Energy-saving process for preparing olefin from synthesis gas

Abstract

The invention discloses an energy-saving process for preparing olefin from synthesis gas. The energy-saving process is characterized by comprising a reactor for reacting CO and H2 synthesis gas under the action of a catalyst to generate olefin gas; a gas-gas heat exchanger, which is provided for feeding a gas inlet pipe through which H2, CO and H2 synthesis gas for reduction, wherein a first pipeline and a second pipeline are arranged between the gas-gas heat exchanger and the reactor, the CO and H2 synthesis gas enters the reactor through the first pipeline, and generated olefin gas enters the gas-gas heat exchanger through the second pipeline; an electric heater, which is arranged on the first pipeline and is used for heating the reduction working condition H2; and a cooling tower, which is communicated with the gas-gas heat exchanger through a third pipeline, wherein the olefin gas flowing out of the gas-gas heat exchanger flows into the third pipeline and then enters the cooling tower to be cooled to generate olefin. Heat energy of hot gas at the outlet of the reactor is conveyed into the gas-gas heat exchanger and used for preheating CO and H2 normal-temperature synthesis gas and H2 for reduction, heat energy recycling is achieved, energy is greatly saved, and the cooling capacity of the cooling tower is reduced.

Description

technical field [0001] The invention relates to an energy-saving synthesis gas preparation process for olefins. Background technique [0002] CO, H 2 In the process of preparing olefins from syngas, a Fischer-Tropsch catalyst is used, with Fe, Co or Ni as the active component, and CO, H 2 The synthesis gas reacts in the reactor to generate olefins. The catalyst must be reduced and activated before use, so that the catalyst is active in the metal state. Because the catalyst reduction temperature (400-500 ° C) is relatively high, it is much higher than the normal reaction requirements. Into the reactor temperature (150 ~ 300 ° C), therefore, under the reduction condition requires an additional heat source for the reduction of H 2 for heating. In the existing process, in order to meet the reduction needs, an electric heater with a large heat load is separately set up, and the reduction uses H 2 Heating from normal temperature air (around 30°C) to reduction temperature. Alt...

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