Pressure-reduction zero-emission energy-saving gas dewatering device

Abstract

The invention relates to a pressure-reduction zero-emission energy-saving gas dewatering device which is adapted to a middle or high pressure (>2.0MPa) double-tower or multi-tower molecular sieve dewatering process and comprises a filter (1), two or a plurality of drying/absorption towers (2A and 2B), an air cooler (3), a gas-water separator (4), a circulating fan (5), an electric heater (6), a gas-gas heat exchanger (8) and a frequency transformer (12). The invention is characterized in that a regeneration discharge branch path is branched at an air outlet of the circulating fan, and the regeneration discharge branch is merged into an adsorption air inlet pipe. Thus, dry gas discharged by a regeneration loop is extracted and discharged into an absorption loop when in regeneration, so that a regeneration tower is depressurized, and the regeneration loop is restored through the switching of a valve after pressure reduction. Thus, not only pressure-reduction regeneration is realized, but also zero emission is realized, and the regeneration time is reduced, thereby reducing the energy consumption and prolonging the service life of a molecular sieve.

Description

technical field [0001] The present invention relates to a kind of CO gas from mixed gas (natural gas, coalbed methane, petroleum associated gas, coke oven gas, coal-to-gas, carbon-based synthesis, H in petrochemical industry) 2 gas, food grade CO 2 etc.), in particular to an energy-saving gas dehydration device with reduced pressure and zero discharge. It is suitable for medium and high pressure (>2.0Mpa) double-tower or multi-tower molecular sieve adsorption and dehydration process. Background technique [0002] At present, a dual-tower process with equal pressure and zero discharge is often used in the industry for dehydration treatment of mixed gases (such as natural gas). When working, one tower absorbs, and the other tower regenerates. When the adsorption is saturated, the adsorption tower immediately turns to regeneration, and the regeneration tower immediately turns to adsorption, so that the dehydration process continues. The adsorption process adopts the molec...

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Problems solved by technology

This isobaric zero-emission process is only applicable to normal pressure (20kPa) working conditions, but for medium and high pressure adsorption pressure (greater than 2.0MPa), if isobaric desorption is still used, the desorption temperature will increase a lot (Because the higher the pressure, the higher the boiling temperature of water), this will not only increase energy consumption, but also reduce the service life of the molecular sieve, and it will also make the desorption time too long. If the desorption time is too long, it is necessary to increase the adsorption capacity. Or drying tower to balance the adsorption and desorption time, resulting in an increase in investment

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