What is your opinion on hydrogen?
We are currently in the process of building a hydrogen economy. What is your opinion on this development? Does biogenic hydrogen have great potential for the bioenergy industry or will it remain a niche product?
Hydrogen in a biogas plant, does that fit together? Are there processes for producing hydrogen in a biogenic plant, plants that are traditionally designed for the production of methane? In this chapter the History of bioenergy is about hydrogen and a look into the future of bioenergy with a focus on the biogas industry.
I like colors. No, I love colors. Black and white, very classic, has its elegance and fits wonderfully for selected festive situations. That being said, I'm a friend of the rainbow civilization. Hydrogen, strictly speaking the movement that is currently forming around it, seems to be similar. As if through a prism, the hydrogen economy is now fanning out into the full spectrum of light with numerous colors. First just hydrogen, then green, later gray, then blue, finally turquoise-colored hydrogen. What's next, purple hydrogen? Element number 1 in the periodic table is popular as if we were a nation of painters. The brownfields of bioenergy will also benefit from this current renaissance of hydrogen, and the star of the slowly disappears on the horizon Biogas 2.0 on. Despite the variety of colors, the focus of this article is on the process for producing hydrogen ("bio-hydrogen") in the course of operating a biogas plant. To start with, we start with the general framework for H2 and the just published National Hydrogen Strategy for Germany.
Hydrogen is the oldest and most common element in our star system. When all the atoms in the solar system celebrate a party together, 93 percent of the guests are from the hydrogen family. The remaining 118 elements are shared by the remaining 7 percent on the guest list. In fact, according to the number of atoms, we live not only in a hydrogen solar system, but in an H2 universe. While on the spiritual level people like to say: In the beginning was the Word, we can proclaim on the material side: In the beginning there was hydrogen.
The promises about the potential of hydrogen are huge. There is hardly an energy topic that has experienced such hype since the peaceful use of nuclear energy. Renewable and fusion energy vibrate longer-term and do not have a peak as acute as the current hydrogen. Missing link of the energy transition, clear water as a waste product, key to sector coupling, entry into the fuel cell, independence from oil, highest energy density. All mouths are full of praise for the fly weight of the periodic table. These Vision for a future hydrogen economy it is also what the government has to embrace Expansion plan for hydrogen has moved.
True to the motto What is worth waiting for was yesterday on June 10.06.2020th, XNUMX and despite adverse circumstances, the coordinated National Hydrogen Strategy for Germany announced by the Federal Government. The first draft of the The BMWi's hydrogen strategy still had vocal criticism from industry associations (VKU, VDMA, DWV) and other departments (BMU, BMBF) obtained. One of the biggest criticisms of the first version of the hydrogen strategy was the question of where the hydrogen should be used primarily. Industry and transport were the most persistent in promoting the rare and therefore valuable resource. In the industrial sector, it is above all the achievement of high temperatures (gas!) And in the transport sector the supply of decentralized and mobile units (cars) that cause headaches when switching to low-carbon alternatives. So currently in the German mobility sector Rule of thumb 1.000 hydrogen cars supplied with 100 tons of hydrogen per year from 2 H10 filling stations. I don't know if that sounds a lot to you, but it's a fraction of the German transport sector.
The industry has also campaigned for the green electricity, which is converted into green hydrogen in the electrolysers, to be exempt from the EEG levy. The current amount is 6,7 cents per kilowatt hour (as of: 04.2020). The question of whether only green or blue hydrogen is desired has also been discussed for a long time. The last major point of criticism negotiated the desired one Electrolysis capacity for manufacturing of hydrogen in Germany until 2030. The level of capacity discussed has fluctuated between 3 and 18 gigawatts to date, which corresponds to a hundredfold increase in current electrolysis plants even at the lowest limit (currently 30 MW!).
