Carbon is to return to Carbon

Carbon emission is a matter of great concern to all the countries around the world due to the global warming and climate change. After the Paris talks many countries are genuinely trying to reduce their emissions either by switching over to renewable energy or cutting down their emissions by reducing their Carbon footprint. In their desperate measure to reduce Carbon emissions some countries like Canada are trying to accelerate carbon emission reduction by promoting innovation technologies with millions of dollars of grant money. Recent fires in the state of Alberta, rich in oil sand deposits have opened the eyes of the world to witness how a disaster can unfold so quickly and thousands of people to be evacuated in a short notice. Many fled their homes leaving behind their valuables and memories. It was one of the worst fire disasters in recent memory. Canada especially the state of Alberta is now all the more determined to avert such incidents in the future but also equally determined to reduce their Carbon emissions. The fire is due to dry conditions due to global warming and accelerated by oil sands. It is a perfect recipe for a disaster. Many countries have switched over from coal to natural gas as a cleaner fuel to reduce their Carbon emission. Natural gas emits less CO2 compared to coal. But does it help combat global warming? One has to compare the two different fuels and their combustion by the following reactions: C + O2 ----> CO2 and CH4 + 2O2 -------> CO2 + 2H2O Combustion of coal requires less Oxygen (air) when compared to combustion of natural gas which requires twice the volume of Oxygen (air). Coal combustion emits oxides of Nitrogen and Sulphur apart from CO2 and a minor quantity of water vapour and particulate matters. Combustion of natural gas releases twice the volume of water vapour apart from oxides of Nitrogen and sulphur. Recent findings by NASA confirms that water vapour is the major greenhouse gas apart from CO2 that is responsible for warming globe and the climate change. Therefore, natural gas does not help combating global warming and climate change. The following excerpts from NASA highlights this fact: Water Vapour Confirmed as Major Player in Climate Change Credit: NASA The distribution of atmospheric water vapour, a significant greenhouse gas, varies across the globe. During the summer and fall of 2005, this visualization shows that most vapour collects at tropical latitudes, particularly over south Asia, where monsoon thunderstorms swept the gas some 2 miles above the land. Water vapour is known to be Earth’s most abundant greenhouse gas, but the extent of its contribution to global warming has been debated. Using recent NASA satellite data, researchers have estimated more precisely than ever the heat-trapping effect of water in the air, validating the role of the gas as a critical component of climate change. Andrew Dressler and colleagues from Texas A&M University in College Station confirmed that the heat-amplifying effect of water vapour is potent enough to double the climate warming caused by increased levels of carbon dioxide in the atmosphere. With new observations, the scientists confirmed experimentally what existing climate models had anticipated theoretically. The research team used novel data from the Atmospheric Infrared Sounder (AIRS) on NASA’s Aqua satellite to measure precisely the humidity throughout the lowest 10 miles of the atmosphere. That information was combined with global observations of shifts in temperature, allowing researchers to build a comprehensive picture of the interplay between water vapour, carbon dioxide, and other atmosphere-warming gases. The NASA-funded research was published recently in the American Geophysical Union's Geophysical Research Letters. AIRS is the first instrument to distinguish differences in the amount of water vapour at all altitudes within the troposphere. Using data from AIRS, the team observed how atmospheric water vapour reacted to shifts in surface temperatures between 2003 and 2008. By determining how humidity changed with surface temperature, the team could compute the average global strength of the water vapour feedback. “This new data set shows that as surface temperature increases, so does atmospheric humidity,” Dressler said. “Dumping greenhouse gases into the atmosphere makes the atmosphere more humid. And since water vapour is itself a greenhouse gas, the increase in humidity amplifies the warming from carbon dioxide." Specifically, the team found that if Earth warms 1.8 degrees Fahrenheit, the associated increase in water vapour will trap an extra 2 Watts of energy per square meter (about 11

