Integrated Coal Gasification Combined Cycle (IGCC) plant and green hydrogen

Integrated Coal Gasification Combined Cycle (IGCC) plant and green hydrogen

Subject: Environment

Section: Climate Change

Context:

Emphasising that green hydrogen will play a crucial role in India’s energy transition, noted scientist and NITI Aayog Member VK Saraswat said it is the future fuel.

• Green hydrogen is not economical, but with technologies such as Carbon Capture Utilisation and Storage (CCUS), grey hydrogen can be made environment friendly

Green Hydrogen:

• Hydrogen is one of the most abundant elements on earth for a cleaner alternative fuel option.
• Green hydrogen is produced by electrolysis of water using renewable energy (like Solar, Wind).
• Electricity splits water into hydrogen and oxygen.
• By Products : Water, Water Vapor.
• Green hydrogen can drive India’s transition to clean energy, combat climate change.
• India has a favourable geographic location and abundance of sunlight and wind for the production of green hydrogen.

How to reduce CO2 emissions for energy transition?

• From models developed by bodies like the IEA or the NITI Aayog, it is clear that thermal power plants(TPP) are still relevant for meeting demand. Since India does not have large quantities of gas, our thermal power will have to come from coal.
• g , the estimation is that even by 2070, around 8-10 per cent of power will come from coal. It can not be wished away, but it pollutes.
• To check emissions is to increase the efficiency of plants. One way is that instead of running subcritical power plants, India should go for super critical, ultra-supercritical, and advanced ultra-supercritical plants. India has already developed the technology for advanced ultra-supercritical plants.
• India can replace aged TPPs, with an installed capacity of around 25 gigawatts (GW), with new plants. Since the base load issue is there, replacement will be with Integrated Coal Gasification Combined Cycle (IGCC) plants and advanced ultra-supercritical plants.
• With this, India’s efficiency will be more than 45 per cent and emissions will go down by 40- 50 per cent, as far as TPPs are con- cerned.
• India should also integrate the thermal plants with carbon capture utilisation and storage. With this green- house gas emissions, particulate matter etc will reduce to less than 1 percent.

What is Integrated Coal Gasification Combined Cycle (IGCC) plants?

• An integrated gasification combined cycle (IGCC) is a technology using a high pressure gasifier to turn coal and other carbon based fuels into pressurized gas—synthesis gas (syngas). It can then remove impurities from the syngas prior to the electricity generation cycle.
• It is a technology that aims to extract the maximum energy out of a fuel that is burnt. In the case of coal, the carbon conversion efficiency in an IGCC plant is significantly higher than that in a conventional pulverised coal (P.C.) fired power plant.
• This is achieved by gasification, which converts coal into synthetic gas or syngas. Syngas is a mixture containing mainly carbon monoxide (CO) and hydrogen (H2) and some carbon dioxide as well.
• In an IGCC plant, high temperature syngas from the gasifier is used to run a gas turbine (G.T.) that generates power. This syngas may also be blended with natural gas, if required, to improve its calorific value.
• The waste heat in gasification and the hot gas coming out of the G.T. are further utilised to produce steam by heating water, which in turn runs a steam turbine to produce additional electricity.