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Slurry Bubble Column Reactor (slurry + bubble_column_reactor)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Enhanced production of lovastatin in a bubble column by Aspergillus terreus using a two-stage feeding strategy

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 1 2007
EM Rodríguez Porcel
Abstract A two-stage feeding strategy is shown to improve the rate of production of lovastatin by Aspergillus terreus when compared with conventional batch fermentation. The feeding strategy consisted of an initial batch/fed-batch phase and a semi-continuous culture dilution phase with retention of pelleted biomass in a slurry bubble column reactor. The batch phase served only to build up the biomass for producing lovastatin, a secondary metabolite that inhibits its own synthesis in the producing microfungus. The semi-continuous dilution phase provided nutrients to sustain the fungus, but prevented biomass growth by limiting the supply of essential nitrogen. (Synthesis of lovastatin does not require nitrogen.) The preferred pelleted growth morphology that favors lovastatin synthesis was readily obtained and maintained in the 20 L bubble column used. In contrast, a stirred tank fermentation had a substantially lower production of lovastatin because mechanical agitation damaged the fungal pellets. The two-stage feeding method increased lovastatin production rate by more than 50% in comparison with the conventional batch operation. Rheological data for the fungal broth are presented. Copyright © 2007 Society of Chemical Industry [source]

Simulation of a slurry-bubble column reactor for Fischer-Tropsch synthesis using single-event microkinetics

AICHE JOURNAL, Issue 8 2009
Gisela Lozano-Blanco
Abstract A single-event microkinetic model for Fischer-Tropsch synthesis including the water-gas shift reaction has been implemented in a one-dimensional, two-bubble class, heterogeneous model with axial effective diffusion to study the performance of a commercial slurry bubble column reactor. Mass balance equations are solved for every species in the reaction network in the large bubbles, small bubbles, and slurry phase, whereas the energy balance is applied to the slurry phase. The catalyst concentration profile is described by a sedimentation-dispersion model. The combination of microkinetics that generate net production rates for the individual reaction products and hydrodynamics allows describing detailed concentration profiles along the reactor axis as a function of operating conditions and design parameters. As example, the effects of catalyst loading, syngas feed flow rate, inlet temperature, or hydrogen to carbon monoxide inlet ratio on the individual hydrocarbons are investigated. To our knowledge, no reactor model in literature is able to describe detailed compositions at the level described by the reactor model developed in this work. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

A model for the dynamic behavior of a commercial scale slurry bubble column reactor applied for the Fischer,Tropch synthesis

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2010
Samira Ghasemi
Abstract Fischer-Tropsch synthesis (FTS) is an important chemical process for the production of liquid fuels. In the present study, a dynamic model for a commercial size slurry bubble column reactor (SBCR) operating under heterogeneous flow regime and dealing with the FTS has been developed. In such a model a detailed kinetics expressions for the FTS and water gas shift (WGS) reactions have been considered. A selectivity model combined with SBCR hydrodynamics and the multicomponent VLE scheme have been applied to estimate the distribution of olefins and paraffins in the products. In addition, the effects of catalyst deactivation on reactor performance and product distribution under transient conditions may be predicted from this model. The data calculated from the model have been correlated with the experimental results available in the literature. It seems that the present model could be applied to estimate the main characteristics of the reactor's dynamic behavior. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]