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Category Archives: Hydrogen

Hydrogen from Coal

Coal is an important fuel that helped industrial revolution. It is still a main fuel for power generation in many parts of the world. It is also an important raw material for number of chemicals and they directly compete with Hydrocarbons such as Naptha.It is abundantly available and it is cheap. We are still able to generate electricity at 5 cents per kwhr using coal. But, now we are entering into a new phase of energy generation and distribution, due to changing environmental and climatic issues of the twenty-first century. We need completely a new fuel to address these issues; a fuel that has a higher heat content, which can generate more power per unit value of fuel, and yet, generates no pollution. It is a challenging job and the world is gearing up to meet these challenges. They affect the world because any issues about energy impacts each and every one of us. Many industrialized countries around the world are reluctant to sign an agreement that compels them to cut their greenhouse emission to an acceptable level set by UN panel of scientists.

Governments such as US, China and India are reluctant to sign such an agreement because their economy and growth depends upon cheap energy, made from coal. Such an agreement will be detrimental to their progress, and the leaders of these nations are not ready to sign such an agreement. They also understand that world cannot afford to continue to use coal as they have used in the past. It is simply unsustainable. It is a precarious situation and they need to carefully plan their path forward. On one hand, they need to keep up their industrial and economic growth, and although they need to cut their emissions and save the world, from catastrophic consequences of global warming.

A simple analysis of the fuel will show that Hydrogen is a potential energy source for the future. It has energy content at least five times more than a coal for a unit value. Coal has an average heat content of 5000 kcal /kg while Hydrogen has an average heat content of 39,000 kcal/kg. Coal has a number of impurities such as ash, sulfur, phosphorous, other than carbon. Burning coal will emit greenhouse gases with toxic fumes that have to be removed. Therefore, these industrialized countries are now looking ways to generate Hydrogen from coal; that too at a cost which will be comparable to other current fuels such as natural gas. It is not an easy task because natural gas is formed by Mother Nature over several hundred thousand years. It is readily available and there is no manufacturing cost except processing cost. We are used to free energy from Mother Nature. This is the crux of the issue.

Hydrogen is the most abundantly available element on earth; yet it is not available in a free form. It is available as a compound, such as, joined with oxygen forming   water H2O molecule; or joined with Carbon forming Methane CH4 molecule.This Hydrogen should be separated in a free form, and this separation requires energy. How can coal, which is just a Carbon, generate Hydrogen?  It requires an addition of water in the form of steam.  When coal is gasified with air and steam, a mixture of Hydrogen and Carbon dioxide is generated, known as Syngas (synthesis gas).

2C + H2O+O2  ———  2H2 +2 CO2

The syngas is separated into Hydrogen and carbon dioxide using various methods using their difference in densities. The Hydrogen can be stored under pressure for further use. Research work is now under way to capture carbon dioxide for sequestering. Carbon sequestration is a method of capturing carbon dioxide and storing it in a place where it cannot enter the atmosphere. But the technical feasibility and economic viability of such a system is yet to be established.

Carbon sequestration is a new concept and the cost of sequestration can potentially increase the cost of energy derived from Hydrogen despite the fact, Hydrogen has energy content five times more the carbon. However, there is no quick fix for our energy problems, and we have to reconcile to the energy cost will increase in the future but eventually cut the greenhouse emissions. These developed countries should at least show to the rest of the world, how they plan to cut their emissions and their action plans; such disclosure should be subject to inspection by UN panel. In the absence of any concrete mechanism, it will be impossible to stop the global warming in the stipulated time frame considering the fact that a number of coal/oil/gas-fired power plants are already under implementation.

Hydrogen assisted combustion

We have been using fossil fuels like diesel, petrol and natural gas for power generation and transportation from the time of industrial revolution. The basic fuel and the combustion technology are practically the same with efficiencies less than 40%. In fact we have become very complacent with both the fuel and the combustion technology and there were no major research and development on both the above issues. In fact we became completely dependent on these two issues and there was no real breakthrough either in substituting the fossil fuel or in the combustion technology. The basic reason behind this situation can be attributed to the discovery of electromagnetism, which opened the way for electricity generation as well as transportation. In both these industries, the key part is the motor which provided a rotary motion. This rotary motion generates electricity in turbines and such motion is created by combustion of a fuel, which is invariably a fossil fuel. We have carried on this for few decades before the emission of greenhouse started rising abnormally and became an issue.

