{"id":183427,"date":"2026-11-10T07:20:00","date_gmt":"2026-11-10T06:20:00","guid":{"rendered":"https:\/\/renewable-carbon.eu\/news\/?p=183427"},"modified":"2026-11-04T14:23:15","modified_gmt":"2026-11-04T13:23:15","slug":"unist-uses-light-and-heat-to-turn-waste-pet-bottles-into-chemical-feedstock","status":"publish","type":"post","link":"https:\/\/renewable-carbon.eu\/news\/unist-uses-light-and-heat-to-turn-waste-pet-bottles-into-chemical-feedstock\/","title":{"rendered":"UNIST uses light and heat to turn waste PET bottles into chemical feedstock"},"content":{"rendered":"\n\n\n<ul class=\"wp-block-list\">\n<li><strong>UNIST and POSTECH developed a method to convert waste PET bottles into terephthalic acid and ethylene using light and heat.<\/strong><\/li>\n\n\n\n<li><strong>Using a cobalt-based nanocatalyst in dilute sulfuric acid at 50\u00b0C, the process yields easily separable solid terephthalic acid and gaseous ethylene.<\/strong><\/li>\n\n\n\n<li><strong>The low-temperature, simplified process may cut recycling costs, but large-scale operation and purification economics must be validated for commercialization.<\/strong><\/li>\n<\/ul>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"680\" height=\"383\" src=\"https:\/\/renewable-carbon.eu\/news\/media\/2026\/11\/975c1d65d9e1dcf4d3553225274e1a69.png\" alt=\"\" class=\"wp-image-183453\" srcset=\"https:\/\/renewable-carbon.eu\/news\/media\/2026\/11\/975c1d65d9e1dcf4d3553225274e1a69.png 680w, https:\/\/renewable-carbon.eu\/news\/media\/2026\/11\/975c1d65d9e1dcf4d3553225274e1a69-300x169.png 300w, https:\/\/renewable-carbon.eu\/news\/media\/2026\/11\/975c1d65d9e1dcf4d3553225274e1a69-150x84.png 150w, https:\/\/renewable-carbon.eu\/news\/media\/2026\/11\/975c1d65d9e1dcf4d3553225274e1a69-400x225.png 400w\" sizes=\"auto, (max-width: 680px) 100vw, 680px\" \/><figcaption class=\"wp-element-caption\">A technology has been developed that decomposes used PET bottles with light and heat to produce chemical feedstock. AI-generated image. \u00a9 UNIST<\/figcaption><\/figure><\/div>\n\n\n<p><strong>A technology has been developed that decomposes waste PET bottles using only light and heat and converts them back into chemical feedstock. The feedstock is recovered in both solid and gaseous form, which is expected to simplify the recovery process.<\/strong><\/p>\n\n\n\n<p>Ulsan National Institute of Science and Technology (UNIST) announced on the 4th that a team led by Professor Ryu Jeongki in the Department of Energy and Chemical Engineering, together with Professor Park Soo-jin\u2019s team at POSTECH, has developed a chemical recycling technology that converts PET into reusable feedstocks, terephthalic acid and ethylene. <a href=\"https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/S1385894726100400?via%3Dihub\">The research results were published on September 30 in the international journal\u00a0<em>Chemical Engineering Journal<\/em>.<\/a><\/p>\n\n\n\n<p>The technology developed by the research team places waste PET powder and a catalyst into a dilute sulfuric acid solution and heats it to 50\u00a0\u00b0C while irradiating it with artificial light similar to sunlight. As the catalyst, they used porous silicon particles coated with a cobalt-containing carbon nanomaterial.\u00a0<\/p>\n\n\n\n<p>When the technology is applied to waste PET, solid terephthalic acid and gaseous ethylene are produced. Terephthalic acid is a feedstock used to make PET, and ethylene is a basic building block for various chemical products. The solid terephthalic acid can be directly filtered out, while the ethylene, generated in gaseous form, can be collected separately.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/image.dongascience.com\/Photo\/2026\/11\/46a730b38d1193ba296b882fb88c695e.png\" alt=\"Conceptual diagram of resource circulation of waste plastic using photothermal catalytic reactions.\" style=\"width:460px;height:auto\"\/><figcaption class=\"wp-element-caption\">Conceptual diagram of resource circulation of waste plastic using photothermal catalytic reactions. \u00a9 UNIST<\/figcaption><\/figure><\/div>\n\n\n<p>In experiments, 73.2% of the PET powder used in the test was converted after 24 hours. The yields of terephthalic acid and ethylene were 69.4% and 39.1%, respectively. Yield refers to the ratio of the amount actually produced to the theoretical amount of each substance. For real waste plastics, such as transparent PET bottles and black food containers, the terephthalic acid yields were 91.4% and 90.8%, respectively.