The emerging development of Extractive Reference Substance (ERS) is a methodology that meets the needs for quality control for Chinese Herbal Medicines (CHM) and respects the holistic viewpoint of Traditional Chinese ...The emerging development of Extractive Reference Substance (ERS) is a methodology that meets the needs for quality control for Chinese Herbal Medicines (CHM) and respects the holistic viewpoint of Traditional Chinese Medicine (TCM) and its clinical use of multiple ingredients with synergistic effects. The convention of using just a selected few Chemical Reference Substances (CRS) cannot adequately assess the quality of intact CHM. A validated chemical spectrum of an ERS provides the global characteristics in order to more specifically identify and assess targeted CHM. This paper describes the fundamental concepts, potential significance, and basic criteria of ERS, along with methods of preparation and calibration. Given the diversity of CHM, the various problems that will occur in establishing the proper process of ERS will need to be solved in a step by step manner. The ERSs of Ziziphi spinosae semen and ERS of Fritillaria thunbergii bulbus are given as examples of the development of ERS and demonstrate why we are optimistic about the utility of this approach.展开更多
Extractive distillation(ED) is one of the most promising approaches for the separation of the azeotropic or closeboiling mixtures in the chemical industry. The purpose of this paper is to provide a broad overview of t...Extractive distillation(ED) is one of the most promising approaches for the separation of the azeotropic or closeboiling mixtures in the chemical industry. The purpose of this paper is to provide a broad overview of the recent development of key aspects in the ED process involving conceptual design, solvent selection, and separation strategies. To obtain the minimum entrainer feed flow rate and reflux ratio for the ED process, the conceptual design of azeotropic mixture separation based on a topological analysis via thermodynamic feasibility insights involving residue curve maps, univolatility lines, and unidistribution curves is presented. The method is applicable to arbitrary multicomponent mixtures and allows direct screening of design alternatives. The determination of a suitable solvent is one of the key steps to ensure an effective and economical ED process. Candidate entrainers can be obtained from heuristics or literature studies while computer aided molecular design(CAMD) has superiority in efficiency and reliability. To achieve optimized extractive distillation systems, a brief review of evaluation method for both entrainer design and selection through CAMD is presented. Extractive distillation can be operated either in continuous extractive distillation(CED) or batch extractive distillation(BED), and both modes have been well-studied depending on the advantages in flexibility and low capital costs. To improve the energy efficiency, several configurations and technological alternatives can be used for both CED and BED depending on strategies and main azeotropic feeds. The challenge and chance of the further ED development involving screening the best potential solvents and exploring the energy-intensive separation strategies are discussed aiming at promoting the industrial application of this environmentally friendly separation technique.展开更多
文摘The emerging development of Extractive Reference Substance (ERS) is a methodology that meets the needs for quality control for Chinese Herbal Medicines (CHM) and respects the holistic viewpoint of Traditional Chinese Medicine (TCM) and its clinical use of multiple ingredients with synergistic effects. The convention of using just a selected few Chemical Reference Substances (CRS) cannot adequately assess the quality of intact CHM. A validated chemical spectrum of an ERS provides the global characteristics in order to more specifically identify and assess targeted CHM. This paper describes the fundamental concepts, potential significance, and basic criteria of ERS, along with methods of preparation and calibration. Given the diversity of CHM, the various problems that will occur in establishing the proper process of ERS will need to be solved in a step by step manner. The ERSs of Ziziphi spinosae semen and ERS of Fritillaria thunbergii bulbus are given as examples of the development of ERS and demonstrate why we are optimistic about the utility of this approach.
基金Supported by the National Natural Science Foundation of China(No.21878028,21606026)the Fundamental Research Funds for the Central Universities(No.106112017CDJQJ228809)+2 种基金Chongqing Technological Innovation and Application Demonstration for Social and Livelihood development(No.cstc2018jscx-msyb X0336)Chongqing Research Program of Basic Research and Frontier Technology(No.CSTC2016JCYJA0474)Hundred Talents Program of Chongqing University
文摘Extractive distillation(ED) is one of the most promising approaches for the separation of the azeotropic or closeboiling mixtures in the chemical industry. The purpose of this paper is to provide a broad overview of the recent development of key aspects in the ED process involving conceptual design, solvent selection, and separation strategies. To obtain the minimum entrainer feed flow rate and reflux ratio for the ED process, the conceptual design of azeotropic mixture separation based on a topological analysis via thermodynamic feasibility insights involving residue curve maps, univolatility lines, and unidistribution curves is presented. The method is applicable to arbitrary multicomponent mixtures and allows direct screening of design alternatives. The determination of a suitable solvent is one of the key steps to ensure an effective and economical ED process. Candidate entrainers can be obtained from heuristics or literature studies while computer aided molecular design(CAMD) has superiority in efficiency and reliability. To achieve optimized extractive distillation systems, a brief review of evaluation method for both entrainer design and selection through CAMD is presented. Extractive distillation can be operated either in continuous extractive distillation(CED) or batch extractive distillation(BED), and both modes have been well-studied depending on the advantages in flexibility and low capital costs. To improve the energy efficiency, several configurations and technological alternatives can be used for both CED and BED depending on strategies and main azeotropic feeds. The challenge and chance of the further ED development involving screening the best potential solvents and exploring the energy-intensive separation strategies are discussed aiming at promoting the industrial application of this environmentally friendly separation technique.