We are now at cross roads wondering what the future holds for the world. Is it possible to carry on the business as usual or look for an alternative source of energy? We started looking at various sources of energy as an alternative. Any alternative energy source should meet two critical parameters namely the lower or no carbon emission and sustainability. Low carbon can be achieved by few methods. The immediate option is to maximize the energy efficiency of existing systems so that for the given input of fuel the output is much higher than what we have achieved all these years. But this increase in efficiency should be real to achieve the emission levels of greenhouse suggested by the UN panel on climate change.

The second option will be to switch over to different fuels with less carbon emission e.g., coal-fired power plants switching over to gas-fired power plants using combined cycle. Retrofitting organic Rankin cycle as a bottoming for steam turbines to squeeze out some extra energy. Decentralizing the power plants in a phased manner in favor of distributed energy systems where gas, instead of electricity, can be supplied to each industry, to generate their own power using CHP process. All these measures can help reduce the emission level but our dependency on fossil fuel will still continue.

W can look at a completely different fuel source and new technology for power generation and transportation. If we look at carefully there are not many alternative fuel sources except Hydrogen that could meet these limits. We are also trying to develop bio fuels. But biofuels are also organic chemicals with carbon backbone which will generate greenhouse emission. Moreover bio fuel sources such as palm oil, corn are also food sources. There is an indiscriminate deforestation and plantation of palm trees in tropical countries like Malaysia, Indonesia and PNG. The focus is now shifting to carbon based organic compounds like biofuel and biogas. This will create a situation where food crops will be substituted with energy crops creating food shortage.But the carbon dioxide level in the atmosphere may not be reduced drastically by these methods.

We need to develop an energy source which does not emit any carbon emission and at the same time we should be able to use existing technology to the possible extent. Only Hydrogen can meet these requirements. In the current situation it is impossible to substitute fossil fuels in a short span of time. We can cut fossil fuels by blending with Hydrogen to the most extent possible so that we can meet two goals. We can cut the carbon emission and at the same time we can deploy Hydrogen as a blended fuel with fossil fuel and not, pure Hydrogen. Since Hydrogen is a very light gas and readily forms an explosive mixture with oxygen, this opens up a new opportunity to develop Hydrogen assisted combustion process in power generation as well as in transportation. It will be easier to handle a mixture of natural gas and Hydrogen for combustion in Gas turbine, or spark ignited reciprocating engines, as well as, gasoline combustion engines in cars. This will also gives us an opportunity to develop advanced and competitive systems like Fuel cell as an alternative technology for combustion process in due course of time.

The hydrogen assisted combustion technology is much easier, faster and economical and at the same time cut the greenhouse emission to an accepted level. But the source of such Hydrogen cannot be natural gas but only renewable sources. The renewable technologies such as solar, wind, geothermal, OTEC (ocean thermal energy conversion) should generate renewable Hydrogen. This is the key for sustainability as well as for greenhouse gas mitigation. These two benefits are too attractive to ignore and it is time we move from total fossil fuel to Hydrogen blended fossil fuel. The blended fuel along with the energy efficiency measures suggested above should go hand in hand, so that we may get over this turbulent period of financial crisis and global warming.

It is also possible that Hydrogen assisted combustion be adopted for coal-fired power plants by simply firing coal slurry, finely powdered coal blended with water and conveyed pneumatically for firing boilers and also for gasification process to generate syngas for IGCC (Integrated gasification and combined cycle) applications. Syngas production will be critical in the near future for a smoother transition from fossil economy to Hydrogen economy irrespective of the route we adopt.

How to generate Hydrogen from you tap water?