<\/p>\n\n\n\n<p>Existing technologies that convert waste PET into chemical feedstock generally require high temperature, high pressure, and organic solvents, making them costly. When the produced feedstock dissolves and mixes with the solution, additional cost is incurred for separation and purification.<\/p>\n\n\n\n<p>The technology developed by the research team can convert waste PET into feedstock at relatively low temperatures without chemical pretreatment. The main products are obtained separately as solid and gas.<\/p>\n\n\n\n<p>The research team explained, &#8220;A purification step is still required to remove unreacted PET mixed with the terephthalic acid, and a process is needed to separate ethylene from hydrogen gas.&#8221;<\/p>\n\n\n\n<p>Professor Ryu Jeongki said, &#8220;PET is the plastic that is currently recycled most efficiently, but chemical recycling technologies that break it down into chemical feedstock remain slow to be commercialized because of high process costs,&#8221; adding, &#8220;This technology will help lower costs by simplifying both the production and recovery of feedstock.&#8221;<\/p>\n\n\n\n<p>He continued, &#8220;For commercialization, we need to scale up the processing capacity to verify productivity and secure the overall economic feasibility of the process, including additional purification costs.&#8221;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/image.dongascience.com\/Photo\/2026\/11\/b83c0395bfb81ec0508c30e121ae5c59.jpg\" alt=\"From left, Professor Ryu Jeongki, researcher Lee Inhee, and researcher Choi Yuri. Provided by UNIST\"\/><figcaption class=\"wp-element-caption\">From left, Professor Ryu Jeongki, researcher Lee Inhee, and researcher Choi Yuri. \u00a9 UNIST<\/figcaption><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">Reference<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/S1385894726100400\">doi.org\/10.1016\/j.cej.2026.182577<\/a><\/li>\n<\/ul>\n\n\n\n<div style=\"height:13px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n","protected":false},"excerpt":{"rendered":"<p>A technology has been developed that decomposes waste PET bottles using only light and heat and converts them back into chemical feedstock. The feedstock is recovered in both solid and gaseous form, which is expected to simplify the recovery process. Ulsan National Institute of Science and Technology (UNIST) announced on the 4th that a team [&#8230;]<\/p>\n","protected":false},"author":59,"featured_media":183453,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"none","nova_meta_subtitle":"UNIST- and POSTECH-researchers have developed a chemical recycling technology that converts PET into reusable feedstocks, terephthalic acid and ethylene","footnotes":""},"categories":[17143],"tags":[6843,22614,14120,17202,10416,10408,24744],"supplier":[1102,13125],"class_list":["post-183427","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-recycling","tag-biochemicals","tag-biofeedstocks","tag-catalysis","tag-chemicalrecycling","tag-circulareconomy","tag-greenchemistry","tag-petwaste","supplier-pohang-university-of-science-and-technology","supplier-unist"],"_links":{"self":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/183427","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/users\/59"}],"replies":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/comments?post=183427"}],"version-history":[{"count":1,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/183427\/revisions"}],"predecessor-version":[{"id":183454,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/183427\/revisions\/183454"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media\/183453"}],"wp:attachment":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media?parent=183427"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/categories?post=183427"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/tags?post=183427"},{"taxonomy":"supplier","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/supplier?post=183427"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}