Published on June 10, 2020
The largest plant for the production of hydrogen worldwide is currently Toshiba's hydrogen plant in Fukushima (commissioning: March 2020). Exactly, the Fukushima. The hydrogen plant can be 1.200 m3 Produce hydrogen per hour, whereby the system is based on a 10 MW electrolyser, which is operated with renewable electricity from an adjacent solar park (20 MW).
The term "Green Hydrogen" is used for hydrogen that is generated by the electrolysis of water with renewable, almost CO2-neutral, electricity. So the splitting of water into its two atomic components, oxygen and hydrogen, with the help of excess electricity from wind, photovoltaic or even biogas plants. In addition to the electrolytic route, there are other approaches for the production of green hydrogen for the bioenergy industry, which is sometimes called Biohydrogen referred to as. After a brief summary of the traditional way of operating a biogas plant, the next step is the procedure for producing hydrogen in a biogas plant, or the increase in efficiency of the biogenic plant with H2.
Put simply, a biogas plant uses the ability of microorganisms (destructors) to break down complex biomass into its basic building blocks and thereby generate high-energy methane (biomethane) as a "waste product". This process takes place in the absence of oxygen and is therefore referred to as anaerobic fermentation. Sophisticated process technologies and operating modes of the plant optimize the microbiological digestion of the biomass. Technological support for the bacteria includes, above all, the bite-sized preparation of the organic starting substrate (digestion, disintegration, homogenization) and the provision of the appropriate framework conditions in the fermenter of the biogas plant (temperature, mixing, etc.). The two classic products of a biogas plant are the gaseous biogas and the liquid digestate. The traditional operation of the biogenic plant leads to the formation of biogas (or syngas) with the following components:
In most cases, after the production of the raw biogas, it is refined or concentrated. This means that unwanted components such as CO2, ammonia or hydrogen sulfide are separated from the desired main product, methane. The high-energy methane is then used in a combined heat and power plant (CHP plant of a biogas plant) converted into renewable electricity and heat. The remaining substances, which could not be converted into biogas in the planned dwell time in the main fermenter, result in the digestate of the biogas process. This comes into the post-fermenter or is used as a fertilizer (manure) to close nutrient cycles. Occasionally the digestate is also dried and in Biochar converted, which has promising properties.
Now to the approaches how a biogas plant can be used for the production of hydrogen. Tomorrow's plant will have at least one other commodity in addition to methane and digestate: hydrogen. Biogas plants are maturing more and more into lively bio factories year after year. The fermenter as a flexible bioreactor that will form the basis for a wide range of hydrocarbons and basic chemicals in the future. This means that biogas plants in Germany can provide a decentralized infrastructure around which Building the bioeconomy continue to support.
The generation of hydrogen in a biogas plant is conceivable in different ways. The graphic shows three approaches to the production of biohydrogen, which are explained in more detail below.
The most obvious and most surprising approach is electrolysis directly in the bioreactor of the biogas plant. Obviously because the fermenter is filled with water, which is forced to separate into hydrogen and oxygen. Surprising because there is a fear that the flow of electricity (electricity) will endanger the work of the fermenting bacteria in the bioreactor.
The research results on electrohydrogenesis show that this does not have to be the case. The foundations for this route to the production of biohydrogen were examined and described in 2007 by Shaoan Cheng, Bruce E. Logan and independently of the first two by René Alexander Rozendal. Building on these foundations, one has also been in the past decade Process for the production of hydrogen introduced into the German biogas landscape. For this purpose, microbEnergy, a company from the heart of the Upper Palatinate, has the BiON®-Procedure developed. This is based on the Biological methanation. I find the name somewhat unfortunate because methane is also formed biologically in the fermenter of a traditionally operated biogas plant. Aside from the name, I find this approach to a power-to-gas plant (PtG) very elegant and it opens the door to a new era of gaseous bioenergy in Germany.
MicrobEnergy, a subsidiary of Viessmann GmbH, was already implementing a larger one Plant for the production of hydrogen from biogas involved. The lighthouse project in Switzerland was realized by Limeco in May 2018. In cooperation with Swisspower, the plant draws on the competencies and plant technology of well-known industry leaders such as Schmack Biogas, Viessmann and Siemens.
