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Category Archives: Hydrogen IC engine

Majority of current power generation technologies are based on thermodynamic principles of heat and work. Heat is generated by  chemical reactions such as combustion of coal, oil or gas with air or pure oxygen. This heat of combustion is then converted into work by a reciprocating engine or steam turbine of gas turbine. The mechanical energy is converted into electricity in power generation and as a motive force in transportation. The fundamental principles remain the same irrespective of the efficiencies and sophistication we incorporated as we progressed. The efficiency of these systems hardly exceeds 30-40 of the heat input, while the remaining 60-70 heat is wasted. We were also able to use this waste heat and improved the efficiency of the system by way of CHP (combined heat and power) up to 80-85%.But this is possible only in situations where one can use both power and heat simultaneously. In a centralized power plant such large heat simply dissipated as a waste heat through cooling towers and in the flue gas. This is a huge loss of heat because a substantial part of heat of combustion is simply vented into the atmosphere in the form of greenhouse gases. If ‘greenhouse gas’ and ‘Global warming’ were not issues of concern to the world, probably we would have continued our business as usual.

Generation of heat by combustion of hydrocarbon is one example of a chemical reaction. In many chemical reactions, heat is either released or absorbed depending upon the type of reaction, whether it is exothermic or endothermic. Sometimes these chemical reactions are reversible. It may release heat while the reaction moves forward and it may absorb heat while it moves backward in the reverse direction. By selecting such reaction one can make use of such energy transformations to our advantages. One need not release the heat and then release the product of reaction into the air like burning fossil fuels.

Ammonia is one such reaction. When Hydrogen and Nitrogen is reacted in presence of a catalyst under high temperature and pressure the reaction goes forward releasing a large amount of energy as practiced in industries using Heber’s process. The heat released by this reaction can be converted into steam and we can generate power using steam cycle. The resulting Ammonia can further be heated in presence of a catalyst by external heat due to endothermic nature of the reaction and split into Hydrogen and Nitrogen.  However, such heat can be supplied only from external sources. One University in Australia is trying use the above principle by using solar thermal energy as a source of external heat. The advantage of this system is power can be generated without burning any fossil fuel or emitting any greenhouse gas. One can use a renewable energy sources such as solar thermal and also use Ammonia as a storage medium.

Ammonia is a potential source of energy to substitute fossil fuels. However, such Ammonia is now synthesized using Hydrocarbon such as oil and gas. The source of Hydrogen is from synthesis gas resulting from steam reformation of a Hydrocarbon. Hydrogen can also be derived from water using electrolysis using renewable energy source. In both the above cases, renewable energy is the key, without which no Hydrogen can be produced without a Hydrocarbon or an external heat is supplied for splitting Ammonia.

Ammonia can also be split into Hydrogen and Nitrogen using external heat.  The resulting Hydrogen can be used to generate power using a Fuel cell or run a Fuel cell car. Nitrogen also has many industrial applications.Thereoefore ammonia is a potential chemical that can substitute fossil fuels in the new emerging renewable economy.

There is a general opinion that Hydrogen is now very expensive compared to Gasoline and Diesel. It depends on how you generate Hydrogen. We have used Gasoline and Diesel for several decades and real cost of crude oil is much lower than what we are paying for Gasoline and diesel at the service stations. Crude oil is formed naturally and all the cost involved is for pumping, transportation and refining. The cost of energy spent on transportation and refining is also comparatively low. It is the geopolitical situation in the world, supply demand gap, Government taxes and levies, inventory levels, financial market and distributors play a key role in fixing the price of these fuels.

Hydrogen can be generated from tap water without involving fossil fuels at all. But Governments are spending on research and development of Hydrogen generation using fossil fuels such as natural gas and coal. It is understandable that these sources are suitable for bulk production of Hydrogen on an industrial scale. We will also be able to use existing fossil fuel infrastructure to the most extent. But the flip side of this approach is Hydrogen generated by this route is still not pure enough to meet Fuel cell requirements. This Hydrogen may be suitable for Hydrogen combustion engines. Why they are not suitable? For example, Hydrogen is generated from natural gas by steam reforming,Syngas is generated as an intermediary product which is a mixture of Hydrogen and Carbon monoxide; but also other impurities present in natural gas such Sulfur,Phosphorus and Mercaptans etc.Natural gas has to be purified to remove all these impurities before it can be subject to steam reformation. In spite of an elaborate purification methods adopted, Fuel cell suppliers are reluctant to guarantee the life of their Fuelcell.The Fuel cell uses expensive Platinum as a catalyst which can be readily poisoned by the presence of impurities in Hydrogen, produced from natural gas. This is one of the main reasons why Hydrogen becomes expensive by this route. Industries can pay high cost for this Hydrogen, but ordinary citizens cannot afford to pay.

Hydrogen can be generated directly from tap water by simply electrolyzing it using a Direct current such as solar and wind. If we use grid power, it requires about 68kwhrs of electricity, costing about $3.40 per Kg of Hydrogen. Assuming Hydrogen will cost about $5 per kg after compression and storage, it is still worth the cost. This Hydrogen will give a mileage of 73.4 miles/kg using Fuel cell car. This is equal to 3.67 Gallons of gasoline costing about $13.76, at the rate of $3.75 per gallon. It is very clear that hydrogen is cheaper than gasoline or diesel. At the current price,Gasoline  costs 275% more than Hydrogen gas.

By converting existing coal and oil based power plants into IGCC, Integrated Gasification and Combined Cycle plants, Government can cut the current emission levels of greenhouse gases, and at the same time supply electricity at the prevailing rates. We do not have to import oil or gas. Government should fund conversion of coal and oil-fired power plants into IGCC plants and create Hydrogen infrastructure, by producing more Hydrogen Fuel cell cars and Hydrogen service stations. By adopting this policy, US Government can bring down the prices of crude oil in the international market which will help cut the prices of all other petrochemical products like fertilizers, plastics, drugs and cosmetics. The crux of the issue is to divert petroleum products from fuel use to other uses. At the same time Governments can reduce their greenhouse emissions to the level demanded by scientists. By reducing the cost of solar panels to less than $.100 per watt, Renewable Hydrogen will become a commercial reality and that will be the end of fossil fuels.

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