Petrochemical processing nickel

Carbon monoxide and carbon dioxide are poisons for many hydrogenation catalysts used in ammonia synthesis, refinery processes and petrochemical processes. Therefore, in steam reformers designed to produce hydrogen for hydrogenations, carbon oxides are removed to very low levels, typically a maximum of 5 ppm [7]. The conventional method of achieving this specification is to use a nickel or ruthenium catalyst to convert carbon oxides to methane. The conversion proceeds in accordance with the following methanation reactions ... 

As will have become apparent, nickel and corrosion-resistant nickel alloys have wide ranges of application, particularly in industries where strongly acidic, strongly alkaline or strongly saline environments are encountered. Table 4.29 lists some of the more important applications in those industries where these conditions most frequently arise, i.e. in the chemical, petrochemical, oil and gas, nuclear and conventional power generating, textile, paper, marine, desalination and food processing industries. The list is by no means exhaustive and there are many other applications of a similar nature in these and other industries. The table should, nevertheless, serve... 

Another current development in the use of F-T chemistry in a three-phase slurry reactor is Exxon s Advanced Gas Conversion or AGC-21 technology (Eidt et al., 1994 Everett et al., 1995). The slurry reactor is the second stage of a three-step process to convert natural gas into a highly paraffinic water-clear hydrocarbon liquid. The AGC-21 technology, as in the Sasol process, is being developed to utilize the large reserves of natural gas that are too remote for economical transportation via pipelines. The converted liquid from the three-step process, which is free of sulfur, nitrogen, nickel, vanadium, asphaltenes, polycyclic aromatics, and salt, can be shipped in conventional oil tankers and utilized by most refineries or petrochemical facilities. 

Methane is the principal gas found with coal and oil deposits and is a major fuel and chemical used is the petrochemical industry. Slightly less than 20% of the worlds energy needs are supplied by natural gas. The United States get about 30% of its energy needs from natural gas. Methane can be synthesized industrially through several processes such as the Sabatier method, Fischer Tropsch process, and steam reforming. The Sabatier process, named for Frenchman Paul Sabatier (1854—1941), the 1912 Nobel Prize winner in chemistry from France, involves the reaction of carbon dioxide and hydrogen with a nickel or ruthenium metal catalyst C02 + 4H2 —> CH4 + 2H20. 

As mentioned earlier, nickel carbonyl is a volatile intermediate in the Mond process for nickel refining. This compound also is used for vapor plating of nickel in the semiconductor industry, and as a catalyst in the chemical and petrochemical industries. The toxicity of the compound has been known for many years Exposure of laboratory animals to the compound has induced a number of ocular anomalies, including aiioplidialiiiiaandinicrophtlialmia, and has been shown to be a carcinogenic for rats. 

Nickel alloys containing chromium and iron of the composition given in Table 4.38 are used widely in chemical, petrochemical and other high-temperature processes. 

Normal Paraffin-Based Olefins, Detergent range -paraffins are currently isolated from refinery streams by molecular sieve processes (see ADSORPTION, LIQUID separation) and converted to olefins by two methods. In the process developed by Universal Oil Products and practiced by Enichem and Mitsubishi Petrochemical, a -paraffin of the desired chain length is dehydrogenated using the Pacol process in a catalytic fixed-bed reactor in the presence of excess hydrogen at low pressure and moderately high temperature. The product after adsorptive separation is a linear, random, primarily internal olefin. Shell formedy produced olefins by chlorination—dehydrochlorination. Typically, C —C14 -paraffins are chlorinated in a fluidized bed at 300°C with low conversion (10—15%) to limit dichloroalkane and trichloroalkane formation. Unreacted paraffin is recycled after distillation and the predominant monochloroalkane is dehydrochlorinated at 300°C over a catalyst such as nickel acetate [373-02-4]. The product is a linear, random, primarily internal olefin. 

Different market conditions rendered attractive the use of the process in the reverse direction to produce polymerization grade propene from ethylene and but-2-ene. In this process, but-2-ene can be obtained directly from the C4 fraction of a naphthta cracker or by dimerization of ethylene. In 1985, the Lyondell Petrochemical Co. started to operate a plant at Channelview (Texas, U.S.A.), for the production of 135000 tons of propene per year. In this process, part of the ethylene formed by cracking units of ethane is dimerized to but-2-ene using a homogeneous nickel catalyst developed by Phillips. This but-2-ene reacts with the rest of ethylene, on the classical Phillips catalyst, to produce propene. 

A common group of catalysts are the platinum-group metals which have become essential factors in many industrial processes such as gas-phase oxidation, selective hydrogenation of petrochemical and pharmaceutical feedstocks, fuel cells for power generation, and many others. Other common catalysts are iron, nickel, and some transition metals. 

In the production of petrochemicals and related products, it is critical for refineries and chemical plants to closely monitor trace element contamination levels at various stages of the manufacturing process. For example, in the refining of crude oil, some elements such as nickel and vanadium, even at ppb levels, can act as catalyst poisons and cause enormous problems owing to the voliunes of hydrocarbons that are pro-cessed. °° In addition, if the final product is intended for use by the food industry or the manufacture of electronic devices, the specifications for trace element contamination are even more stringent. 

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