Integrated multi-functional pipeline system for delivery of chilled mixtures of natural gas and chilled mixtures of natural gas and ngls

Abstract

Herein pipeline pressure, temperature and NGL constituents are manipulated for the transportation and optional storage in a pipeline system of natural gas mixtures or rich mixtures for delivery of chilled Products for downstream applications. Pressure reduction from a last compression section delivers internally chilled Products for reduced capital and operating costs. A high lift compressor station before the pipeline terminus provides pressure differential for Joule-Thompson chilling of the pipeline contents. The chilling step can be retrofitted to existing pipeline systems, and the chilling steep can include a turbo expander or the like for recovery of pipeline pressure energy for power generation. For like throughout, with this higher pressure operation, the effects of enhanced NGL content results in a reduction in diameter of the pipeline by at least one standard size. Substantial overall reduction in energy consumption and associated CO2 emissions is thereby achieved through integrated pipeline/processing applications.

We claim: 
     
         1 . A terminus for a natural gas pipeline comprising:
 a high pressure storage section of the pipeline for storing rich gas mixtures remaining supercritical in the pressure range of between about 2500 and about 4500 psig; and   a Joule-Thompson (J-T) device for reducing the pressure of the stored rich gas mixture to form a chilled product without liquid fallout.   
     
     
         2 . The pipeline terminus of  claim 1 , wherein the pressure range is between about 2500-3250 at ambient conditions 
     
     
         3 . The pipeline terminus of  claim 1 , wherein the cooled product is reduced in pressure to the range of about 1200 to 800 psig. 
     
     
         4 . The pipeline terminus of  claim 1 , wherein the J-T device is a valve or a turbo expander. 
     
     
         5 . The pipeline terminus of  claim 1 , wherein the J-T device is coupled to a shaft for energy recovery therefrom. 
     
     
         6 . The pipeline terminus of  claim 1 , the rich gas mixtures comprise: from 40% to 98% by mol volume of methane, from trace to 35% by mol volume of ethane; from trace to 22% by mol volume of propane; from trace to 9% by mol volume of butane; residual amounts of N2 not exceeding 2% by mol volume; trace elements of C5+ (ie C5, C6 . . . ) hydrocarbons not exceeding 0.25% of mol volume; and the total being 100%, wherein the operating conditions of the mixture is completely gaseous or in the supercritical-dense phases with no liquid phase. 
     
     
         7 . The pipeline terminus of  claim 6 , wherein a single component of one of more of the light hydrocarbons of ethane, propane, or butane is at its lowest range, while a standalone % mol of remaining Light Hydrocarbons is sufficient to bring about the reduction in Z factor value and dense phase flow/storage behavior and/or chilling effects. 
     
     
         8 . The pipeline terminus of  claim 7 , wherein such standalone % mol are 6% for ethane, 1.5% for propane and 0.5% for butanes for Rich Gas mixtures: and 2% for ethane, 1% for propane and 0.25% for butanes in the 2500 psig or higher pressure Standard Transmission specification mixtures. 
     
     
         9 . The pipeline terminus of  claim 7 , wherein chilled product is delivered for LNG production, separation and fractionation, or for enhanced storage of CNG. 
     
     
         10 . A high pressure natural gas pipeline comprising:
 one or more transmission staging sections for moving rich gas from a source to a destination with recompression to pressures of above about 2150 psig;   a high pressure storage section of the pipeline adjacent the destination for storing rich gas mixtures remaining supercritical in the pressure range of between about 2500 and about 4500 psig; and   a Joule-Thompson device for reducing the pressure of the stored rich gas mixture to form a chilled product without liquid fallout.   
     
     
         11 . The pipeline of  claim 10 , wherein the cooled product is reduced in pressure to the range of about 1200 to 800 psig. 
     
     
         12 . The pipeline of  claim 10 , wherein the J-T device are located at an exit points one or more of the transmission staging sections. 
     
     
         13 . The pipeline of  claim 10 , wherein the J-T device is a turbo expander system have a shaft coupled for electrical recovery of pipeline energy from the high pressure storage section. 
     
     
         14 . The pipeline of  claim 10 , wherein the rich gas mixtures comprise: from 40% to 98% by mol volume of methane, from trace to 35% by mol volume of ethane; from trace to 22% by mol volume of propane; from trace to 9% by mol volume of butane; residual amounts of N2 not exceeding 2% by mol volume; trace elements of C5+ (ie C5, C6 . . . ) hydrocarbons not exceeding 0.25% of mol volume; and the total being 100%, wherein the operating conditions of the mixture is completely gaseous or in the supercritical-dense phases with no liquid phase. 
     
     
         15 . The pipeline terminus of  claim 14 , wherein a single component of one of more of the light hydrocarbons of ethane, propane, or butane is at its lowest range, while a standalone % mol of remaining Light Hydrocarbons is sufficient to bring about the reduction in Z factor value and dense phase flow/storage behavior and/or chilling effects. 
     
     
         16 . The pipeline terminus of  claim 15 , wherein such standalone % mol are 6% for ethane, 1.5% for propane and 0.5% for butanes for Rich Gas mixtures: and 2% for ethane, 1% for propane and 0.25% for butanes in the 2500 psig or higher pressure Standard Transmission specification mixtures.