Abstract:
Needs of bioethanol in Indonesia in 2011 reached 1.4 million kilo liters / year, while national production of
bioethanol at present about 240 million liters / year. This suggests that ethanol demand in Indonesia is still
not being met. Therefore, it is important to do research to produce bioethanol from renewable raw material
or non-fossil material. Bioethanol can be made by fermentation using microorganisms help. The purpose of
this study was to determine the effect of phosphorus concentration on bioconversion reject pineapple into
bioethanol with a maximum ethanol content. The substrate used was obtained from the pineapple and
pineapple reject microorganism used was Saccharomyces cereviciae. Bioethanol production process
consists of several stages, namely preparation of raw materials, fermentation, and purification products. The
independent variable in this study is the variation of the concentration of phosphorus concentration 0.04%,
0.05%, 0.06%, 0.07%, 0.08% and the fermentation time 12, 24, 36, 48, 60, 72, 84, 96, 108, 120 hours, while
variable fixed at 0.3% of yeast concentration, glucose concentration of 16%, and urea concentration of
0.5%. The results showed that the optimum phosphorus concentration of 0.08% is obtained which is capable
of producing ethanol by 10%, ethanol yield 6.67% and 5.12 g cell dry weight / L within 36 hours of
fermentation.
