{"id":169049,"date":"2025-10-17T07:23:00","date_gmt":"2025-10-17T05:23:00","guid":{"rendered":"https:\/\/renewable-carbon.eu\/news\/?p=169049"},"modified":"2025-10-13T12:19:23","modified_gmt":"2025-10-13T10:19:23","slug":"turning-ocean-carbon-into-biodegradable-plastic","status":"publish","type":"post","link":"https:\/\/renewable-carbon.eu\/news\/turning-ocean-carbon-into-biodegradable-plastic\/","title":{"rendered":"Turning ocean carbon into biodegradable plastic"},"content":{"rendered":"\n\n\n

Researchers have invented a system\u00a0that captures carbon dioxide from ocean water and converts it to succinic acid<\/a>, a key monomer used to make the commonly used biodegradable plastic polybutylene succinate (Nat. Catal.<\/em>\u00a02025, DOI: 10.1038\/s41929-025-01416-4<\/a>). The first-of-its-kind system could also be tailored to make other chemicals, opening a route to sustainable drugs, fuels, and food products.<\/p>\n\n\n

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\"A
A new system converts carbon dioxide from ocean water to a monomer used to make polybutylene succinate (pellets above), a common biodegradable plastic.\u00a0\u00a9 Shutterstock<\/figcaption><\/figure><\/div>\n\n\n

\u201cIt taps the ocean\u2019s dissolved carbon for low-carbon chemicals, avoids energy-intensive air capture, and enables coastal manufacturing compatible with renewable power,\u201d says\u00a0Chuan Xia<\/a>, a materials chemist at the University of Electronic Science and Technology of China, who led the study with\u00a0Xiang Gao<\/a>\u00a0at the Shenzhen Institutes of Advanced Technology.<\/p>\n\n\n\n

Large-scale projects to capture CO2<\/sub> from air<\/a> are underway around the world to combat climate change. But oceans absorb almost a third<\/a> of CO2<\/sub> emissions from the atmosphere, and pulling dissolved carbon out of seawater is more straightforward than capturing it from air. So researchers at universities and start-ups are now starting to pursue direct ocean capture<\/a> (DOC) of CO2<\/sub>.<\/p>\n\n\n\n

But no one has yet coupled DOC with conversion of CO2<\/sub> to valuable products<\/a>. \u201cThis is the first demonstration that\u2019s going from ocean carbon dioxide all the way to a usable feedstock for bioplastic,\u201d says CX Xiang<\/a>, a specialist in chemical physics and materials science at the California Institute of Technology and cofounder and chief technology officer of the DOC company Captura<\/a>; Xiang was not involved in this work.<\/p>\n\n\n

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\"A
Seawater flows into an electrochemical reactor and a filtration device that extracts carbon dioxide from the water. The CO2<\/sub>\u00a0is converted to formic acid, which goes to a fermentor to be converted to succinic acid, a bioplastic monomer.\u00a0\u00a9\u00a0Nat. Catal.\/C&EN<\/figcaption><\/figure><\/div>\n\n\n

The new system combines electrochemistry with microbial fermentation. Seawater flows through a reactor containing five chambers separated by membranes. At the cathode and anode, each in separate chambers, water is split into hydroxide ions and protons. An electric field drives the ions to the two sides of the reactor.<\/p>\n\n\n\n

The main reactions occur in the middle three chambers, which are filled with solid electrolytes. In the central chamber, a salty brine is separated into sodium and chloride ions. In the cathode-side chamber, hydroxide and sodium ions react to form sodium hydroxide.<\/p>\n\n\n\n

Seawater is fed into the anode-side chamber, where protons acidify the water, converting carbonate ions in the seawater to CO<\/a>2<\/sub><\/a> and increasing the CO2 <\/sub>content.<\/p>\n\n\n\n

A filtration device called a hollow-fiber membrane separates CO2\u00a0<\/sub>from the water and feeds the gas to a second reactor that contains an in-house designed catalyst: a metal-organic framework containing bismuth. This catalyst converts CO2<\/sub>to formic acid, which flows to a bioreactor that holds\u00a0Vibrio natriegens<\/em>, an engineered strain of bacteria. The bacteria ferment the formic acid and transform it to succinic acid. The researchers note that using other engineered microbes should make it possible to produce other industrial chemicals such as lactic acid, alanine, and butane-1,4-diol.<\/p>\n\n\n\n

After the carbon is removed, the acidic seawater is neutralized with the sodium hydroxide produced by the system so it can be discharged back into the ocean.<\/p>\n\n\n\n

Xia says the use of solid electrolytes and separate chambers makes the new DOC reactor stable. Electrochemical DOC devices made so far only last for a few hours because \u201cseawater contacts electrodes or membranes, which promotes scaling and fouling,\u201d he says.<\/p>\n\n\n\n

In contrast, the team\u2019s five-chamber reactor extracted CO2<\/sub> from natural seawater from Shenzhen Bay for more than 530 h. It produced around 6.54 L of CO2<\/sub> from 177 L of seawater, showing a carbon capture efficiency of 70%. And the reactor consumes about 3 kW h of energy for each kilogram of CO2<\/sub>. The team calculates the cost of capture to be about $230 per metric ton of CO2<\/sub>, which is competitive with today\u2019s carbon capture approaches.<\/p>\n\n\n\n

Xiang says Captura\u2019s technology has a much higher carbon capture efficiency\u201490%\u2014and much lower energy use. \u201cWe do a better job with the capture aspect, but that\u2019s not the highlight of this work,\u201d he says. Instead, the focal point is \u201ctaking that CO2 <\/sub>and turning it into a bioplastic monomer with promising stability and economics.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

Researchers have invented a system\u00a0that captures carbon dioxide from ocean water and converts it to succinic acid, a key monomer used to make the commonly used biodegradable plastic polybutylene succinate (Nat. Catal.\u00a02025, DOI: 10.1038\/s41929-025-01416-4). The first-of-its-kind system could also be tailored to make other chemicals, opening a route to sustainable drugs, fuels, and food products. […]<\/p>\n","protected":false},"author":59,"featured_media":169064,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"none","nova_meta_subtitle":"System is first to pull carbon dioxide from the ocean and convert it to valuable product","footnotes":""},"categories":[5572,5571],"tags":[6843,11270,5847,10744,12330,16364,10743],"supplier":[2530,27036,27035,27034],"class_list":["post-169049","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bio-based","category-co2-based","tag-biochemicals","tag-biodegradability","tag-bioplastics","tag-carboncapture","tag-ccu","tag-seawater","tag-useco2","supplier-california-institute-of-technology","supplier-captura","supplier-shenzhen-institutes-of-advanced-technology","supplier-university-of-electronic-science-and-technology-of-china"],"_links":{"self":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/169049","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=169049"}],"version-history":[{"count":0,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/169049\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media\/169064"}],"wp:attachment":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media?parent=169049"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/categories?post=169049"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/tags?post=169049"},{"taxonomy":"supplier","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/supplier?post=169049"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}