US 12,017,981 B2 · Method for preparing acetaldehyde from acetylene under catalysis of ZAPO molecular sieve

Abstract

Disclosed is a method for preparing acetaldehyde from acetylene under the catalysis of a ZAPO molecular sieve. The method comprises the steps of pre-heating an acetylene raw material gas and water, subjecting same to continuous hydration in a fluidized bed under the catalysis of the ZAPO molecular sieve to prepare acetaldehyde, and then subjecting same to separation, absorption and rectification to obtain an acetaldehyde product, wherein the catalyst can be continuously regenerated for use. The process of the present application is simple, stable and efficient, solves the problem of the dependence nature of the production of acetaldehyde by means of acetylene hydration on a mercury catalyst, avoids the harm caused by mercury to the human body and the environment, and has higher production and use values.

A preparation method for continuously producing acetaldehyde by catalyzing gas phase hydration of acetylene with ZAPO molecular sieve, comprising:

(1) allowing acetylene to enter a buffer from a gas tank, and to be pressurized by a water-ring acetylene compressor before entering a gas-liquid separator to remove moisture therein, and then transferring the same to a mixer after being metered;
transferring saturated steam to a superheater for heating, then passing it through a hot steam drum, and allowing it to enter the mixer after being metered, so as to be evenly mixed with acetylene gas to obtain a mixed gas;
(2) transferring the mixed gas to fluidized bed hydration reactor, and subjecting it to a gas-solid phase catalytic hydration reaction by a catalyst in the fluidized bed hydration reactor at a certain temperature and pressure, to obtain a reaction gas;
(3) after the hydration reaction, cooling and then introducing the reaction gas into a quench column, onto the top of which a dilute acetaldehyde aqueous solution is sprayed by a dilute acetaldehyde pump, while injecting a large amount of soft water through the bottom of the column from a water storage tank to wash and cool the reaction gas;
upon cooling the reaction gas, concentrating the dilute acetaldehyde by heat of the reaction gas;
allowing the cooled reaction gas from the top of the quench column to enter a water condenser and to be condensed with industrial water, to obtain a condensate and an uncondensed gas;
allowing the condensate to flow into a dilute acetaldehyde intermediate trough, and then enter a dilute acetaldehyde holding tank, and allowing the uncondensed gas to enter a brine condenser to be condensed, and to be separated by a gas-liquid separator;
allowing the separated liquid to flow into a dilute acetaldehyde holding tank;
(4) allowing the uncondensed gas from the gas-liquid separator to enter an acetaldehyde absorption column, and transferring water via a solvent pump to the top of the acetaldehyde absorption column for spraying after being cooled to 5° C. by a water cooler, to obtain an absorption liquid and an unabsorbed gas;
draining the absorption liquid through the bottom of the column to the dilute acetaldehyde holding tank;
pumping out the dilute acetaldehyde from the dilute acetaldehyde holding tank by a dilute acetaldehyde feed pump, and then allowing it to enter an acetaldehyde distillation column for distilling after being preheated by a preheater, to obtain a distilled water and an acetaldehyde vapor;
returning the distilled water to the water storage tank for reusing;
allowing the acetaldehyde vapor at the top of the column to enter an acetaldehyde cooler and to be condensed, to obtain an uncondensed gas and a condensate;
further condensing the uncondensed gas by a tail gas condenser;
allowing the condensate to enter the gas-liquid separator for gas-liquid separation;
allowing the condensate after gas-liquid separation enter the acetaldehyde intermediate trough, and then enter the acetaldehyde holding tank to obtain acetaldehyde product.

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Method for preparing acetaldehyde from acetylene under catalysis of ZAPO molecular sieve

Life of this patent

Method for preparing acetaldehyde from acetylene under catalysis of ZAPO molecular sieve

Life of this patent

Abstract

Claims15