As the process sketch of the plant shows, the production of the biogas takes place in two phases. In the first phase, electrolysis takes place separately from the generation of biogas. In the following step, the biogas from the digesters (sewage gas) is combined with the hydrogen and a second phase of biomethane production is started in a downstream bioreactor (fermenter). In this, the hydrogen acts like a bacterial doping for a more complete methanation. This process turbo is due to the improved ratio of carbon to hydrogen. In methane (CH4) there are four hydrogen atoms (H2) per carbon atom (C). The magic of this process sequence is also hidden in the support of the stoichiometry, since one third of the carbon source is carbon dioxide (CO2!). In the sense of a closed circular economy, this comes from the classic anaerobic fermentation in the digesters.
When using mircobEnergy or Limeco, the hydrogen generated is directly used again in order to increase the methane yield in the second bioreactor. I would be interested in what the energy balance of the power plant looks like and whether the higher methane content pays off energetically today despite electricity-intensive hydrogen electrolysis or whether the business case is realized through the good climate balance? As the overview of the specialist agency for renewable raw materials shows, the methane rate in a traditional biogas plant is between 50 and 70 percent, depending on the biomass used. According to microbEnergy, the methane content in the biogas can be increased to over 90 percent (!) By adding hydrogen. The stronger the CO2 price for industry increases, the faster the two-stage biomethane, including CO2 recycling, will pay off.
In Germany, the national hydrogen strategy will open up new funding opportunities for modern biogas plants. Funding for innovative pilot projects in bioenergy (biogas and syngas) is also likely, especially for building up the planned electrolysis capacity, which the hydrogen strategy specifies. The classic fermentation of biomass to produce hydrogen is limited to biomolecules containing sugar, while the application of electricity can also break down organic acids.
The second basic approach for a process for the production of hydrogen within a biogas plant is the recourse to the diligently destructive (decomposing) microorganisms in the fermenter. By making specific adjustments to the way the plant is operated, hydrogen production can be converted. A correction of temperature, pH, starting substrate and micronutrients changes the composition of the biocenosis in the fermentation reactor, which also changes the composition of the biogas. In addition to adapting the physical and chemical framework for the microorganisms, technical innovations are also useful to transform today's biogas plant into an efficient hydrogen plant of tomorrow. Upcoming chapters will take a deeper look at the necessary adaptations of the processes and technologies.
The following are two research projects dedicated to this approach to the production of biohydrogen:
The Dutch-German research cooperation for the production of biohydrogen with and from biomass is funded by the European Union and Interreg. Since April 2019, the scientists have been investigating how residues can be used as a starting substrate for the production of hydrogen. The goal of the team (Münster University of Applied Sciences, PlanET, bio-energy cluster Oost-Nederland and H2 bv) is to research the optimal framework conditions for releasing stored bioenergy from organic waste and waste water. In a second step, BioTecH2 aims to build a hydrogen reactor (hydrogen plant).
The research project has been running since July 2019 and is also funded by the European Regional Development Fund and, like BioTecH2, is dedicated to dark fermentation for the production of biohydrogen. One advantage is that the production of hydrogen and methane in the biogas fermenter can take place separately, both in terms of time and space. It should be investigated where the Sweet Spot the separation, so that the overall efficiency reaches its maximum. Another focus of the research project is the isolation and adaptation of the strains of microorganisms, which can digest the previously unfermented biomass particularly well. Previous results already show bacterial cultures that can produce a biogas with a hydrogen content of 50 to 60 percent under the appropriate framework and starting substrates.
The Dutch-German research cooperation on the production of hydrogen with and from biomass is funded by the European Union and Interreg. Since April 2019, the scientists have been investigating how residues can be used as a starting substrate for the production of hydrogen. The goal of the team (Münster University of Applied Sciences, PlanET, bio-energy cluster Oost-Nederland and H2 bv) is to research the optimal framework conditions for releasing stored bioenergy from organic waste and waste water. In a second step, BioTecH2 aims to build a hydrogen reactor (hydrogen plant).
