Hydrogen - the developing alternative fuel
Feb 9, 2020 16:13:23 GMT 10
KeithB, nsgnomad, and 1 more like this
Post by collyn on Feb 9, 2020 16:13:23 GMT 10
I had intended to put this on my website - but will do another version for that. Please note the following is copyright.
Collyn
A Hydrogen Economy
The Industrial Revolution changed our economy. For thousands of years it was based on human labour-intensive agriculture and later plus-agriculture, and minor very small scale manufacturing. Then, and mainly in Britain, newly-found energy sources such as coal (and then oil) enabled machines that multiplied human energy. This transformed manufacturing, transport and more recently communications. Within decades it spread substantially worldwide. Virtually all, however, was based directly and indirectly on burning hydrocarbon fuels like coal and oil. Not realized at the time, all such fuels release damaging carbon to the atmosphere: e.g. carbon dioxide, carbon monoxide and unburnt hydrocarbons. The result was global warming
In 1970, the University of Michigan’s Lawrence Jones suggested hydrogen could be a far better form (of energy). He stressed it can be used to run existing internal combustion engines. Burning hydrogen nevertheless releases nitrous oxide (that forms smog). It also results in a major loss in efficiency (as with any process that ignites and burns fuel). That loss, long since known) is quantified by Carnot’s Law. Hydrogen can nevertheless produce energy without being burned. It is done chemically by converting it to electricity via so-called fuel cells.
The major case for changing to a hydrogen-based economy is that it automatically reduces global warming. Its usage produces no polluting emissions. In industrial and home use, large fuel cells already produce both heat and electricity. That heat usefully warms water and (in an improbable-seeming process) also cooling.
Honda (USA) states using a hydrogen fuel cell to power an electric motor is two to three times more efficient than burning hydrogen in a combustion engine. An alternative technique bonds hydrogen with air-borne nitrogen. The result (ammonia) is a clean fuel. In 2018, Australia’s CSIRO successfully ran a Toyota Mirai and a Hyundai Nexo using hydrogen (separated
Germany and Japan have even more hydrogen supply stations, but with over 5000 hydrogen-powered cars, California is using them.
Downsides exist, but relative to otherwise ongoing global warming seem minor.
One is that, even if compressed or liquefied, hydrogen takes up a lot of room. Its energy density (by volume) is 25% that of petroleum. By weight, however, it has about three times the energy of petroleum and natural gas. A fuel cell/electric motor
There are still problems to overcome, however it is two to three times more efficient than those currently petrol or diesel-engined.
Fuel cells are now available, but still initially costly. Expensive too is the high-quality methanol that some require. Hydrogen is corrosive. Further, that used in current fuel cells must be ultra-pure. The benefit (of a truly major fall in emissions) is so great that massive efforts are being made globally to achieve this. Present indications are that this can be achieved between now and about 2040.
Producing Hydrogen
On Earth, at least, hydrogen does not occur naturally. Most is bonded to oxygen in the form of water. It can be released but requires heat to do so. This requires using some existing energy, but that most seemingly promising is from large scale solar farms, wind turbines, wave and tidal power. Right now, however, most are produced via a steaming process powered by coal, natural gas or oil but even then there is major emissions reduction as once made it usage does not add further.
Hydrogen can also be produced by electrolysing water (i.e. passing an electric current through it). This, currently (as it were) is about 70-80% efficient. Roughly, producing a kilogram of hydrogen (in terms of energy that’s 40 kW hours) need 50–55 kWh of electricity. Not a problem if solar-generated because storing negates any need for battery storage.
Another and totally different approach is using bacteria. In one process, hydrogen is produced from organic matter – including sewage. It can also be done by depriving algae of sulphur produces it produces hydrogen (i.e. no oxygen). It works also with many waste feedstocks.
There are many other methods. One uses a solar photochemical ‘cell’ breaks down water into hydrogen and oxygen by electrolysis. Another, already trialled in Spain, used concentrated solar to heat water (to over 1000o C) to break it down to hydrogen and oxygen.
Hydrogen can also be harvested from non-wanted by-products of processes such as producing chlorine.
Storing Hydrogen
In terms of mass, molecular hydrogen has a very high energy density. As a non-pressurised gas, however, it has very low energy density by volume. For vehicle use hydrogen must be stored in an energy-dense form to provide sufficient driving range. Increasing its pressure assists, but whilst tanks can be smaller, they need to be strong. Further, some energy is needed to compress the gas (typically to 70 Mpa). The hydrogen molecule is tiny. It can diffuse through whatever contains it, weakening that container.
