Phase equilibrium data prediction and process optimizationin butadiene extraction process

In response to the lack of reliable physical parameters in the process simulation of the butadiene extraction,a large amount of phase equilibrium data were collected in the context of the actual process of butadiene production by acetonitrile.The accuracy of five prediction methods,UNIFAC(UNIQUAC Functional-group Activity Coefficients),UNIFAC-LL,UNIFAC-LBY,UNIFAC-DMD and COSMO-RS,applied to the butadiene extraction process was verified using partial phase equilibrium data.The results showed that the UNIFAC-DMD method had the highest accuracy in predicting phase equilibrium data for the missing system.COSMO-RS-predicted multiple systems showed good accuracy,and a large number of missing phase equilibrium data were estimated using the UNIFAC-DMD method and COSMO-RS method.The predicted phase equilibrium data were checked for consistency.The NRTL-RK(non-Random Two Liquid-Redlich-Kwong Equation of State)and UNIQUAC thermodynamic models were used to correlate the phase equilibrium data.Industrial device simulations were used to verify the accuracy of the thermodynamic model applied to the butadiene extraction process.The simulation results showed that the average deviations of the simulated results using the correlated thermodynamic model from the actual values were less than 2%compared to that using the commercial simulation software,Aspen Plus and its database.The average deviation was much smaller than that of the simulations using the Aspen Plus database(>10%),indicating that the obtained phase equilibrium data are highly accurate and reliable.The best phase equilibrium data and thermodynamic model parameters for butadiene extraction are provided.This improves the accuracy and reliability of the design,optimization and control of the process,and provides a basis and guarantee for developing a more environmentally friendly and economical butadiene extraction process.

Consolidated bioprocess of corn stover to polysaccharide using Chaetomium globosum CGMCC 6882

Polysaccharide produced from medicinal endophytic fungus not only has applications in foods,but also exhibits multiple biological activities.In this work,an endophytic fungus Chaetomium globosum CGMCC 6882 could use corn stover to produce a polysaccharide(GCP-SC)by consolidated bioprocess and the titer of GCP-SC reached 3.2 g/L.The transcriptional levels of genes related to cellulose degradation(cbh,cdh,glu and egl)in C.globosum CGMCC 6882 were 4.38,3.85,3.13,and 2.17 folds compared to the control group when corn stover was used as the sole carbon source.Moreover,GCP-SC showed a time-and dose-dependent manner of inhibitory effect on A549 cells and the inhibitory rate reached 93.3%.This work provides meaningful data on agricultural residues utilization and facilitation of future relative resource conversion studies.