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Wednesday, April 30, 2014

“Petrol from seawater “, a Carbon neutral fuel to mitigate climate change !


Recent news from USA has got the attention of many people around the world. “Scientists with the United States Navy say they have successfully developed a way to convert seawater into jet fuel, calling it a potentially revolutionary advancement. Researchers at the Naval Research Laboratory (NRL) developed technology to extract carbon dioxide from seawater while simultaneously producing hydrogen, and then converted the gasses into hydrocarbon liquid fuel. The system could potentially shave hours off the at-sea refueling process and eliminate time spent away from missions.” They estimate the cost of the jet fuel will be anywhere between $3 and $6 per gallon. It may not be able to compete with traditional petroleum sources due to high energy requirement. However, the main attraction of this process is to extract Carbon dioxide absorbed by the ocean to avoid acidification and to mitigate climate change while making petrol as a Carbon neutral fuel. Ocean has become a rich source of Carbon (Carbon sink) absorbing excess atmospheric Carbon dioxide caused by human beings. Generating Carbon neutral fuel such as SNG (synthetic natural gas), diesel and petrol from air and sea water will be the fastest way to reduce Carbon from the atmosphere. Probably Governments, business and industries will embarrass this concept much quicker than any other mitigating methods simply because it is a revenue generating proposition with a potential to earn carbon credit. Carbon-neutral fuel is a synthetic fuel (including methane, gasoline, diesel fuel, jet fuel or ammonia) that is produced using carbon dioxide recycled from power plant flue exhaust gas or derived from carbonic acid in seawater and renewable Hydrogen. Such fuels are potentially carbon-neutral because they do not result in a net increase in atmospheric greenhouse gases. It is a Carbon capture and recycling (CCR) process. “To the extent that carbon-neutral fuels displace fossil fuels, or if they are produced from waste carbon or seawater carbonic acid, and their combustion is subject to carbon capture at the flue or exhaust pipe, they result in negative carbon dioxide emission and net carbon dioxide removal from the atmosphere, and thus constitute a form of greenhouse gas remediation. Such power to gas carbon-neutral and carbon-negative fuels can be produced by the electrolysis of water to make hydrogen used in the Sabatier reaction to produce methane which may then be stored to be burned later in power plants as synthetic natural gas, transported by pipeline, truck, or tanker ship, or be used in gas to liquids processes such as the Fischer–Tropsch (FT) process to make traditional fuels for transportation or heating. Carbon-neutral fuels are used in Germany and Iceland for distributed storage of renewable energy, minimizing problems of wind and solar intermittency, and enabling transmission of wind, water, and solar power through existing natural gas pipelines. Such renewable fuels could alleviate the costs and dependency issues of imported fossil fuels without requiring either electrification of the vehicle fleet or conversion to hydrogen or other fuels, enabling continued compatible and affordable vehicles. A 250 kilowatt synthetic methane plant has been built in Germany and it is being scaled up to 10 megawatts.” (Wikipedia). We have been writing about renewable hydrogen (RH) for the past couple of years and often use the phrase, “Water and energy are two sides of the same coin” because we can mitigate climate change using renewable hydrogen (RH) even while the fossil fuel economy can carry on as usual. By generating Carbon neutral fuels using excess Carbon from air and sea and hydrogen from water (even seawater) using renewable energy sources, the problem of global warming and climate change can be solved because we will not be adding any further Carbon into the atmosphere than what it is today! Instead of generating solar and wind power and storing them in batteries it will be prudent to generate Carbon neutral fuel from CO2 already available in the system and use them as usual. Meanwhile Hydrogen based power generation and transportation can be developed as a long term solution. Fossil- fuel fired power plants produce CO2 (Carbon dioxide) which could be captured and converted to CO (Carbon monoxide) for production of synthetic fuels. CO2 can be converted to CO by the Reverse Water Gas Shift Reaction, CO2 + H2--> CO + H2O. CO could then be used in the F-T reaction with additional hydrogen from water-splitting to produce synthetic fuel such as diesel and petrol as carbon neutral fuels. Synthetic fuel by CO2 Capture + H2 from Water-splitting: Reverse Water Gas Shift CO2 + H2 ----> CO + H2O F-T reaction CO + 2H2 ----> CH2 + H2O Water-splitting 3H2O + Energy --> 3H2 + 3/2O2 Net reaction CO2 + H2O + Energy ---> CH2 + 3/2O2 In this case, no coal is needed at all, and CO2 is consumed rather than produced. The excess O2 (oxygen) would be used in the fossil power plant that provides the CO2, simplifying CO2 capture. There is currently considerable effort underway on developing CO2 capture systems for new and extant power plants. The increasing concern with Global Climate Change suggests that there is a reasonable likelihood of such plants operating in the timeframe associated with synthetic fuel from carbon dioxide. Such a synergistic system has the potential to significantly reduce our current emissions of CO2 since the carbon in the coal is used once for power production and then again for liquid hydrocarbon fuel synthesis. Synthetic fuel plant with capacities as low as 1000 barrels/day are commercially feasible using specially designed micro-reactors as shown in the attached photograph.(Ref:velocys system). Utilizing carbon dioxide from sea and air is the smartest way to mitigate climate change while maintaining fossil fuel based power plants and automobiles without any change or modifications. The same technique can also be applied for biomass gasification plants.

Saturday, March 22, 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.