There various other solutions, but mainly for large scale transport. One is to freeze it to -2520 C. Another is to store as a chemical hydride (i.e. bonding it with another material such as magnesium hydrate).
Another (and simpler) is to store it in huge underground caverns (ICI has done for many years) but some is lost in doing so. It can also be stored in already depleted oil wells. Existing natural gas networks may also be suitable. Germany’s natural gas is mostly hydrogen anyway. Here, some hydrogen resistant internal coating will almost certainly be required to protect against corrosion.
Electricity grid balancing
Apart from emissions, a major issue with coal-fired power stations is they lack the equivalent of instant volume control. Much of the time they produce far more energy than is required but struggle to cope with peaks. Here again, storing that excess energy in the form of hydrogen.
Transporting hydrogen
This requires an industrial-scale system. It is likely to be a mix of pipelines and filling stations, plus large cylinders similar to those for LP gas, and possibly mobile tankers. Experience already exists. The USA has over 1100 km of hydrogen pipelines.
There is a probability that hydrogen gas as stored energy for use in various sectors of the economy. Producing hydrogen from primary energy sources other than coal, oil, and natural gas, would result in lower production of the greenhouse gases characteristic of the combustion of these fossil energy resources. Another solution is to avoid the problem by expanding the electricity network by enabling filling stations to literally produce hydrogen via electrolysis. There will be some loss of efficiency.
Safety
The main risk is of explosion if hydrogen leak in enclosed areas. When burning the flame is virtually ultra-violet and may not be seeable. It acks odour. Hydrogen sensors already exist and there are codes and standards in this area. Canada has already noted that the risks are similar to those of compressed natural gas.
Emissions & reductions
Using hydrogen by and large is emission-free. This is a huge plus. There is some concern, however, that attempts may be made it produce it in a manner that has environmental impacts. By the best way is by electrolysing water via solar-generated electricity. Some emissions occur in the process of producing the cells, but very low compared with reforming fossil fuels.
There could also issues because some molecular hydrogen leaks from most containment vessels. If it does, ultraviolet radiation can cause it to form free radicals (unstable atoms) in our upper atmosphere and (indirectly) deplete ozone. It would, however, be very minor.
The UK and other governments are looking at a process enabling aimed at reducing emissions from coal-fired power stations whereby coal is converted into syngas (a mix of primarily of hydrogen and carbon monoxide) The gas is then further cleaned to remove sulphur and other impurities. It then fuels a gas turbine generator that produces electricity. The technology works but imposes an energy loss (of a currently claimed) 8-12%.
Cost
Little reliable data on hydrogen production (as such) is currently available. A decade of so back, if produced by electrolysis or steam reformation, it was several times more costly then energy equivalent of natural gas. It needs a lot of electricity to produce (30-40 kWh per 1 kg of hydrogen) but once generated it is cheaper to store.
Whilst not realistically quantifiable, even were hydrogen to cost far more than emission-producing alternatives, the huge reduction in global warming and health issues must be taken into account. We cannot possibly burn oil or coal much longer.
Hydrogen usage right now
Many car and truck makers are not just experimenting with hydrogen energy, several are already producing them. Others have committed to. To some, it is a chicken and situation, in that the demand for hydrogen-powered vehicles depends on the availability of hydrogen. And vice versa.
Iceland probably leads the world in a commitment to a hydrogen economy. Currently, all oil products are imported, but its massive geothermal resources provide ultra-cheap electricity. The country already has hydrogen-powered buses. It has committed to having a hydrogen-based economy by 2050.
In 2003, Turkey (together with the UN Industrial Development Organisation created the International Centre for Hydrogen Energy Technologies.
Hydrogen alternatives
Whilst some governments seem unaware of (or do not wish to know about) global warming, most now do. Because of this a possible hydrogen economy seems increasingly probable. There are, however, a few alternatives.
Hydrogen appeals as it is a relatively simple way of storing and transmitting energy without wrecking the environment whilst doing so. It is, however, possible to combine a hydrogen approach with various alternatives.
One (allied technology) is to bond with (airborne) nitrogen to produce ammonia (a clean and readily transported fuel). This can readily be used in an internal combustion engine. It will not be emission-free but there will be a major reduction. Another is to use hydrogen to produce methanol. Methanol fuel cells have been around since 2004 or so, but are not that efficient.
Yet another approach is to use hydrogen to produce methane. This assists storage as methane has over three times the energy density (of liquid hydrogen). Methane can readily be transported via existing natural gas networks. The fuel is readily usable by in only mildly-modified existing vehicles.
