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Power Projects | September 2015

Clean Coal Technology, Low Carbon Power - are these Oxymorons?

Do you know about Kiribati? In case you do not, it is a nation of 100,000 people living on 32 atolls in the Pacific Ocean, feeling increasingly threatened by the creeping rise in sea water levels due to melting ice caps, caused in turn by the phenomenon known as global warming. Under the circumstances, the people of Kiribati are doing what they can do to save themselves-by seeking a global ban on expansion of coal mining. It is quite clear that different group of stakeholders are putting pressure on coal in their own ways, and the sum total of all these influences can be quite effective. Many organised financial bodies (semi-government or private) are gradually, but decisively disinvesting from the coal sector. Burning of coal is associated with emission of CO2 gas, which in turn is the cause of climate change. So, it is not a surprise that there is no dearth of people in this world today, who would wish coal to die an ignoble death, after reigning for more than three centuries as the ´King of Energy´.

In the last decade, the world has grown more sensitive to the reality of climate change. Fictional movies like Day after Tomorrow, documentaries like The Inconvenient Truth, award of Nobel Peace Prize to IPCC, and mandates like Kyoto Protocol have contributed to heightened awareness regarding CO2 issues, and helped bring this to the forefront of geopolitical debates. On the other hand, what does a poor farmer´s family in India´s rural hinterland care about CO2? The benefits of power have not reached him yet, also keeping him in the dark about global warming. He wants electricity and all things which are driven by electricity, and rightly, he could not care less about the melting ice caps. He also cannot be made to believe that his minuscule electricity consumption will contribute in any way to volatile monsoon patterns. But hold on - he has a vote, and therefore, his wish counts - and he is not alone.

Given India´s coal reserves and our need to make every Rupee of capex count more, only coal-based thermal power plants can fulfil the dreams of our power-hungry nation in the most capital efficient manner- much better and faster than other alternatives like nuclear power, hydro power, renewables, or even gas based power plants, each of which has some negative point. The bad news is, it also happens to top in CO2 intensity.

So, in the middle of this controversy, where does coal stand? Or, even more importantly for us, what can India do to meet its energy needs? What is the answer to this vexing conflict between our energy strategies and climate change imperatives? The answer lies somewhere in the middle. Adopting a low carbon strategy for thermal power generation, rather than a ´No-Carbon´ renewables only strategy, this will enable us to feed our grids, exploit our mineral wealth, leverage our strategic advantages, improve competitiveness of our energy sector and at the same time achieve our emission mitigation goals in INDC (Intended Nationally Determined Contribution). In our days, we heard a lot about low carbon steel, but low carbon power is definitely new, and needs some explaining.

Clean Coal Technology
Over the last 50 years or so, man has begun disliking the adverse impact of fossil fuels on our environment. This dislike, coupled with the continuous need to enhance efficiencies, has driven technological innovations in the apparently mundane field of coal fired power stations. In this series of developments, first came Clean Coal Technologies (CCT). At that time, in the eighties, hazardous gases and pollutants like oxides of nitrogen and sulphur, mercury, etc., were considered more harmful from ´acid rain´ perspective, and technologies such as Coal Gasification, Circulating Fluidised Bed Boilers, Low-NOx Burners, Selective Catalytic reduction, Flue Gas Desulphurisation, Wet Scrubbers, etc., emerged to eliminate these noxious gases from the chimney. Here, the focus was not so much on reducing CO2, but on eliminating the noxious elements which were also part of the basket of ´Green House Gases´. Then came the nineties, and the advent of super-critical boilers.

Super Critical Boilers/Power Plants
Though not in the class of a game-changer, super critical technology definitely has brought about a step change in thermal power generation, in terms of efficiency, and is consequently beneficial to carbon intensity.

Carbon intensity is the amount of carbon dioxide gas that is emitted for producing one unit of power (or cement, or anything, for that matter). Low carbon strategy for developing nations like India needs to aim for reduction in carbon intensities, as an effective middle-point between banning coal altogether and taking the country forward on the path of development.

Supercritical power plants have better thermal efficiencies, and thus, help us bring down carbon intensity by at least 8-9 per cent. In fact, ultra-supercritical plants (technology that has been recently commercialised) bring down carbon intensity by even 15-17 per cent over the base values. These significant improvements in power plant technologies have been made possible through advancements in metallurgical sciences, and more improvements can be expected in the future.

Carbon Capture and Sequestration
Clean Coal combustion as well as super critical power stations are surely steps in the right direction, but these are just steps. Carbon capture and sequestration (CCS) technology promises to be a disruptive change, a ´game changer´ shall we say, in the field of low carbon power. The research going on in this area aspires to capture up to 90 per cent of the CO2 that is emitted and store it in underground reservoirs, or absorb it gainfully in a chemical reaction process. When commercialised, this technology will have far-reaching consequences on the way we run our ´smoke-stack´ industries and simultaneously address environmental concerns. Path-breaking work has been done in this direction by SaskPower of Canada in their Boundary Dam Project, and by Mississippi Power of USA at Kemper County, among other pilot or commercial scale plants across the world - all of which are trying to commercially establish CCS Technology. We need CCS, and we need it fast.

So, with all these past and present advancements in science and technology, my case is that the proverbial smoke-stack will stay and thrive in India, for now - but I guess we may have less and less of ´smoke´ (CO2). And thereby, our next generations, who are expecting that we limit global temperature rises within 2 degrees till the year 2100, will not have much to complain about. And, maybe, the people of Kiribati will also rest easy.

After decades of slothful slumber, it is only now that our coal mining sector is waking up, and it would be a pity to put it back to sleep.

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