Hydrogen is the cleanest source of energy that can power your homes and fuel your cars. It can potentially substitute diesel and petrol or coal and clean up our environment. Hydrogen has been manufactured industrially for the past several decades and transported across thousand of kilometers by pipelines in Europe. The science and technology of Hydrogen is well known but its application to generate power and fuel a car is relatively new. The gasoline internal combustion engines that drive our gasoline cars can be modified to suit Hydrogen fuel. But the physical and chemical properties of Hydrogen gas created a necessity to alter existing gasoline engines for commercialization. But such conversion has been painfully slow for couple of reasons. There is a stiff resistance from gasoline cars to switch over to Hydrogen because they have a well established infrastructure to manufacture gasoline cars and to supply gasoline through well established distribution network. But Hydrogen cars lack both of them. Even if the cars can be modified for Hydrogen, there are no sales or distribution network for the fuel Hydrogen, similar to Gasoline. Even consumers need to be educated that Hydrogen is safe, environmentally friendly and we need not depend on import of oil and so on. It is a blessing in disguise that Hydrogen can be generated by each home, business and industries for their captive use from their tap water. Recently Hydrogen fuelled scooters have been introduced in the market. There are number of advertisements in the media too; that you can fit a Hydrogen generator at your car that will reduce your gasoline bills substantially and also cut your emissions.But these Electrolyzers can generate only water gas and not a pure Hydrogen. Yet such simple devices can help reduce your petrol bills to an extend .If things are so simple why are we still struggling with high crude oil prices and increasing electricity bills? Let us examine this in detail. Water (H2O) can be split into Hydrogen (H2) and Oxygen (O2) by simply passing an electric current through water using a battery. The water disassociate as follows: 2    H2o———   2 H2+ )2 Stochiometrically, it means 36 lits of water will generate 4 Kgs of Hydrogen and 32 kgs of Oygygen.The current PEM (Proton exchange membrane) Fuel cell car (Honda FCX clarity) can drive 100 miles with just 0.105 kgs of Hydrogen from 5000 psi Hydrogen tank. Similarly 4kgs of hydrogen can generate about 100 kws of electricity using PEM Fuel cell, based on a conservative estimate; but 4Kgs of gasoline can generate only 15 kW electricity. The gasoline engine offers only 100km mileage from 13 kgs (16lits) of gasoline. In other words, 0.105 kgs of Hydrogen at 5000 psi gives the same mileage as 16 lits of Gasoline.  This is the amazing power of water, yet to be unleashed! The tap water is suitable to generate Hydrogen by adding a little amount of potash lye to improve the electrical conductivity. An Alkaline water electrolyzer can be attached to the water tank to generate required amount of Hydrogen based on the above calculation. The resulting Hydrogen has to be compressed to a required level. The power consumption to electrolyze water will be about 75-80 kwhrs per Kg of Hydrogen generated at 5000 psi.Therefore 4Kgs of Hydrogen will need a power of 300kwhrs costing about $30 for a total mileage of 3800 miles. You will need a small reverse osmosis unit to be attached to your water tap so that the water is de-ionized so that there is no precipitation in the Electrolyzer or reduction in the efficiency of electrolysis. Recently, Suzuki Bargeman introduced Hydrogen Fuel cell scooter which claims to offer a mileage of 200km from 12 lits Hydrogen (carbon composite material) tank at an higher pressure of 10,000psi.The future of Hydrogen car is very promising and finally the world can hope to get rid of smoke and noise from our roads and cities.

Water- Fuel of the future

Water makes up 71% of the planet earth and it is the most potential energy source of the future. Water is a product of combustion between Hydrogen and Oxygen, two most abundantly available elements and   vital for life on earth. The bondage between Hydrogen and Oxygen is so strong that it requires a certain amount of energy to separate them. Separation of Hydrogen and Oxygen using the process of Electrolysis is a well-known technology. Separation of water by high temperature using Thermolysis has also been studied.  In both the processes the separation of Hydrogen and Oxygen after decomposition is a key step because of the strong affinity between the two elements. Hydrogen has to be separated in a pure form without any trace of Oxygen. Currently most of Hydrogen is generated commercially by steam reforming natural gas because of its easy availability as piped gas in many developed countries. Moreover steam reforming is a well established commercial technology that has been used for decades in chemical process industries. The hydrogen resulting from steam reforming is acceptable for combusting in Hydrogen internal combustion engines but not pure enough for a Fuel cell car. Any trace of impurity from natural gas such as Sulfur or Mercaptans can potentially poison the catalyst used in fuel cell which is very expensive. Hydrogen with purity less than 99.99% is not recommended for Fuel cell applications.

