Mass transfer phenomena in the processing of biopolymer aerogels: in situ studyand modeling

生物聚合物气凝胶加工中的传质现象：原位研究和建模

• 批准号: 417890189
• 负责人: Professor Dr.-Ing. Andreas Bräuer
• 金额: --
• 依托单位: Institut für Thermische Verfahrenstechnik, Umwelt- und Naturstoffverfahrenstechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/417890189?language=en
• 关键词: Mass; transfer; phenomena; processing; biopolymer

Aerogels based on bio-polymers and especially those which are based on naturally available proteins are a new class of highly porous material. Their enormous potential for the food- or pharma-sectors as low-calorie ingredients, taste masking materials, selective adsorbents or as packaging material, are based on their biocompatibility and porosity. The (i) solvent exchange and the subsequent (ii) drying process in compressed carbon dioxide (CO2) are the two crucial process steps during the generation of bio-polymer-based aerogels. The kinetics of both process steps in combination with the thermodynamics relevant for the gel’s interior, determine the costs as well as the quality of the product.Within this project, concentration profiles are determined in the gels’ interior and outside the gels during the solvent exchange and drying processes using optical measurement techniques. Internal and external mass transfer resistances are derived from the concentration profiles. The found resistances are correlated with the properties of the obtained gels and the flow conditions around the gels and are reflected in mass transfer models for porous material. Based on these models the solvent exchange as well as the drying process can be optimized with respect to the costs and quality of the product.

基于生物聚合物的气凝胶，特别是基于天然蛋白质的气凝胶是一种新型的高孔材料。它们作为低卡路里配料、遮味材料、选择性吸附剂或包装材料在食品或制药行业的巨大潜力，是基于它们的生物兼容性和孔隙度。在生物聚合物基气凝胶的制备过程中，(I)溶剂交换和随后的(Ii)压缩二氧化碳干燥过程是两个关键的工艺步骤。这两个工艺步骤的动力学结合与凝胶内部相关的热力学，决定了产品的成本和质量。在这个项目中，使用光学测量技术来确定在溶剂交换和干燥过程中凝胶内部和外部的浓度分布。内部和外部传质阻力是根据浓度分布得出的。发现的阻力与所得凝胶的性质和凝胶周围的流动条件相关联，并反映在多孔材料的传质模型中。基于这些模型，可以根据产品的成本和质量来优化溶剂交换和干燥过程。