The research project has been running since July 2019 and is also dedicated to dark fermentation for the production of biohydrogen. The methane and hydrogen production can take place separately, both spatially and temporally. The Sweet Spot the separation to be examined to increase the overall efficiency. Another focus of the research project is the isolation and adaptation of the strains of microorganisms, which can break down the biomass particularly well. Previous results already show a biogas with a hydrogen content of 50 to 60 percent.
One advantage of producing hydrogen via dark fermentation is the possibility of using the residual heat that is generated in the bioreactor anyway. The temperatures of around 50 ° C required to operate the plant are low, which enables energy-efficient production of the hydrogen. Classic water vapor reformation processes or high-temperature electrolysis not only require significantly higher pressures (several hundred bars!), but also temperatures around 1.000 ° C. Another energy advantage is the comparatively small amount of electricity required for dark fermentation. The water is not split electrically, but biologically (enzymatically) by the prokaryotes. Instead of using electricity, bacteria and archaea can form the hydrogen with the help of nitrogenases in the fermenter of the biogas plant. However, the nitrogenases only work under absolutely anaerobic conditions. Smallest amounts of oxygen stop hydrogen production and make the enzyme inactive.
This process has only limited to do with a traditional biogas plant. Nevertheless, this process approach should be briefly presented because it also relies on microorganisms to generate hydrogen. In this process for producing biohydrogen, algae are cultivated in a bioreactor. This process has similarities to the dark fermentation presented, whereby algae belong to the third, independent domain of life alongside bacteria and archaea. For a long time, cyanobacteria were thought to be blue-green algae and there was a parallel use of both terms. Biologists have been separating microalgae and bacteria since 1990. The structure of algae is much more complex and, in contrast to the prokaryotic bacteria (without a real cell nucleus), they are classified as eukaryotes. One of the functional differences of the microorganisms is that bacteria and archaea use hydrogen, as already mentioned in 2.1. presented, produce via nitrogenases (enzyme), while green algae use hydrogenases. What sounds like microbiological shop talk leads to two completely different energy metabolisms. It would be exciting to hear what a microbiologist can report on this difference.
The discovery that algae can give off hydrogen instead of oxygen was the first to be discovered by biochemist Hans Gaffron. The hydrogen pioneer Gaffron studied in Berlin and came across the end of the 1930s by chance that, in addition to prokaryotes, unicellular eukaryotes, in the case of green algae, can also form biohydrogen. Half a century later, in the 1990s Anastasios Melis from the University of California at Berkeley found that the green algae Chlamydomonas reinhardtii starts hydrogen to generate as soon as it does not have enough sulfur available. The sulfur is necessary to assemble the hydrogenase, which acts as the catalyst enzymatic breakdown of molecular hydrogen in hydrogen ions.
The advantage of producing biohydrogen via algae is that sunlight is mainly used as an energy source to split the water. The microorganisms act as a biocatalyst and do the photolysis.
The third way to generate hydrogen from biomass follows the regular biogas process and the process can also be used completely detached from a biogas plant. With a focus on a biogas plant, one of the two classic products of biomass fermentation is used: the biomethane or the residue. Especially in a NawaRo plant, the proportion of bound hydrogen in the digestate is still very high and is both organic (lignin, cellulose, lignocellulose) and inorganic (ammonia, ammonium). Instead of using the digestate as a commercial fertilizer, it can be further digested directly at the location of the biogas plant and the hydrogen released in parallel. In these thermochemical processes, the digestate is exposed to high pressures and temperatures, causing biomass that is difficult to digest to lose its molecular bond.
A handful of thermal processes are available to syngas to gain from biomass. In addition to the carbon oxides (mono- and di-) that have to be separated anyway, this generated syngas also contains hydrogen.
