Developed a new process to convert low-value plastic waste into high-value chemicals

J. Daley explains the procedure by Houqian Li et al. to obtain valuable products from mixed plastic wasteLow-value waste plastic can be converted into high-value chemicals in a new process developed by UW?Madison researchers. Although many Americans deposit their plastic trash into the appropriate bins each week, many of those materials, including flexible films, multilayer materials and a lot of colored plastics, are not recyclable using conventional mechanical recycling methods. In the end, only about 9% of plastic in the United States is ever reused, often in low-value products. With a new technique, however, University of Wisconsin?Madison chemical engineers are turning low-value waste plastic into high-value products. The new method, described in the journal Science, could increase the economic incentives for plastic recycling and open a door to recycling new types of plastic. The researchers estimate their methods could also reduce greenhouse gas emissions from the conventional production of these industrial chemicals by roughly 60%. The new technique relies on a couple of existing chemical processing techniques. The first is pyrolysis, in which plastics are heated to high temperatures in an oxygen-free environment. The result is pyrolysis oil, a liquid mix of various compounds. Pyrolysis oil contains large amounts of olefins?a class of simple hydrocarbons that are a central building block of today's chemicals and polymers, including various types of polyesters, surfactants, alcohols and carboxylic acids. In current energy-intensive processes like steam cracking, chemical manufacturers produce olefins by subjecting petroleum to extremely high heat and pressure. In this new process, the University of Wisconsin?Madison team recovers olefins from pyrolysis oil and uses them in a much less energy-intensive chemical process called homogenous hydroformylation catalysis. This process converts olefins into aldehydes, which can then be further reduced into important industrial alcohols. "These products can be used to make a wide range of materials that are higher value," says George Huber, a professor of chemical and biological engineering who led the work alongside postdoctoral researcher Houqian Li and Ph.D. student Jiayang Wu. These higher-value materials include ingredients used to make soaps and cleaners, as well as other more useful polymers. Using a process called hydroformylation, Professor George Huber (left) and postdoctoral researcher Houqian Li are able to recover the olefins in an oil made from waste plastic and transform them into high-value chemicals. Credit: Joel Hallberg"We're really excited about the implications of this technology," says Huber, who also directs the Center for the Chemical Upcycling of Waste Plastics. "It's a platform technology to upgrade plastic waste using hydroformylation chemistry." ? Read the full article of Jason Daley below.? Source"New recycling process could find markets for 'junk' plastic waste", by?Jason Daley, University of Wisconsin-Madisonhttps://phys.org/news/2023-08-recycling-junk-plastic.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter Divulgation article based on?Hydroformylation of pyrolysis oils to aldehydes and alcohols from polyolefin wasteHOUQIAN LI, JIAYANG WU, ZHEN JIANG, JIAZE MA, VICTOR M. ZAVALA, CLARK R. LANDIS, MANOS MAVRIKAKIS?& GEORGE W. HUBER Science?(2023).?DOI: 10.1126/science.adh1853