Transportation of natural gas

Efficient transportation of natural gas either upstream or downstream is an important step in the natural gas industry that affects all the consumers. Here, upstream is defined as the portion in which the crude natural gas as obtained from the gas reserve is transported to the refineries for treatment. Downstream is the portion wherein the processed natural gas is transported to the ultimate destinations (e.g., households, industries, etc.). 

Natural gas (gas phase), liquefied natural gas (LNG), substitute natural gas (SNG), and liquefied petroleum gas (LPG) are considered to be integral parts of the gas transport industry. The criterion for selection of the mode of gas transportation depends on several factors among which the following are very important [1]  

A system can be designed to carry either the gaseous or liquid phase allowing greater flexibility in the transport of the gas although this might not 

The diameter of the pipeline to be used is also a major concern for the economic and efficient transportation of the natural gas. As the diameter of the pipeline increases the inlet pressure of the gas can be increased and in turn the throughput capacity of the pipeline is increased. However, with the larger pipelines the associated pressure drop is also higher and hence more compressor stations have to be installed which might increase the cost of the 

The first gas pipeline in the erstwhile Soviet Union [3] was from Saratov to Moscow which was about 325 mm (about 13 in.) in diameter. Based on this throughput capacity, new flow capacity value for 1000 mm, 1200 mm and 1400 mm diameter pipe was calculated to be 10, 15 and 20 times this original value, respectively. The consumption of metal per unit volume of gas transported, the capital investments, and operation and maintenance expenses can be reduced by using pipelines of larger diameter. 

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Although many problems still remain to be overcome to make the process practical (not the least of which is the question of the corrosive nature of aqueous HBr and the minimization of formation of any higher brominated methanes), the selective conversion of methane to methyl alcohol without going through syn-gas has promise. Furthermore, the process could be operated in relatively low-capital-demand-ing plants (in contrast to syn-gas production) and in practically any location, making transportation of natural gas from less accessible locations in the form of convenient liquid methyl alcohol possible. 

Petroleum pipe hues before 1969 were built to ASA (now ANSI) Standard B31.4 for liquids and Standard B31.8 for gas. These standards were seldom mandatoiy because few states adopted them. The U.S. Department of Transportation (DOT), which now has responsi-bihty for pipe-line regulation, issued Title 49, Part 192—Transportation of Natural Gas and Other Gas by Pipeline Minimum Safety Standards, and Part 195—Transportation of Liquids by Pipehne. These contain considerable material from B31.4 and B31.8. They allow generally higher stresses than the ASME Pressure Vessel Code would allow for steels of comparable strength. The enforcement of their regulations is presently left to the states and is therefore somewhat uncertain. 

Transportation of natural gas across state lines from production to consuming areas is a function of interstate pipeline companies. The modern U.S. natural gas industry also includes natural gas exploration and production companies, intrastate pipelines, local distribution companies (LDCs), end-users and, the most recent addition to the industry, marketers. 

Transportation of natural gas through pipelines began in the United States in the early part of the nineteenth century. One of the first known uses occurred in 1821 with the building of a system of metallic lead pipes to transport natural gas from a nearby shallow well to commercial establishments in Fredonia, New York, Gas lights—burning gas made from coal—illuminated the streets of Baltimore beginning in 1816. 

The final link in the physical transportation of natural gas IS distribution, the delivery of natural gas by local distribution customers (LDCs) to local consumers. LDCs deliver gas to consumers from storage or from wellheads accessed by pipelines. 

Louisiana, is the dclivei y site for these contracts. Henry Hub consists of an interconnection of seven interstate pipelines, two interstates and one gathering system. These interconnections allow natural gas to move from major production areas to major consumption areas. The transportation of natural gas to and from Henry Hub is contracted separately by the seller and buyer, respectively. 

I. Morris and G. Perry. High pressure storage and transport of natural gas containing added C2 or C3, or ammonia, hydrogen fluoride or carbon monoxide. Patent US 6217626, 2001. 

Ota, S. Uetani, H. Kawano, H. (2002). Use of hydrate pellets for transportation of natural gas - III - safety measures and conceptual design of natural gas hydrate pellet carrier. Proc. Fourth Int. Con. Gas Hydrate, Yokohama, Japan, Vol. I 991-996. 

The transportability of natural gas in pipelines and the clean combustion in its oxidation make it the fuel of choice in maiiy applications. 

In this section we will discuss some technical issues and relate these to economic considerations in order to illustrate that pipeline transportation of natural gas is recognized as a natural monopoly. The core expression of gas flow in a pipeline can be expressed as follows (Weymouth s equation) 36... 

Because of its lower density, transportation of GH2 through pipelines requires more energy than does transportation of natural gas. Transportation of compressed GH2 by trucks is inefficient, because the trucks can hold only about 400 kg of H2. Therefore, a busy gas station could require 10-20 deliveries of GH2 each day, whereas if LH2 is used, a single delivery would suffice. 

Current polymer pipes used for transportation of natural gas at pressures under 0.4 MPa have sufficient strength to carry hydrogen, and diffusion losses arising mainly from pipe connectors have been estimated at three times higher for hydrogen than for natural gas (Sorensen et al, 2001). Transmission of natural gas at pressures up to 8 MPa uses steel pipes with welded connections. Most metals can develop brittleness after absorption of... 

When the transportation of natural gas in a pipeline Is not feasible for economic or other reasons, it is first liquefied at about 160°C, and then transported in specially insulated tanks placed in marine ships. Consider a 4-ni-diame(er spher ical tank that is filled with liquefied natural gas (LNG) at - 160 C. The lank is exposed to ambient air at 24°C with a heat transfer coefficient of 22 W/m °C. The tank is thin shelled and its temperature can be taken to be the same as the J.NG temperature. The tank is insulated with 5-cm-lhick super insulation that has an effective thermal conductivity of 0.00008 W/in °C. Taking the density and the specific heat of LNG to be 425 kg/m and 3.475 kJ/kg C, respectively, estimate how long it will take for the LN G temperature to rise to -ISO C. 

Adsorption by activated carbons is used extensively in large-scale industrial processes to remove various pollutants. The material has also been used in cigarette filters and in faucet-mounted household water purification devices. There is also interest in the use of these materials for the storage and transport of natural gas. 

Gudmundsson, J. Borrehaug, A. Frozen hydrate for transport of natural gas. Proceedings of the Second International Conference on Natural Gas Hydrates, Toulouse, France, June 2-6, Guillon, O., Ed. INP ENGISC, 1996 983-986. Takaoki, T. Iwasaki, T. Katoh, T. Takashi, A. Kiyoshi, H. Use of hydrate pellets for natural gas transportation. I. Advantage of pellet form of natural gas hydrate in sea transportation. Proceedings of the Fourth International Conference on Gas Hydrates, Yokohama, Japan, May 17-20, 2002 406. 

A 0.6 m diameter gas pipeline is being used for the long-distance transport of natural gas. Just past a pumping station, the gas is found to be at a temperature of 25°C and a pressure of 3.0 MPa. The mass flow rate is 125 kg/s, and the gas flow is adiabatic. Forty miles down the pipeline is another pumping station. At this point the pressure is found to be 2.0 MPa. At the pumping station the gas is first adiabatically compressed to a pressure of 3.0 MPa and then isobar-ically (i.e., at constant pressure) cooled to 25°C. 

Several factors make hydrogen pipelines more expensive to install than those for the transport of natural gas. The hydrogen molecule is smaller than the methane molecule and therefore diffuses more readily through materials, which necessitates the use of special gaskets and flanges. Since the volumetric energy... 

Korotaev J. P., Margulov R. D. (Eds.), Production, preparation and transport of natural gas and condensate (Handbook in 2 Volumes), Nedra,... 

Over time, various applications were demonstrated on laboratory or pilot plant scale, including the fractionation of gases, the concentration of aqueous solutions, the desalination of water, cool energy storage, and the storage and transport of natural gas. All of these await future developments of commercially viable technologies. 

Montiel H, Vilchez JA, Amaldos J, Casal J. 1996. Historical analysis of accidents in the transportation of natural gas. Journal of Hazardous Materials 51, 77-92. 

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