Currently there are few issues to be addressed before Hydrogen becoming a commercial fuel. The energy required to separate Hydrogen from water by commercial electrolysis is about 6Kws (kilowatts) to generate 1 m3 (cubic meter) of Hydrogen. Two key factors for electrolysis are purity of water and  direct current source. Water of certain purity is a critical part for Hydrogen generation. Deionized water with electrical conductivity less than 0.10 micro Siemens/cm is required. Normal drinking water conductivity is less than 100micro Siemens/cm. The potable water can be deionized with reverse osmosis system to get necessary quality. In fact both high purity water and direct current are not commercially available. A renewable energy sources such as solar or wind that generates direct current can be used for electrolysis. This will drop batteries and rectifier that we normally use in renewable energy systems. The generated Hydrogen can be stored in cylinders under high pressure. The stored hydrogen is the stored energy that can be used as and when required.  We can use the stored Hydrogen to generate electricity to meet our power requirement whether it is a home or business or industry. The major advantage with this system is that we can generate power when we need and we don’t have to depend on the grid power. We can also export surplus power to the grid. In fact all DC appliances can be connected with DC power from Fuel cell and operated to improve the efficiency. Such a system is ideal for remote locations without any grid supply such as remote villages or islands.

The same stored Hydrogen can also be used as fuel for a car whether it is a combustion engine or a Fuel cell car. Hydrogen can be compressed and stored under high pressure. Alternatively, Hydrogen can be stored using metal hydrides in smaller volumes. Honda introduced the first fuel cell car in the market in 1999. Since then they have made considerable improvements. Honda FCX Clarity, sedan offers a mileage of 270 miles for a single cylinder of Hydrogen at 5000 psi pressure. They are introducing a latest model with Hydrogen pressure at 10,000 psi which will considerably improve the mileage further. Unlike Hybrid cars, Fuel cell cars run silently and experts who have test-driven the car are very much impressed with the performance. Similarly Ford introduced Hydrogen combustion engine 6.8 liters V-10 engine to power E-450 Hydrogen shuttle bus. Ford modified their Gasoline engine to suit Hydrogen fuel.

Substituting Gasoline with Hydrogen is no longer a theory but a commercial reality. More and more research is being undertaken to improve the performance. Currently the cost of Hydrogen cars and Hydrogen fuel is expensive, due to lack of infrastructures to manufacture such cars or to distribute Hydrogen. However these cars will soon replace gasoline cars. Similarly homes and business can generate their own electricity for their daily use using stored Hydrogen. Water will become the fuel of the future and Hydrogen will clean up the air that has been heavily polluted by fossil fuels for decades.

Renewable Hydrogen- Future source of clean energy

I use the word ‘renewable Hydrogen’ for the Hydrogen derived from water using  renewable energy sources such as solar, wind, geothermal, wave energy, ocean thermal energy conversion systems and biological processes. Hydrogen is clearly the energy source of the future because it has got the highest energy content, compared to any other fossil fuels such a diesel, gasoline, or Butane. The energy content is more than three times that of natural gas, which is considered as the cleanest commercial fuel available in the market. The heating value of Hydrogen is 61,100Btu/lb compared to 23,879 Btu/lb of natural gas. Moreover, only Hydrogen can guarantee a complete reduction of Carbon dioxide from the atmosphere. The problem with renewable Hydrogen is the cost, at current situation. The DOE (department of energy, USA) has targeted a cost for Hydrogen production at $10to $15 per mmBtu, which is comparable with current Natural gas cost. Currently bulk of the Hydrogen is commercially produced by steam reforming natural gas. However; this process will emit carbon dioxide at the rate of 11,888gms per Kg of Hydrogen produced. Though the cost of Hydrogen by this route is cheaper, mitigation of carbon dioxide is clearly an environmental issue. However it is an important route during the transition process from fossil fuel to a full fledged Hydrogen economy of the future.