Steam reforming is based on two Nobel Prizes in chemistry (Fritz Haber 1918, Carl Bosch 1931) and is the most widely used process for Production of hydrogen from hydrocarbons (e.g. digestate). Even today, 100 years after its development, the majority of hydrogen plants are still based on the Haber-Bosch process, the original goal of which was the synthesis of ammonia. The basic principle of a steam reforming plant is the partial oxidation (POX) of fossil or renewable biomass. In order to apply the activation energy for this variant of hydrogen production (steam reforming is an endothermic process), heat (TPOX) or chemical catalysts (CPOX) can be used. In the optimal case, both are combined, which often leads to the use of magnetite as a catalyst and reactor temperatures of 500 ° C. A high pressure (300 bar) is also applied to shift the equilibrium reaction towards molecular hydrogen. The efficiency of the process depends on the starting substrate (biomethane would be optimal) and is between 50 and 70 percent in today's plant.
The gasification of biomass (wood gasification) has accompanied our species for thousands of years (tar at the arrowhead of Ötzi) and was the central one Procedure for building up the first wave of the methanol economy. During the beginning of gasification, the proportion of hydrogen formed was very low and the process is now much more efficient. The yield from the gasification of the digestate from a biogas plant also depends on the quality of the remaining organic matter.
The Hydrothermal carbonization (HTC) is a special form of gasification. The special thing about hydrothermal carbonization is that, in addition to the high temperatures, very high pressures are also used to break down the organic matter. The aim is to generate supercritical water (T> 375 ° C, p> 221 bar) in order to convert the biomass as completely as possible with its energy. Depending on the exact process structure, solid hydrocarbon or gaseous hydrogen is produced. Like Carl Bosch, the discoverer of the HTC, Friedrich Bergius, received a Nobel Prize in Chemistry (1931) for his contribution to the development of high pressure chemical processes.
Plants that use the Kvaerner process were designed for the production of hydrogen right from the start. The main products of these hydrogen plants based on a plasma torch are also 48% hydrogen and 40% activated carbon. At temperatures around 1.600 ° C there is no CO2 and only pure carbon. The process is not only suitable for solid biomass (digestate, wood, waste, etc.), but can also use untreated biogas as a source of the hydrocarbons.
Under anaerobic Conditions, biomass is split at temperatures around 500 ° C. Since this thermochemical process takes place in the absence of oxygen, classic combustion (oxidation) is prevented. The endothermic pyrolysis products are mainly liquid pyrolysis oil and solid charcoal. There are various adjustments within the plant to influence hydrogen production. These parameters include the quality of the starting substrate, the reaction temperature and the reaction time. The process is only suitable for the production of hydrogen from biogas or digestate after a longer pyrolysis period of several hours.
The upscale of the plants with the thermal processes for hydrogen production presented has progressed to different degrees. The largest plants have so far been used for steam reforming and gasification. The HTC and pyrolysis are still at the level of pilot plants. The main reason for the missing upscale is not the technological feasibility, but the economic viability. The economies of scale of cost reduction are linked to investments from the economy. For cost reasons, the large hydrogen plants today are (still) often based on fossil biomass such as coal, oil and, above all, natural gas (methane) as the source of the hydrocarbons.
Finally, a critical look at The dark side of the hydrogen. One of the greatest challenges in the production and use of hydrogen is safety. Nobody likes to talk about this tragedy, but the first wave of the hydrogen economy ended abruptly in 1937 with the dramatic crash of the Hindenburg. 80 years later, our civilization is technologically on a completely different planet, but the point of security should not be forgotten with all the euphoria for the hydrogen economy. Hydrogen remains a highly volatile and, in combination with oxygen, highly explosive element (oxyhydrogen reaction). Penetrating even deeper into matter, the largest amount of energy released by human hands to date is also based on hydrogen. The first detonated hydrogen bomb (1953/1954) released 10.000 megatons of TNT, 666 times as much energy as the catastrophic bomb on Hiroshima (15 Mt TNT). If Homo Sapiens succeed in making this form of hydrogen energy controllable (fusion energy), our species would take a quantum leap and clean atomic energy 2.0 could become the backbone of the energy industry of tomorrow. For the fusion of heavy hydrogen, a temperature of 100 million degrees Celsius must be generated and controlled on earth, which corresponds to six times the fusion temperature of the sun, which, due to its high gravity, needs “only” 6 million ° C. It is not for nothing that the time window for the first fusion reactor is said to be “only 15 years away”. And the industry has been repeating this mantra for 30 years.
