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Category Archives: Carbon recycling

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.oxy-fuel-directly-heated-sco2-power-cycle-flow-diagram-1sco2-power-cycle

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.

 

 

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 the SNG from coal will cut 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 cut 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 cut 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 cut 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 now 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 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 cut 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.

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.

“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 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 cut 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 cut 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 : http://www.basf.com/group/press release/P-13-351‎ claiming a break-through technology to generate Hydrogen from natural gas without any CO2 emissions.

The Carbon emission in the atmosphere is steadily increasing.  The latest statistics indicates that it has reached a staggering 35.6 billion tons/yr, a 2.6% increase over the previous year, thanks to the growth of China. It is becoming clear that there is a relationship between the Carbon emission, global warming and erratic weather patterns around the world. According to ‘The Guardian’,

“The chances of the world holding temperature rise to 2C – the level of global warming considered “safe” by scientists – appear to be fading fast with US scientists reporting the second-greatest annual rise in CO2emissions in 2012. Carbon dioxide levels measured at Mauna Loa observatory in Hawaii jumped by 2.67 parts per million (ppm) in 2012 to 395ppm, said Pieter Tans, who leads the greenhouse gas measurement team for the US National Oceanic and Atmospheric Administration (NOAA). The record was an increase of 2.93ppm in 1998.

The jump comes as a study published in Science on Thursday looking at global surface temperatures for the past 1,500 years warned that “recent warming is unprecedented”, prompting UN climate chief, Christiana Figures, to say that “staggering global temps show urgent need to act. Rapid climate change must be countered with accelerated action.” Tans told the Associated Press the major factor was an increase in fossil fuel use. “It’s just a testament to human influence being dominant”, he said. “The prospects of keeping climate change below that [two-degree goal] are fading away.

Preliminary data for February 2013 show CO2 levels last month standing at their highest ever recorded at Manua Loa, a remote volcano in the Pacific. Last month they reached a record 396.80ppm with a jump of 3.26ppm parts per million between February 2012 and 2013. Carbon dioxide levels fluctuate seasonally, with the highest levels usually observed in April. Last year the highest level at Mauna Loa was measured at 396.18ppm. What is disturbing scientists is the acceleration of CO2concentrations in the atmosphere, which are occurring in spite of attempts by governments to restrain fossil fuel emissions. According to the observatory, the average annual rate of increase for the past 10 years has been 2.07ppm – more than double the increase in the 1960s. The average increase in CO2 levels between 1959 to the present was 1.49ppm per year.

The Mauna Loa measurements coincide with a new peer-reviewed study of the pledges made by countries to reduce CO2 emissions. The Dutch government’s scientific advisers show that rich countries will have to reduce emissions by 50% percent below 1990 levels by 2020 if there is to be even a medium chance of limiting warming to 2C, thus preventing some of climate  change‘s worst impacts.”The challenge we already knew was great is even more difficult”, said Kelly Levin, a researcher with the World Resources Institute in Washington. “But even with an increased level of reductions necessary, it shows that a 2° goal is still attainable – if we act ambitiously and immediately.” Extreme weather, which is predicted by climate scientists to occur more frequently as the atmosphere warms and CO2 levels rise, has already been seen widely in 2013. China and India have experienced their coldest winter in decades and Australia has seen a four-month long heat wave with 123 weather records broken during what scientists are calling it ‘angry summer’. “We are in [getting] into new climatic territory. And when you get records being broken at that scale, you can start to see a shifting from one climate system to another. So the climate has in one sense actually changed and we are now entering a new series of climatic conditions that we just haven’t seen before”, said Tim Flannery, head of the Australian government’s climate change commission, this week. Earlier this week the Met Office warned that the “extreme” patterns of flood and drought experienced by Britain in 2012 were likely to become more frequent. One in every five days in 2012 saw flooding but one in four days were in drought”.

