Optimal Control Of Starch Quality Improvement In The Wet Process

Jilin fuel ethanol plant with corn as raw materials to produce the modified wet process the corn soaking,germ,broken starch is made,starch after liquefaction,saccharification,fermentation,distillation and dehydration produce fuel ethanol.Improvement of the wet starch process,germ,skin fiber extraction rate is low,cause distillation column blocking,greatly reduces the effectiveness of distillation and long time operation;starch at low temperature,large size,miscellaneous bacteria multiple directly affect liquid saccharification and fermentation effect,reduce the rate of alcohol extraction.Through the research of this topic,we can solve the technical bottleneck of starch slurry quality control in the process of ethanol production by wet method,and form the industry competitiveness,environmental friendly,and industrial technology with independent intellectual property rights.The research based on starch process of 30 million tons one year and according to actual production,after the corn conveying water were the heat exchanger and injection heater immersion were studied that the heat exchanger and injection heater after corn,with longer soaking time and soaking temperature decreased after breaking into starch stained bacteria have a chance to increase,but made by the jet heating soaking corn starch dye probability of bacteria than for heat exchanger is used for heating is greatly reduced,starch quality guaranteed.Through the above experiments,the optimal process conditions for the control of bacterial contamination in starch pulp production process:the direct heating method,the soaking time 11 hours,the soaking temperature 62?.In the verification conditions,through a month continuous production the number of starch bacillus is 4-6 per milliliter,volatile acid is 0.05-0.07.The research based on starch process of 30 million tons one year and according to actual production,through the ground clearance and flushing water flow adjustment and grinding time on the effect of particle size of found with grinding clearance and flushing water flow rate is increased and the grinding time prolonged,particle size of starch slurry showed a rising trend,through reasonable adjustment and economic accounting can ensure the starch slurry particle size in the optimum range.Through the above experiments,the optimum technological conditions of controlling the particle size in the production process of starch slurry:grinding gap 1 mm,washing water flow rate 15m3·h-1,grinding time is not more than 1.5 weeks.Through a month of continuous production verification under the above conditions the size of starch slurry in 1.0-1.6(3mm_standard sieve).The research based on starch process of 30 million tons one year and according to actual production,after on top of the germ separator flow,liquid tank material concentration and primary germ separation feed pressure of germ and leather fiber content of study found with germ separator top flow rate and liquid tank material concentration increased and a germ separation into the feeding pressure increase,germ and leather fiber content showed a rising trend,through reasonable adjustment and economic accounting can be that starch slurry particle size within the optimum range.Through the test,the starch production process control germ amount and leather fiber content,the optimum technological conditions:germ separator top flow 200 m3.h-1,material concentration 6 Be°,germ separation into material pressure 0.75 Mpa.Through a month of continuous production to verify the amount of genn in the above conditions in the 7.8-8.2 t.h-1,the percent of the fiber is 24-27.