Device and method for preparing furan by furfural gas-phase decarbonylation

Abstract

The invention relates to a device and a method for preparing furan by furfural gas-phase decarbonylation. The method is characterized by comprising the following steps: (1) introducing furfural into a furfural vaporizing tower heater at 300-350Kg / h, preheating to 110-138 DEG C, then introducing the furfural into a vaporizing tower, introducing hydrogen for protection, and controlling the temperature in the tower to 130-160 DEG C; (2) a gas phase from the tower top enters an electric heater to be heated to 260-330 DEG C after heat exchange and then enters a decarbonylation reactor, hydrogen is introduced for protection, the temperature in the reactor is controlled to be 260-350 DEG C, and the pressure in the reactor is controlled to be 0.01-0.03 Mpa; (3) the gas phase from the reactor exchanges heat with the gas phase of the furfural vaporizing tower and then enters a quenching tower, and the tower bottom liquid returns to the furfural vaporizing tower; (4) the gas phase in the tower enters a crude product tank after being deeply cooled, and the gas phase in the crude product tank enters an absorption tower; and the liquid phase in the crude product tank enters into a rectifying tower, and reduced-pressure rectification is performed to obtain qualified high-quality furan. The method has the advantages that the high-temperature side reaction of furfural is reduced, the furan conversion rate is increased to 50-60% from original 40-45%, and the operation cycle of the catalyst is prolonged to 30-60 days from 7-10 days; the steam energy consumption of each ton of furan is reduced to 2-2.5 tons from the original 3.5-5 tons, and the purity of furan is improved to 99-99.8% from the original 98-98.5%.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and relates to a device and a method for preparing furan by gas-phase decarbonylation of furfural. Background technique [0002] Furan is an intermediate product of Jiale musk. At present, the main industrialization routes mainly include: ⑴ furan decarboxylation of furoic acid; ⑵ butadiene oxidation; Law. [0003] However, in the industrial production of furan ammonium salt, most of the above-mentioned furan production methods have the problems of poor catalyst activity, environmental pollution, and low furan yield. At present, furfural decarbonylation is basically used in industrial production. [0004] The traditional decarbonylation reactor is a multi-stage shock-type fixed-bed reactor, and the reactor is prone to uneven local reactions, resulting in rapid temperature rise and rapid temperature rise. When the temperature rises rapidly, it can only rely on hydrogen shock to cool do...

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Problems solved by technology

[0003] However, in the industrial production of furan ammonium salt, most of the above-mentioned methods of furan production have the problems of poor catalyst activity, environmental pollution, and low yield of furan. At present, furfural decarbonylation is basically used in industrial production.

[0004] The traditional decarbonylation reactor is a multi-stage shock-type fixed-bed reactor, and the reactor is prone to uneven local reactions, resulting in rapid temperature rise and rapid temperature rise. When the temperature rises rapidly, it can only rely on hydrogen shock to cool down, but hydrogen cannot be supplied in large quantities in a short period of time. Therefore, the effect of slow cooling is not good; furfural is very easy to coke on the catalyst to form carbon black at high temperature, causing the catalyst to become cohesive and deactivated. In the case of oxygen and water, it is easy to oxidize furfural to furoic acid, corrode the equipment, and operate normally. In 7-10 days, the production equipment must be shut down to regenerate the catalyst by burning charcoal. The treatment takes 3-5 days, which seriously affects the production efficiency

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