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Showing posts with label Super critical CO2 power cycle. Show all posts
Showing posts with label Super critical CO2 power cycle. Show all posts

Friday, April 19, 2019

Why Carbon is inevitable to achieve Zero Carbon emissions?

Generating electricity using fossil fuel is a well-established technology, that has been practiced over several decades all over the world, despite its low efficiency. But this technology inherited certain disadvantages even before it was commercialized such as post combustion emissions, large amount of waste heat, and water intensity. Millions of people died of Carbon pollution over decades. Large scale usage of water both inland and on shore power stations created shortage of drinking water in many parts of the world resulting in desalination technologies creating its own environmental issues. Large scale mining of coal and unsustainable exploitation of oil and gas both on shore and off shore caused enormous environmental pollution. However, such emissions were completely ignored while the world celebrated the discovery of electro-magnetism, steam engine and petrochemicals. Millions of people were employed, and industries grew worldwide. Energy became synonymous with security of a nation. Population grew exponentially. However, we have reached a point in the history of mankind and all great discoveries once acclaimed as human achievements have started a new painful chapter of warming globe and changing climate for new generations to deal with. It is a great challenge of our time, but new generation can take this challenge and convert them into opportunities. The past lessons can show them a new clean and sustainable pathway while dealing with ever increasing population growth. The challenge for the new generation is to curtail and eliminate Carbon pollution completely while meeting the energy demand in a time bound manner because we are running out of time. Currently renewable energy generation is too low to meet these challenges within the time frame to avert disastrous consequences scientists predict. Renewable Hydrogen is a potential substitute for fossil fuel to eliminate Carbon pollution but that will not solve our current problem soon because renewable energy generation is too small and too slow while our energy demand is huge. Battery technology is only a storage technology and without a base load power generation all other forms of technologies will not meet our current challenges. I am not discounting the potential of renewable energy and its critical role in the future energy mix but that alone will not solve the current crisis. Hydrogen is a weak and unstable atom and it requires a backbone such as Carbon. That is why Hydrogen do not exist in a free state in Nature, but it exists in the form of water or natural gas. Therefore, it is only logical to convert renewable hydrogen into renewable natural gas so that it can be used as a fuel as we have been using for decades. It does not require to create a special type of infrastructure such as required for Hydrogen or any storage technologies. Our focus should be to achieve Zero Carbon emission in the shortest time scale possible while generating a base load power of 24 x7 using a renewable energy source. It looks like a daunting task but, it is not too big a challenge to overcome. In fact, the technologies are already available, and we are almost there to achieve the above, but governments should understand the challenge and its gravity and extend all the support it requires. Government around the world should implement the following with great urgency to achieve the above objectives. 1.Tax Carbon with immediate effect and minimum tax should be $500/ Mt of CO2 emitted. It should be centrally monitored by government agencies with appropriate technology implementations. 2. Encourage Oxy combustion technologies for coal, oil and gas-based power plants with incentives to eliminate emissions pollution and reduce the cost of Carbon capture. 3. Encourage large scale deployment of super critical Carbon dioxide power generation technologies with liberal grants and low interest loans for research and development of super critical CO2 technologies using Brayton cycle using fossil fuels with Zero Carbon emission. 4.Encourage large scale deployment of SNG plants using CO2 and renewable Hydrogen. By using the above steps all fossil fuel-based power plants existing and operating can be converted and continue to generate base load power 24 x7 with Zero Carbon Emission within a time frame. Simultaneously it will generate large scale renewable hydrogen and renewable synthetic natural gas which can generate base load power with Zero Carbon emission. Such Zero emission power plants can then power all electric and fuel cell cars and eliminate Carbon pollution completely from our roads. The above implementation will create millions of jobs worldwide! The greatest advantage of these technologies is to recycle Carbon indefinitely while generating power using renewable natural gas with Zero Carbon emission and fresh fossil fuel usage will be gradually eliminated from our planet earth.

Friday, February 24, 2017

Super critical CO2 power cycle with zero Carbon emission – a possibility.

There is likely to be a dramatic change in energy landscape with introduction of super critical CO2 power cycle. It not only increases the power efficiency, reduces the foot print considerably, utilizes part of CO2 emission internally in the form of super critical fluid and open a new path to eliminate Carbon emission completely (zero Carbon emission). It also reduces the water consumption in power generation unlike current conventional Rankine cycle power plants. We will soon be able to continue to generate base load power using fossil fuels with zero carbon emission. Unlike Carbon capture and sequestration already tried unsuccessfully in many parts of the world, Carbon capture and recycle will open a new chapter in the history of power generation. By capturing carbon in a solid form with potential industrial applications such a possibility is now within our reach. It means utilization of existing fossil fuel based power generation infrastructure without any Carbon emission and continue to generate continuous power to meet the increasing demand at a reasonable cost. The current focus on renewable energy will continue but until a practical and viable energy and mature storage technology is developed the renewable energy will have uncertainties. Whatever may be the case the overall cost of energy is likely to go up. Introduction of Oxy combustion in natural gas turbine has eliminated the oxides of Nitrogen from flue gas thus facilitating separation of CO2 from water and recycling water vapour into combustion process. The condensate from gas turbine is a by-product. Despite the usage of CO2 in the form of super critical fluid there is still an excess CO2 to be disposed of. A conceptual design to capture CO2 and convert them into SNG while generating additional power using the superheated steam obtained as a by-product of methanation has created a new opportunity to achieve zero carbon emission. It is an exciting development and our company is now in an advanced stage of developing and commercializing such a technology. Our new reformation process of natural gas using the captured CO2 and steam allows to precipitate Carbon in a solid form. The chemistry of the process can be explained by the following final methanation process using a proprietary catalyst involving few steps. 3CH4 +CO2 +H2O ----> 2CH4 + 3 H2O + 2 C which will take a final form as follows: CH4 + CO2 ------>
2H2O + 2C The superheated steam generated in the process can be exported to generate additional power while the condensate water can be exported and recycled. By using an excess of natural gas the captured CO2 is converted into SNG (synthetic natural gas) which can be recycled into the gas turbine thus achieving a zero-carbon emission while continuing to generate base load power. Such a technology can easily be integrated with other sources of energy such as solar, biomass, waste heat and nuclear.