| Summary: |
The work performed during the last years by our research team lead to the development of new measuring techniques of crystal growth kinetics and new theoretical models characterizing the role of the main variables involved in the process. Some of the new theories were already published in recognized international journals, while others are under development or in a submission process. This framework should now be explored in a new project with strong experimental and theoretical component. Emphasis will continue to be given to the crystallization (lab scale) and evaporative crystallization (pilot scale) of sucrose. It Is also expected to use the recently proposed concepts on the growth of high-quality protein crystals.
The ongoing cooperation between the Chemical Engineering Department of the Engineering Faculty of University of Porto (FEUP) and the Audubon Sugar Institute (ASI), Louisiana State University will allow the use of ASI's pilot facilities to conduct crystallization experiments that reproduce the conditions found in industry. Departing from the theoretical basis given by the competitive adsorption model In equilibrium, it is aimed to establish the conditions that promote the least impurity transfer in to sugar crystals. Because of their economical and practical interest, the impurities to be studied will be dextran, starch, invert sugars and colorants. At same time, the development of a method for on-line determination of supersaturation, solution purity and crystal content will continue for patenting.
Crystal growth experiments of sucrose will be performed at the laboratories of the Chemical Engineering Department of FEUP, using fluidized bed crystallizers, batch crystallizers and growth cells/microscopic techniques. The objective is to measure the isolate effect of specific impurities on the growth kinetics, keeping the main parameters of the system closely controlled. The impurity transfer in to crystals will be determined by direct and indi  |
Summary
The work performed during the last years by our research team lead to the development of new measuring techniques of crystal growth kinetics and new theoretical models characterizing the role of the main variables involved in the process. Some of the new theories were already published in recognized international journals, while others are under development or in a submission process. This framework should now be explored in a new project with strong experimental and theoretical component. Emphasis will continue to be given to the crystallization (lab scale) and evaporative crystallization (pilot scale) of sucrose. It Is also expected to use the recently proposed concepts on the growth of high-quality protein crystals.
The ongoing cooperation between the Chemical Engineering Department of the Engineering Faculty of University of Porto (FEUP) and the Audubon Sugar Institute (ASI), Louisiana State University will allow the use of ASI's pilot facilities to conduct crystallization experiments that reproduce the conditions found in industry. Departing from the theoretical basis given by the competitive adsorption model In equilibrium, it is aimed to establish the conditions that promote the least impurity transfer in to sugar crystals. Because of their economical and practical interest, the impurities to be studied will be dextran, starch, invert sugars and colorants. At same time, the development of a method for on-line determination of supersaturation, solution purity and crystal content will continue for patenting.
Crystal growth experiments of sucrose will be performed at the laboratories of the Chemical Engineering Department of FEUP, using fluidized bed crystallizers, batch crystallizers and growth cells/microscopic techniques. The objective is to measure the isolate effect of specific impurities on the growth kinetics, keeping the main parameters of the system closely controlled. The impurity transfer in to crystals will be determined by direct and indirect methods as a function of the crystallization time at constant supersaturation. The data obtained will be used to develop and validate the competitive adsorption model for unsteady state.
Protein crystals of high crystallographic perfection are crucial in the determination of the 3-D arrangement of the amino acids. This has been the bottleneck in (i) the development of new drugs acting at the protein active sites, and (ii) the efforts to decode the extensive amount of Information from Genomics studies nowadays. As an example, a great interest has been devoted by the main Space Agencies on crystal growth under microgravity environment. Even though such conditions increase the quality of the crystalline arrangement by about 20 % of studied cases, the cost and means involved in those experiments turn out essential further research for valid alternatives under earth gravity conditions. In this project it is intended to carry out growth experiments of proteins employing the liquid-liquid diffusion technique and the vapor diffusion technique. In an initial phase, a well-known protein (lysozyme) will be used to study the major factors affecting growth such as supersaturation, pH, temperature and type/concentration of precipitant. The fundamentals of crystal growth recently proposed by the spiral nucleation model provide the theoretical basis for this study. |