The production of lactic acid from kitchen garbage, the precursor for production of biodegradable plastics is described in detail. The influence of temperature on the lactic acid concentration, sugar concentration, an...The production of lactic acid from kitchen garbage, the precursor for production of biodegradable plastics is described in detail. The influence of temperature on the lactic acid concentration, sugar concentration, and decrement of garbage were evaluated through experiments. Fermentation were carried out in an incubator at 5, 25, 37 and 50 ℃. The latic acid produced was maximum at initial pH 6.0 and 37 ℃, i.e. 38 g/L with a yield of 0.23 g/gVS. It is concluded from the experimental results that temperature has quite a considerable effect on the production of lactic acid; lactic acid concentration increases with temperature until 37 ℃, and production rate of lactic acid drops at 50 ℃; the optimal fermentation is 37 ℃. This study shows that production of lactic acid from kitchen garbage is feasible and reduction of garbage can be realized.展开更多
The digestibility of sorted municipal solid waste （MSW） is often limited by the high content of structured green waste. The objectives of this study are to investigate the effect of alkaline hydrothermal pretreatmen...The digestibility of sorted municipal solid waste （MSW） is often limited by the high content of structured green waste. The objectives of this study are to investigate the effect of alkaline hydrothermal pretreatment on the anaerobic digestion of sorted waste and to analyze the biogas production of different parts of the waste. The waste was hydrothermally pretreated in a dilute alkali solution. The hydrolysis product was then incubated in a 500 mL saline bottle to determine the biochemical methane potential （BMP） under mesophilic anaerobic conditions. The optimum hydrothermal condition was 170℃ at 4 g NaOH/100 g solid for one hour. The concentration of chemical oxygen demand （COD） was 13 936 mg/L and the methane yield was 164 mL/g volatile solid （VS） for 6 days incubation at the optimum conditions. The biogas production was increased more than 50% over the control, with the methane conversion ratio on a carbon basis enhanced to 30.6%. The organic part of the sorted waste was mainly kitchen garbage and leaves. Model kitchen garbage completely liquified at 130℃ for one hour had a methane yield of 276 mL/g VS. The alkali addition slightly enhanced the hydrolyzation rate and methane yield. The biogas potential of leaves was improved by pretreatment at above 150℃ under alkaline conditions.展开更多
文摘The production of lactic acid from kitchen garbage, the precursor for production of biodegradable plastics is described in detail. The influence of temperature on the lactic acid concentration, sugar concentration, and decrement of garbage were evaluated through experiments. Fermentation were carried out in an incubator at 5, 25, 37 and 50 ℃. The latic acid produced was maximum at initial pH 6.0 and 37 ℃, i.e. 38 g/L with a yield of 0.23 g/gVS. It is concluded from the experimental results that temperature has quite a considerable effect on the production of lactic acid; lactic acid concentration increases with temperature until 37 ℃, and production rate of lactic acid drops at 50 ℃; the optimal fermentation is 37 ℃. This study shows that production of lactic acid from kitchen garbage is feasible and reduction of garbage can be realized.
基金Supported by the National High-Tech Research and Development(863) Program of China (No. 2006AA10Z422)
文摘The digestibility of sorted municipal solid waste （MSW） is often limited by the high content of structured green waste. The objectives of this study are to investigate the effect of alkaline hydrothermal pretreatment on the anaerobic digestion of sorted waste and to analyze the biogas production of different parts of the waste. The waste was hydrothermally pretreated in a dilute alkali solution. The hydrolysis product was then incubated in a 500 mL saline bottle to determine the biochemical methane potential （BMP） under mesophilic anaerobic conditions. The optimum hydrothermal condition was 170℃ at 4 g NaOH/100 g solid for one hour. The concentration of chemical oxygen demand （COD） was 13 936 mg/L and the methane yield was 164 mL/g volatile solid （VS） for 6 days incubation at the optimum conditions. The biogas production was increased more than 50% over the control, with the methane conversion ratio on a carbon basis enhanced to 30.6%. The organic part of the sorted waste was mainly kitchen garbage and leaves. Model kitchen garbage completely liquified at 130℃ for one hour had a methane yield of 276 mL/g VS. The alkali addition slightly enhanced the hydrolyzation rate and methane yield. The biogas potential of leaves was improved by pretreatment at above 150℃ under alkaline conditions.