square feet) "That number may not sound like much, but add up all of that energy over the entire Earth surface and you find that water vapour is trapping a lot of energy," Dressler said. "We now think the water vapour feedback is extraordinarily strong, capable of doubling the warming due to carbon dioxide alone." Because the new precise observations agree with existing assessments of water vapour’s impact, researchers are more confident than ever in model predictions that Earth's leading greenhouse gas will contribute to a temperature rise of a few degrees by the end of the century. The amount water vapour released by burning natural gas is twice the volume of natural gas burnt. A plant using 10,000 m3/day natural gas can release 20,000m3/day water vapour that can be recovered. In fact, if the Gulf countries can recover water from exhaust of their gas fired power plants they may not require any water by desalination of seawater at all. Current consumption of natural gas world-wide exceeds 3.5 trillion cubic meters which roughly translates to 7 trillion cubic meters of water vapour into the atmosphere. Such a large volume has a potential to change our climate system.What goes up as water vapour has to condense into water and come down.It has a potential to flood many parts of the world and we are already witnessing flash flooding more frequently.The economic loss by such natural disasters may run into several hundreds of billion dollars in future.It is absoluetly critical that human induced emissions are curtailed with great urgency. It is interesting to examine how the state of Alberta is trying to reduce their carbon emissions by promoting innovative technologies. Majority of the proposals are supposed to convert CO2 emissions into “a useful product” so that the emission can be curtailed or reduced. A quick glance on the list of the proposals they have funded so far indicates they will convert CO2 into an industrial chemical such as Methanol or a Fertilizer such as Urea or alkaline chemicals such as bicarbonates and calcium carbonates etc. Can they really solve the problem of carbon emissions by turning them into useful products? The answer is most likely no. It will help capture CO2 at Alberta but it will be released somewhere else where the end products are used. It will simply shift the problems of Carbon emission from Alberta into some other region of the world. For example, Urea synthesised from captured CO2 will again be released into the atmosphere when Urea is used by farmers. An enzyme in the soil will release the CO2 from Urea into the atmosphere. The only real solution is to convert captured CO2 back into a fuel such as SNG (synthetic natural gas) so that it can be recycled into the power plant. By this way the CO2 emission will be converted into solid Carbon. One need not bury CO2 under the ground or emit it into the atmosphere but constantly recycle into SNG so that power plant can generate power continuously without emitting any greenhouse emissions. To do this we need Hydrogen. At present Hydrogen is produced commercially from natural gas but with carbon emission. Other methods of producing Hydrogen without carbon emissions are expensive. But Hydrogen can be generated from natural gas without Carbon emission and it can be used to convert captured CO2 from power plants into SNG. In other words, two greenhouse gases namely CO2 and methane (CH4) will be reacted to generate commercially valuable Carbon nanotube as a main product as shown below. This high temperature reaction can generate superheated steam that can generate power while a valuable solid Carbon is regenerated. Such a process is still in a developmental stage but has a potential to become a commercial reality in the near future. CH4 + CO2 ------------> 2C + 2 H2O In fact, the carbon emission is converted back into a solid Carbon. The Carbon is to return to Carbon to avoid GHG emission (CO2, N2O, NO2 and H2O) that is changing our climate.

Fuelcell can become a commercial reality

We currently generate electric city from heat, obtained by combustion of fossil fuel such as coal, oil and gas. But such combustion generates not only heat but also greenhouse gases such as Carbon dioxide and oxides of Nirogen.The only alternative to generate power without any greenhouse gas emission is to use a fuel with zero carbon. However, oxides of Nitrogen will still be an issue as long as we use air for combustion because atmospheric air contains almost 79% Nitrogen and 21% oxygen. Therefore it becomes necessary to use an alternative fuel as well as an alternative power generation technology in the future to mitigate greenhouse problems. Hydrogen is an ideal fuel to mitigate greenhouse gases because combustion of Hydrogen with oxygen from air generates only water that is recyclable. Combining Hydrogen with Oxygen using Fuel cell, an electrochemical device is certainly an elegant solution to address greenhouse problems. But why Hydrogen and Fuel cell are not commonly available? Hydrogen is not available freely even though it is abundantly available in nature. It is available as a compound such as water (H2O) or Methane (CH4) and Ammonia (NH3). First we have to isolate Hydrogen from this compound as free Hydrogen and then store it under pressure. Hydrogen can easily form an explosive mixture with Oxygen and it requires careful handling. Moreover it is a very light gas and can easily escape. It has to be compressed and stored under high pressure. Generation of pure Hydrogen from water using Electrolysis requires more electricity that it can generate. However, Hydrogen cost can be reduced using renewable energy source such as solar thermal. The solar thermal can also supply thermal energy for decomposing Ammonia into Hydrogen and Nitrogen as well as to supply endothermic heat necessary for steam reformation of natural gas into Hydrogen. Onsite Hydrogen generation using solar thermal using either electricity or heat can currently become a commercial reality. Hydrogen generation at higher temperatures such as Ammonia decomposition or steam reformation can be directly used in Fuel cell such as Phosphoric acid Fuel cell. Phosphoric acid fuel cell is a proven and tested commercial Fuel cell that is currently used for base load power generation. It is also used for CHP applications. Hydrogen generation using solar thermal and power generation using Fuel cell is already a commercial reality and also an elegant solution to mitigate greenhouse gases. Large scale deployment of Fuel cell and solar thermal will also reduce the cost of installations and running cost competing with fossil fuel.Fuecell technology has a potential to become a common solution for both power generation and transportation. While Government can encourage renewable energy by subsidizing PV solar panels and discourage fossil fuel by imposing carbon tax, they should give preference and higher tariff for power purchase from Solar thermal and Fuel cell power generators. This will encourage large scale deployment of Fuel cell as a potential base load power source.

