invested in hydrogen projects so far. According to McKinsey, hydrogen is expected to play a crucial role in achieving decarbonization targets in the region.

Hydrogen can be produced from a variety of resources, such as natural gas, nuclear power, biogas and renewable power like solar and wind. The challenge is harnessing hydrogen as a gas on a large scale to fuel our homes and businesses, he said.

Hydrogen can also be produced through methane that can be generated by solid waste. Western province alone generates 300 tonnes of biodegradable municipal solid waste a day and this can be used to produce 7.2 tonnes of methane per day.

“This in turn can be used to produce two tonnes of hydrogen a day. We are talking about the western province alone. With efficient collection of biodegradable waste, Sri Lanka can produce 10 tonnes of hydrogen a day. Sri Lanka can generate over 3,000 tonnes of hydrogen per annum while providing a solution for municipal solid waste disposal. The project needs an investment of 11 million U.S. dollars but the annual revenue generation is expected to be 4.5 million dollars,” he said.

Eng. Nagahawatte, however, pointed out that there are some engineering challenges in the production of hydrogen. The production of hydrogen needs ultra-pure water, a high-grade water that’s free from impurities like microbes, minerals, and dissolved gases through high levels of purification.

“Generating this water is more difficult than producing hydrogen,” he said.

The Head of the Mechanical Engineering Sectional Committee added that hydrogen also needs to be stored below minus (-) 253 centigrade in insulated tanks to maintain this temperature and minimize evaporation. These temperatures are called cryogenic temperatures, i.e., the temperature at which molecular motion comes as close as theoretically possible to ceasing completely.

Eng. Nagahawatte added that hydrogen must be stored at high pressure (350-700 bars) but the technology is improving and that the cost of capital is decreasing rapidly, making it affordable.

“Despite all challenges, the world is very much enthusiastic about hydrogen. This is because of high value as well as environmental considerations. We can start small. We can actually start producing methane first and sell it to consumers. Methane is natural gas, the only difference between this and what we have in cylinders is that this is not liquefied,” he said.