In one of the previous chapters of the History of bioenergy was about the approaches and potential of Methanol economy. In this chapter, the focus was on the Hydrogen economy. The question arises whether the two approaches contradict each other? To make a long story short: No. On the contrary, the methanol and hydrogen industries complement each other in many places and, in my opinion, are two important pieces of the puzzle for restructuring our economic system or overcoming the fossil energy and raw material base.
If the same “Party of Elements” from the beginning of the article is only held for elements of the earth and not for the entire solar system, the hydrogen participants only form 0.03 percent (instead of 93 percent) of the party guests. Light hydrogen is rare on our planet and the elemental composition is dominated by the following fantastic four: oxygen, iron, silicon and magnesium. Because of its low mass (gravity), we do not find hydrogen in its atomic form on Earth and it immediately escapes into space. The element therefore occurs almost exclusively in chemically bound, molecular form.
In addition to the connection with oxygen (H2O), hydrogen is particularly often combined with carbon. Both compounds, water and hydrocarbons, have led to the flowering of life on our home planet. Hydrocarbons are not only the focus of organic chemistry, but in their fossil version the motor of our economic system. Our organisms are not only composed of water and hydrocarbons, the modern civilization of our species is also based on the intensive use of coal, natural gas and oil.
One of these terrestrial hydrocarbon compounds is methanol. With the empirical formula CH3OH, methanol allows itself not only hydrogen and carbon, but also the luxury of polarizing oxygen. In the article on the Potentials of the methanol economy it is presented as a sustainable pioneer in a post-fossil world. Innovative paths of methanol production can bind the greenhouse gas number one, carbon dioxide, and return it to the carbon cycle. The speed of construction of these CCU paths is mainly dependent on the political framework and the Amount of the CO2 price dependent. Many countries are already using methanol.
From the perspective of the hydrogen economy, methanol, as the simplest alcohol, is a first-class LOHC (Liquid Organic Hydrogen Carrier), which only weakens the weakness of molecular H2, only at very low temperatures (- 252 ° C) or very high pressures (700 bar) to be balanced. There is a greater amount of hydrogen in one liter of liquid methanol (98 g) than in 1 liter of liquefied hydrogen (70 g). So methanol is an effective and safe carrier of hydrogen. The methanol industry in turn needs hydrogen for the production path via CO2, which suggests a close symbiosis of both energy sources. Both make use of resources that were previously unused in their manufacture: hydrogen on excess electricity and methanol on CO2. Sector coupling and closing of circuits are important system functions that can be taken over by the methanol and hydrogen industry. Both system approaches benefit from the expansion of the respective colleague.
We are currently in the process of building a hydrogen economy. What is your opinion on this development? Does biogenic hydrogen have great potential for the bioenergy industry or will it remain a niche product?
3 comments on “The biogenic production of hydrogen”
Hydrogen as an "energy source"? Now we have to pay taxpayers once again billions to research institutions and industry just to have another look at how hydrogen can be used as "energy".
Germany started the hydrogen age at 5 p.m. on May 1999, 12.
At that time, the “world's first public” hydrogen filling station went into operation at Munich Airport. It was the first step into the much touted hydrogen economy. In 2006, the next German superlative came about in terms of hydrogen. The “world's largest” hydrogen filling station opened in the middle of Berlin.
