United States gases

Polymerization in liquid monomer was pioneered by Rexall Drug and Chemical and Phillips Petroleum (United States). Gas-phase polymerization of propylene was pioneered by BASF, who developed the Novolen process which uses stirred-bed reactors, Eastman Chemical has utilized a unique, high temperature solution process for propylene polymerization. In the 1970s, Solvay introduced an advanced TiCl3 catalyst with high activity and stereoregularity. 

United States Gas Hand Grenade, M-H (Fig. 10).—This grenade, which is typical of all the World War gas grenades, consisted of a shcet-Bteel body, steel bu.shing, detonator thimble, detonator, and autt>mufir firing mechanism (bouchon)j as shown in Fig. 10. 

Projection of the United States gas supply-demand balance through 1990 is summarized in Table IV and Figure 8. The availability of gas from all sources is expected to fall increasingly behind demand. An an-... 

U3. U.S. Department of Energy United States Gas Centrifuge Program for Uranium Enrichment, 1978. 

Estimates of United States gas production in 1984 are approximately 18 quadrillion BTU or 83 billion dollars. In this case an error of one BTU has a potential of gains and losses to transmission and pipeline companies and public utihties of 83 million dollars a year. 

Gas pressure The force exerted by a gas in its surroundings. In the United States, gas pressure is commonly designated in pounds per square inch (psi). The analogous SI unit is the kilopascal (kPa). One psi equals 6.894757 kPa. The term psia refers to absolute pressure. Absolute pressure is based on a zero reference point, the perfect vacuum. Measured from this reference, the standard atmospheric pressure at sea level is 14.696 psi however, local atmospheric pressure may deviate from this standard value because of weather conditions and distance above or below sea level. Gauge pressure, designated by the term psig, is that pressure above local atmospheric pressure. Therefore, psia minus local atmospheric pressure equals psig. 

The most important source of helium is the natural gas from certain petroleum wells in the United States and Canada. This gas may contain as much as 8 % of helium. Because helium has a lower boiling point Table 12.1) than any other gas, it is readily obtained by cooling natural gas to a temperature at which all the other gases are liquid (77 K) almost pure helium can then be pumped off. The yearly production in this way may be many millions of m of gas. but something like 10 m per year is still wasted. 

Ethylene is the cornerstone of the world s mam moth petrochemical industry and is produced in vast quantities In a typical year the amount of ethylene produced in the United States (5 x 10 ° lb) exceeds the combined weight of all of its people In one process ethane from natural gas is heated to bring about its dissociation into ethylene and hydrogen... 

If 10% of the U.S. gasoline consumption were replaced by methanol for a twenty year period, the required reserves of natural gas to support that methanol consumption would amount to about one trillion m (36 TCF) or twice the 1990 annual consumption. Thus the United States could easily support a substantial methanol program from domestic reserves. However, the value of domestic natural gas is quite high. Almost all of the gas has access through the extensive pipeline distribution system to industrial, commercial, and domestic markets and the value of gas in these markets makes methanol produced from domestic natural gas uncompetitive with gasoline and diesel fuel, unless oil prices are very high. 

Dipentaerythritol is sold by Perstorp AB and by Hercules (United States), ditrimethylolpropane by Perstorp AB both in relatively pure form. Tripentaerythritol is also available however, the purity is limited. Trimethylolethane is produced commercially by Alcolac (United States) and Mitsubishi Gas Chemicals (Japan). 

Olefins are produced primarily by thermal cracking of a hydrocarbon feedstock which takes place at low residence time in the presence of steam in the tubes of a furnace. In the United States, natural gas Hquids derived from natural gas processing, primarily ethane [74-84-0] and propane [74-98-6] have been the dominant feedstock for olefins plants, accounting for about 50 to 70% of ethylene production. Most of the remainder has been based on cracking naphtha or gas oil hydrocarbon streams which are derived from cmde oil. Naphtha is a hydrocarbon fraction boiling between 40 and 170°C, whereas the gas oil fraction bods between about 310 and 490°C. These feedstocks, which have been used primarily by producers with refinery affiliations, account for most of the remainder of olefins production. In addition a substantial amount of propylene and a small amount of ethylene ate recovered from waste gases produced in petroleum refineries. 

