Dissertation > Excellent graduate degree dissertation topics show

Studies on Supercritical Fluid Chemistry Reaction to Synthesis P-hydroxybenzoic acid

Author: ZhengZuoWu
Tutor: LiYan
School: Jinan University
Course: Process and analysis of food additives
Keywords: Hydroxybenzoate Supercritical chemical reaction Synthesis Koble-Schmitt reaction
CLC: TQ245.24
Type: Master's thesis
Year: 2000
Downloads: 245
Quote: 4
Read: Download Dissertation

Abstract


Parabens are a class of broad-spectrum , efficient and safe preservatives . Due to low production in our country , is only used with the pharmaceutical industry . The low production of the root causes of its intermediate backward of hydroxybenzoic acid production process , low yield , and has not been improved and enhanced . At home and abroad hydroxybenzoic acid synthesis process gas - solid-phase method and suspension . These methods yield is low, generally below 45% , a long reaction time , energy consumption , complicated operation , but also pollutes the environment . This study is a supercritical carbon dioxide as a reaction medium and reactants synthetic -hydroxybenzoic acid. Has good solvent properties of supercritical carbon dioxide , the reaction mass and heat transfer have been greatly improved , so as to shorten the reaction time , reducing the stirring speed and improve the yield . This experiment investigated different carboxylation conditions hydroxybenzoic acid yield , and these conditions on Orthogonal Optimization ideal process as follows: the carboxylation pressure 8.5Mpa, time 60min, temperature 220 ??° C , stirring rate 400rpm . This experiment to improve the operation of acid precipitation in the original production process , the use of the segmented approach of acid precipitation , this method is beneficial by-product recovery of potassium sulfate, etc. , and to make our products to reduce the losses , purity improved . Acid analysis after the mother liquor can be recycled to reduce the number and difficulty of the sewage treatment . Hydroxybenzoate yield stability in the above process more than 80% . Test with this Law synthesis the solid catalyst phosphotungstic acid catalyzed esterification of hydroxy benzoic acid and ethanol , and use this common mold Aspergillus niger ethylparaben mildew performance evaluation results prove a highly effective fungicide .

Related Dissertations

  1. Studies on the Synthesis and Technology of Dipentaerythritol and Its Derivative,TQ223.164
  2. Synthesis and Characterization on Semi-Aromatic Polyamides Containing Benzoxazole Units,O633.5
  3. Hydrothermal Synthesis of Oxide Hollow Spheres,TB383.4
  4. Video Coding Research Based on Texture Characteristics,TP391.41
  5. Poetic alienation : graphics,J506
  6. Urothermal Synthesis, Structure and Characterization of Functional Coordination Polymers,O631.3
  7. The Total Synthesis of a Flavonoid Glycoside Apigenin-7-O-β-D-glucuronide,R284.1
  8. Atovaquone analogues Design, Synthesis and antitumor activity of,R914
  9. Synthesis and Seperation of 1,1’-binaphthol,O625.3
  10. Flexible,rigid,Synthesis and characterization of mixed ligand complexes,O621.1
  11. Synthesis and Performance Study of Bisphenol AP-based Polybenzoxazines,TQ320.1
  12. Study on the Mechanism of Night Temperature to Grain Filling of Inferior in Rice,S511
  13. Curing Mechanism and Properties of Fluorenyl Epoxy Resin,TQ323.5
  14. Study on Antioxidant Activities and Lipase-catalyzed Transesterification of Lard to Produce L-ascorbyl Fatty Acid Esters,TS202.3
  15. Expression of β-Catenin in Pig’s Ovary and the Effect of β-Catenin on Porcine Granulosa Cells Apotosis and Steroidogenesis Related Enzyme,S828
  16. The Problems and Solutions of University’s Ideological and Political Education under Network Environment,G641
  17. The Research on Texture Synthesis Technology from Cloud Theory & Been Evolution Genetic Algorithm,TP391.41
  18. Synthesis and Properties of Novel Low Viscosity Difluorooxymethylene-Bridged Liquid Crystals Compounds,O753.2
  19. Synthesis and Structures of Metal (Mn, Zn and Sn) Complexes Incorporating with the Sily-linded Bis (Amidinate) Ligands,O621.2
  20. The Study of Protection of Amino Acid and Peptide Bond Synthesis,O629.71
  21. The Oxidation Mechanism and Stability Improved of Conjugated Polyunsaturated Fatty Acids,O621.25

CLC: > Industrial Technology > Chemical Industry > Basic Organic Chemistry Industry > The production of aromatic compounds > Aromatic carboxylic acids and their derivatives > Aromatic acid functional derivatives > Fang ester
© 2012 www.DissertationTopic.Net  Mobile