A unique alternative for converting solar energy into fuel

Is there a way to save solar energy for a rainy day? - A new method developed at the Weizmann Institute is relatively cheap, very effective and does not produce environmentally hazardous waste

One of the obstacles that must be overcome on the way to widespread use of renewable energy sources, such as sunlight or wind, is the fact that these do not necessarily provide the energy at the time and place where it is needed. Solar radiation and wind at our disposal can operate all the machines, air conditioners and computers in the world - but supplying energy from these sources according to demand and needs is still not practical, and not worthwhile.

Is there a way to save solar energy for a rainy day? Coal, for example, is a source of stored energy: you can burn it whenever you want and produce steam, and from the steam produce electricity. In contrast, solar cells and wind farms convert sunlight and wind directly into electricity. Although this process is useful for operating household devices, it is impossible to store and transport it. Many solutions have been proposed for the problem, but most of them (such as huge batteries, or the most accepted solution - pumping large amounts of water) are limited, expensive, or cumbersome. A promising possibility that many scientists are exploring is the conversion of the energy collected from the sun or the wind into another type of energy, which can be stored, transported and burned at the desired time and place. In the 80s and 90s of the 20th century, scientists at the Weizmann Institute of Science began researching ways to store solar energy within high-energy chemical bonds, while using concentrated light rays created in the institute's solar tower - a method known as a thermo-chemical heat pipe.

Recently, Prof. Igor Lubomirsky, from the Department of Materials and Surfaces in the Faculty of Chemistry at the Weizmann Institute of Science, developed a unique alternative for converting solar energy into fuel. The new method is relatively cheap, very effective, and does not produce environmentally hazardous waste. Instead of using coal (which was created over millions of years and its burning causes the emission of pollutants), in Prof. Lubomirski's new method carbon monoxide gas (CO) is created - which does not cause corrosion processes, and can be burned directly in turbines or generators - or turned into fuel liquid. Despite the fact that high concentrations of this gas are toxic, carbon monoxide has been in use for more than 100 years as a chemical intermediate; Tens of millions of tons of gas are produced every year from coal or wood, in a well-known industrial process. In the method proposed by Prof. Lubomirsky, carbon monoxide is produced from carbon dioxide (CO2) - instead of from wood or coal - in a relatively simple chemical process, using a system similar to a battery big and hot In a special chamber, a chemical substance (titanium) is heated to a temperature of 900 degrees Celsius, and an electric current is passed through it. Under these conditions, the carbon dioxide continuously injected into the cell breaks down into carbon monoxide and oxygen.

"It may be possible to produce carbon monoxide next to the chimneys of power plants, or any other source of polluting carbon dioxide," says Prof. Lubomirski, "so that the greenhouse gases emitted from the chimney will be removed and recycled before entering the atmosphere." The metal we use is titanium, a standard material, cheap, and several times more accessible than the more expensive metals, such as platinum, which are used in other similar devices." Other advantages of the new method include a thermal efficiency of more than 85% (not including the energy needed to heat the system (much higher efficiency than other energy conversion systems), and the ease with which the gas can be transported and burned. Prof. Lubomirsky: "In the future, it is possible that the method will be used This is to absorb solar or wind energy in places where they are abundant, convert it into carbon monoxide that will be stored or converted to a liquid fuel such as methanol. This research is entirely a product of the Alternative Energy Research Initiative at the Weizmann Science Institute (AERI). This initiative allows the institute to support a number Important studies in the field".

The "Knowledge Research and Development" company, which promotes the development of applications based on the inventions of Weizmann Institute of Science scientists, submitted an application to register a patent for the process. The development licenses were granted to the Campus-Tech company from the Clal Industries and Investments group, and to the Arte Venture group. Initial trials are planned for the near future.

Within 25 years we must abandon oil and gas and switch to solar and wind energy, says Nobel Laureate in Chemistry Walter Kuhn in a lecture at Bar-Ilan