The future – we have lift-off!

Microorganisms chow down on CO₂

The cement industry faces significant challenges because of the energy transition. This sector is responsible for
8 percent of CO₂ emissions worldwide. Two-thirds of those are process related and hence unavoidable, just like in the lime industry. That’s why these industries are currently exploring numerous avenues for capturing CO₂, which in turn raises the obvious question of what to do with the resulting huge quantities of this greenhouse gas. One novel solution uses bioreactors, inside which rapid-acting microorganisms convert the CO₂ mixed with green hydrogen into biomethane for feeding directly into the natural gas grid. The advantage is that the CO₂ does not require pre-treatment: the bugs do a great job on impure gas as well. The technology was recently tested in a research project in Switzerland. Endress+Hauser participated by supplying pressure and temperature instrumentation, in addition to flowmeters for the hydrogen and biomethane. The technology will now be scaled up to commercial plant operation, with a pilot project at a lime manufacturer in Belgium scheduled to launch soon. The goal is to recycle up to 90,000 tonnes of carbon dioxide annually and supply the biomethane product to as many as 15,000 households.

More power for the tower

Solar tower plants comprise hundreds of mirrors that reflect sunlight to a receiver at the top of a tower, where heat from the concentrated rays is transferred to a carrier medium – usually liquid sodium and potassium nitrate, which can absorb especially high temperatures. Energy in this form can be cost-effectively stored in tanks and piped to a steam generator to produce electricity, even when the sun is not shining. To date, the operating temperature of such power plants has maxed out at 565 degrees Celsius, but the Institute for Solar Research at the German Aerospace Center (DLR) wants to change that. In a project funded by the German Federal Ministry for Economic Affairs and Energy, a consortium of industry and research partners led by the DLR developed a receiver that enables temperatures of up to 600 degrees Celsius. The next step is to adapt power plant circulatory systems to such temperatures. “The challenges with this application are density fluctuations in the liquid salts, the chemical resistance of materials employed for containment and the extremely high temperatures,” says Markus Schmitz, initiator of the project at Endress+Hauser. For precise flow monitoring between the two storage tanks, Endress+Hauser recommended the use of differential pressure measurement technology. The sensors are now undergoing tests in circulating liquid salts. “If the diaphragm seals meet those demanding requirements, then we have found the solution for this difficult new application,” adds Markus Schmitz.

Sleep well with carbon dioxide technology

Covestro is one of the world’s largest polymer manufacturers. As a pioneer in the plastics industry, the company has fully committed itself to the circular economy; its endeavors include replacing raw materials such as crude oil with alternative sources. CO₂ plays a central role in the strategy because it too contains that essential element, carbon. Covestro collaborated with partners to develop a groundbreaking process in which up to 20 percent CO₂ is integrated into a chemical building block for plastics, thus conserving a corresponding amount of crude oil. To date the product has been used mainly to manufacture soft foam materials, such as for mattresses. What sounds simple is in fact complicated. “Carbon by itself does not readily bond with chemical compounds,” explains Jörn Matthies, Global Strategic Account Manager at Endress+Hauser. “But special catalyzers from Covestro and the Catalytic Center in Aachen are helping to make this difficult reaction possible at last.” Covestro manufactures its novel material in Dormagen. The requisite CO₂ comes from exhaust outflows of nearby chemical plants. Instruments from Endress+Hauser monitor the process. Covestro relies on its instrumentation partner’s know-how at other locations as well. “We’re the primary global supplier of flow, level, temperature and analysis instrumentation,” explains Jörn Matthies.