Formaldehyde continuous production process with high conversion rate

Abstract

The invention discloses a formaldehyde continuous production process with high conversion rate. The process is as below: (1) metering a raw material of methanol water solution by a metering device, sending the raw material to a methanol evaporator through a transfer pump, spraying the raw material upwards by means of atomization, and conducting heating gasification through a heat exchange section of the methanol evaporator; at the same time, bubbling the filtered air to carry part of the methanol and water, so as to rise with the atomized methanol solution under the effect of negative pressure suction, and heating and mixing in the heat exchange section; and (2) passing the three original gases through a superheater, a flame arrester and an oxygenizer for oxidation, and then absorbing to obtain the formaldehyde solution. The process uses atomization way to spray methanol upwards, and the methanol rises with air through negative pressure in the heat exchange section, thereby greatly improving the evaporation efficiency of methanol, reducing energy consumption of evaporation, and maximizing the methanol gasification to avoid entrance of too much liquid methanol droplets into the oxygenizer. Therefore, the process ultimately achieves the purposes of saving energy, reducing emission, and adjusting conversion rate to a higher level.

Description

technical field [0001] The invention belongs to the technical field of chemistry and chemical engineering, and in particular relates to a formaldehyde production process technology. Background technique [0002] Formaldehyde is one of the important organic chemical raw materials with a wide range of uses. At present, the production of formaldehyde by the silver method is mainly divided into two unit operations, that is, the oxidation reaction unit, the absorption unit, and the oxidation reaction unit are completed by four devices, namely, methanol evaporation, ternary gas heating, ternary gas filtration, and oxidizer reaction. Methanol evaporation is a relatively large energy-consuming device for formaldehyde plants; at present, there are mainly two evaporation methods. The first is the rising film evaporator, which uses steam directly as the heat source for methanol evaporation, and the methanol evaporation temperature is controlled at 60~80°C. The main reason is that stea...

AI Technical Summary

Problems solved by technology

In the formaldehyde production process, in order to maintain and maintain the general control of the reaction temperature, it is necessary to add ingredient steam, and the added ingredient steam does not participate in the reaction and heat exchange, and is basically absorbed in the formaldehyde absorption unit or directly discharged in the tail gas, and these two parts The heat has not been effectively used, basically wasted