Design parameters Processing capacity: 20×104Nm3/day Feed gas CO2 design point: 3% The operating pressure of absorption tower is 5.0MpaG Operating temperature of absorption tower: 40 ℃ ~ 60 ℃ Operating pressure of regeneration tower: 0.03 MpaG~0.05 Mpa.G Operating temperature of regeneration tower: 95 ℃ ~ 120 ℃ Regenerative heat source heat transfer oil heating CO2 content in decarbonization gas ≤ 50ppm 3.2.2.2 Mercury removal and drying unit of feed gas 1）Process description The natural gas from the feed gas deacidification unit enters the sulfur impregnated activated carbon adsorber. Mercury reacts with the sulfur on the sulfur impregnated activated carbon to generate mercury sulfide, which is adsorbed on the activated carbon, so as to achieve the purpose of mercury removal. The mercury content of natural gas from mercury remover is less than 0.01μg/Nm3。 One mercury remover shall be set, and the sulfur impregnated activated carbon shall be replaced according to the test conditions. The natural gas after mercury removal enters the drying unit. The unit adopts temperature swing adsorption technology for gas separation and purification. Temperature swing adsorption technology is based on the physical adsorption of gas molecules on the internal surface of adsorbent (porous solid material), and uses the characteristics that the adsorption capacity of adsorbent for gas changes with different adsorption temperature and pressure, Under the condition that the adsorbent selectively adsorbs different gas components, some components in the mixture are adsorbed at low temperature and high pressure, and the non-adsorbed components flow out through the adsorber layer. These adsorbed components are desorbed at high temperature and low pressure for the next low temperature and high-pressure adsorption. Multiple adsorption towers can be used to achieve the purpose of continuous gas separation. The feed gas drying and heavy hydrocarbon removal unit is equipped with three adsorbers for switching operation, one for adsorption, one for cold blowing and one for heating regeneration. The feed gas from the demercuration tower enters the top of the adsorber, removes water through molecular sieve adsorption, comes out from the bottom of the adsorber, and enters the feed gas heavy hydrocarbon removal unit after dehydration. The feed gas drying unit uses a small amount of feed gas as the cold blowing and regeneration medium. After the regeneration gas leaves the adsorption tower, it returns to the inlet of the drying tower in the adsorption state after cooling and separation. The regeneration gas first passes through the cooled adsorber from top to bottom, and then the regeneration gas is heated to the regeneration temperature of 180 ~ 260 ℃ through the regeneration heater, and then enters from the bottom of the adsorber to hydrolyze and adsorb the adsorbed adsorbent. The regeneration gas comes out from the top of the dryer and enters the regeneration gas separator after being cooled by the regeneration cooler. After separating the liquid, it returns to the front end of the adsorber. After passing through the unit, the water in the dry natural gas is ≤ 1ppm. The main equipment is adsorption tower, regeneration heater, regeneration gas cooler and regeneration gas separator. 2）Design parameters Feed gas processing capacity 20×104Nm3/d Operating pressure: 5.0MpaG Adsorption temperature 40 ℃ Regeneration mode: isobaric regeneration Regeneration temperature 180 ℃ ~ 260 ℃ Regenerative heat source heat transfer oil heating H2O content in purified gas ≤ 1ppm Content of Hg in purified gas ≤ 0.01μg/Nm3 3.2.2.3 Feed gas filtration unit 1）Process description The filter unit is equipped with a filter, which can be switched according to the resistance data to achieve the purpose of filtering molecular sieve and activated carbon dust. After dust removal, the dust particles in the feed gas are less than 10μm。 The main equipment is dust filter. 2）Design parameters Feed gas processing capacity 20×104Nm3/d Operating pressure: 5.0MpaG Dust content in purified gas ≤ 5μm