Singapore is taking steps to study how planet-warming carbon dioxide (CO2) from natural gas power plants can be captured and locked away, as the Republic is likely to continue relying on fossil fuel over the next few decades.

Natural gas is expected to continue to power more than 50 per cent of Singapore’s energy needs by 2035. Currently, it represents more than 90 per cent of the electricity mix, with the energy sector accounting for around 40 per cent of greenhouse gas emissions.

The Energy Market Authority (EMA) has issued a grant call to study two methods of deploying carbon capture and storage (CCS) technologies in the sector to remove carbon emissions and store them in deep underground structures, Deputy Prime Minister Gan Kim Yong announced on Oct 21 at the Singapore International Energy Week.

The first method involves installing an on-site unit to capture CO2 from exhaust gas, after natural gas has been combusted.

The waste gas typically contains CO2, water vapour, nitrogen, and oxygen.

The Straits Times previously reported that research is underway to determine the most cost-effective way of capturing CO2 from the natural gas plants, as its low concentration in exhaust gas makes it difficult to extract.

The other technique involves capturing the CO2 generated when hydrogen is produced from natural gas.

The hydrogen can be combusted to generate electricity and does not produce any CO2 when burned.

But it is considered a clean fuel only if no CO2 is emitted in its production process.

From 2024, all new and upgraded natural gas power plants must be able to run on at least 30 per cent hydrogen and be retrofitted to run on 100 per cent in the future.

In tandem, the Singapore Government is developing a CCS project to collate CO2 emissions on Jurong Island for overseas storage, with the first phase likely to start around 2030.

It is looking to collaborate with Indonesia, which has passed a law to allow CCS operators to set aside storage capacity to lock away CO2 from international entities.

The Government is partnering with an industry consortium formed by ExxonMobil and Shell, known as S Hub, to evaluate the technical and economic feasibility of cross-border CCS projects.

S Hub has plans to develop a CCS project that can permanently store 2.5 million tonnes of CO2 a year by 2030, either in rock formations deep underground or under the seabed.

If the power sector succeeds in capturing its emissions, it would be able to leverage future phases of the cross-border CCS project on Jurong Island, EMA said.

Delivering the Singapore Energy Lecture, DPM Gan noted that a study by consulting firm McKinsey has identified 12 categories of climate technologies that would potentially reduce more than 90 per cent of total man-made greenhouse gas emissions by 2050 if deployed extensively.

Of these, commercially viable technologies, such as solar and hydropower, will reduce only about 10 per cent of emissions.

An additional 45 per cent must come from technologies that require support to be competitive, including offshore wind and biofuels.

Another 40 per cent depends on technologies such as CCS, which have been proven in prototypes but have not yet been deployed at scale, DPM Gan said at the Sands Expo and Convention Centre.

Experts previously told ST that the cost of a CCS project can be very high, with the carbon tax not being sufficient to make such projects economically attractive. By 2030, Singapore’s carbon tax will be set at between S$50 and S$80 per tonne of CO2, up from S$25 per tonne currently.

The Republic plans to reach net zero emissions by 2050 and is studying the viability of other clean technologies such as geothermal and nuclear.

Mr Alvin Ee, a research fellow from the NUS Energy Studies Institute, previously told ST that the weighted average cost of capturing carbon from industrial sources is around US$85 (S$110) per tonne of CO2, while shipping could cost an additional US$16 to US$31, and storage between US$3 and US$31.

Conventional methods to capture CO2 from natural gas involve using chemical compounds to absorb CO2 from the exhaust gas mixture. But some of these solutions can be corrosive and pose a risk to human health.

Research and development has also been underway to come up with new CCS techniques for power plants here.

For example, scientists at NUS are using sponge-like materials, also known as metal organic frameworks, to selectively absorb CO2 at a waste-to-energy plant in Tuas South.

Another group of scientists from NUS are testing the use of membrane technology – typically used for water filtration – to capture CO2 molecules from power plants.

Generation companies keen to participate in EMA’s grant call must have completed a pre-feasibility study for either post-combustion or pre-combustion carbon capture at their power plants.

Their proposal must be evaluated based on three criteria: the amount of additional land required, the quality of the proposal, and the funding requested from EMA.

Proposals must be submitted to the authority by 31 January 2025.

Source: The Straits Times ©️ SPH Media Limited. Permission required for reproduction.