Energy-saving type acetic acid or ethyl acetate hydrogenation ethyl alcohol production process and device

Abstract

The invention discloses an energy-saving type ethyl alcohol production process and device. The energy-saving type ethyl alcohol production process and device can make effective use of heat self-balancing of a synthesizing system to heat and vaporize acetic acid or ethyl acetate and involves short processes and less equipment. The production process comprises a synthesizing loop including at leastone circulating machine; under the condition that the molar ratio of hydrogen to acetic acid or ethyl acetate which are fed into a synthesizing reactor is 20-50, external heating can be saved, and reaction heat of acetic acid or ethyl acetate hydrogenation is applied to heating the raw materials of acetic acid or ethyl acetate from a liquid state at normal temperature to an evaporated state at 100-120 DEG C and then heating a mixed gas composed of hydrogen and acetic acid or ethyl acetate at a molar ratio of 20-50 to a catalytic hydrogenation reaction temperature higher than 200 DEG C for ethyl alcohol production.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a production process and a device for preparing ethanol by hydrogenating acetic acid or ethyl acetate. Background technique [0002] Syngas is hydrogenated with acetic acid or ethyl acetate to produce ethanol, which can replace grain fermentation biological ethanol and be used as ethanol clean fuel. It is of great economic and environmental significance, and it is an industry that the petroleum and coal chemical industry at home and abroad attaches great importance to. However, in the existing production technology, the required hydrogen content in the tower gas for synthesizing ethanol reaction is very high, and its volume or molar hydrogen-acid ratio or hydrogen-ester ratio is as high as dozens of times, even higher than 100. Originally, hydrogenation of acetic acid or ethyl acetate Hydrogenation is an exothermic reaction: [0003] CH 3 COOH+2H 2 →CH 2 CH 2 OH+H...

AI Technical Summary

Problems solved by technology

After the reaction, the gas is heated to the outlet gas, hydrogen and ethyl acetate of the vaporization tower. The heating of the above three streams in this process requires high-level thermal energy at the outlet of the reactor. Power consumption is 75-80 degrees, and 0.8-0.9 tons of 1.6MPa pressure steam needs to be supplied externally, and the temperature of 1.6MPa saturated steam is higher than 200°C. It is difficult to achieve the heat balance of the system by using the reaction heat of the synthesis system itself. The external energy is provided by electric heating and steam heating, the process is long and there are many heat exchange equipment

[0007] The reason for the current high power consumption and energy consumption of acetic acid or ethyl acetate hydrogenation is that the hydrogen-acid ratio or hydrogen-ester ratio required by the hydrogenation synthesis reaction is much higher than the raw material hydrogen-acid ratio or hydrogen-ester ratio consumed by the hydrogenation synthesis reaction The consumption of 2 is as high as tens to 100, and the large excess hydrogen circulation ratio increases the power consumption; the second is that the hydrogenation synthesis is carried out under 20-80 atmospheric pressure, and the raw material hydrogen and acetic acid or ethyl acetate need to be heated by normal pressure and normal temperature. High-pressure circulating hydrogen into mixed feed gas into the tower for reaction

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