The future had also begun in Hamburg and Stuttgart. Until the end of 2006, both cities each operated three fuel cell buses as part of the European CUTE project (Clean Urban Transport for Europe); The follow-up project HyFLEET: CUTE started at the beginning of 2007. Hamburg had increased its fleet from 3 fuel cell buses to a total of 9. Berlin had purchased 14 buses with hydrogen combustion engines. Another European project was launched at the beginning of 2007: As part of “HyChain Minitrans”, more than 2010 small vehicles with fuel cell drives should be on the road by 150.
With news like this, one might think that the age of clean transportation using pollutant-free hydrogen is finally within reach. But the impression could not be more wrong: While publicly funded projects are continuing their celebrated progress everywhere, some experts increasingly come to the conclusion after a calculation that the journey into the hydrogen economy is actually a wooden path.
When BMW presented its Hydrogen 2006, a hydrogen-powered 7 Series, in 7 with the defined goal that celebrities from politics and business should drive the model, then Bundestag Vice President Katrin Göring-Eckhardt (Greens) rejected the 7 Series BMW because of its poor energy balance . Group colleague Toni Hofreiter refused an invitation to present on the grounds that: "A car that swallows 100 liters in 50 km in XNUMX km at the beginning of the third millennium cannot claim sustainability."
It appears that our politicians assume that hydrogen is an almost inexhaustible source of energy and thus a tempting alternative to energy supply. You can be persuaded that all climate problems are solved in one fell swoop. The energy supply with hydrogen and fuel cells is fascinatingly clean, because hydrogen combines with the oxygen in the air and only a little electricity and water are required.
Everything is correct, and in view of such obvious facts, it is no wonder that the hydrogen idea fascinates the public, business and politics alike. The voices of the critics are still suppressed, especially since enthusiasts put a triumphant note on their trombone tones.
In early 2004, the former President of the European Commission proclaimed the "European Hydrogen and Fuel Cell Technology Partnership". The transformation of our fossil fuel based economy into a “hydrogen-oriented economy” should be completed by 2030. With widespread hydrogen pipelines that exclusively transport hydrogen produced from renewable sources, with ubiquitous fuel cells in traffic, with decentralized power generation in everyone's home and in thousands and thousands of small appliances.
In order to realize this vision, around 6 million euros have been spent in the EU's 300th Research Framework Program. In Germany alone, around 2004 million euros flowed into hydrogen and fuel cell research from the federal government, the federal states and the EU in 85, and the Merkel government also put a “national innovation program on hydrogen technologies” on the flag and in the coalition agreement in 2005. The then Federal Transport Minister Wolfgang Tiefensee provided an additional 500 million euros in funding for the development of hydrogen cars. BMW, Mercedes gratefully accepted the gift.
But what is not answered when propagating a hydrogen revolution is where the huge amounts of hydrogen for this paradise on earth are supposed to come from: hydrogen is not an energy source like oil or natural gas.
Hydrogen hardly occurs in nature in its free form. Instead, it is bound in water, biomass or fossil hydrocarbons such as coal and natural gas. Before the gas can be used as an energy supplier, it must be released from its existing compounds. That costs a lot of energy - only a small part of which can then be stored in the released hydrogen.
Anyone who does the whole thing from front to back will come to the conclusion that the hydrogen economy cannot come. Hydrogen could never become competitive as an artificial source of energy that has to be produced at a loss using other energies.
The total energy consumption of diesel and petrol in the transport sector (710 TWh) corresponds approximately to the energy of Germany's total electricity consumption (650 TWh). With conversion losses one would need three times the capacity of today's power generation to max. Covering 50 percent of traffic needs with hydrogen.
Another problem is storage. Because the hydrogen atom is the smallest of all atoms. “Hydrogen contains three times more energy than gasoline, based on its weight, but the energy density per volume is much more important. And hydrogen does very, very badly there, ”said Martin Wietschel from the Fraunhofer Institute for Systems and Innovation Research (ISI) in Karlsruhe.
Frozen or under pressure
In order to use hydrogen as drive energy in cars with acceptable ranges, the gas on board must be stored either at very high pressures of up to 700 bar or in liquid form at minus 253 degrees.
