Researchers have found a method for combining synthetic biology with synthetic chemistry to create artificial enzymes that interact with the metabolic processes of living cells to generate hydrogen gas. According to a new scientific paper, researchers at Uppsala University have found a way to design enzymes which produce hydrogen gas using the energy of living cells sourced from solar energy.
The Journey So Far in the Quest for Viable Sources of Hydrogen Gas
For over a century, there’s been a relentless quest in the scientific world to find methods for mass producing hydrogen gas. Hydrogen gas has long been identified as one of the most potent energy carriers on the planet, but it rarely occurs in its pure form naturally and is lighter than air, therefore, rises into the atmosphere rapidly.
It is usually obtained from numerous naturally occurring molecules such as water and fossil materials. However, the technologies for doing so have so far not been as efficient as they were envisioned to be in the distant past.
Over 100 years ago, the first proposition for the production of hydrogen through the use of solar energy and photosynthetic processes emerged. In 1975, a team of Japanese researchers published the modalities of the most efficient process yet at that time for the generation of hydrogen gas through solar energy.
This prototype featured a photovoltaic wafer with two electrodes held apart by a membrane in an electrolyte solution. These electrodes, which are made with photosensitive semiconductor materials and coated with a catalyst, produced oxygen at the anode and hydrogen at the cathode. However, its applicability in mass production was untenable.
Production of Hydrogen through solar energy
So far, there are only a few technologies for producing hydrogen gas on a large scale using solar energy. One such has been the use of solar-generated electricity through PV-electrolysis, although this technology is still not economically feasible.
This technology was invented in 1983 by NASA-funded researchers at the Florida Solar Energy Center. One of the main drawbacks of this technology is that it uses a highly efficient energy carrier, electricity, to produce another energy carrier, hydrogen, which is then converted back to electricity. The amount of electricity, as well as the physical space required for the large-scale deployment of this technology, make it unfeasible.
Another similar technology that has had its day under the sun is the solar thermochemical water splitting cycles. Although this technology produces hydrogen gas with a remarkable efficiency of over 40%, it requires the use of concentrated solar receivers and reactors that can be heated up to 800º C or more.
Biomass gasification is another technology that has been invented for the mass production of hydrogen gas using solar energy. The technology revolves around using heat to convert biomass (organic materials such as agricultural waste) to synthetic gas. The type of gas produced depends on a number of factors, including the type of organic material, the amount of oxygen present, the applied temperature, and more.
All in all, these technologies are still facing limitations that prohibit their large-scale deployment.
The Production of Hydrogen Gas Through Artificial Enzymes Powered By Solar Energy
According to a scientific paper published by an interdisciplinary European research team in the journal Energy and Environmental Science, scientists have found a new method for creating artificial enzymes that harness solar energy through the metabolic processes of living cells to generate hydrogen gas.
This method, which has been under development at the Uppsala University for years now, revolves around inserting synthetic enzymes together with certain synthetic compounds in photosynthetic microorganisms.
The aim is to harness the tools for trapping sunlight supplied by evolution to produce hydrogen gas. The artificial enzyme introduced into the photosynthetic microorganism harnesses the natural metabolic processes of photosynthesis to convert solar energy stored in the living cells to hydrogen gas.
This latest discovery, though it has been in the pipelines for several years, centers around the simple natural process of photosynthesis. However, the challenge now is to find ways of expanding the capacity of the hydrogenase enzymes used in this technology to produce hydrogen gas through the natural process of photosynthesis.
The issue of the large space required to generate hydrogen gas through solar energy on a large scale from vast quantities of microorganisms is the major challenge for the technology’s economic viability.
But scientists a group of researchers at the Max Planck Institutes for Chemical Energy Conversion and Coal Research in Germany have proffered a way around this by altering certain amino acids and enzymes in a microalgae cell. By doing this, the team of researchers has been able to increase the volume of hydrogen generated by hydrogenase enzymes by 5 folds.