Further (and referred to earlier in this article) excess electrical energy from solar farms and wind generators could be used to electrolyse water to produce hydrogen. That hydrogen could be combined with CO2 to make natural gas.
Copyright (2019) Collyn Rivers
Collyn
A Hydrogen Economy
The Industrial Revolution changed our economy. For thousands of years it was based on human labour-intensive agriculture and later plus-agriculture, and minor very small scale manufacturing. Then, and mainly in Britain, newly-found energy sources such as coal (and then oil) enabled machines that multiplied human energy. This transformed manufacturing, transport and more recently communications. Within decades it spread substantially worldwide. Virtually all, however, was based directly and indirectly on burning hydrocarbon fuels like coal and oil. Not realized at the time, all such fuels release damaging carbon to the atmosphere: e.g. carbon dioxide, carbon monoxide and unburnt hydrocarbons. The result was global warming
In 1970, the University of Michigan’s Lawrence Jones suggested hydrogen could be a far better form (of energy). He stressed it can be used to run existing internal combustion engines. Burning hydrogen nevertheless releases nitrous oxide (that forms smog). It also results in a major loss in efficiency (as with any process that ignites and burns fuel). That loss, long since known) is quantified by Carnot’s Law. Hydrogen can nevertheless produce energy without being burned. It is done chemically by converting it to electricity via so-called fuel cells.
The major case for changing to a hydrogen-based economy is that it automatically reduces global warming. Its usage produces no polluting emissions. In industrial and home use, large fuel cells already produce both heat and electricity. That heat usefully warms water and (in an improbable-seeming process) also cooling.
Honda (USA) states using a hydrogen fuel cell to power an electric motor is two to three times more efficient than burning hydrogen in a combustion engine. An alternative technique bonds hydrogen with air-borne nitrogen. The result (ammonia) is a clean fuel. In 2018, Australia’s CSIRO successfully ran a Toyota Mirai and a Hyundai Nexo using hydrogen (separated
Germany and Japan have even more hydrogen supply stations, but with over 5000 hydrogen-powered cars, California is using them.
Downsides exist, but relative to otherwise ongoing global warming seem minor.
One is that, even if compressed or liquefied, hydrogen takes up a lot of room. Its energy density (by volume) is 25% that of petroleum. By weight, however, it has about three times the energy of petroleum and natural gas. A fuel cell/electric motor
There are still problems to overcome, however it is two to three times more efficient than those currently petrol or diesel-engined.
Fuel cells are now available, but still initially costly. Expensive too is the high-quality methanol that some require. Hydrogen is corrosive. Further, that used in current fuel cells must be ultra-pure. The benefit (of a truly major fall in emissions) is so great that massive efforts are being made globally to achieve this. Present indications are that this can be achieved between now and about 2040.
Producing Hydrogen
On Earth, at least, hydrogen does not occur naturally. Most is bonded to oxygen in the form of water. It can be released but requires heat to do so. This requires using some existing energy, but that most seemingly promising is from large scale solar farms, wind turbines, wave and tidal power. Right now, however, most are produced via a steaming process powered by coal, natural gas or oil but even then there is major emissions reduction as once made it usage does not add further.
Hydrogen can also be produced by electrolysing water (i.e. passing an electric current through it). This, currently (as it were) is about 70-80% efficient. Roughly, producing a kilogram of hydrogen (in terms of energy that’s 40 kW hours) need 50–55 kWh of electricity. Not a problem if solar-generated because storing negates any need for battery storage.
Another and totally different approach is using bacteria. In one process, hydrogen is produced from organic matter – including sewage. It can also be done by depriving algae of sulphur produces it produces hydrogen (i.e. no oxygen). It works also with many waste feedstocks.
There are many other methods. One uses a solar photochemical ‘cell’ breaks down water into hydrogen and oxygen by electrolysis. Another, already trialled in Spain, used concentrated solar to heat water (to over 1000o C) to break it down to hydrogen and oxygen.
Hydrogen can also be harvested from non-wanted by-products of processes such as producing chlorine.
Storing Hydrogen
In terms of mass, molecular hydrogen has a very high energy density. As a non-pressurised gas, however, it has very low energy density by volume. For vehicle use hydrogen must be stored in an energy-dense form to provide sufficient driving range. Increasing its pressure assists, but whilst tanks can be smaller, they need to be strong. Further, some energy is needed to compress the gas (typically to 70 Mpa). The hydrogen molecule is tiny. It can diffuse through whatever contains it, weakening that container.
There various other solutions, but mainly for large scale transport. One is to freeze it to -2520 C. Another is to store as a chemical hydride (i.e. bonding it with another material such as magnesium hydrate).
