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Showing posts with label Hydrogen-rich syngas. Show all posts
Showing posts with label Hydrogen-rich syngas. Show all posts

Friday, March 21, 2014

It is time to switch over from Carbon to Hydrocarbon


When Carbon emission is high and the globe is warming due to such emissions then the simple and immediate solution to address this issue is to convert Carbon into Hydrocarbon, and the simplest Hydrocarbon is Methane (CH4).By simply introducing Hydrogen atom into Carbon atom the entire fuel property changes. For example the heating value of coal is only 5000-6500 kcal/kg at the maximum while the heating value of Methane (natural gas) increases to 9500 kcal/m3 by the above conversion. It means the same power generated by coal can be generated by using almost half the quantity of natural gas. Converting Carbon into substituted natural gas (SNG) is one way of addressing climate change in a short span of time. By switching over to SNG from coal will reduce the CO2 emission almost by 50%. Global warming due to GHG emission has become a serious environmental issue in recent times and more and more investments are made on renewable energy projects such as solar and wind etc. In spite of the major thrust on renewable energy projects the main source of power is still generated around the world using fossil fuel especially Coal due to its abundance and low cost. Moreover the investment already made on fossil fuel infrastructures are too big to be ignored and investment required to substitute coal-fired power plants by renewable energy are too large and gestation periods are too long to maintain the current electricity demand and to meet the future demands. The cost of renewable energy also is high and there is great resistance by consumers to switch over to renewable energy. Many Governments are reluctant to subsidize renewable energy due to their financial constraints. That is why countries like China which is growing at the rate of more than 8% pa are trying to decrease the ‘Carbon intensity’ rather than closing down the coal–fired power plants by setting up SNG (synthetic natural gas) plants by gasification of coal . This will reduce their Carbon emissions almost by 50% surpassing all other countries around the world in short span of time, thus meeting their emission targets agreed in “Kyoto protocol”. They can also meet the increasing electricity demand by using “syngas” generated by coal gasification plants, while reducing the Carbon pollution. They will also be able to produce Diesel and Gasoline from coal similar to the “SESOL” plant in South Africa which is already operating successfully for the past 50 years. “Leveraging Natural Gas to Reduce Greenhouse Gas Emissions” – a summary report by Center for Energy and Climate Solutions (C2ES) have highlighted the following in their report. “Recent technological advances have unleashed a boom in U.S. natural gas production, with expanded supplies and substantially lower prices projected well into the future. Because combusting natural gas yields fewer greenhouse gas emissions than coal or petroleum, the expanded use of natural gas offers significant opportunities to help address global climate change. The substitution of gas for coal in the power sector, for example, has contributed to a recent decline in U.S. greenhouse gas emissions. Natural gas, however, is not carbon-free. Apart from the emissions released by its combustion, natural gas is composed primarily of methane (CH4), a potent greenhouse gas, and the direct release of methane during production, transmission, and distribution may offset some of the potential climate benefits of its expanded use across the economy. This report explores the opportunities and challenges in leveraging the natural gas boom to achieve further reductions in U.S. greenhouse gas emissions. Examining the implications of expanded use in key sectors of the economy, it recommends policies and actions needed to maximize climate benefits of natural gas use in power generation, buildings, manufacturing, and transportation. More broadly, the report draws the following conclusions: •The expanded use of natural gas—as a replacement for coal and petroleum—can help our efforts to reduce greenhouse gas emissions in the near- to mid-term, even as the economy grows. In 2013, energy sector emissions are at the lowest levels since 1994, in part because of the substitution of natural gas for other fossil fuels, particularly coal. Total U.S. emissions are not expected to reach 2005 levels again until sometime after 2040. • Substitution of natural gas for other fossil fuels cannot be the sole basis for long-term U.S. efforts to address climate change because natural gas is a fossil fuel and its combustion emits greenhouse gases. To avoid dangerous climate change, greater reductions will be necessary than natural gas alone can provide. Ensuring that low-carbon investment dramatically expands must be a priority. Zero-emission sources of energy, such as wind, nuclear and solar, are critical, as are the use of carbon capture-and-storage technologies at fossil fuel plants and continued improvements in energy efficiency. • Along with substituting natural gas for other fossil fuels, direct releases of methane into the atmosphere must be minimized. It is important to better understand and more accurately measure the greenhouse gas emissions from natural gas production and use in order to achieve emissions reductions along the entire natural gas value chain.” Countries like India should emulate the Chinese model and become self-sufficient in meeting their growing energy demand without relying completely on imported Petroleum products. Import of petroleum products is the single largest foreign exchange drain for India, restricting their economic growth to less than 5%. Countries that rely completely on coal-fired power plants can set up coal hydro-gasification and gasification plants to reduce their Carbon emissions in the immediate future while setting up renewable energy projects as a long-term solution. Transiting Carbon economy into Hydrogen economy is a bumpy road and it will not be easy to achieve in a short span of time. The logical path for such transition will be to switch coal based power generation into gas based power generation for the following reasons. The largest Carbon emissions are from power generation and transportation. Transportation industry is already going through a transition from fossil fuel to Hydrogen. More future cars will be based either on Fuel cell or Electric and in both cases the fuel is the critical issue. Battery technology also will be an issue for Electric cars. It is more practical to generate Hydrogen from natural gas and to set up Hydrogen fuel stations than generating Hydrogen from solar powered water electrolysis. With improvement on Fuel cell technology it is more likely that PEM Fuel cell may be able to operate on Hydrogen derived from natural gas that is completely free from any Sulphur compounds. Even for Electric cars, natural gas will play an important role as a fuel for power generation and distribution in the near future as we transit from Carbon economy to full fledged Hydrogen economy. Countries like India with highest economic growth will have to be pragmatic by setting up more SNG plants with indigenous coal than depending on imported LNG. India has only two LNG terminals currently in operation but do not have gas transmission infrastructure. With increasing demand for natural gas from all over the world and lack of LNG receiving terminals, India will have to face a serious fuel and power shortage in the future. By installing more coal gasification and SNG plants with down-stream products like like Diesel and petrol, India can overcome the fuel and power shortage. In fact India set up the first coal gasification and Ammonia and Urea plant in Neyveli (Neyveli Lignite Corporation) way back in Fifties after her independence and it is time to visit the past. Renewable energy is certainly the long term solution for energy demand but we have to consider the amount of GHG emission associated with production PV solar panels, wind turbines and batteries. There is no easy fix to reduce GHG emission in short span of time but switching Carbon to hydrocarbon will certainly reduce the emissions scientists are advocating and water (steam) is the key to introduce such Hydrogen atom into the Carbon atom. That is why we always believe “Water and Energy are two sides of the same coin” and renewable Hydrogen will be the key to our future energy. President Obama's recent announcement of Carbon reduction plan by coal-fired power plants in USA is a bold step in the right direction.A more ambitious plan may be required to avoid catastrophic climate change that might cost billions of dollar in health related issues and on rebuilding damaged infrastructure. For more information on the above topic please refer to the following link: Source: Harvard University Link: Coal to Natural gas Fuel switching and Carbon dioxide (CO2) emission reduction. Date: Apr 2011. Author: Jackson Salovaara.

