New process for producing glyoxal by using complex silver catalyst to oxidize glycol

Abstract

The invention relates to a new process for producing glyoxal by using a complex silver catalyst to oxidize glycol. The process comprises the following steps: adopting a high-pressure steam-spraying and far-infrared combining heating mode to gasify glycol; uniformly mixing the gasified glycol, steam, preheated filtrated air and circulating air in a tertiary mixer before entering a grid-type oxidation furnace integrated with a feed gas-purifying and refining device and filled with an Ag-P-Se / ceramic catalyst; carrying out a catalytic oxidation reaction; rapidly quenching the reacted gas; sendingthe gas to an absorption tower for repeated absorption; and decoloring the gas to obtain a glyoxal product. The process uses the Ag-P-Se / ceramic catalyst with strong activity and has high glyoxal yield up to 85 percent and small impurity formaldehyde product; a grid-type supporting plate overcomes the defects of easily deformed and crack catalyst bed and decreases the resistance of the bed; and the process integrates the purifying and refining device and the oxidation furnace and adopts the high-pressure steam-spraying and far-infrared combining heating mode to gasify the glycol to save energy and shorten the process flows.

Description

1. Technical field [0001] The invention belongs to a preparation process of glyoxal, in particular to a new process for producing glyoxal by adopting ethylene glycol composite silver catalytic oxidation method. 2. Background technology [0002] Glyoxal, also known as oxalic acid aldehyde, is the simplest aliphatic dialdehyde. The glyoxal molecule contains two interconnected carbonyl groups, which can undergo addition or condensation reactions with alcohols, amines, amides, aldehydes, and hydroxyl-containing compounds, and can also react with protein-like animal glue, cellulose, polyvinyl alcohol, and Urea and other cross-linking reactions occur. Glyoxal reacts with a compound with a single nucleophilic center to generate a linear compound; reacts with a compound with a double nucleophilic center to generate a cyclic compound, especially a heterocyclic compound, making it widely used in textile printing and dyeing, building materials, leather, medicine, and pesticides. , na...

AI Technical Summary

Problems solved by technology

There are several problems to be solved urgently in this process: (1) During the catalytic oxidation process, due to the low activity and selectivity of the catalyst, part of ethylene glycol breaks the C-C bond at high temperature and oxidizes to formaldehyde, and the formed formaldehyde is partially destroyed. Deep oxidation is carbon dioxide and water, and part is absorbed by water together with glyoxal, causes the content of formaldehyde ≥ 0.2% in the glyoxal product, and the life-span of catalyst is short, and this is also the common problem and difficulty of present glyoxal industry; (2 ) The components of the oxidation furnace cannot meet the requirements of large-scale production, and the structure of the oxidation furnace needs to be further innovated to meet the needs of large-scale production; (3) The process flow needs to be further optimized to facilitate system integration and realize energy saving and consumption reduction

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