[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-606607-105":3,"doc-detail-606607-en":81,"detail-sidebar-cat-0-en-105":98},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","chain-elongation-of-acetate-and-ethanol-in-an-upflow-anaerobic-filter-for-high-rate-mcfa-production","Chain elongation of acetate and ethanol in an upflow anaerobic filter for high rate MCFA production","","Interest has returned in medium chain fatty acids (MCFAs) as low-cost feedstock for biobased chemical and fuel production. Cost-effectiveness requires higher volumetric MCFA production rates through chain elongation. A process was studied in an upflow anaerobic filter at a 17 h hydraulic retention time to enhance the rate. Volumetric MCFA production reached 16.6 g/L/day, over sevenfold higher than prior production, exceeding sevenfold and comparable to other fermentation processes such as methane, butanol, and ethanol. Increasing ethanol loading raised production rates and achieved 91% MCFA selectivity, while methane stayed below 0.1% in reactor headspace.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/research-report/","Research & Report",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/chain-elongation-of-acetate-and-ethanol-in-an-upflow-anaerobic-filter-for-high-rate-mcfa-production/606607/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/chain-elongation-of-acetate-and-ethanol-in-an-upflow-anaerobic-filter-for-high-rate-mcfa-production/606607.png","ImageObject",300,407,{"name":42,"@type":43},"Terk","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-30","2026-10-16",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",8,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"Why is chain elongation used to produce medium chain fatty acids (MCFAs) instead of direct fermentation products like ethanol?","Question",{"text":63,"@type":64},"Chain elongation extends carbon chains of volatile fatty acids using diluted ethanol, producing MCFAs with lower water solubility than VFAs and ethanol. This improves separation and can enable production in non-sterile conditions without costly sterilization.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"How was the MCFA production process improved in the studied upflow anaerobic filter?",{"text":68,"@type":64},"The study used a hydraulic retention time of 17 hours and investigated how ethanol loading affected production. The approach increased the volumetric MCFA production rate to 16.6 g/L/day, more than seven times higher than current production.",{"name":70,"@type":61,"acceptedAnswer":71},"What effects did increasing ethanol load have on MCFA selectivity and by-product methane formation?",{"text":72,"@type":64},"Increasing ethanol load increased volumetric production rates and improved MCFA selectivity to 91%. During operation, methane percentages below 0.1% were detected in the reactor headspace.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},606607,1792231770,{"code":4,"msg":82,"data":83},"success",{"doc_id":79,"user_id":84,"nickname":42,"user_avatar":85,"doc_module":4,"category_id":55,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":86,"file_id":87,"file_url":88,"file_type":89,"file_size":90,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":91,"language":92,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":93,"faqs":94,"seo_title":95,"seo_description":12,"update_tm":96,"read_time":97},1099525198933,"https://ap-avatar.wpscdn.com/davatar_155a257f0dc6eb9ab79c44ca47cae57d","Bioresource Technology 135 (2013) 440–445  \n| Chain elongation of acetate and ethanol in an upflow anaerobic filter for high rate MCFA production\u003Cbr>T.I.M. Grootscholten ⇑, K.J.J. Steinbusch, H.V.M. Hamelers, C.J.N. Buisman Sub-Department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA Wageningen, The Netherlands |  |  |\n| --- | --- | --- |\n| h i g h l i g h t s |  |  |\n| \" A new reactor system for chain elongation in non-sterile conditions was investigated.\" The volumetric MCFA production rate is in the range of other fermentation processes.\" The volumetric caprylate production rate was improved more than 16 times.\u003Cbr>\" Highest reported caprylate concentration by chain elongation was achieved.\u003Cbr>\" By increasing the ethanol load, the selectivity of MCFA production improved. |  |  |\n| a r t i c l e i n f o |  | a b s t r a c t |\n| Article history:\u003Cbr>Available online 16 November 2012 |  | Recently, interest has regained for medium chain fatty acids (MCFAs) as a low cost feedstock for biobased chemical and fuel production processes. To become cost-effective, the volumetric MCFA production rate by chain elongation should increase to comparable rates of other fermentation processes. We investigate the MCFA production process at a hydraulic retention time of 17 h in an upflow anaerobic filter to improve the volumetric MCFA production rate. This approach resulted in a MCFA production with a volumetric production rate of 16.6 g l􀀂1 d􀀂1, which is more than seven times higher than the current production rate. Moreover the rate is now in the range of other fermentation processes like methane, butanoland ethanol production. Increasing the ethanol load lead to higher volumetric production rates and a high MCFA selectivity of 91%. During operation, methane percentages lower than 0. 