Sugarcane molasses fermentation with in situ gas stripping using low and moderate sugar concentrations for ethanol production: Experimental data and modeling

Low-cost nitrogen sources, i.e., dried spent yeast (DSY), rice bran (RB), soybean meal (SM), urea and ammonium sulfate were used for batch butanol fermentation from sugarcane molasses by Clostridium beijerinckii TISTR 1461 under anaerobic conditions. Among these five low-cost nitrogen sources, DSY at 1.53 g/L (nitrogen content equal to that of 1 g/L of yeast extract) was found to be the most suitable. At an initial sugar level of 60 g/L, the maximum butanol concentration (PB), productivity (QB) and yield (YB/S) were 11.19 g/L, 0.23 g/L·h and 0.31 g/g, respectively. To improve the butanol production, the concentrations of initial sugar, DSY and calcium carbonate were varied using response surface methodology (RSM) based on Box–Behnken design. It was found that the optimal conditions for high butanol production were initial sugar, 50 g/L; DSY, 6 g/L and calcium carbonate, 6.6 g/L. Under these conditions, the highest experimental PB, QB and YB/S values were 11.38 g/L, 0.32 g/L·h and 0.40 g/g, respectively with 50% sugar consumption (SC). The PB with neither DSY nor CaCO3 was only 8.53 g/L. When an in situ gas stripping system was connected to the fermenter to remove butanol produced during the fermentation, the PB was increased to 15.33 g/L, whereas the YB/S (0.39 g/g) was not changed. However, the QB was decreased to 0.21 g/L·h with 75% SC.

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Integrated in situ gas stripping–salting-out process for high-titer acetone–butanol–ethanol production from sweet sorghum bagasse

Biotechnology for Biofuels ◽

10.1186/s13068-018-1137-5 ◽

2018 ◽

Vol 11 (1) ◽

Cited By ~ 10

Author(s):

Hao Wen ◽

Huidong Chen ◽

Di Cai ◽

Peiwen Gong ◽

Tao Zhang ◽

...

Keyword(s):

Ethanol Production ◽

Sweet Sorghum ◽

High Titer ◽

Sweet Sorghum Bagasse ◽

Gas Stripping ◽

Salting Out ◽

Sorghum Bagasse ◽

Acetone Butanol Ethanol

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In-Situ Vacuum Assisted Gas Stripping Recovery System for Ethanol Removal from a Column Bioreactor

Fibers ◽

10.3390/fib6040088 ◽

2018 ◽

Vol 6 (4) ◽

pp. 88

Author(s):

Martina Andlar ◽

Damir Oros ◽

Tonči Rezić ◽

Roland Ludwig ◽

Božidar Šantek

Keyword(s):

Statistical Analysis ◽

Ethanol Production ◽

Gas Stripping ◽

Biomass Hydrolysis ◽

Solids Concentration ◽

Recovery System ◽

Beet Pulp ◽

Major Factors ◽

Ethanol Removal

A three-step process consisting of biomass hydrolysis, fermentation and in-situ gas stripping by a vacuum assisted recovery system, was optimized to increase the ethanol production from sugar beet pulp. The process combines the advantages of stripping and vacuum separation and enhances the fermentation productivity through in-situ ethanol removal. Using the design of experiment and response surface methodology, the effect of major factors in the process, such as pressure, recycling ratio and solids concentration, was tested to efficiently remove ethanol after the combined hydrolysis and fermentation step. Statistical analysis indicates that a decreased pressure rate and an increased liquid phase recycling ratio enhance the productivity and the yield of the strip-vacuum fermentation process. The results also highlight further possibilities of this process to improve integrated bioethanol production processes. According to the statistical analysis, ethanol production is strongly influenced by recycling ratio and vacuum ratio. Mathematical models that were established for description of investigated processes can be used for the optimization of the ethanol production.

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On the Fluctuation Induced Excess Conductivity in Stainless Steel Sheathed MgB2 Tapes

Journal of Materials ◽

10.1155/2013/898607 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Suchitra Rajput ◽

Sujeet Chaudhary

Keyword(s):

Magnetic Field ◽

Experimental Data ◽

Stainless Steel ◽

Coherence Length ◽

Three Dimensional ◽

Excess Conductivity ◽

Scaling Functions ◽

Critical Fluctuations ◽

Scaling Models

We report on the analyses of fluctuation induced excess conductivity in the - behavior in the in situ prepared MgB2 tapes. The scaling functions for critical fluctuations are employed to investigate the excess conductivity of these tapes around transition. Two scaling models for excess conductivity in the absence of magnetic field, namely, first, Aslamazov and Larkin model, second, Lawrence and Doniach model, have been employed for the study. Fitting the experimental - data with these models indicates the three-dimensional nature of conduction of the carriers as opposed to the 2D character exhibited by the HTSCs. The estimated amplitude of coherence length from the fitted model is ~21 Å.

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Investigation of Emulsion Flow in Steam-Assisted Gravity Drainage

SPE Journal ◽

10.2118/157830-pa ◽

2013 ◽

Vol 18 (03) ◽

pp. 440-447 ◽

Cited By ~ 13

Author(s):

C.C.. C. Ezeuko ◽

J.. Wang ◽

I.D.. D. Gates

Keyword(s):

Experimental Data ◽

Numerical Simulation ◽

Oil Recovery ◽

Vital Role ◽

Gravity Drainage ◽

Steam Assisted Gravity Drainage ◽

Emulsion Flow ◽

Very High ◽

Effective Representation

Summary We present a numerical simulation approach that allows incorporation of emulsion modeling into steam-assisted gravity-drainage (SAGD) simulations with commercial reservoir simulators by means of a two-stage pseudochemical reaction. Numerical simulation results show excellent agreement with experimental data for low-pressure SAGD, accounting for approximately 24% deficiency in simulated oil recovery, compared with experimental data. Incorporating viscosity alteration, multiphase effect, and enthalpy of emulsification appears sufficient for effective representation of in-situ emulsion physics during SAGD in very-high-permeability systems. We observed that multiphase effects appear to dominate the viscosity effect of emulsion flow under SAGD conditions of heavy-oil (bitumen) recovery. Results also show that in-situ emulsification may play a vital role within the reservoir during SAGD, increasing bitumen mobility and thereby decreasing cumulative steam/oil ratio (cSOR). Results from this work extend understanding of SAGD by examining its performance in the presence of in-situ emulsification and associated flow of emulsion with bitumen in porous media.

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