Zeolite development

Alpha A process for making aromatic hydrocarbons and LPG from C3-C7 olefins. The catalyst is a metal-modified ZSM-5 zeolite. Developed by Asahi Chemical Industries and Sanyo Petrochemical and used since 1993 at Sanyo s Mitzushima refinery. 

CERNOX [Ceramic NOx] A process for destroying NOx by reaction with ammonia, catalyzed by a zeolite. Developed by Steuler Industrie Werke in the 1950s for treating vapors from nitric acid baths used for pickling stainless steel. The zeolite was developed for this process by Mobil Corporation and is still proprietary. The process was introduced to the market in 1982, and by 1988 100 units had been installed in Europe alone. 

MBR [Mobil benzene reduction] A catalytic process for reducing the benzene content of gasoline. It combines features of three earlier processes benzene alkylation with tight olefins, olefin equilibration with aromatization, and selective paraffin cracking. The olefins are obtained from FCC offgas. The catalyst is a modified ZSM-5 zeolite. Developed by Mobil Research Development Corporation in 1993. 

MIDW [Mobil isomerization dewaxing] A petroleum refining process which improves yield and quality by isomerizing and selectively cracking paraffins in waxy oils. The catalyst is a noble metal, supported on a zeolite. Developed by Mobil Corporation from 1991 to 1996. 

MS-2 A molecular sieving processes for separating branched-chain aliphatic hydrocarbons from unbranched ones by selective adsorption on a zeolite. Developed by the British Petroleum Company in the 1970s but not commercialized. 

Selectoforming A process for increasing the octane rating of a petroleum fraction by selectively cracking the n-pcntanc and n-hcxanc in it. The catalyst is a metal-loaded synthetic zeolite. Developed by Mobil Corporation and first commercialized in the mid-1960s. 

SPGK [Shell PolyGasoline and Kerosene] A process for oligomerizing C2 - C5 olefins to liquid transport fuels. The reaction takes place at 200 to 280°C and is catalyzed by a zeolite. Developed by the Shell Petroleum Company, Amsterdam, in 1990. 

Alkylation over the MWW Zeolite. The MWW (or MCM-22) zeolite developed by Mobil as catalyst for ethylbenzene and cumene production deserves particular attention. Indeed, this zeolite presents unique structural features (Figure 12.5). Its structure is constituted of three independent pore systems " large supercages (inner diameter of 7.1 A dehned by a 12-member-ring [12-MR], height 18.2 A) each connected to six others through 10-MR apertures... 

N-ISELF A process for separating linear hydrocarbons from light naphtha by selective ad-sorphon on a zeolite. Developed by Societe Nationale Elf-Aquitaine, France. 

More recently phosphorus-containing zeolites developed by Union Carbide (alu-minophosphates, silicoaluminophosphates) were shown to be equally effective in methanol condensation.439-444 ZSM-5 was also shown to exhibit high activity and selectivity in the transformation of Fischer-Tropsch oxygenates to ethylene and propylene in high yields.445 Silicalite impregnated with transition-metal oxides, in turn, is selective in the production of C4 hydrocarbons (15-50% isobutane and 8-15% isobutylene).446... 

Of the processes likely to favor its production, only the one proposed by Mobil currently appears capable of industrialization. This is because, among the different forms of zeolite developed by this company, tbe catalyst HZSM5, modified by magnesium mid phosphorus, is capable of alkylating toluene by ethylene with a high para isomer selectivity. Thus, a 95/5 blend of p- and m>methylethylbenzenes can be obtained, which considerably simplifies separation problems and yields p-meth styrene by dehydrogena ... 

The first step operates in the liquid phase with ammonia and H2O2 as the reactants and titanium-silicalite (TS-1) as the catalyst. TS-1 is a zeolite, developed by Eni, having a structure that belongs to the same MEI family as ZSM-5, but in which A1 is absent (acid sites are detrimental for selectivity) and substituted by tetravalent Ti ions, which can activate H2O2 and give selective reactions of oxidation (Eigure 2.33 see also Chapter 6 on propene oxide for further aspects). 

One of the first industrial adsorption processes was the separation of n/iso-paraffins in molecular sieves 5A zeolite developed by Union Carbide in the sixties for the octane improvement of gasoline pools and solvent production (Symoniak [1]). Since the seventies, the development of Hysomer and TIP (Total Isomerisation Process) by Shell and UOP respectively, and the demand of environment protection with the restriction of lead in fuel, makes this separation coupled with an isomerisation reactor one of the most licensed adsorption... 

Flow system for in situ studies of reactions on zeolites developed by Hunger [50]. 

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