Natural and Refinery Gases

Yw Total sales Domestic and motor fuel Industrial and misc. Gas manu- facture Chemical manu- facture Rubber compo- nents 

The lighter hydrocarbons, such as propane, isobutane, butane, and the corresponding olefins, removed from natural gasoline and refinery gases, are widely used as so-called bottle gas (Table 3-5). The enormous growth of the liquefied petroleum gas (L.P.G.) industry is indicated in Table 22-1. 

Natural gas is still the major source of carbon black (Table 22-2), but increasing amounts of oil are being utilized. About 94 per cent of the carbon black used in the United States is compounded into rubber goods. S3rnthetic rubber requires much more black (Table 22-2) than natural rubber. Most of the rest of the black is used for piinter s ink and paint  

Year Millions lb, by process Millions lb by raw material source Lb per 1001b rubber  

Chemical Economics Handbook, Stanford Research Institute. 

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The largest use of NMP is in extraction of aromatics from lube oils. In this appHcation, it has been replacing phenol and, to some extent, furfural. Other petrochemical uses involve separation and recovery of aromatics from mixed feedstocks recovery and purification of acetylenes, olefins, and diolefins removal of sulfur compounds from natural and refinery gases and dehydration of natural gas. 

Since the 1950 s there has been a remarkable growth in sulfur production from the hydrogen sulfide of natural and refinery gases. Once a minor source of world brimstone, sour gas now makes a very significant contribution to world sulfur production. 

Sulfur is also a constituent of petroleum and natural gas (as H2S). Thus, removing hydrogen sulfide from natural and refinery gases with absorbents such as monoethanolamine and/or diethanolamine also produces elemental sulfur. The hydrogen sulfide is then converted to elemental sulfur by the Claus or modified Claus process (Fig. 2). 

I860, 397, Beilstein. vol. 1, 118. Recovery of butanes from natural and refinery gases Kirkbride, Bertelli. ind. Eng. 

Ethylene is baric to the American petrochemical industry and is one of the most important of ril chemical raw materials. Approximately 2.2 billion lb of ethylene was produced in 1953, 2.4 billion lb in 1954, and 2.9 billion lb in 1955. It was consmratively estimated that this figure woidd reach 3.2 billion lb by 1956 and 4.0 billion lb by 1960. About 10 per cent of the ethylene produced in 1953 was recovered from the off-gases from refineries that crack petroleum stocks. Most of the remaining 90 per cent was derived, in rou y equal amounts, from the pyrolyris of propane and of ethane recovered from natural and refinery gases. A minor proportion was produced by the dehydration of ethanol. 

The recovery of hydrogen sulfide from natural and refinery gases, and its conversion into sulfur or sulfuric acid, is being conducted extenavely. In Wyoming oil and gas fields alone, the available sulfur is estimated to be 5,678,400 long tons (1950), in Arkansas sour gas fields (1942) at least 1,500,000 long tons, and in the Permian Basin of West Texas and southeastern New Mexico a daily production of at least 400 long tons (1950). 

Since 1960, about 95% of the synthetic ammonia made in the United States has been made from natural gas worldwide the proportion is about 85%. Most of the balance is made from naphtha and other petroleum Hquids. Relatively small amounts of ammonia are made from hydrogen recovered from coke oven and refinery gases, from electrolysis of salt solutions, eg, caustic chlorine production, and by electrolysis of water. In addition there are about 20 ammonia plants worldwide that use coal as a hydrogen source. 

Carbonyl sulfide occurs as a by-product ia the manufacture of carbon disulfide and is an impurity ia some natural gases, ia many manufactured fuel gases and refinery gases, and ia combustion products of sulfur-containing fuels (25). It tends to be concentrated ia the propane fraction ia gas fractionation an amine sweetening process is needed to remove it. 

Both butanes occur in natural gas, petroleum, and refinery gases. They show little chemical reactivity at ordinary temperatures but bum readily when ignited in air or oxygen. In atmospheric burning smoke production normally occurs. 

Partial oxidation has practically no restrictions regarding the nature of the hydrocarbon and the sulfur content. Natural gas, refinery gases, LPG, naphtha, heavy fuel, vacuum residue, visbreaker oil, asphalt, and tar can be used as feedstock. As the investment costs for partial oxidation are higher than for steam reforming, mainly because of the cyrogenic air separation, it is usually not a choice for the lighter hydrocarbons, but heavy feedstocks from fuel oil to asphalt, when favorably priced, can be a competitive option for various locations and circumstances. In some special cases, where the primary reformer is a bottleneck for a capacity increase, a small parallel partial oxidation unit based on natural gas could be installed, if a surplus of... 

As stated above, some of the chemicals and compounds produced in a refinery are destined for further processing and as raw material feedstocks for the fast growing petrochemical industry. Such nonfuel uses of crude oil products are sometimes referred to as its nonenergy uses. Petroleum products and natural gas provide two of the basic starting points for this industry methane from natural gas, and naphtha and refinery gases. 

There is ample experimental evidence to show that the efficiencies of different components in a multicomponent system are not all equal. The first clear statement of this fact can be found in a paper by Walter and Sherwood (1941) who, on the basis of an extensive experimental study of Murphree vapor and liquid efficiencies for absorption, desorption, and rectification operations, concluded The results indicate that different efficiencies should be used for each component in the design of absorbers for natural gasoline and refinery gases. Since the publication of their paper many others have provided additional data to confirm this view [see Krishna and Standart (1979) for a list of references]. We review some of these data below. 

Figure 2.21 shows a schematic of Shell s Sulfinol process, which removes H2S, COS, RSH, and C02 from refinery offgases or natural gases [38]. The process is also applicable to gas cleanup of synthetic and refinery gases. The total sulfur content in the treated gas can be reduced to ultra low ppm levels. 

Natural gas and refinery gases are two main sources for the raw materials used by the organic chemical industry today. An analysis of the derivation of petrochemicals reveals that ethylene has been a more widely used and productive building block than propylene. Tables II and III indicate the more important derivatives of these two raw materials. 

The hydrocarhon-steam process involves the reaction of hydrocarbons, such as natural gas, refinery gases, or propane, with steam over a catalyst (such as nickel on magnesia) at about 800 C, to produce a mixture of hydrogen, carbon monoxide, and carbon dioxide. Starting with methane, the following reactions take place ... 

Uses Defoamer/antifoam for aq. and anhydrous media, crop protection prods., natural or refinery gases, detergents, chemicals deaeration of detergent slurries Regulatory Exempt from tolerance under EPA40CFR 180.1001 (c)(e) Australia AICS, Canada DSL, Korea ECL, China SEPA, Philippines PICCS listed Properties Grayish-wh. opalescent vise. Iiq., odorless misc. with diethylether, aliphatic and aromatic hydrocarbons, chlorinated solvents pract. insol. in water sp.gr. 1.0 dynamic vise. 3500 mPa.s 100% act. 

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