The biggest question now is how to put this Carbon genie back into the bottle? renewable energy may be an answer to curtail future Carbon emissions but what about the existing coal-fired power plants that constitutes 60% of the existing power generation in the world? There is no easy solution. But the “Law of conservation of mass” gives us a clue.The Carbon we dig from the earth in the form of coal, combusted into the atmosphere as Carbon dioxide may be captured and recycled back into the system in the form of a fuel.By this way, we may not need fresh coal to be mined.To achive this feat,we need Hydrogen from a renewable source.The renewable Hydrogen can be combined with Carbon dioxide captured from the coal-fired power plants to generate synthetic natural gas (SNG).The SNG generated by this method can be used for future power generation, substituting Coal and future carbon emission can be recycled in the form of SNG. This approach will open up a range of possibilities and potentially cut the carbon emission to zero.Annual CO2 growthAtmospheic Carbon increaseCO2 emissionsGlobal Carbon emissionHydrosol cycleHydrosol thremocycle

Many companies round the world including DOE (Department of energy,Govt of USA) are trying to develop an economically viable method to generate Hydrogen with an estimated cost of poduction at  $ 2.50 /kg of Hydrogen. One potential method is to generate Hydrogen by splitting water using a thermo-chemical process using concentrated solar therml energy developed by European Union called “Hydrosol cycle”. The method by which Hydrogen is generated should be free from any Carbon emision. To clean up  1 Kg Carbon dioxide one will require at least 0.2kg Hydrogen. For example, a 100Mw coal fired power plant emitting about 2256 Mt CO2/day will require about 451 Mt of Hydrogen/day, costing about $1,127,500 per day.It will cost roughly $500/Mt of C02 to  put the ‘ Carbon genie’  back into the bottle! One can imagein the cost of cleaning up  35.6 billion tons of Carbon dioxide  from the atmosphere.Only a Carbon free Hydrogen derived from water can save the world from a potential catastrophe.

Nature has a wonderful way of capturing Carbon and recycling it through a process called ‘carbon cycle’ for millions of years. The greenhouse gases in the atmosphere were restricted  within certain limits when it was left to Nature. But when human being started burning fossil fuels to generate power or to run cars, the GHG emission surpassed the limit beyond a point where global warming became an issue. The GHG level has increased to 392 ppm level for the first in our long history. Many Governments and companies are exploring various ways and means to reduce greenhouse emissions to avoid global warming. Some Governments are imposing taxes on carbon emission in order to reduce or discourage such emissions. Others are offering incentives to promote alternative energy sources such as wind and solar. Some companies are trying to capture Carbon emission for sequestration.

While we try to capture Carbon and store them underground, there are many potential commercial opportunities to recycle them. This means the Carbon emission is captured and converted into a commercial fuel such as Gasoline or Diesel or Methane so that future sources of fossil fuels are not burnt anymore. But this is possible only by using ‘Renewable Hydrogen’. Hydrogen is the key  to reduce carbon emission by binding carbon molecules with Hydrogen molecule, similar to what Nature does.

When NASA plans to send a man to Mars they have to overcome certain basic issues. Mars has an atmosphere with 95% Carbon dioxide, 3% Nitrogen, 1.6% Argon and traces of oxygen, water and methane.Nasa is planning to use Carbon dioxide to generate Methane gas to be used as a fuel and also generate water by using the following reaction.

CO2 + 4H2—–CH4 + 2 H2O

2H2O——-2H2 + O2

The water is electrolyzed to split water into Hydrogen and Oxygen using solar power. The resulting Hydrogen is reacted with Carbon dioxide from Mars to generate Methane gas and water using a solid catalyst. This methanation reaction is exothermic and self sustaining. How this can be achieved practically in Mars in those conditions are not discussed here. But this is a classical example on how the Carbon emission can be tackled to our advantages, without increasing the emissions into the atmosphere. There are several methods available to convert Carbon emission in to valuable products including gasoline. The  reaction of the methane with water vapor will result in Methanol.

2H2 + CO——– CH3OH

On Dehydration, 2CH3OH —– CH3COCH3 + H2O.Further dehydration with ZSM-5 Catalyst gives Gasoline 80% C5+ Hydrocarbon. Gas to liquid by Fischer-tropic reaction is a known process.

Carbon dioxide is also a potential refrigerant to substitute CFC refrigerants that causes Ozone depletion. Carbon recycling is a temporary solution to mitigate Greenhouse gas emission till Hydrogen becomes an affordable fuel of the future. It depends upon individual Governments and their policies to make Hydrogen affordable. Technologies are available and only a political will and leadership can make Hydrogen a reality.

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