All roads lead to Hydrogen

We have discussed about the formation of fossil fuel as part of carbon cycle. It takes several million years before the carbon from the plants and animals turn into fossil fuels due to chemical reactions under higher pressure and temperature. The fossil fuels include solid coal, liquid oil and gaseous Hydrocarbons such as crude oil and natural gas. The natural gas forms the top layer due to its lightness. Natural gas is also the result of anaerobic reaction by microorganism in the absence of air converting organic matter under the earth into a gas. The gas during exploration comes with great pressure to be transported across several kilometers. We are actually duplicating this process to generate Biogas from our food and agriculture wastes and other organic matters. The end product is a mixture of methane and carbon dioxide. During oil and gas exploration we get methane and carbon dioxide and other gases such as Hydrogen sulfide depending upon the location of the oil field. That is why Sulfur and other products such as Mercaptnans are present in crude oil and natural gas. When these fossil fuels are burnt the gaseous combustion products contain sulfur dioxide and oxide of nitrogen along with oxides of carbon. Air is normally used for combustion which is a mixture of Nitrogen and oxygen in the ration of 71:21,therefore, the combustion products invariably consist of oxides of nitrogen. We are so addicted to oil and we are even trying to convert natural gas into oil, similar to gasoline using GTL (gas to oil) process. However all these combustion processes can be reacted with steam to form synthesis gas, a precursor for liquid Hydrocarbon. It is quite obvious that water in the form of steam is a key component in future energy mixes because that is how one can introduce a Hydrogen molecule in the reaction process. Hydrogen in the form of water is the key. Even if we can successfully steam reform natural gas to get Hydrogen we still have problems deal thing with traces of sulfur and mercaptans, potential poison for catalyst in PEM (Proton exchange membrane) Fuelcells.The idea is to generate Hydrogen using a carbonaceous source such as fossil fuel for simple reasons. It is abundantly available but it emits greenhouse gases; but when you introduce Hydrogen into the mix then there is a good possibility of reducing greenhouse emission, even though we still use fossil fuels. Secondly, we are cautious to handle pure Hydrogen due to its explosive nature and the best available option is to mix Hydrogen with combustion products of fossil fuels. The result is the formation of Syngas. Syngas is an important intermediary that will lead us to the Hydrogen economy of the futue.The syngas can be generated by various methods as long as we have an organic source and water (steam) source. In fact all food and agriculture waste can be converted into syngas either using a biological process or by gasification process. Both will lead to formation of Methane or syngas. Syngas is a mixture of hydrogen with carbon dioxide formed in the following sequences, starting with carbon ,air and steam. 2C + O2-------- 2 CO, 2CO + 2H2O---------2H2 +2 CO2 The carbon source can be any organic source such as coal, coke, wood etc.As you can see in the reaction, the quantity of carbon source is equally important to generate Hydrogen. One can say that Syngas is a match maker between fossil economy of the past and Hydrogen economy of the future. It is a very important chemical reaction that will change the future energy scene in the world. That is why many counties like US and Australia and in Europe who have considerable coal deposits are now trying to generate Hydrogen from coal. Once coal is converted into a gas such as syngas then they are one step closer to separate Hydrogen from syngas.Number of companies and Research organizations around the world are trying to develop an efficient and economical method of generating Hydrogen from coal. They have to find suitable conditions to generate higher yield of Hydrogen from syngas and then find an efficient system to separate Hydrogen from carbon dioxide. As I have mentioned earlier, the purity of Hydrogen is important especially when we use coal as the basic material because it contains number of impurities to be removed before converting into a syngas. As we can see, all energy roads are now leading to Hydrogen as the ultimate clean fuel of the future. When the demand for Hydrogen increase, the demand for water too will increase because it is the direct source of Hydrogen. Energy and water are two side of the same coin as I have mentioned earlier in the past.