The effect of flux and residence time in the production of biodiesel from various feedstocks using a membrane reactor

Fuel ◽  
2012 ◽  
Vol 91 (1) ◽  
pp. 126-133 ◽  
Author(s):  
H. Falahati ◽  
A.Y. Tremblay
2019 ◽  
Vol 12 (04) ◽  
pp. 1950046
Author(s):  
Hany A. Hosham

In this work, we analyze the existence of discontinuous bifurcation and stability issues in discontinuous flow of bioreactor and membrane reactor models with or without recycle. The reaction is assumed to be governed by certain types of discontinuities in Monod growth kinetics curve leading to discontinuous dynamical system. The criteria for the existence and stability of steady-states of these models are established. More generally, our analysis highlights the presence of several types of bifurcation depending upon the effect of the dilution factor (residence time), biomass concentration and solid-liquid-gas separator efficiency. As well, we present bifurcation conditions defining the dynamics near steady-state branches on the border, providing a possible framework for existing of saddle-node, nonsmooth fold, persistence and grazing-sliding scenarios. It is shown that the critical values of residence time dependence upon recycle ratio, decay rate and existence of discontinuity surface. Further, the performance of the reactor at largest residence times will be discussed. In addition, numerical simulations to illustrate and confirm the results will be carried out.


Author(s):  
Zhaowei Cui ◽  
Hong Wang ◽  
Zishang Chen ◽  
Yujun Zhang ◽  
Hao Tian ◽  
...  

Abstract An electrocatalytic membrane reactor (ECMR) with an anode consisting of Pt nanoparticles (NPs) loaded on a Ti membrane electrode (Pt NPs/Ti) was designed to oxidize cyclohexanone (K) to produce sodium adipate (SA) under mild conditions. The effects of residence time, reaction temperature, current density and initial K concentration on K conversion were investigated. Optimization experiments were conducted to determine the effects of and interactions between different operating parameters on K conversion using a central composite design within the response surface methodology. A 88.3% conversion of K and 99% selectivity to SA were obtained by the ECMR under the optimum conditions of reaction temperature = 30.8 °C, K concentration = 22.54 mmol L−1, residence time = 25 min and current density = 2.07 mA cm−2. The high performance of the ECMR is attributed to electrocatalytic oxidation (at the Pt NPs/Ti electrode), convection-enhanced mass transfer, and the timely removal of the desired products.


Author(s):  
Angang Li ◽  
Susana Bernal ◽  
Brady Kohler ◽  
Steven A. Thomas ◽  
Eugènia Martí ◽  
...  

Author(s):  
N. P. Benfer ◽  
B. A. King ◽  
C. J. Lemckert ◽  
S. Zigic

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