Natural gas is increasingly in demand and the price of natural gas keeps increasing as the supply demand gap widens. Large natural gas liquefaction plants are already in operation in many parts of the world and number of new plants are under implementation or under planning stages. Japan, South Korea, Taiwan are three largest importers of LNG (liquefied natural gas) from Australia in Pacific region. There are many coal seam methane gas facilities already in operation in Australia and many are under planning. Due to the disaster at Fukushima nuclear plant, Japan has stepped up its import of LNG. India and China, which have been traditionally using coal as a major fuel, have started importing LNG for their power plants. This has pushed the prices of LNG in the international market significantly. Though LNG is relatively a cleaner fuel, it is very expensive to build import terminals. Moreover countries like India and China do not have a good distribution network by peipelines.The economy of scale also favor only large capacity LNG plants and terminals.  However it is not a sustainable solution in the long run considering the fact that supply of natural gas also keeps dwindling steadily. Despite all these obstacles, Governments around the world are looking only for short-term solutions like LNG, simply because it is an easy fix.

Biogas can be generated from organic waste and waste waters by anaerobic digestion. Many sewage treatment plants around the world have started generating biogas to generate power for captive use and to export the surplus power to the grid. Similarly municipalities are also implementing projects to convert ‘waste garbage’ to ‘energy’. However, the scale of operation favors only large capacity plants in larger cities. However these biogas plants will still emit carbon dioxide because biogas will be combusted using conventional engines, micro turbines and Fuelcells.This is once again a temporary solution only. We need to look beyond all these technologies to really cut the greenhouse emissions.

The only option is by Renewable Hydrogen and we need to take steps to make it a commercial reality. Biohydrogen is another potential technology. However the technology is still in a nascent stage but it is promising. Renewable Hydrogen using renewable energy sources are our best bet. Countries have already started investing in renewable energy infrastructures such as solar and wind. They can as well plan for renewable Hydrogen so that they can be certain about three things. One, they can generate and use uninterrupted power supply without importing oil or gas. Secondly they can be certain that greenhouse emissions can be reduced to pre-industrialization level. Thirdly they can be certain about the last cost of energy and its stability in the long run. These are three important factors every citizen of a country is looking for. It requires political will, determination and swift action on the part of each Government.

Carbon and human survival

Carbon is the backbone of an organic life on earth. Every life from the smallest microorganism to human beings is made up of carbon. A cycle  called ‘carbon cycle’ that decomposes carbon into carbon dioxide which is used to synthesis Carbohydrates by the  process known as  ‘photosynthesis’ in presence of water and sunlight, as described in the following equation:

6CO2+ 6H2O   + sunlight →  C6H12O6 + 6O2

The oxygen generated during the above process and carbohydrates sustains life of animals and microorganism on earth. These lives consume oxygen and carbohydrates and releases Carbon dioxide by respiration into the atmosphere. The released carbon dioxide breaks down carbohydrates and other organic matters and regenerates carbon dioxide for reuse by animals and other lives. Not all organic matters are decomposed and part of it is stored as carbon biomass in the roots of plants and other organic matters and buried under earth. After millions of years these organic matters turns into fossil fuels under pressure and higher temperature. Carbon is distributed on earth, in water and in atmosphere. Due to increase in population and industrial growth over several decades the carbon dioxide increased gradually in soil, water and atmosphere. Carbon dioxide is also released by natural events like volcanic eruptions.

But the level of carbon dioxide in the atmosphere increased rapidly after industrialisation, when industries unearthed buried fossil fuels and burnt. In fact we are burning carbon at a faster rate than it is regenerated. It is purely man-made and it increases the presence of carbon dioxide both in atmosphere as well as in oceans. The rapid increase of green house emission started 240 years ago when industrial revolution started. The consequences of this unabated greenhouse gases due to combustion has caused ‘global warming’ with many consequences.