In most of the rest of the world the olefins industry was originally based on naphtha feedstocks. Naphtha is the dominant olefins feedstock in Europe and Asia. In the middle 1980s several large olefins complexes were budt outside of the United States based on gas Hquids feedstocks, most notable in western Canada, Saudi Arabia, and Scotiand. In each case the driving force was the production of natural gas, perhaps associated with cmde oil production, which was in excess of energy demands. 

Since the early 1980s olefin plants in the United States were designed to have substantial flexibiHty to consume a wide range of feedstocks. Most of the flexibiHty to use various feedstocks is found in plants with associated refineries, where integrated olefins plants can optimize feedstocks using either gas Hquids or heavier refinery streams. Companies whose primary business is the production of ethylene derivatives, such as thermoplastics, tend to use ethane and propane feedstocks which minimize by-product streams and maximize ethylene production for their derivative plants. 

X 10 GJ (436 x 10 BTU) of methane was processed into 15, 200 x 10 kg of ammonia (9) and 924 X 10 kg of methanol (3) in the United States in 1990. Natural gas prices generally foUow cmde oil prices in the United States because they compete in energy markets, but natural gas prices exhibit less volatiHty and have been lower in cost on a fuel basis. Historical natural gas and cmde oil prices are shown in Eigure 4. 

The reason for the popularity of anhydrous ammonia is its economy. No further processing is needed and it has a very high (82.2%) nitrogen content. Additionally if held under pressure or refrigerated, ammonia is a Hquid. Being a Hquid, pipeline transport is practical and economical. A network of overland pipelines (Fig. 4) is in operation in the United States to move anhydrous ammonia economically from points of production near natural gas sources to points of utilization in farming areas (see Pipelines). 

Essentially all the ammonium sulfate fertilizer used in the United States is by-product material. By-product from the acid scmbbing of coke oven gas is one source. A larger source is as by-product ammonium sulfate solution from the production of caprolactam (qv) and acrylonitrile, (qv) which are synthetic fiber intermediates. A third but lesser source is from the ammoniation of spent sulfuric acid from other processes. In the recovery of by-product crystals from each of these sources, the crystallization usually is carried out in steam-heated sa turator—crystallizers. Characteristically, crystallizer product is of a particle size about 90% finer than 16 mesh (ca 1 mm dia), which is too small for satisfactory dry blending with granular fertilizer materials. Crystals of this size are suitable, however, as a feed material to mixed fertilizer granulation plants, and this is the main fertilizer outlet for by-product ammonium sulfate. 

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. 

Coal is expected to be the best domestic feedstock alternative to natural gas. Although coal-based ammonia plants have been built elsewhere, there is no such plant in the United States. Pilot-scale projects have demonstrated effective ammonia-from-coal technology (102). The cost of ammonia production can be anticipated to increase, lea ding to increases in the cost of producing nitrogen fertilizers. 

Company and country are as follows Dead Sea Bromine, Israel (DS) Dainippon Ink and Chemical, Japan (DI) Dow Chemical USA, United States (DC) Great Lakes, United States (GL) Hitachi, Japan (H) Keil Chemical Div., Ferro Corp., United States (KC) Manac Inc., Japan (MI) Mitsubishi Gas Chemical Co., Japan (MG) Sakamoto Yukuhin Kogyo Co., Ltd., Japan (SY) Teijia, Japan (T) Tohto Kasei Co., Ltd., Japan (TK). 

Manufacturers. Besides manufacturers in the United States, commercial fluorine plants are operating in Canada, France, Germany, Italy, Japan, and the United Kingdom (see Table 5). Fluorine is also produced in the Commonwealth of Independent States (former Soviet Union) however, details regarding its manufacture, production volumes, etc, are regarded as secret information. The total commercial production capacity of fluorine in the United States and Canada is estimated at over 5000 t/yr, of which 70—80% is devoted to uranium hexafluoride production. Most of the gas is used in captive uranium-processing operations. 

Storage and Shipment. VDF or HFC-1132a is stored and shipped in gas cylinders or high pressure tube trailers without polymerization inhibitor and is placarded as flammable compressed gas. Terpenes or quinones can be added to inhibit polymerization. Elf Atochem North America, Inc. and Ausimont USA, Inc. supply VDE in the United States other producers are in Japan and Europe. 

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