Another disadvantage is that the tank content of a hydrogen car dissolves in air after a short time. Because the hydrogen atom is so small that it is hardly possible to seal all components against leakage in vapor form. Liquid hydrogen warms up over time and then simply evaporates. For a while, the hope for better tanks also rested on metal hydride stores that absorb gaseous hydrogen and release it when heated. However, they proved to be too expensive and heavy to be used only in submarines and ships, where both factors hardly play a role.
For the time being, only storage under high pressure or at low temperatures remains. However, both processes continue to contribute to the poor energy balance of hydrogen. Even the compression of gaseous hydrogen to 700 bar consumes 13 percent of the energy it contains, and even under this high pressure it has only about a third of the energy density of gasoline. All in all, not even half of the highly subsidized electrical wind photovoltaic energy that was used to generate the hydrogen ends up in the pressure tank. It looks worse with liquefaction. It eats between 30 and 50 percent of the energy in hydrogen. Transport is not included in these figures.
Overall, no more than 20 to 25 percent of the original “primary energy” arrives at the wheels of a hydrogen-powered fuel cell car. The hydrogen combustion engine is much less because of its poorer efficiency.
Scientists and engineers already calculated all this in detail at the beginning of 2003 in "The Future of the Hydrogen Economy: Bright or Bleak?" Hydrogen economy is nothing more than a waste of energy. These are very simple engineering calculations! I blame the hydrogen prophets for not even understanding these calculations. At Linde AG, one of the largest hydrogen manufacturers in the world, there is no denying that the calculations are correct.
There is no doubt that Germany is 98 percent dependent on oil, the economy has to think and act strategically, then you have to think about what you can do because we have an energy and a CO2 problem.
There is no doubt about that - but why the German economy pounced on hydrogen as an antidote does not make sense to me. In 2020, 20 years after the start of the hydrogen age in Germany, there will be neither fuel cell cars at competitive prices nor affordable hydrogen for them in the foreseeable future.
The wind and photovoltaic lobby, however, do a different calculation today. The expansion has stalled because the power grids collapse when the wind farms are expanded due to strong winds and high levels of solar radiation. The companies in the wind farm industry do not want to do without the constantly bubbling billions of taxpayers. Therefore, they propose to advance the expansion of wind turbines against civil protests. The "overproductions" can then be converted into hydrogen and stored, which is then converted back into electricity when the wind is calm and at night. One thing is already evident without arithmetic skills; that will be quite expensive electricity!
The hydrogen prophets are happy to keep silent about the fact that every conversion from one energy source to another occurs. German private consumers are already paying the highest electricity price in Europe. Ascending trend!
Let me end with the words of a great German physicist.
When asked which the most common element in the universe was, Albert Einstein once answered: “Hydrogen and the stupidity of people. But I'm not quite sure about hydrogen. ”
Here are the data tables:
Thank you for the informative article! Mr Ahlers' comment and arguments are valid. That is why I see the area of application of hydrogen primarily in the industrial sector and not in the transport sector, especially in the car. I therefore see the NWS as an opportunity to replace the industrial demand for gray hydrogen with green hydrogen. The sealed off renewable energy output was 5,5 GWh last year. However, this electricity should be used! It should be examined whether this electricity can be used to produce hydrogen economically and sustainably in electrolysis plants.
The severe limitation of available hydrogen in the first few years makes it a very valuable resource / commodity on the market. I agree that it makes a lot of sense to use the limited, CO2-neutral hydrogen in industry. In an industrial nation like Germany, the use of green hydrogen in industry offers the greatest leverage. The reduction of C02 in industrial processes is not only the hardest (high temperatures, 24/7 RE energy demand), but also saves additional costs (CO2 price for certificates of the EU ETS), which is what German / European industry makes in the international price war Markets are even more competitive and thus secure jobs and prosperity. And not to use the renewable electricity produced is actually pretty much the most senseless thing an energy industry can "treat" itself to.