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DC FieldValueLanguage
dc.contributorFaculty of Construction and Environmenten_US
dc.contributor.advisorLeu, Shao-yuan (CEE)-
dc.creatorWang, Li-
dc.identifier.urihttps://theses.lib.polyu.edu.hk/handle/200/9538-
dc.languageEnglishen_US
dc.publisherHong Kong Polytechnic University-
dc.rightsAll rights reserveden_US
dc.titleFeasibility analysis of fermentative lactic acid production from waste-derived crude glycerolen_US
dcterms.abstractGlycerol is considered as an ideal carbon source for lactic acid fermentation, which has received attractive interest especially in the development of poly-lactic acid. In order to improve the industrial lactic acid production, a fermentation process using crude glycerol as carbon source and Lactobacillus species was investigated. E. faecalis QU 11 could convert glycerol to lactic acid with a high yield. Two essential parameters, pH value and fermentation temperature, were optimized with pure glycerol (30 g/L). The results indicated that pH value of 6.5 and fermentation temperature of 30 °C were optimal conditions that gave the best lactic acid yield (>98.5%). Then, under the same optimal conditions, the effect of substrate concentration on fermentation was investigated using crude glycerol (70 wt.%) as the substrate, a crude glycerol concentration of 30 g/L exhibited the optimum performance with a high lactic acid yield (0.743 g/g) and total carbon yield (0.997 C-mol/C-mol). Furthermore, the industrial process of lactic acid production from crude glycerol was designed and simulated by Edraw Max and Aspen Plus. A crude glycerol stream (30 g/L) was obtained during the glycerol purification process, and lactic acid was produced with a high yield of 0.751 g/g during the fermentation process. After that, a lactic acid product stream was further distillated. As a result, lactic acid with 99.92 wt.% was obtained. At the same time, economic analysis in different locations was carried out, the results indicated that the process was potentially profitable. In conclusions, the system of fermentation from crude glycerol to lactic acid was successfully established. This system could be a potential treatment for crude glycerol surplus, and provide a stepping stone to enhance the lactic acid production in industrial processes.en_US
dcterms.extent100 pages : color illustrationsen_US
dcterms.isPartOfPolyU Electronic Thesesen_US
dcterms.issued2017en_US
dcterms.educationalLevelM.Sc.en_US
dcterms.educationalLevelAll Masteren_US
dcterms.LCSHHong Kong Polytechnic University -- Dissertationsen_US
dcterms.LCSHLactic acid -- Biotechnologyen_US
dcterms.LCSHGlycerin -- Industrial applicationsen_US
dcterms.accessRightsrestricted accessen_US

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Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/9538