ABSTRACT
An exergy equilibrium model was established to obtain the exergy efficiency under different conditions of compound bacteria pretreatment and anaerobic digestion (AD) of corn stalk. The Genetic Algorithm (GA) was applied to optimize the exergy efficiency of the combination process of the pretreatment and AD. The maximum exergy efficiency with the GA was 19.04%, corresponding to the optimal pretreatment parameters: pretreatment temperature 33.34â, stalk particle size 0.50 mm, ventilation rate 0.88 L/min, pretreatment time 169.03 h. The optimal AD parameters were: digestion temperature 38.08â and stirring rate 48.04 r/min. The validation experiment exergy efficiency reached to 19.25%, which was 24.37% higher as compared to that of the non-pretreatment process. Under these optimal conditions, the energy consumption of the compound bacteria pretreatment and the time of the bio-methane production process were effectively reduced.
Subject(s)
Methane , Zea mays , Algorithms , Anaerobiosis , Bacteria , BiofuelsABSTRACT
In order to improve the yield of reducing sugar from corn stalk, ultrasonic-assisted ammonium bicarbonate pretreatment of corn stalk was proposed. Three ultrasonic factors (time (0-30 min), temperature (30-60 °C) and liquid/solid mass ratio (5-20)) were optimized by response surface experiment. The optimal conditions of ultrasonic pretreatment were obtained (liquid/solid mass ratio is 12:1, temperature is 42 °C and time is 11 min). The highest saccharification rate of corn stalk was of 82.61%, which was remarkably increased by 355% compared to the control group.
