36results about How to "Reduce acetic acid content" patented technology

The invention provides a low-energy consumption method for preparation of ethanol by acetic acid hydrogenation. The method includes the steps of: (1) first stage gas phase hydrogenation; (2) gas-liquid separation and second stage hydrogenation; (3) esterification reaction; and (4) product refining: sending a liquid phase product B to a first rectification tower, sending first tower bottom fraction to a second rectification tower, returning part of the second tower top fraction into a hydrogenation reactor of (1), and recovering part of the second tower top fraction as a mixed solvent product, sending second tower bottom fraction into a neutralization reactor, adding an alkaline substance to carry out neutralization reaction; and sending the neutralized second tower bottom fraction to a third rectification tower. The method can reduce energy consumption and improve the quality of ethanol product.

The invention provides a low-energy consumption method for preparation of ethanol by acetic acid hydrogenation. The method comprises the steps of: (1) gas phase hydrogenation; (2) gas-liquid separation; (3) esterification reaction; and (4) product refining: sending a liquid phase product B to a first rectification tower, sending first tower bottom fraction to a second rectification tower, returning part of second overhead fraction into a hydrogenation reactor involved in (1), and recovering part of the second overhead fraction as a mixed type solvent product, sending second tower bottom fraction into a neutralization reactor, adding an alkaline substance to carry out neutralization reaction; and sending the neutralized second tower bottom fraction into a third rectification tower. The method can lower energy consumption and improve the quality of ethanol products.

The invention discloses a water-rich solvent classification utilization emission reduction system for preparing terephthalic acid, which comprises a plurality of units, such as oxidation reaction, rectification dehydration, oxidation and purification filtration, solvent stripping, multi-effect distillation and the like. According to the system, through the optimized configuration of materials, water-rich solvents with different levels of acetic acid concentration are classified and utilized, and on the premise of ensuring product quality and effectively utilizing the reaction heat, the use amount of fresh water is greatly reduced and the organic matter content in a discharged liquid is reduced. The key technology lies in that: (1) a dehydration unit is provided with a three-stage rectifying column, the water-rich solvent produced by each unit in the oxidation and refining process is re-circulated to the rectifying columns according to a concentration matching rule, and the water-rich solvents obtained by rectification are respectively used for oxidation filter washing, refining filter washing, exhaust gas spraying and the like as required by different acetic acid concentrations; (2) self-produced low-pressure steam of the system is utilized for multi-effect distillation of the discharged liquid, thereby fully recovering acetic acid in the discharged liquid, and reducing systemacetic acid consumption.

The invention discloses a method for removing acetic acid in a sucrose-6-acetate solution and application thereof. The method comprises the following steps: under a certain residence time condition, in tower equipment for removing acetic acid, vapor formed by tertiary amide of certain temperature is in contact with the sucrose-6-acetate solution containing acetic acid in a continuous countercurrent manner, thereby achieving the purpose of removing the acetic acid from the sucrose-6-acetate solution. The method provided by the invention can be applied to the synthesis of sucrose-6-acetate and sucralose, has the advantages of simple process, high acetic acid removal rate, no damage to a sucrose-6-acetate product, continuity and the like, and is very suitable for industrial production.

The invention provides a low-energy consumption method for production of ethanol by acetic acid hydrogenation. The method comprises the steps of: (1) gas phase hydrogenation; (2) gas-liquid separation; (3) esterification reaction; and (4) product refining: sending a liquid phase product B to a neutralization reactor, adding an alkaline substance to carry out neutralization reaction, bringing the neutralization product into a first rectification tower so as to obtain first overhead fraction containing acetaldehyde, ethyl acetate and acetone and first tower bottom fraction, i.e. a crude ethanol product containing ethanol and water, returning part of the first overhead fraction into a gas phase hydrogenation reactor, and sending the first tower bottom fraction to a second rectification tower so as to obtain second tower bottom fraction containing water, ethanol, butanol and acetate. The method can reduce energy consumption and improve the quality of ethanol product.

The invention provides a low-energy consumption method for preparing ethanol through acetic acid hydrogenation. The method comprises 1, gas phase hydrogenation, 2, gas-liquid separation, 3, esterification reaction and 4, product refining: feeding a liquid product B into a first rectifying tower, feeding a part of the first rectifying tower top fraction containing acetaldehyde, ethyl acetate and acetone back to a gas phase hydrogenation reactor, feeding the first rectifying tower bottom fraction as a crude ethanol product containing ethanol, ethyl acetate and water into a neutralization reactor, adding an alkaline substance into the neutralization reactor, carrying out a neutralization reaction process, feeding the neutralized first rectifying tower bottom fraction into a second rectifying tower, and carrying out separation to obtain a second rectifying tower top fraction containing ethanol and water and a second rectifying tower top fraction containing water, butanol and acetate, wherein the second rectifying tower top fraction has ethanol content of 85-95wt% and an acidity value of 0-25mg/L. The method can reduce energy consumption and improve ethanol product quality.

The invention provides a mixed solvent product with acetic ether and ethyl alcohol which serve as main components. The solvent product contains 30 to 75 weight percent of the ethyl alcohol and 20 to 60 weight percent of the acetic ether; an acid value is 0 to 5 mg/L, which is calculated based on acetic acid, and the moisture content is 0 to 20 weight percent.

The invention discloses an apparatus and a method for recovery of rectification residue effective components and comprehensive treatment of waste gas in a polyvinyl alcohol production process. According to the present invention, the apparatus comprises a residue tank, a U-shaped pipe, a condenser, a vacuum unit, a distillation groove, a distillate discharge pump, a residue pool, an alkali washingtower, an alkali liquid circulating pump, an induced draft fan, an acetylene gas scrubber and an alkali liquid supplementing pump; the method comprises: light component and heavy component separation,light component cooling, and waste gas alkali washing and water washing; and through the effectively utilization and comprehensive treatment of residue components, the utilization rate of raw materials is increased, the production cost is reduced, the recycling of the waste alkali liquid generated in the synthesis section is achieved, and the pollutant discharge is reduced.