PREPARATION PLANT OF HYDROCARBON GAS FOR LOW-TEMPERATURE PROCESSING Russian patent published in 2015 - IPC B01D53/04 

FIELD: oil and gas industry.

SUBSTANCE: plant includes a supply line of compressed feed gas, a feed gas inlet separator having outlet lines of separated gas and harmful impurities, an adsorption unit containing at least three parallel connected adsorbers filled with an adsorbent with piping arrangement with shutoff valves and having a gas supply line, a gas discharge line through a strainer for low-temperature processing, as well as a recycle gas supply line with a recycle gas heating system and a cooling gas system and a waste recycle gas discharge line. The plant also includes a unit for cooling and separation of waste recycle gas with a water outlet line and a discharge line of separated waste recycle gas, a unit for membrane separation of recycle gas with an outlet line of gas that did not penetrate through the membrane, and an outlet line of a gas mixture that penetrated through the membrane. The outlet line of separated gas from the feed gas inlet separator is connected to an additionally installed unit for amine cleaning of gas from CO₂ and methanol, which has a CO₂ outlet line and a clean gas outlet line connected through the installed heat exchanger - cooler to a separator for gas preparation for drying, which has a water outlet line and a gas outlet line connected to the adsorption unit. Each adsorber of the adsorption unit has a combined layer of adsorbents; a layer of regenerated molecular sieves, which provides absorption of CO₂, water, methanol, is located as the first one in the supply direction of hydrocarbon gas in the adsorber; then, a layer of a regenerated adsorbent is located, which provides gas cleaning from mercury. The outlet line of separated waste recycle gas from the unit for cooling and separation of waste recycle gas is connected to the unit of membrane separation of recycle gas; with that, the outlet line of the gas mixture that penetrated through the membrane is connected to a fuel network, and the outlet line of gas that did not penetrate through the membrane is connected to the installed assembly of adsorption non-regenerative cleaning of recycle gas from mercury, which has an outlet line of dried and clean recycle gas, which is connected through the strainer to a user for auxiliary needs or through a compressor to the outlet line of separated gas of the feed gas inlet separator or to the clean gas outlet line. The plant is provided with pipelines connecting the equipment and with shutoff and control valves.

EFFECT: enlarging the scope of application of the plant due to preparation of hydrocarbon gas for complex process lines for liquefaction of natural gas at improvement of efficient operation of an adsorption unit both for gas drying and for its cleaning from harmful impurities, including from mercury, and at complete utilisation of waste recycle gas.

2 dwg