ศึกษาศักยภาพการผลิตไบโอเอทานอลจากลำไยตกเกรดและลำไยเน่าเสีย

Abstract

One of the significant fruits in the economy and industry is longan fruits. The longan (Dimocarpus longan Lour.) is a subtropical enduring tree belonging to the family Sapindaceae whose name is a well - known subtropical fruit in many countries, particularly in China, Thailand, Vietnam, India, Australia, and some tropical and subtropical regions in the USA. On the other hand, the status of fruit waste, which becomes stuck previous to landfills, is concerned by researchers over the years. Low grade and waste longan fruits are also no exceptions that are feedstock material for bioethanol production. In this study, physical pretreatment has been carried out which include boiling (30 min) and autoclave (15, 30, 45 minutes and 0 min for control). Afterward, samples were scanned by scanning electron microscope (SEM) to recognize differences between raw materials, boiled samples, and autoclaved samples. Hydrolysis process has done with three varied hydrolysis which were utilized in samples: 2% commercial cellulase, 20% algal enzyme and combination of 1% commercial cellulase and 10% algae enzyme (C+A). Response Surface Methodology (RSM) was utilized to determine and optimize condition lead to the best pretreated and hydrolysed ways. For fresh longan, the optimum condition produce high amount of sugar by using 2% commercial celullase in hydrolysis and 30 min autoclave lead to the highest bioethanol production (9.25 ± 0.25 g/L) after 24 hours of fermentation. For dried longan, the optimum condition produce high amount of sugar by using 2% commercial celullase in hydrolysis and 15 min autoclave lead to the highest bioethanol production (16.74 ± 0.62 g/L) after 24 hours of fermentation. As result, dried longan has been chosen for a large scale. Results showed that after pretreatment, the total and reducing sugar are 157.19 and 36.43 g/L, respectively; the total and reducing sugar was increased in hydrolysis with 271.07 and 48.21 g/L, respectively. Fermentation with 1% Saccharomyces cerevisiae 24 hours bioethanol production reached 1.4%; alcohol concentration increase to 9% in distillation. The High Heating Value (HHV) was 4.55 MJ/kg. In this experiment, mass balance, energy, and economic analysis were analyzed to consider to invest as a project.