Solvent replacement condensation tower and method for producing anhydrous formaldehyde

A solvent and condensation technology, which is applied in the field of solvent displacement condensation tower and production of anhydrous formaldehyde, can solve the problem of low yield of formaldehyde in one pass, achieve the effect of increasing yield of formaldehyde in one pass, simple structure, and improved unit utilization rate

Active Publication Date: 2019-05-03
潍坊惠丰化工有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

U.S. patents US2848500 and US6414196 propose a method for producing high-purity formaldehyde gas, using various alcohols as solvents to prepare formaldehyde solvent condensate and using an evaporator for pyrolysis to obtain high-purity formaldehyde gas, but the condensation is performed in a batch stirred tank The yield of one-way formaldehyde is not high when performing distillation and dehydration after condensation, and there are still about 4% formaldehyde remaining in the solvent during pyrolysis

Method used

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  • Solvent replacement condensation tower and method for producing anhydrous formaldehyde
  • Solvent replacement condensation tower and method for producing anhydrous formaldehyde
  • Solvent replacement condensation tower and method for producing anhydrous formaldehyde

Examples

Experimental program
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Effect test

Embodiment 1

[0052] as attached figure 1 , 2 , As shown in 3, a ring-shaped diversion distribution groove is set in a rectification tower with an inner diameter of φ200mm. The specific dimensions are: the outer diameter of the annular plate 1 is φ200mm, the inner diameter is φ60mm, the diameter of the circular baffle 4 is φ140mm; the height of the circular air riser 2 and the circular baffle 4 is 240mm, and the inner diameter of the downcomer 5 is 4mm , close to the outer side of the circular riser 2 and the inner side of the circular baffle 4, a total of 18 pieces are arranged in two circles, and the height of the downcomer 5 is 180mm; the openings 7 at the bottom of the circular baffle 4 are circular holes at equal intervals, and the circular holes The diameter is 8mm, 20 in total, and the hole spacing is 22mm.

[0053] During installation, assemble the annular diversion distribution groove of the above structure and CY700 corrugated wire mesh packing into a tower section with flange c...

Embodiment 2

[0055] as attached figure 1 , 2 As shown in , 3, another annular diversion distribution groove is set in a rectification tower with an inner diameter of φ200mm. The specific dimensions are: the outer diameter of the annular plate 1 is φ200mm, the inner diameter is φ60mm, the diameter of the circular baffle 4 is φ140mm; the height of the circular air riser 2 and the circular baffle 4 is 500mm, and the inner diameter of the downcomer 5 is 4mm , close to the outer side of the circular riser 2 and the inner side of the circular baffle 4, a total of 18 pieces are arranged in two circles, and the height of the downcomer 5 is 440mm; the openings 7 at the bottom of the circular baffle 4 are circular holes at equal intervals. The diameter is 8mm, 20 in total, and the hole spacing is 22mm.

[0056] During installation, assemble the annular diversion distribution groove of the above structure and CY700 corrugated wire mesh packing into a tower section with flange connections at both en...

Embodiment 3

[0058] Place one section of the tower section assembled in Example 1 on the upper end, place two identical sections of the tower section assembled in Example 2 in the middle and the lower end, and rely on flange connection to form a main tower section of a solvent displacement condensation tower, equipped with a top condenser 14. Phase separation tank 15 and tower bottom reboiler 19. The condenser 14 has a heat transfer area of ​​4 m 2 and is cooled with circulating water; the reboiler 19 has a heat transfer area of ​​5 m 2 and is heated with heat transfer oil; the volume of the phase separation tank 15 is 75 L.

[0059] Attached Figure 4 Experiments are carried out on the process of the above-mentioned technology, operated under normal pressure, the concentration of formaldehyde solution is 48.5%, the flow rate is 20kg / h, the feed temperature is 80°C, and the feed position is the top of the second tower section; the solvent is benzyl alcohol, and the flow rate is 48kg / h , t...

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Abstract

The invention discloses a solvent replacement condensation tower and a method for producing anhydrous formaldehyde, and mainly relates to the technical field of organic synthesis. The solvent replacement condensation tower is composed of a plurality of annular flow-guide distribution grooves and filler sections which are alternately arranged; each annular flow guide distribution groove comprises an outer groove, an inner groove, a central gas rising tube, and liquid descending tubes arranged in the inner groove. During use, a material fed from outside and a liquid flowing down from the upper part of the inner tower first flow downwards along the outer groove, passe through an opening at the bottom of a baffle to enter the inner groove, then flow upwards, and finally flow to the surface offiller under the annular flow-guide distribution grooves from the plurality of liquid descending tubes for carrying out mass exchange with a gas phase. Liquid flows through a filler section, enters the outer groove of the next-stage annular flow-guide groove, and then sequentially flows through the inner groove and the liquid descending pipes to enter the next-stage filler section until flowing tothe bottom of the tower. Gas rises along filler gaps in the tower to enter the gas rising tube of the annular flow-guide distribution grooves, bypasses an umbrella-shaped baffle plate to enter the previous-stage filler layer, and flows out from the tower top according to the process step by step.

Description

technical field [0001] The invention mainly relates to the technical field of organic synthesis, in particular to a solvent replacement condensation tower and a method for producing anhydrous formaldehyde. Background technique [0002] Formaldehyde is used as a basic chemical raw material in a wide range of applications, but the use of formaldehyde is generally carried out under the condition of being dissolved in water. In the field of synthesis of some pharmaceutical intermediates or fine chemicals, the reaction often requires an anhydrous environment. At this time, most of them use paraformaldehyde pyrolysis to obtain formaldehyde raw materials. Paraformaldehyde forms a chain structure, and the capping groups at both ends are hydroxyl and hydrogen. After pyrolysis to form monomer formaldehyde, the capping groups naturally form water molecules. Therefore, the water content of paraformaldehyde pyrolysis often still reaches 2~ About 4%, still produces not small influence to...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D3/00B01D3/14B01J19/00C07C45/82C07C47/04
Inventor 付冠卿王成习孙玉石
Owner 潍坊惠丰化工有限公司
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