As I have mentioned in my previous articles, power generation and transportation are the two major industries that emit bulk of the greenhouse emission. Both industries use age-old technologies of combustion. The world has been complacent about fossil fuels and grossly indifferent to industrial pollution for decades. Global warming is looming as the biggest threat of the twenty-first century, yet we are not acting. Politicians deny global warming and they want to carry on the business as usual, at the peril of the future generations.

Powerful countries like US, China and India are reluctant to pass a unanimous resolution to set target for carbon emission, while smaller nations remain as powerless onlookers. These powerful nations can drag the rest of the world with them to face the wrath of the Mother Nature with disastrous consequences for their inaction.

It is quite obvious that world have no choice but switch to cleaner energy sources and leave the fossil fuels buried deep under the earth. A new paradigm shift in the way we generate energy and use them is the key for the survival of mankind. We need to develop Hydrogen as an alternative fuel source and Government should encourage innovations in such technologies, while they simultaneously price carbon. In the absence of a concrete legislation and mechanism to penalize polluters, industries will continue to use fossil fuels. A simple cost benefit analysis will show that taxing on polluters and simultaneously introducing renewable technologies will benefit the world in the long run.

 

 

 

 

 

 

 

Hydrogen-the only alternative to Petrol

Our modern civilization has been shaped by oil or Hydrocarbons for several decades to such an extent that there is no immediate substitute for petrol, the world can count on. In fact the world has been complacent about the availability of Hydrocarbon, its applications and its future. Political leaders have competed with each other to make sure that their supply of oil and gas is guaranteed as a  matter of national security. Some countries even waged wars to secure oil fields. This situation is getting worse, as the supply of oil and gas are becoming uncertain and supplies dwindling. Each and every human being in the world is affected by oil and gas in one way or other, irrespective of the size, geography and rate of industrialization. The main reason for this situation is, the contribution of hydrocarbons made in the field of power generation and transportation.

Currently more than 80% of power generation comes from fossil fuels such as oil, gas and coal. The entire transportation industry all over the world depends on oil and gas. The petrochemical industry’s contribution to our modern civilization is tremendous. It encompasses a whole range of industries whether it is fertilizers or plastics and resins or chemical industries or drugs and pharmaceuticals or cosmetic and toiletries and so on. These major industries determine the progress, civilization and industrialization of a nation. Countries who have vast resources of oil and gas are one of the richest countries in the world, even though these countries have no other resources. Countries with vast population and resources have to depend on oil and gas imports for their industries and transports. Countries with vast mineral resources cannot run their mines without power or transportation.

It is time we look at why oil and gas has become such a critical components in the progress of a nation and how this situation can be overcome. The two major technologies, which depend upon hydrocarbons, are power generation and transportation. Both these technologies use heat as a primary energy. In power generation, heat energy is converted into mechanical energy and then to electrical energy. In transport industry, the heat energy of the fuel is converted into mechanical energy. In petrochemical industry; oil and gas are converted into various chemical products by various chemical reactions and processes.

If we closely look at the Hydrocarbon molecule, one thing is obvious. In a Hydrocarbon molecule, Hydrogen atoms are attached to carbon atoms. A simple example is, Natural gas or Methane gas, represented by chemical formula CH4. Four Hydrogen atoms are attached to a carbon atom, which actually imparts the heat energy (heat content) to the molecule. Without Hydrogen atoms, it is nothing but carbon. If we look at the heat value of Natural gas and Hydrogen, one will understand that Hydrogen has got a higher heating value. What is more interesting is there will be no greenhouse emission (carbon dioxide or carbon monoxide) by combusting Hydrogen. It is only water that is the byproduct of combustion of Hydrogen. If we can generate power or drive a car by combusting a Hydrocarbon, then why not combust Hydrogen to generate power or drive a car using the same combustion process? Even if one considers Hydrogen as too dangerous to handle, a mixture of a minor part of biogas or natural with Hydrogen should solve the issue. It is certainly possible and only Hydrogen can replace oil and gas. We can use a combustion technology we knew for decades or use Fuel cell technology that we start using recently with Hydrogen. It is a clean technology and it does not emit smoke or make noise. Whichever way we looks at it, only hydrogen can replace Petrol. Sooner it does, better for the world.

 

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