Patent ID: 6128919
Filing Date: 2000-10-10
Classification: B01D,C01B,C10L,Y02C

Abstract:
A process for separating carbon dioxide from a raw feed stream containing natural gas and carbon dioxide, comprising:dehydrating the raw feed stream;liquefying and removing from the system, natural gas liquids from the raw feed stream and resultingly forming a treated feed stream;altering the temperature and pressure of said treated feed stream to preselected values of an optimum operating range of a first stage membrane and resultingly forming a first altered feed stream;filtering the first altered feed stream in a first filtering system and forming a first stage membrane feed stream;passing the first stage membrane feed stream through the first stage membrane and resultingly separating said feed stream into a first permeate stream and a first nonpermeate stream;recovering the first permeate stream;altering the temperature and pressure of the first nonpermeate stream to preselected values of a second stage membrane and forming a second altered feed stream;filtering the second altered feed stream in a second filtering system to form a seocnd stage membrane feed stream;passing the second stage membrane feed stream through a second stage membrane and resultingly separating said feed stream into a second permeate stream and a second nonpermeate stream;recovering the second nonpermeate stream;altering the temperature and pressure of the second permeate stream to a preselected value of the optimum operating ranges of the first stage membrane; andrecycling the temperature and pressure altered second permeate stream into the first filter system.