Reaction Engineering (reaction + engineering)

Distribution by Scientific Domains

Selected Abstracts

Book Review: Supercritical Carbon Dioxide in Polymer Reaction Engineering.

By Maartje
No abstract is available for this article. [source]

Designing an Inducer-Feeding Schedule To Enhance Production of Recombinant Protein in Escherichia coli by Microbial Reaction Engineering

Jesus M. Gonzalez
Metabolic constraints during the production of recombinant protein in Escherichia coli impede the efficient utilization of resources by the cells, thus reducing their production potential. In order to minimize these adverse effects, we have proposed to segregate the cell population into two groups: the first one formed by non-induced cells, growing at a high specific growth rate and rapidly contributing cells to the system, and the second one formed by fully induced cells, growing slowly but using the cell machinery to express the target protein. An adequate balance between these two populations should maximize the protein expression in a given system. This segregation is accomplished experimentally by taking advantage of the "all or none" phenomenon, in which at subsaturated inducer conditions the cells are either fully induced or fully uninduced. Based on this two-population theory, a mathematical model was developed in which a parameter , was defined as the fraction of the fully induced cells in the total population. In this study three different induction strategies were investigated and their effect on the protein production was established. It was found that the linear increase of this fraction, achieving maximum induction (, = 1) only at the end of the fermentation and with a slope m = 0.15 gave the best results. Finally these results were validated experimentally with the finding that they closely match the mathematical simulation with a 26% increase in protein production with respect to the conventional induction approach described. [source]

Kinetic studies on the influence of temperature and growth rate history on crystal growth

P. M. Martins
Abstract Crystallization experiments of sucrose were performed in a batch crystallizer to study the effect of temperature and growth rate history on the crystal growth kinetics. In one of the growth methods adopted, the isothermal volumetric growth rate (RV) is determined as a function of supersaturation (S) at 35, 40 and 45 șC. In the other, crystals are allowed to grow at constant supersaturation by automatically controlling the solution temperature as the solute concentration decreased. Using the latter method RV is calculated as the solution is cooled. The obtained results are interpreted using empirical, engineering and fundamental perspectives of crystal growth. Firstly, the overall activation energy (EA) is determined from the empirical growth constants obtained in the isothermal method. The concept of falsified kinetics, widely used in chemical reaction engineering, is then extended to the crystal growth of sucrose in order to estimate the true activation energy (ET) from the diffusion-affected constant, EA. The differences found in the isothermal and constant supersaturation methods are explained from the viewpoint of the spiral nucleation mechanism, taking into account different crystal surface properties caused by the growth rate history in each method. Finally, the crystal growth curve obtained in the batch crystallizer at 40 șC is compared with the one obtained in a fluidized bed crystallizer at the same temperature. Apparently divergent results are explained by the effects of crystal size, hydrodynamic conditions and growth rate history on the crystallization kinetics of sucrose. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Phytochemical engineering: Combining chemical reaction engineering with plant science

AICHE JOURNAL, Issue 1 2005
Jacqueline V. Shanks
First page of article [source]

An Integrated Model-Based Analysis of Polymer Chemistry and Polymerisation Reactors

Charles D. Immanuel
Abstract In this paper, a simple demonstration is presented on the analysis of the combined effect of polymer chemistry and the polymerisation reactor on the polymer properties. The model would ideally account for the raw material and end-product characteristics and properties on the one hand; the polymerisation kinetics and reaction engineering on the other hand. This system-wide model-driven approach enables the interlinking of the widely disparate facets of polymer science and engineering, and thereby provides a tool for rapid and efficient identification and scale-up of new polymeric materials that would be exploited in future studies. The ideas are demonstrated with regard to a hyper-branched polymerisation chemistry. [source]

Benefit of enzyme reaction engineering in developing the enzyme cascade system for amino acid production

Article first published online: 18 OCT 200
No abstract is available for this article. [source]