Apparatus and method to co-produce formaldehyde and UFC (urea-formaldehyde concentrate) by iron-molybdenum process

Abstract

An apparatus to co-produce formaldehyde and UFC (urea-formaldehyde concentrate) by iron-molybdenum process comprises a methanol evaporator, a methanol oxidizer and an absorbing column; fresh air and methanol vapor are mixed in the methanol evaporator, and formaldehyde is generated in the methanol oxidizer; formaldehyde vapor enters the absorbing column via the methanol evaporator; in the absorbingcolumn, the formaldehyde vapor is liquefied, and a liquid formaldehyde product is attained from the bottom; urea and an alkali liquid are added into the absorbing column to react with the formaldehyde to obtain UFC. The apparatus has the advantages that consumption indexes are good, single consumption of formaldehyde is 0.422-0.426 t, byproduct vapor specification is high, up to 22 bar 0.75 t / t,oxidation temperature is controlled to 245-380 DEG C, the methanol oxidizer has designed life up to 20 years and longer, the whole apparatus has designed life of not shorter than 35 years, the apparatus is suitable for flexibly producing formaldehyde products having a concentration of 37-55%, UFC can be produced just by proportionally adding an alkali liquid, and in order to further increase absorbing efficiency of process water, sodium hydroxide solution can be injected into the system to remove the byproduct, formic acid.

Description

technical field [0001] The invention belongs to the technical field of petrochemical industry, and specifically relates to a device and method for producing formaldehyde and co-producing UFC by an iron-molybdenum method. Background technique [0002] At present, one kind of industrial formaldehyde production in my country is "silver method formaldehyde" using silver catalyst, and the other is "iron molybdenum method formaldehyde" using iron molybdenum catalyst. The advantages of silver method formaldehyde are small investment and low power consumption. It has more advantages in large-scale devices (less than 50,000 tons / year), and the formaldehyde product has low acid content, which is suitable as a raw material for gas-phase method urotropine. However, the unit consumption of methanol is high (generally 0.445t / t), and the production capacity of a single set is limited (no more than 120,000 tons / year). Compared with silver-based formaldehyde, iron-molybdenum-based formaldehy...

AI Technical Summary

Problems solved by technology

The disadvantage is that the one-time investment is large and the power consumption is high

However, the iron-molybdenum method formaldehyde plant has shortcomings and deficiencies such as unstable domestic process technology, high investment, and most of the core catalysts are controlled by foreign countries at the current stage.

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