Computer applications for selecting operating parameters of stationary grain crop thresher

In this study,various operating parameters influencing performance of stationary grain crop threshers were established.These parameters were deduced from the established analytical models describing the underlying principles for the crop characteristics and machine variables as factors influencing the overall machine performance of a stationary multi-crop thresher.A computer programme written in Visual Basic was used to select optimum operating performance of the threshing process in a stationary tooth–peg grain crop thresher.An IITA-popularized stationary multi-crop thresher was used to test the practical feasibility of the computer based output of the threshing process.A split–split–unit statistical design was used for data collection.The data collected were analyzed using the GENSTAT 5 statistical package with its computer programme.The results showed that graphs of data from measured thresher performance indices against the predicted data for all the established models indicated high correlation between the models and the measured data at p≤5%significance level.The minimum energy requirements for detachment of sorghum and rice were observed at the threshing cylinder speed of 500 r/min(10.5 m/s)and 615 r/min(13.0 m/s),respectively.The combination of the threshing cylinder speed of 500 r/min(10.5 m/s)and 615 r/min(13.0 m/s)at crop moisture content of 12.8%and 16.2%indicated optimum threshing conditions for sorghum and rice,respectively.

Optimizing extrusion pretreatment and big bluestem parameters for enzymatic hydrolysis to produce biofuel using response surface methodology

Biomass has been identified as alternative renewable energy resource to replace 30%transportation fossil fuel through biofuels by 2.025.Big bluestem is a warm season native perennial grass warrants attention and studies revealed its potential as energy feedstock.Extrusion pretreatments employed on big bluestem showed a significant improvement on sugar recovery.The current study was undertaken to understand and optimize pretreatment conditions such as barrel temperature(45-225℃),screw speed(20-200 r/min),moisture content(10%-50%w.b.),and particle size(2-10 mm)for maximum sugar recovery from big bluestem;and to propose a model to predict the glucose,xylose,and combined sugar recovery.Statistical analyses confirmed that all the independent variables included in this study had a strong influence on sugar recovery.A quadratic polynomial model was proposed to predict the glucose,xylose,and combined sugar recoveries from big bluestem,which had high F and R2 values with low p values.The optimum pretreatment conditions such as barrel temperature 180℃,screw speed 150 r/min,moisture content 20%w.b.,and particle size 8 mm resulted in maximum glucose,xylose,and combined sugar recoveries of 71.3%,78.5%,and 56.9%,respectively.Surface area of the optimum pretreated big bluestem increased 68.5%than that of control sample,which is the main cause for increase in sugar recovery.