Foam CO 2 based foam
Foam CO 2 based foam “The chemical industry has long known that we need an alternative to petroleum that offers both economic and environmental benefits,” says Dr. Markus Steilemann, Covestro Board Member responsible for Innovation, Marketing and Sales. Besides plant-based renewable raw materials, the company (headquartered in Leverkusen, Germany) is also increasingly focusing on CO 2 . “Carbon dioxide contains the element carbon – the basis of all organisms and also the most important building block for the chemical industry. The next logical step is therefore to make greater use of CO 2 as a source of carbon,” explains researcher Dr. Christoph Gürtler, who has been working on this goal for years at Covestro. The advantages appear obvious. Far from being a scarce resource like petroleum, carbon dioxide benefits from almost unlimited availability. And yet the challenges of finding a good way to use the carbon contained in CO 2 appeared considerable and presented scientists across the globe with a fundamental problem for decades. Carbon dioxide as such is low in energy and slow to react, which means it is reluctant to form compounds with other substances. Gürtler explains the problem as follows: “A high-energy partner is needed to be able to use the CO 2 efficiently. Otherwise, more CO 2 is ultimately emitted than incorporated, which would not have a positive, sustainable effect.” Giant step forward for the plastics industry Together with partners from academia and industry, Covestro finally achieved a breakthrough in the quest to find alternative raw materials. Following a research phase lasting several years, it succeeded in developing a suitable zinc-based catalyst that helped create a new kind of precursor containing CO 2 – polyol. This innovative process makes it possible to incorporate up to 20 % carbon dioxide in the polyol, thereby saving the same proportion of petroleum. There are also further advantages. Overall, less energy is required and less carbon dioxide emitted. That results in a better carbon footprint than a manufacturing process based entirely on petroleum. The new CO 2 -based polyol is sold under the name cardyon and is initially intended for the manufacture of flexible polyurethane foam that can be used in mattresses and upholstery. “The quality of the foam containing CO 2 at least matches that of material manufactured the conventional way using petroleum only,” explains Dr. Berit Stange, who is responsible for cardyon sales at Covestro. A demonstration plant with a capacity of 5,000 metric tons per year at the company’s Dormagen site near Cologne, Germany has been manufacturing the new polyol since 2016. The carbon dioxide it uses is a by-product from a neighboring chemical company. Expanding the production portfolio Making mattress foam from this greenhouse gas is just the first step for Covestro. There are many different possible applications and ambitious goals have been set. “Our goal is to make intelligent use of carbon and no longer use petroleum to manufacture plastic in the future where this is possible and expedient. It’s naturally always a balancing act, because the quality of the end product and the costefficiency of the process have to be right,” says Steilemann. Production Dreams, one of the research projects being led by Covestro, is looking into using carbon dioxide to make elastomers. Such elastically deformable plastics are used for items including hoses and seals. Like flexible polyurethane foam, they are normally based entirely on petroleum. Around a quarter of this can now be replaced with CO 2 . In the Dream Resource project, meanwhile, 48 bioplastics MAGAZINE [01/18] Vol. 13
Foam Dr. Berit Stange is responsible for commercializing the new CO 2 -based building block on the marketplace Covestro is collaborating with partners on developing a special polyol for rigid polyurethane foam, molded polyurethane foam and additives. In this case, too, the precursor is to comprise around 20 % carbon dioxide and could be used to make insulating materials and car seats. Carbon4PUR, a research project funded by the European Union with 14 partners from seven different countries, is even going one step further. Led by Covestro, the European partners intend to investigate how smelting gases from the steel industry can be used to produce plastics in a particularly efficient and sustainable way. Waste gas producers and plastics manufacturers are looking to find a way of using waste gas mixtures from the steel industry, initially to produce polyols and ultimately to make insulating materials or coatings. The special feature of this method is that it eliminates the laborious step of separating the waste gas into its different components and enables it to be turned directly into precursors. This can reduce the carbon footprint by 20 to 60 %, thereby turning large waste gas producers into raw material suppliers. At a new production plant in Dormagen, Covestro is incorporating up to 20% CO 2 into a building block for flexible polyurethane foam “The numerous initiatives surrounding CO 2 exploitation put this waste gas in a new light and help to expand the chemical industry’s raw materials base,” explains Steilemann. “Resource efficiency is one of the driving forces behind a more sustainable future, and we want to move it forward with innovative solutions,” he adds. Carbon dioxide thus appears to be well on the way to transforming from a waste product that is harmful to the environment into a sustainable all-rounder in the plastics industry. MT www.co2-dreams.covestro.com Covestro achieved a scientific breakthrough: A team under researcher Dr. Christoph Gürtler discovered the right catalyst to enable the efficient use of CO 2 for plastics production (all photos © Covestro) bioplastics MAGAZINE [01/18] Vol. 13 49
