Gas, natural pipelines

Natural gas pipeline Natural gas wells Natural graphite Natural Graphite Natural gums... 

Although there are no new methane VPO competitive processes, current technology may be usehil for the production of impure methanol in remote areas for use as a hydrate inhibitor in natural gas pipelines (119,120). 

Essentially all of the methane [74-82-8] is removed ia the demethanizer overhead gas product. High recovery of ethane and heavier components as demethanizer bottoms products is commonplace. The work that is generated by expanding the gas ia the turboexpander is utilized to compress the residue gas from the demethanizer after it is warmed by heat exchange with the inlet gas. Recompression and deUvery to a natural gas pipeline is performed downstream of the plant. A propane recovery of 99% can be expected when ethane recoveries are ia excess of 65%. 

Some U.S. natural gas pipeline companies are subsidiaries of gas hoi ding companies. The largest U.S. natural gas pipeline companies, in terms of overall length of transmission systems are Northern Natural Gas Company, 26,539 km Tennessee Gas Pipeline Corporation, 23,567 km Columbia Gas Transmission Company, 18,481 km Natural Gas Pipeline Company of America, 17,200 km and Transcontinental Gas Pipe Line Corporation, 17,071 km. For gas moved in 1994, the four largest pipelines were ANR Pipeline Company, 95,278 x 10 m (3,363,275 MMcf), of which 40.8% was gas moved for others Transcontinental Gas Pipe Line Corporation, 87, 050 x 10 m (3,073,801 MMcf), of which 99.7% was moved for others Natural Gas Pipeline Company of America, 83,089 x 10 m (2,933,940 MMcf), of which 87.1% was moved for others and Northern Natural Gas Company, 56, 523 x 10 m ... 

When constmction is complete, the pipeline must be tested for leaks and strength before being put into service industry code specifies the test procedures. Water is the test fluid of choice for natural gas pipelines, and hydrostatic testing is often carried out beyond the yield strength in order to reHeve secondary stresses added during constmction or to ensure that all defects are found. Industry code limits on the hoop stress control the test pressures, which are also limited by location classification based on population. Hoop stress is calculated from the formula, S = PD/2t, where S is the hoop stress in kPa (psig) P is the internal pressure in kPa (psig), and D and T are the outside pipe diameter and nominal wall thickness, respectively, in mm (in.). 

Map of Major Natural Gas Pipelines, U.S. Dept, of Energy, for sale by the Superintendent of Documents, U.S. Printing Office, Washington, D.C. Cmde oil and products pipeline maps also available. 

Liquefied Natural Gas (LNG) plants can be categorized as peakshaving or baseload. Peakshaving LNG plants are built at the consumer end of natural gas pipelines to accumulate LNG in storage tanks for later vaporization and sendout into the local grid during periods of peak demand. Baseload LNG plants provide a steady base supply of natural gas to utiHty companies, generally by transportation of LNG by ship from one country to another. 

Because the value of Z for natural gas is significantly less than unity at ambient temperatures and at pressures greater than 1 MPa (145 psia), the compressibility must be taken into account in gas measurement gas purchased at high line pressure will fflve a greater volume when the pressure is reduced than it would if the gas were ideal. Natural gas pipeline operators use a.. supercompre.s.sihility faclor, also called Z, out defined as... 

Probably the largest natural gas proeessing straddle plant in North Ameriea is BP-Amoeo s Empress, Alberta faeility. Here, EPBC (ethane, propane, butanes, and eondensate) are extraeted as liquids from natural gas before the gas is delivered to the TransCanada and Foothills (Saskatehewan) pipelines (Figure 8-5). The term straddle plant refers to the faet that the plant straddles the natural gas pipeline and extraets liquid eomponents before passing the natural gas further along the pipeline. 

Gas treating is defined here as removal of H2S and CO2. Other sulfur compounds are discussed where applicable. Dehydration and sulfur production are not included, except for discussing sulfur production in the Stretford Process and for selective H2S removal. H2S must be removed from natural gas and process streams for health reasons and prevention of corrosion. Natural gas pipeline specifications require no more than % grain/100 SCF. This is equivalent to 4ppmv or 7ppmw (for a 0.65 specific gravity gas). By comparison, the human nose can detect... 

Predicting the appropriate level of duetile fraeture resistance involves an analysis of fluid properties, operating conditions, and material properties. For natural gas pipelines containing mostly methane with very... 

In another incident a backhoe ruptured a 3-in. polyethylene natural gas pipeline fortunately the gas did not ignite. The drawings were complex and cluttered, and the contractor overlooked the pipeline. A metal detector was not used. This would have detected the pipe as a metal wire was fixed to it, a good practice. In a third incident a worker was hand-digging a trench, as an electric conduit was believed to be present. It was actually an old transfer line for radioactive waste, and he received a small dose of radioactivity. The planner had misread the drawing. 

For example, there was a dead-end branch, 12 in. in diameter and 3 m long, in a natural-gas pipeline operating at a gauge pressure of 550 psi (38 bar). Water and impurities colleeted in the dead-end, which corroded and failed. The escaping gas ignited at once, killing three men who were looking for a leak [4J. 

Safety of Interstate Natural Gas Pipelines Power 87 Casualities/Approx. 3000 pipe failures U S. interstate Natural Gas large diameter, high pressure transmission pipelines 43. 

Pipeline Failure Characteristics and Analysis of Pipeline Failure Rates Gas oil and natural gas pipelines ... 

In the United States, pipeline transport is regulated by the Department of TransporUition (DOT) through the Natural Gas Pipeline Safety Act of 1968 and... 

Natural gas pipelines are generally defined as intrastate, those transporting gas to markets within state boundaries, or interstate, those crossing state lines. Natural gas from Canada, a grooving source of natural gas consumed in the United States, also enters the U.S. through iuterconnectious with interstate pipelines. 

Today, a network of more than 300,000 miles of interstate natural gas pipelines sei"vcs markets across the U.S, Construction of this network began in the 1920s, but large-scale expansion was limited by the technology of the day, the Great Depression and, finally. World War II. 

Because of their role as the link between producing and market areas, interstate natural gas pipelines play a crucial role in balancing supply and demand. To do so, the interstate pipelines continually monitor pipeline performance. These companies rely heavily on computers to gather, analyze and retain information on the performance of their pipelines, and to control the flow of gas in remote sections of the line. 

The first major federal regulatory event affecting natural gas pipelines was the Natural Gas Act of 1938, which gave the Federal Power Commission jurisdiction to regulate three areas (1) pipeline sales of gas purchased from producers and resold to local distribution companies in interstate commerce (2) transportation m interstate commerce and (3) the facilities used for such sales and such transportation. 

Adamantane and diamantane are usually the dominant diamondoids found in petroleum and natural gas pipeline deposits [74, 75]. This is because diamondoids are soluble in light hydrocarbons at high pressures and temperatures. Upon expansion of the petroleum fluid coming out of the underground reservoir and a drop in its temperature and pressure, diamondoids could deposit. 

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