二次盐水过滤用的超精密澄清过滤技术

分析了３类可用于二次盐水过滤的超精密澄清过滤技术,介绍了刚性微孔聚乙烯管压滤机连续多年在盐水二次过滤的使用中所取得的主要效果。     

过滤技术在油浆分离中的应用

在催化裂化、加氢裂化等催化反应过程中,产品油浆中催化剂细粉不仅会导致下游设备的腐蚀和堵塞,也限制和降低了其直接作为产品、副产品的应用领域和经济价值。而对于低温费托合成反应而言,将费托合成蜡从气液固三相的浆态床反应器内分离出来,是整个费托合成工艺的的技术难点和关键之一。由此看出,油浆分离和净化技术的选择关系到以上催化反应的稳定运行和产品质量。本文回顾了目前国内外油浆过滤技术的研究及工业应用现状,总结了以美国MOTT公司为代表的金属烧结粉末和Pall公司为代表的金属烧结丝网两种主流滤芯的机械加工特性和过滤精度等特点,从操作条件、分离效率、反冲洗方式等方面进行比较,分析了各种油浆过滤技术的工艺特点,以及过滤工艺与参数对过滤效果和过滤技术选择的影响,可以为传统石油化工油浆过滤以及费托合成浆态床过滤分离技术在滤芯和过滤工艺选择等方面提供参考。     

Trends towards rigidised filtration media dust collectors

In recent years, various forms of structured filter media have been developed which provide high surface area and hence more compact filter units. A range of techniques have been adopted to rigidise different filter materials such that they retain their extended surface even when subjected to continuous pulse cleaning. The paper reviews the advantages, limitations and selection of these compact filter media, and suggests possible areas for further development.     

Protein deamidation in biopharmaceutical manufacture: understanding,control and impact

Understanding of product‐related variants, such as variants with post‐translational modifications, is an important part of biopharmaceutical development. Deamidation is a common post‐translational modification occurring in biopharmaceutical proteins, affecting L‐asparagine (Asn) and to a lesser extent, L‐glutamine (Gln) residues. The rate of deamidation reactions are influenced by factors including protein structure (primary, secondary and higher structure), temperature and pH. In the vast majority of cases, deamidation is undesirable in biopharmaceuticals, and may lead to potential changes in protein structure, function, stability and immunogenicity. Measurement and characterisation of deamidated biopharmaceutical variants may be challenging, particularly with regard to quantitation of the two L‐aspartate isoforms that are created, L‐aspartic acid (Asp) and isoaspartate (isoAsp). Deamidation may occur intracellularly or during biopharmaceutical manufacture and storage, and must be understood, minimised and controlled, particularly in a regulatory context. Process control strategies that have been employed to date include alterations to fermentation steps, additives to cell cultures, chromatographic separation of charge variants and protein engineering to remove deamidation‐prone Asn residues. However, the impact of deamidated forms of biopharmaceuticals should also be thoroughly studied, as they may not necessarily represent deleterious changes to the function of the molecule or the quality of the final product. This mini‐review provides a summary of the current understanding of the origins, control and measurement of deamidation during biopharmaceutical development. © 2015 Society of Chemical Industry