Another (and simpler) is to store it in huge underground caverns (ICI has done for many years) but some is lost in doing so. It can also be stored in already depleted oil wells. Existing natural gas networks may also be suitable. Germany’s natural gas is mostly hydrogen anyway. Here, some hydrogen resistant internal coating will almost certainly be required to protect against corrosion.
Electricity grid balancing
Apart from emissions, a major issue with coal-fired power stations is they lack the equivalent of instant volume control. Much of the time they produce far more energy than is required but struggle to cope with peaks. Here again, storing that excess energy in the form of hydrogen.
Transporting hydrogen
This requires an industrial-scale system. It is likely to be a mix of pipelines and filling stations, plus large cylinders similar to those for LP gas, and possibly mobile tankers. Experience already exists. The USA has over 1100 km of hydrogen pipelines.
There is a probability that hydrogen gas as stored energy for use in various sectors of the economy. Producing hydrogen from primary energy sources other than coal, oil, and natural gas, would result in lower production of the greenhouse gases characteristic of the combustion of these fossil energy resources. Another solution is to avoid the problem by expanding the electricity network by enabling filling stations to literally produce hydrogen via electrolysis. There will be some loss of efficiency.
Safety
The main risk is of explosion if hydrogen leak in enclosed areas. When burning the flame is virtually ultra-violet and may not be seeable. It acks odour. Hydrogen sensors already exist and there are codes and standards in this area. Canada has already noted that the risks are similar to those of compressed natural gas.
Emissions & reductions
Using hydrogen by and large is emission-free. This is a huge plus. There is some concern, however, that attempts may be made it produce it in a manner that has environmental impacts. By the best way is by electrolysing water via solar-generated electricity. Some emissions occur in the process of producing the cells, but very low compared with reforming fossil fuels.
There could also issues because some molecular hydrogen leaks from most containment vessels. If it does, ultraviolet radiation can cause it to form free radicals (unstable atoms) in our upper atmosphere and (indirectly) deplete ozone. It would, however, be very minor.
The UK and other governments are looking at a process enabling aimed at reducing emissions from coal-fired power stations whereby coal is converted into syngas (a mix of primarily of hydrogen and carbon monoxide) The gas is then further cleaned to remove sulphur and other impurities. It then fuels a gas turbine generator that produces electricity. The technology works but imposes an energy loss (of a currently claimed) 8-12%.
Cost
Little reliable data on hydrogen production (as such) is currently available. A decade of so back, if produced by electrolysis or steam reformation, it was several times more costly then energy equivalent of natural gas. It needs a lot of electricity to produce (30-40 kWh per 1 kg of hydrogen) but once generated it is cheaper to store.
Whilst not realistically quantifiable, even were hydrogen to cost far more than emission-producing alternatives, the huge reduction in global warming and health issues must be taken into account. We cannot possibly burn oil or coal much longer.
Hydrogen usage right now
Many car and truck makers are not just experimenting with hydrogen energy, several are already producing them. Others have committed to. To some, it is a chicken and situation, in that the demand for hydrogen-powered vehicles depends on the availability of hydrogen. And vice versa.
Iceland probably leads the world in a commitment to a hydrogen economy. Currently, all oil products are imported, but its massive geothermal resources provide ultra-cheap electricity. The country already has hydrogen-powered buses. It has committed to having a hydrogen-based economy by 2050.
In 2003, Turkey (together with the UN Industrial Development Organisation created the International Centre for Hydrogen Energy Technologies.
Hydrogen alternatives
Whilst some governments seem unaware of (or do not wish to know about) global warming, most now do. Because of this a possible hydrogen economy seems increasingly probable. There are, however, a few alternatives.
Hydrogen appeals as it is a relatively simple way of storing and transmitting energy without wrecking the environment whilst doing so. It is, however, possible to combine a hydrogen approach with various alternatives.
One (allied technology) is to bond with (airborne) nitrogen to produce ammonia (a clean and readily transported fuel). This can readily be used in an internal combustion engine. It will not be emission-free but there will be a major reduction. Another is to use hydrogen to produce methanol. Methanol fuel cells have been around since 2004 or so, but are not that efficient.
Yet another approach is to use hydrogen to produce methane. This assists storage as methane has over three times the energy density (of liquid hydrogen). Methane can readily be transported via existing natural gas networks. The fuel is readily usable by in only mildly-modified existing vehicles.
Further (and referred to earlier in this article) excess electrical energy from solar farms and wind generators could be used to electrolyse water to produce hydrogen. That hydrogen could be combined with CO2 to make natural gas.
Copyright (2019) Collyn Rivers