This systematic review evaluates the production of polylactic acid (PLA) from organic waste, focusing on methodological, techno-economic, and environmental implications, during the study period 1991-2025. The review was conducted following the PRISMA 2020 guidelines and a bibliometric analysis using VOSviewer V.1.6.20 to identify research trends, co-authorship networks, and keyword co-occurrence patterns. A literature search was performed across scientific databases using keywords related to PLA synthesis, applications, life-cycle assessment, and organic waste. The screening process included identification, duplicate removal, title and abstract screening, and full-text eligibility assessment. From 1045147 identified records, 96880 articles were screened, 7073 full texts were assessed for eligibility, and 94 studies met the inclusion criteria according to the PRISMA workflow. Eligibility criteria required detailed reporting of operational conditions, applicability, economic assessments, or environmental analysis, others were excluded. The analyzed studies show that Lactic-acid yields above 90% were commonly achieved using microwave-assisted autohydrolysis, enzymatic hydrolysis, and fermentation with Lactobacillus spp. Ring-opening polymerization using Sn-modified cation-exchange resins produced high-quality PLA. Environmental assessments reported CO2 emissions ranging from -3400 kg CO2/t to 696926.1 kg CO2/t. Overall, PLA synthesis from organic waste shows environmental potential, although the evidence is limited by variability in process. No funding was received for this research.
Sornoza-Macias et al. (Tue,) studied this question.