The chances to reduce emissions through coal gasification are very remote, says CSE
The Centre’s announcement on coal gasification-pilot projects in the Union Budget 2022-23 is contrary to Delhi-based non-profit, Centre for Science and Environment (CSE)’s assessment about the process not being attractive from a climate change point of view.
“Four pilot projects for coal gasification and conversion of coal into chemicals required for the industry will be set up for technical and financial viability,” Union finance minister Nirmala Sitharaman said while presenting the budget in the Lok Sabha February 1, 2022.
However, coal gasification actually produces more carbon dioxide than a conventional coal-powered thermal power plant, according to CSE’s assessment.
Also, coal gasification plants are costlier than conventional power plants. Since, coal is the main feed for gasification, it, in no way helps in India’s decarbonisation goals.
According to CSE estimates, one unit of electricity generated by burning gasified coal generates 2.5 times more carbon dioxide than what would result when burning the coal directly.
“The emission ratio comes around to 800 million tonnes of CO2 per kilo joule for coal-based power stations and 1,974 million tonnes of CO2 per kilo joule for coal gasification plants. The same is the case for steel plants.” Parth Kumar, deputy programme manager, industry pollution unit, CSE, said.
Steel companies typically use coking coal in their manufacturing process. Most of the coking coal is imported and is expensive. To cut costs, plants can use syngas, which comes from coal gasification plants in the place of coking coal. Although they might financially effective, these coal gasifier using steel plants have higher greenhouse gas emissions than many of their counterparts. Their emissions range 2.8-3.1 tonnes of CO2 per tonne of steel manufacture while the sector average emissions is only 2.5.
Coal gasification is a process in which coal is partially oxidised with air, oxygen, steam or carbon dioxide to form a fuel gas. This gas is then used instead of piped natural gas , methane and others for deriving energy.
International studies have also reiterated the same.
A recent study by the Princeton University in the United States found that using synthetic natural gas for residential cooking and heating, for electricity generation, or for industrial heat generation, results in 10, 40 and 70 per cent more CO2 emissions than directly burning coal that provides the same amount of energy in each sector.
According to a study by Duke University in the US, the syngas process converts a relatively high-quality energy source (coal) to a lower quality state (gas) and consumes a lot of energy in doing so.
Thus, the efficiency of conversion is also low. From an environmental perspective, the CO2 emissions from syngas production are much higher than conventional natural gas and worse than burning coal for power directly.
Coal gasification is prominent in China. Five per cent of China’s total coal consumption is from its gasifier.
China has the biggest number of coal gasification projects in the world due to the support of the Chinese Government through its 9th-12th Five-Year Plans.
Other Asian countries such as Japan are focusing on more efficient power generation cycles; for instance, coupling gasification with fuel cells.
The US has some coal gasification plants running. The Queensland Government in Australia announced the decision to prohibit all underground coal gasification activities and the in situ gasification of oil shale in April 2016.
The Queensland Parliament passed legislation August 24, 2017, which places a moratorium on all activities relating to underground coal gasification.
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