The new frontiers of hydrogen production and steps forward by Italy and China

Commentary: China and Europe are increasing their dialogue on climate policy as well as their cooperation in the field of green development 

The new frontiers of hydrogen production and steps forward by Italy and China

A hydrogen fuel-cell bus is parked at a local bus station in the Chinese city of Wuhan in May 2019. Photo: Oriental Image via Reuters

In the traditional hydrogen production industry, hydrogen is derived from fossil fuels. It is the most widely used method and there are mature technologies and industrial devices for this purpose.

The methods mainly include hydrogen production by partial oxidation of heavy oil, by natural gas steam and by coal gasification.

Natural gas and coal reserves, however, are limited and the hydrogen production process pollutes the environment.

According to the requirements of scientific development, this method is obviously not the best choice in the future hydrogen production technology. 

Conversely, water electrolysis has a long history in the hydrogen production industry. The commonly used electrolytic cell generally adopts a bipolar filter press structure or a single-stage box structure.

The advantages of such a structure are simple equipment, easy maintenance and low investment. The disadvantage is that it covers a large area and the space-time yield is low. The filter press structure is more complex and the advantages are compactness, space-saving, small footprint and high space-time yield. 

Nevertheless, it is difficult to maintain and requires a large investment. With the development of science and technology, a cell with a Solid Polymer Electrolyte (SPE) has emerged. SPE cell materials are easy to obtain, suitable for mass production, and the same number of anodes and cathodes are used for H2 and O2 separation. Its efficiency is higher than that of conventional alkaline electrolysis cells. 

The phase flow rate of the SPE cell is the conventional alkaline electrolysis of 1/10 of the tank, and the service life is about 300 days. The disadvantage is that the energy consumption of water electrolysis is still very high.

The water electrolysis industry in many countries remains at the level of the bipolar filter press structure electrolysis cell or single-box electrolysis cell, which is still far behind the level of more advanced industry and research.

The catalytic thermal decomposition of methane to produce hydrogen is accompanied by a large amount of carbon dioxide emissions, but in recent years - due to the thermal decomposition of methane - CO2 emissions can be avoided for hydrogen production.

The decomposition of one mole of hydrogen by methane requires 37.8 KJ of energy and releases 0.05 mole of CO2. The main advantage of this method is that while producing high purity hydrogen, solid carbon is produced which is cheaper and easier to produce, so that carbon dioxide is not released into the atmosphere and the greenhouse effect is reduced.

Because it essentially produces no CO2, it is considered a transition process between fossil fuels and renewable energy. The cost of production, however, is not low: if the carbon by-product has broad market prospects, this method will become promising for hydrogen production.

Biological hydrogen production lies in the fact that hydrogen is produced by microorganisms using hydrogen-containing substances (including plant starch, cellulose, sugar and other organic matter, as well as water) as substrates to produce hydrogen gas at normal temperature and pressure. 

So far the hydrogen-producing organisms reported in research can be divided into two categories: photosynthetic organisms (anaerobic photosynthetic bacteria, cyanobacteria, and green algae) and non-photosynthetic organisms (strict anaerobic bacteria, facultative anaerobic bacteria, and aerobic bacteria).

Photosynthetic organisms, cyanobacteria and green algae can use the ingenious photosynthetic structure to convert solar energy into hydrogen energy. Therefore, their research on hydrogen production is much more thorough than that of non-photosynthetic organisms. 

Both can photo split water to produce hydrogen. Water photo splitting to produce hydrogen is an ideal way to extract it. However, when cyanobacteria and green algae release hydrogen photosynthetically, the process is accompanied by the release of oxygen.

In addition to low hydrogen production efficiency, the inactivation of enzymes when exposed to oxygen is a key problem that this technology is expected to solve. It is quite simple: anaerobic photosynthetic bacteria compared to blue-green bacteria and algae, an anaerobic photosynthetic hydrogen process that does not generate oxygen. 

Due to the complexity and precision of the photosynthetic hydrogen desorption process, research is still mainly focused on screening or breeding of high activity hydrogen-producing strains, cultivating and controlling environmental conditions to increase hydrogen production. All of this is still at the experimental level.

Non-photosynthetic organisms can degrade macromolecular organic matter to produce hydrogen and bioconvert renewable energy materials (cellulose and its degradation products, starch, etc.) to produce energy from hydrogen. 

Research shows its advantages over photosynthetic organisms. Research on this type of microorganisms as a source of hydrogen began in the 1960s. Around the late 1990s, Chinese scientist Ren Nanqi and others researched and developed the biological hydrogen production technology of organic wastewater fermentation using anaerobic activated sludge and organic wastewater as raw materials.

This technology overcomes the limitation that biological hydrogen production technology must use pure bacteria and fixed technology, and creates a new way to use non-immobilized bacteria to produce hydrogen. Pilot test results show that the biological hydrogen production reactor has the highest continuous hydrogen production. The ability to achieve certain quantities and the production cost is about half of the hydrogen production cost of the water electrolysis method. 

With specific reference to China, in his speech delivered in September 2020 during the debate at the 75th session of the United Nations General Assembly, President Xi Jinping announced that China would enhance its autonomous contribution to tackle pollution problems and would "strive to peak carbon dioxide emissions before 2030 and achieve carbon neutrality before 2060."

In October 2020, peak carbon and carbon neutrality were included for the first time in the Fourteenth Five-Year Plan ("The Path to Decarbonization"). 

In April 2021, during the video meeting between China, France and Germany, President Xi Jinping once again recalled this tough battle and stressed that China and Europe should strengthen climate policy dialogue and cooperation in the field of green development, so as to make climate change - the pillar of Sino-European cooperation - relevant.

It is a general trend for China and Europe to strengthen the climate policy dialogue and cooperation in the field of green development, and it is also in their common interest. The latest generation of photovoltaic technology for power generation and hydrogen production from ocean waves (green renewable energy through clean renewable energy), which have long been proposed by China, are attempts and initiatives to achieve the goal of carbon peak and carbon neutrality. 

In this regard, the Memorandum of Understanding (November 25, 2019) between the International World Group and the National Ocean Technology Center - directly run by the Chinese Ministry of Natural Resources, led by Lu Hao - and IWG-Eldor Group's proposals regarding state-of-the-art technologies - currently available - to be developed in partnership for the Chinese market, constitute the first substantial progress achieved in this field.

The Chinese government is strongly committed to the path of low carbon energy transition that allows a significant reduction of CO2 emissions, converting energy production from oil combustion in traditional industrial sites to green (clean) sustainable energy from renewable sources in the Silk Road.

Eldor Group is already operating in the Chinese territory in the automotive sector or in the production of engines and components for electric motors (ELDOR Automotive Powertrain) in Dalian (Liaoning Province). It is the production centre for the Asian market of ignition systems of manufacturing excellence.

These are projects in an advanced phase of development with "pilot" plants already operating in Italy, which can be carried out in China and in any part of the world, with the support of local investors. 

 

Professor Valori is President of the International World Group

You might be interested also