Patent RU-2709119-C1 (RU)
Title: Method for optimizing the process of washing the inhibitor from unstable gas condensate at low-temperature gas separation plants
Inventor: ARNO OLEG BORISOVICH
IPC: F17D3/16
Filed: 2019-06-10
Granted: 2019-12-16
Abstract: FIELD: technological processes. 
     SUBSTANCE: method is intended for optimization of process of washing inhibitor from unstable gas condensate (UGC) at installations of low-temperature separation (LTS) of gas, implemented by automated process control system (APCS). Method includes automatic control of LTS gas process, which provides: automatic maintenance within specified boundaries of process parameters of process parameters of process of gas and gas condensate preparation to long-distance transport; separation of water-methanol solution (MWS) from UGC in gas separators and separators of liquids of the first and second stages of gas separation with washing of methanol from condensate in separator of liquids of second stage of gas separation and its subsequent regeneration from obtained MWS with return of regenerated methanol into process of gas and gas condensate preparation for long-distance transportation at plant; extraction of gas from UGC in separators of liquids of the first and second stages of gas separation for its transportation for utilization or compression and supply to the main gas line; transportation of UGC from fluid separators of first and second stages of gas separation into main condensate line; removal of one part of MWS with low concentration of methanol from separator of liquids of first stage of gas separation through valve-controller of following level of MWS in separator of liquids of first stage of separation of gas of plant for utilization, for example by pumping of this solution into formation, and withdrawing the other portion of MWS with low concentration of methanol through the regulator valve and injector into the separator of liquids of the second gas separation stage for washing methanol from UGC, wherein when starting the plant in operation for current process parameters of APCS with due allowance for its inertia, searching for optimum flow rate of MWS with low concentration of methanol supplied from separator of liquids of first stage of gas separation, which must be injected into combined stream of mixture UGC and MWS, supplied to input of injector from intermediate and low-temperature separators, to achieve maximum possible washing of methanol in separator of liquids of second stage from UGC to MWS, withdrawn for regeneration, after that APCS fixes found value of optimum flow rate MWS with low concentration of methanol in form of setting in its database, and then, automatically, in PID-control mode maintains supply of found optimum flow rate MWS with low concentration of methanol for injection into combined flow of UGC and MWS, supplied to injector from intermediate and low-temperature gas separators, and this support of supply of optimum flow rate of MWS with low concentration of methanol is carried out until significant change of parameters of technological process or receipt of a command for the next cycle of searching for a new optimum flow rate MWS with low concentration of methanol injected into the combined flow of the mixture UGC and MWS, supplied to the input of the injector. 
     EFFECT: reduced power consumption for methanol recovery. 
     7 cl, 2 dwg