摘要:

A continuous mixed-suspension mixed-product removal lpar;CMSMPR) crystallizer was used to study the crystallization kinetics and product purity of glutamic acid crystal in pure solution and impure solution with L-phenylanaline as the impurity. Under the assumption that the crystal growth rate was a function of crystal size, the population balance equation was solved to give the crystal growth and nucleation rates by use of the steady-state population density data. The crystal growth and nucleation rates were suppressed by the presence of impurity. The impurity contents in the crystal products, which were analyzed by a HPLC pre-column method, were found to be related to crystal size, supersaturation, and impurity concentration of solution

ISSN:0098-6445    

DOI:10.1080/00986449308936130

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0098-6445    

DOI:10.1080/00986449308936131

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Nonideal effects are analyzed for the separation of C02from tertiary gas mixtures by polymeric membranes. The analysis includes comparison between the behaviour of ideal and nonideal gas properties during the separation process. Separation characteristics are made as function of feed composition, pressure difference across the membrane, and membrane area. Gas flow in the feed and permeate compartments is modelled by both plug flow and complete mixing models. Results show that the nonideal behaviour of C02affects the separation characteristics and exhibits large deviations from the predictions of the ideal gas law. This behaviour is more pronounced at high feed pressures and large C02mole fraclions in the feed stream.

ISSN:0098-6445    

DOI:10.1080/00986449308936132

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A five-compartment electrodialyzer with immobilized urease was developed for the removal of urea from aqueous solution. The immobilized urease supported on polyurethane foam was placed in the central (dilute) compartment, where urea was hydrolyzed and the products were transported simultaneously into the concentrate compartments on its both sides by electrodialysis. The effect of the kinds of buffer salts on the product distribution of urea hydrolysis between two concentrate compartments was investigated under phosphate and citrate buffer systems. It was found that no ammonium-nitrogen was present in the concentrate compartment on the anodic side for both buffer systems. This result could be due to the half-life of carbamate ions was too short to transport into anodic concentrate compartment before they decomposed to ammonium carbonate. The removal of urea from buffer-free aqueous solution was also studied. It was shown that urea and its hydrolysis product could be removed by the electrodialyzer with immobilized urease.

ISSN:0098-6445    

DOI:10.1080/00986449308936133

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor