Natural Gas Uses

Natural gas is usually saturated with water as it leaves the well, and as a result, the gas hydrates can form in the pipeline restricting the flow of gas. To destroy such plugs in the cold Siberian pipeline, large amounts of methanol are introduced at the approximate rate of 1 kg/1,000 m of gas. This represents more methanol than can be produced by a standard methanol plant. 

Methane—the major constituent of natural gas—is not only an excellent fuel but an important chemical. This is illustrated by the various reactions in Fig. 6.4 where each of the products are important reactants themselves. The thermodynamics of methane pyrolysis reactions is shown in Fig. 6.5 for equilibrium conditions. If, however, the hydrogen produced is removed from the reaction system, then the product yields can be substantially higher. This has been demonstrated using thin palladium membranes which allow only H2 to pass through. Similarly, when the pyrolysis occurs on a hot wire, the hydrogen produced can diffuse out of the reaction zone faster than the other heavier product, and therefore, equilibrium conditions do not prevail. Thus, in Fig. 6.5, though reaction 1 is preferred thermodynamically, it is found that experimentally reaction 4 occurs on a hot wire forming aromatic oil. 

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Natural gas Hquids are recovered from natural gas using condensation processes, absorption (qv) processes employing hydrocarbon Hquids similar to gasoline or kerosene as the absorber oil, or soHd-bed adsorption (qv) processes using adsorbants such as siHca, molecular sieves, or activated charcoal. Eor condensation processes, cooling can be provided by refrigeration units which frequently use vapor-compression cycles with propane as the refrigerant or by... 

Relatively new methods for separating helium from natural gas use pressure swing adsorption (PSA) processes to recover helium at better than 99.99% purity. This type of process is probably less costiy for the production of gaseous helium but might be uneconomical for liquefied helium production. The PSA process is widely used to produce specification pure helium from 85+% cmde helium in conjunction with cryogenic enrichment of the ca 50% helium raffinate. 

Like M( F(7s, S()F(7s can integrate fuel reforming within the fuel cell stack, A prereformer converts a substantial amount of the natural gas using waste heat from the fuel cell, (iornpoiinds containing sulfur (e,g, thiophene, which is cornrnonlv added to natural gas as an odorant) must be removed before the reformer. Typically, a hvdrodesiilfii-rizer combined with a zinc oxide absorber is used. 

Atmospheric particulate emissions can be reduced by choosing cleaner fuels. Natural gas used as fuel emits negligible amounts of particulate matter. Oil-based processes also emit significantly fewer particulates than coal-fired combustion processes. Low-ash fossil fuels contain less noncombustible, ash-forming mineral matter and thus generate lower levels of particulate emissions. Lighter distillate oil-based combustion results in lower levels of particulate emissions than heavier residual oils. However, the choice of fuel is usually influenced by economic as well as environmental considerations. 

Despite the environmental benefits of natural gas vehicles, large numbers of compressed natural gas stations need to be built or compressed natural gas will never be more than a niche fuel servicing large fleets of buses, cabs, and delivei y trucks that can be fueled at a central location. Nonroad short-range vehicles such as forklifts, backhoes, street sweepers, and airport ground support equipment are also ideally suited for natural gas use. 

Demand for natural gas, in all markets—residential, commercial, and industrial—is projected to grow into the foreseeable future, particularly in the electric power generation market and the industrial sector. Total natural gas use in the United States is projected to grow from 20.1 quadrillion British thermal units in 1992 to 26.1 by 2010, an average growth rate of 1.6 percent per year. 

For oil-base muds Equation 4-197 can be applied, but K and p must be calculated for an average natural gas using tables or the corresponding algorithms. 

Sublette [285] describes a process for desulfurizing sour natural gas using another commonly known chemolithotrophic microorganism, the aerobic bacterium T. denitrifi-cans. This patent describes a process wherein bacteria of the Thiobacillus genus convert sulfides to sulfates under aerobic conditions. Sublette defined the ideal characteristics of a suitable microorganism for the oxidative H2S removal from gaseous streams as ... 

Although, in large-scale hydrogen plants, the cost of producing hydrogen is dominated by the cost of feedstock (most often natural gas) used and the cost of fuel used to supply heat... 

Haines A process for recovering sulfur from natural gas, using a zeolite adsorbent. The hydrogen sulfide in the gas is adsorbed on the zeolite when the bed is saturated, hot sulfur dioxide is passed through it. The zeolite catalyzes the reaction between hydrogen sulfide and sulfur dioxide to fonn elemental sulfur, which sublimes out and is condensed. The process was invented by H. W. Haines in 1960 it was developed by Krell Associates and piloted in Canada from 1961 to 1962, but not commercialized because of problems caused by fouling of the zeolite with heavy hydrocarbons. 

Sodium calcium pentaborate pentahydrate, 4 242t, 278-279 Sodium carbide, 22 765 Sodium carbonate, 20 631, 22 765, 787-797, 23 669, 3 416. See also Soda ash applications of, 22 794-795 from brine, 5 799-800 carbon dioxide recovery from natural gas using, 4 811... 

Plug Power, a Latham, NY, based manufacturer of stationary hydrogen fuel cell generator units for backup power has developed a hydrogen fueling station with the help of Honda. This station uses a small steam reformer that extracts hydrogen fuel from natural gas using steam. The steam reformer has been reduced to half the size of the previous version. 

Global energy use nearly triples from 2000 to 2050. World wide nuclear power production also nearly triples during this time. Natural gas use is large in this scenario, and its use more than triples over these 50 years. Renewable energy is also abundant. 

Figure 15.1. Projected natural gas use in the United States by sector (USDOE, 2007a), and projected demand for natural gas to make hydrogen for fuel-cell vehicles until 2030 (based on extension of USDOE s most aggressive scenario for introducing hydrogen fuel-cell vehicles (Gronich, 2006)).

Arruebo, M., Coronas, J., Menendez, M., and Santamaria, J. (2001) Separation of hydrocarbons from natural gas using silicalite membranes. Sep. Purif. Tech., 25, 275-286. 

NATURALHY - project aims to define the technical and socio-economic conditions to inject hydrogen in natural gas using the existing infrastructure in a transition to the Hj economy. 48 partners are involved including major EU gas utilities with a budget of 11 million. 

Petroleum is also versatile. It contains all the commercially important hydrocarbons, such as those that make up gasoline, diesel fuel, jet fuel, motor oil, heating oil, tar, and even natural gas. Using fractional distillation (Section 12.1), oil refineries can convert one type of petroleum hydrocarbon to another, thereby tailoring their output to fit consumer demand. Furthermore, petroleum contains much less sulfur than does coal and so produces less sulfur dioxide when burned. So, despite its vast coal reserves, the United States has a royal thirst for petroleum, the king of fossil fuels, consuming about 20 million barrels each day. This is about 11 liters per U.S. citizen per day. 

Fig. 6, Plant for nitrogen removal from natural gas using cryogenic upgrading. (Petrocarbon Developments, Ltd)...

Delgado-Morales, W., Zingaro, R.A. and Mohan, M.S. (1994) Analysis and removal of arsenic from natural-gas using potassium peroxydisulfate and polysulfide absorbents. International Journal of Environmental Analytical Chemistry, 54(3), 203-20. 

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