{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T11:18:04Z","timestamp":1774610284031,"version":"3.50.1"},"reference-count":108,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2019,11,20]],"date-time":"2019-11-20T00:00:00Z","timestamp":1574208000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["FCT UID\/EMS\/50022\/2019"],"award-info":[{"award-number":["FCT UID\/EMS\/50022\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/EMS-ENE\/4865\/2014"],"award-info":[{"award-number":["PTDC\/EMS-ENE\/4865\/2014"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Energies"],"abstract":"<jats:p>Energy security and environmental concerns, related to the increasing carbon emissions, have prompted in the last years the search for renewable and sustainable fuels. Biodiesel, a mixture of fatty acids alkyl esters shows properties, which make it a feasible substitute for fossil diesel. Biodiesel can be produced using different processes and different raw materials. The most common, first generation, biodiesel is produced by methanolysis of vegetable oils using basic or acid homogeneous catalysts. The use of vegetable oils for biodiesel production raises serious questions about biodiesel sustainability. Used cooking oils and animal fats can replace the vegetable oils in biodiesel production thus allowing to produce a more sustainable biofuel. Moreover, methanol can be replaced by ethanol being totally renewable since it can be produced by biomass fermentation. The substitution of homogeneous catalyzed processes, nowadays used in the biodiesel industry, by heterogeneous ones can contribute to improve the biodiesel sustainability with simultaneous cost reduction. From the existing literature on biodiesel production, it stands out that several strategies can be adopted to improve the sustainability of biodiesel. A literature review is presented to underline the strategies allowing to improve the biodiesel sustainability.<\/jats:p>","DOI":"10.3390\/en12234408","type":"journal-article","created":{"date-parts":[[2019,11,20]],"date-time":"2019-11-20T11:06:03Z","timestamp":1574247963000},"page":"4408","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":309,"title":["Biodiesel Production Processes and Sustainable Raw Materials"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4967-4850","authenticated-orcid":false,"given":"Marta","family":"Ramos","sequence":"first","affiliation":[{"name":"ADEQ, Instituto Superior de Engenharia de Lisboa, Instituto Polit\u00e9cnico de Lisboa, R. Conselheiro Em\u00eddio Navarro, 1, 1959-007 Lisboa, Portugal"},{"name":"LAETA, IDMEC, CERENA, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4585-470X","authenticated-orcid":false,"given":"Ana Paula Soares","family":"Dias","sequence":"additional","affiliation":[{"name":"LAETA, IDMEC, CERENA, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2763-3655","authenticated-orcid":false,"given":"Jaime Filipe","family":"Puna","sequence":"additional","affiliation":[{"name":"ADEQ, Instituto Superior de Engenharia de Lisboa, Instituto Polit\u00e9cnico de Lisboa, R. Conselheiro Em\u00eddio Navarro, 1, 1959-007 Lisboa, Portugal"},{"name":"LAETA, IDMEC, CERENA, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2579-6669","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Gomes","sequence":"additional","affiliation":[{"name":"ADEQ, Instituto Superior de Engenharia de Lisboa, Instituto Polit\u00e9cnico de Lisboa, R. Conselheiro Em\u00eddio Navarro, 1, 1959-007 Lisboa, Portugal"},{"name":"LAETA, IDMEC, CERENA, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal"}]},{"given":"Jo\u00e3o Carlos","family":"Bordado","sequence":"additional","affiliation":[{"name":"LAETA, IDMEC, CERENA, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,20]]},"reference":[{"key":"ref_1","unstructured":"U.S. Energy Information Administration (2017). International Energy Outlook 2017."},{"key":"ref_2","unstructured":"(2019). 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