Thursday, July 11, 2013

How to control Carbon emissions in coal-fired power plants?


“Over two-thirds of today’s proven reserves of fossil fuels need to still be in the ground in 2050 in order to prevent catastrophic levels of climate change” – a warning by scientists. There is a great deal of debate on climate change due to man-made Carbon emissions and how to control it without any further escalation. The first obvious option will be to completely stop the usage of fossil fuel with immediate effect. But it is practically not feasible unless there is an alternative Non-Carbon fuel readily available to substitute fossil fuels. The second option will be to capture carbon emission and bury them under ground by CCS (Carbon capture and sequestration) method. But this concept is still not proven commercially and there are still currently many uncertainties with this technology, the cost involved and environmental implications etc.The third option will be not to use fresh fossil fuel for combustion or capture and bury the Carbon emissions but convert the Carbon emissions into a synthetic hydrocarbon fuel such as synthetic natural gas (SNG) and recycle them. By this way the level of existing Carbon emission can be maintained at current levels without any further escalation. At least the Carbon emission levels can be reduced substantially and maintained at lower levels to mitigate climate changes. It is technically feasible to implement the third option but it has to be implemented with great urgency. One way of converting Carbon emission is to capture and purify them using conventional methods and then react with Hydrogen to produce synthetic natural gas (SNG) CO2 + 4 H2 ----------> CH4 + 2 H2O The same process will be used by NASA to eliminate carbon built-up in the flights by crew members during their long voyage into the space and also to survive in places like Mars where the atmosphere is predominantly carbon dioxide. But we need Hydrogen which is renewable so that the above process can be sustained in the future .Currently the cost of Hydrogen production using renewal energy sources are expensive due to high initial investment and the large energy consumption. We have now developed a new process to generate syngas using simple coal, which is predominantly Hydrogen to be used as a Carbon sink to convert Carbon emissions into synthetic natural gas (SNG). The same Hydrogen rich syngas can be directly used to generate power using gas turbine in a simple or combined cycle mode. The Carbon emission from the gas turbine can be converted into SNG (synthetic natural gas) using surplus Hydrogen-rich syngas. The SNG thus produced can be distributed for CHP (combined heat and power) applications so that the Carbon emission can be controlled or distributed. By implementing the above process one should be able to maintain Carbon at specific level in the atmosphere. Existing coal fired power plants can retrofit this technology so that they will be able to reduce their Carbon emissions substantially; they can also produce SNG as a by-product using their Carbon emissions and achieve zero Carbon emission at their site while generating revenue by sale of SNG. Coal is the cheapest and widely used fossil fuel for power generation all over the world. Therefore it will be a win situation for everyone to use coal and also to reduce Carbon emissions that can address the problems of climate change. Meanwhile research is going on to generate renewable Hydrogen cheaply directly from water using various technologies. But we believe we are still far away from achieving this goal and we require immediate solution to address our climate change problems. Recently BASF made a press release :www.basf.com/group/pressrelease/P-13-351‎ claiming a break-through technology to generate Hydrogen from natural gas without any CO2 emissions.