How a climate killer became a climate protector: Researchers at Bayer are using carbon dioxide instead of petroleum to produce plastics. It’s an innovation that scientists have been trying to achieve for decades.
“Dream Production” is all about teamwork. The only way of achieving the goal of gradually replacing more and more crude oil with CO2 is to pool the expertise of all the partners in the various disciplines. Former German Environment Minister Klaus Töpfer, the founding director of the Institute for Advanced Sustainability Studies (IASS) in Potsdam, is full of praise for the project.
The production of polyurethane using CO2 is still in the test phase, but the scientists are optimistic that Dream Production will go into commercial production from 2015, thus reducing substantially the need for petroleum-based raw materials. The intention is to manufacture numerous consumer articles from polyurethanes like this. Mattresses will be the first product to reach the market, and they are currently doing well in initial tests under practical conditions.
It’s probably one of the best-known chemical compounds in the world – and certainly one of the most feared: carbon dioxide. CO2 is a greenhouse gas that is playing a role in the phenomenon of climate change. A tiny amount in the air is all it takes. The current level is 0.039 percent, and that’s far too much, as the experts never tire of warning us. They estimate that every year more than 29 billion tons of carbon dioxide are released into the atmosphere from the coal and petroleum that are burned on our planet. About one third of greenhouse gases is accounted for by emissions from buildings.
“Since 2000, carbon dioxide emissions due to burning fossil fuels have increased by an average of 3.5 percent annually – three times as much as between 1990 and 1999,” comments Christopher Field, one of the leading members of the UN’s Intergovernmental Panel on Climate Change.
The proportion of CO2 in the atmosphere is increasing as global reserves of crude oil are dwindling. Scientists from a wide variety of disciplines have been looking for years for ways of meeting these challenges. Experts working at Bayer are currently demonstrating that they’re not afraid to take an unusual approach. Their objective is to use the climate-damaging waste gas carbon dioxide as a component in the production of plastics and to save crude oil in the process.
They developed a novel catalyst that finally enabled a process to be implemented that has been causing scientists all over the world headaches for decades. In the past, their attempts to use CO2 were foiled by two factors: the tremendous stability of the compound and its pronounced inertia. It would have been possible to solve these problems by injecting large amounts of energy into the process, but the cost of doing this would have made the entire project unfeasible.
The new catalyst provides an answer to all these problems, facilitating the long-awaited dream reaction and making it possible to use carbon dioxide efficiently. “It gives the CO2 a kick in the backside to make it react,” is the down-to-earth way that Dr. Christoph Gürtler explains the complicated chemical reaction. He is a chemist at Bayer and manager of the “Dream Production” project. This is the title of an unusual form of collaboration, in which industry and science are joining forces in the search for efficient ways of turning carbon dioxide into polymers.
The project was initiated by Bayer in conjunction with the energy company RWE, RWTH Aachen University and the CAT Catalytic Center, which is operated jointly by Bayer and the university. Each partner in the team provides expertise in a specialized area. RWE, a supplier of electricity and gas, provides liquid carbon dioxide obtained from the flue gas scrubbing process at its lignite power plant in Niederaussem near Cologne. The Catalytic Center is making a substantial contribution to work on refining the catalyst, and RWTH is investigating fundamental aspects of catalysis and process development. One of the things that RWTH is doing is an ecoefficiency analysis. “We are scrutinizing each and every stage of the process,” explains Professor Walter Leitner. The aim is to find answers to questions such as: Can the new process save energy? What is its CO2 balance?
The project partners inaugurated a pilot plant for the manufacture of the novel polyurethane raw material at Bayer’s site in February 2011. The ceremony in Leverkusen was attended by guests from politics and the business community, among them Professor Klaus Töpfer. The former German Environment Minister and founding director of the new Institute for Advanced Sustainability Studies in Potsdam underlined the need to close the carbon cycle. “Carbon dioxide should be used as a resource and not disposed of as waste,” he insisted.
When Dream Production got off the ground it soon became clear that even major revolutions often have very modest beginnings. The stainless steel tanks and reactors in the pilot plant are housed in a tiny space barely larger than a living room. Accompanied by the continual thud of the pumps and the whistling of the valves, the reactor combines liquid CO2 with other substances to produce a viscous liquid. This is then mixed with a second raw material to form polyurethane, a plastic.
Usually petroleum is used to manufacture materials of this kind. Around 500 million liters of crude oil are used worldwide to manufacture plastics every day. That’s barely four percent of the total petroleum consumed in the world, but it’s a substantial amount if you consider that this is a diminishing resource.
This is why the goal of Dream Production is to replace as much crude oil as possible by CO2 in the manufacture of plastics. The team has set its sights on a percentage well into double-digit figures. “We are gradually testing various combinations to identify the ideal ratio of the components,” says Dr. Michael Traving, the manager of the pilot plant.
The work being done at Bayer’s technical service center, located close to the pilot plant, shows that the effort is worthwhile. Various formulations of the raw material obtained from the CO2-based process are being used to make thick slabs of foam for mattresses. These have to undergo a stringent testing program to show that their quality is equal to – or even better than – that of slabs produced from petroleum-derived raw materials. The results so far are good. The lying properties are as good as those of mattresses produced in the conventional way.
The company wants to put a further four years of intensive research into the project to ensure that the pilot plant fully meets expectations. If all goes well, the process could go into industrial production from 2015. Chemist Dr. Christoph Gürtler comments, “This process won’t save the climate – the amounts of CO2 generated by human activity worldwide are simply too great for that.” But the researchers hope that it will substantially reduce the volume of petroleum-based raw materials used in polyurethane production.
The project manager is confident of reaching another goal as well. “We and our partners also want to use carbon dioxide to produce another polyurethane material and save even more crude oil,” he explains. This idea is still at a very early stage, yet Gürtler is optimistic. After all, the Dream Production project has shown that Bayer’s scientists dare to go where others hold back. “It’s not only the new material that’s tough,” Gürtler laughs. “We are too!”
By Karin Widera