Dark fermentation could be key to Malaysia’s green hydrogen future

By: Ts. Dr. Hassan Mohamed

As the world fights the escalating climate change crisis and the urgent need to transition to more sustainable and cleaner energy sources, harnessing the power of hydrogen has emerged as a promising solution. Credited as the fuel of the future, hydrogen’s energy density is significantly higher than other standard fossil fuels. To put into perspective, its energy density of 141.9 MJ/kg far surpasses methanol (20 MJ/kg), diesel (44.8 MJ/kg), gasoline (47.5 MJ/kg), ethane (51.9 MJ/kg), and methane (55.5 MJ/kg).

In a statement read by Science, Technology and Innovation Minister Chang Lih Kang at the National Science Centre on 7 June 2023, Malaysia’s Prime Minister, Datuk Seri Anwar Ibrahim, affirmed that the market for green hydrogen alone is expected to reach a remarkable US$ 189.19 billion. Furthermore, under the proposed Hydrogen Economy Technology Roadmap (HETR), around 45,000 job opportunities are expected to be created, reinforcing the country’s Low Carbon Aspirations 2040 under the 2022–2040 National Energy Policy and its commitment to sustainable development.

Despite these optimistic projections, the current production methods of hydrogen, which are expensive and heavily reliant on fossil fuels, present significant challenges. As reported by the International Energy Agency, in 2020, the demand for hydrogen was 90 Mt, primarily generated from fossil fuels: 79% from dedicated hydrogen production plants and 21% as by-products from gasoline refining processes. The conventional ‘grey’ hydrogen production process produces significant carbon dioxide emissions, mainly from natural gas through steam methane reforming. ‘Blue’ hydrogen, albeit cleaner than grey hydrogen, still involves fossil fuels but uses carbon capture and storage (CCS) technologies to lessen the environmental impact. The cleanest of all is ‘green’ hydrogen, produced from water electrolysis powered by renewable energy sources, resulting in zero carbon emissions during operations. Indeed, various colours of hydrogen have been identified in many prior research works, each representing a different production method and associated environmental impact.

Nevertheless, the quest for greener and more sustainable hydrogen production methods continues, and one such promising approach is dark fermentation. Think of dark fermentation as composting. Just like composting turns our garden and kitchen waste into rich soil, dark fermentation uses microbes to turn waste materials, like leftover crops, food waste, and sewage, into hydrogen gas. It is like we are recycling our waste into something valuable. Here is a neat way to imagine it: we are putting nature’s tiny helpers – bacteria – to work. We give them our waste, and in the dark, these bacteria start to break down the waste.

Just as our bodies break down food, these bacteria break down waste, producing gases in the process. Among those gases is hydrogen. We can capture this hydrogen as a clean, renewable energy source. In other words, we are converting what we often discard into a source of clean energy because of these tenacious microorganisms. It’s easy, eco-friendly, and helpful as we transition to cleaner, greener energy sources.

However, some technical challenges persist in the dark fermentation process. One notable concern is the relatively low hydrogen yield, which necessitates a substantial amount of raw materials to generate only a modest quantity of hydrogen. This has significant implications for the process’s efficiency and scalability. Furthermore, precise control of fermentation conditions is crucial to optimise microbial activity. The microorganisms involved are sensitive to temperature, pH, nutrient availability, and waste product concentrations. Maintaining optimal conditions for their health and productivity can be demanding and costly, as even slight deviations can diminish system efficiency or halt hydrogen production entirely.

To address some of these obstacles, researchers at the Institute of Sustainable Energy (ISE) Universiti Tenaga Nasional (UNITEN) and France’s National Research Institute for Agriculture, Food, and the Environment (INRAE) have collaborated on an innovative approach that combines dark fermentation with lactic acid storage. This integration has yielded a significant 57% increase in the maximum hydrogen production rate for stored waste, paving the way for improved efficiency and viability in green hydrogen production.

In parallel, in collaboration with the Fuel Cell Institute at Universiti Kebangsaan Malaysia (UKM), we are also investigating the coupling effect of the dark fermentation process with a microbial electrolysis cell (MEC). By optimizing the interaction between dark fermentation and MEC, the research team anticipates achieving higher hydrogen production rates and further advancing the efficiency of green hydrogen production.

With international and local collaborative efforts, we are driving the advancement of green hydrogen production through dark fermentation for hydrogen generation, aligning with the government’s aspirations for the Hydrogen Economy Technology Roadmap (HETR). Our initiatives represent significant strides towards a greener and more sustainable future, reducing our reliance on fossil fuels.

Let us continue exploring and innovating, working towards a cleaner future.

(The author is a Senior Lecturer at the College of Engineering. He is certified Energy Manager and is attached with the Institute of Sustainable Energy (ISE), Higher Institution Centre of Excellence (HICoE), Universiti Tenaga Nasional (UNITEN). He may be reached at [email protected])

-DG