1% were detected in the headspace of reactor.\u003Cbr>􀀂 2012 Elsevier Ltd. All rights reserved. |\n| Keywords:\u003Cbr>Mixed culture fermentation\u003Cbr>Caproate\u003Cbr>Caprylate\u003Cbr>Bioreactor\u003Cbr>Carboxylate |  |  |\n\n1. Introduction  \nIn the search for bio-based chemical and fuel production processes, often costs are limiting the transition from fossil to bio-based chemicals and fuels. Fermentations are one the key processes for the production of bio-based chemicals and fuel. However, fermentations have a high water content and their products are often soluble in water. The extraction of miscible fermentation products in water (like ethanol) is a large cost factor, because it is energy intensive. Ethanol requires significant amount of the energy for its distillation from the fermentation broth. As alternative feedstock for fuel production, medium chain fatty acids (MCFA) could be produced. The MCFA fermentation got recently more interest, because its products can be produced in high concentrations close to the solubility of their undissociated form in water (Steinbusch et al., 2011). Furthermore, the MCFA fermenta-  \n⇑ Corresponding author. Tel.: +31 317 483227; fax: +31 317 482108. E-mail [address:](address: Tim.Grootscholten@wur.nl)[ Tim.Grootscholten@wur.nl](address: Tim.Grootscholten@wur.nl) (T.I.M. Grootscholten).  \ntion can use diluted ethanol directly (without its ineffective distillation) as a substrate (Agler et al., 2012). Moreover, MCFAs, straight carboxylic acids with six to eight carbon atoms, can be produced in a non-sterile environment and have more versatile applications than ethanol, including antimicrobials (directly), biofuels or bioplastics (both indirectly) (Levy et al., 1981; Witholt and Kessler, 1999). By producing these biochemical in a non-sterile environment, no costly sterilisation step is required.  \nMCFAs can be produced from intermediate biochemical produced in the anaerobic digestion process, like acetate, propionate and other volatile fatty acids (VFAs). These intermediate products can be produced from low grade biomass (Agler et al., 2011; D’Addario et al., 1993). However, they are mostly completely miscible in water and are di","cbCaitEECsJtSJDr","https://ap.wps.com/l/cbCaitEECsJtSJDr","pdf",560248,6,"English","# Highlights\n## MCFA production improvements under non-sterile conditions\n# Article information\n## Article history and keywords\n# Introduction\n## Cost barriers and extraction challenges\n## MCFA fermentation and the role of ethanol\n## Non-sterile chain elongation advantages\n## Key limitations: rate, selectivity, and robustness","[{\"question\":\"Why is chain elongation used to produce medium chain fatty acids (MCFAs) instead of direct fermentation products like ethanol?\",\"answer\":\"Chain elongation extends carbon chains of volatile fatty acids using diluted ethanol, producing MCFAs with lower water solubility than VFAs and ethanol. This improves separation and can enable production in non-sterile conditions without costly sterilization.\"},{\"question\":\"How was the MCFA production process improved in the studied upflow anaerobic filter?\",\"answer\":\"The study used a hydraulic retention time of 17 hours and investigated how ethanol loading affected production. The approach increased the volumetric MCFA production rate to 16.6 g/L/day, more than seven times higher than current production.\"},{\"question\":\"What effects did increasing ethanol load have on MCFA selectivity and by-product methane formation?\",\"answer\":\"Increasing ethanol load increased volumetric production rates and improved MCFA selectivity to 91%. During operation, methane percentages below 0.1% were detected in the reactor headspace.\"}]","Chain elongation of acetate and ethanol in an upflow anaerobic filter for high rate MCFA production | PDF",1792185244,15,{"code":4,"msg":82,"data":99},[100,104,108,112,117,121,126,129,134,137,141],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":101,"show_sort_weight":102,"slug":103},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":105,"show_sort_weight":106,"slug":107},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":109,"show_sort_weight":110,"slug":111},"Exam",70,"exam",{"id":113,"doc_module":4,"doc_module_name":25,"category_name":114,"show_sort_weight":115,"slug":116},5,"Comic",60,"comic",{"id":91,"doc_module":4,"doc_module_name":25,"category_name":118,"show_sort_weight":119,"slug":120},"Technology",50,"technology",{"id":122,"doc_module":4,"doc_module_name":25,"category_name":123,"show_sort_weight":124,"slug":125},7,"Healthcare",40,"healthcare",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":127,"slug":128},30,"research-report",{"id":130,"doc_module":4,"doc_module_name":25,"category_name":131,"show_sort_weight":132,"slug":133},9,"Religion & Spirituality",20,"religion-spirituality",{"id":132,"doc_module":4,"doc_module_name":25,"category_name":135,"show_sort_weight":132,"slug":136},"World Cup","world-cup",{"id":138,"doc_module":4,"doc_module_name":25,"category_name":139,"show_sort_weight":138,"slug":140},10,"Lifestyle","lifestyle",{"id":142,"doc_module":4,"doc_module_name":25,"category_name":143,"show_sort_weight":113,"slug":144},19,"General","general"]