Gasoline catalyst

Studies at Mobil Research have shown that light olefins instead of gasoline can be made from methanol by modifying both the ZSM-5-type MTG (Methanol-to-Gasoline) catalyst and the operating conditions. Work carried out in micro-scale fluidized-bed reactors show that methanol can be completely converted to a mixture of hydrocarbons containing about 76 wt% C2-C5 olefins. The remaining hydrocarbons are 9% C1-C5 paraffins, of which the major component is isobutane, and 15% C6+, half of which is aromatic. 

Another limitation on the use of catalytic oxidation is the susceptibility of the catalysts to various deactivators or poisons, although according to the vendor the phase out of the use of volatile lead alkyls as antiknock agents in U.S. gasoline, catalyst poisoning is today rarely encountered. 

In a further example of the hydrogenation of CO2 over composite catalysts, for instance, Cu-Zn-chromite and HY zeolite,134 it has been demonstrated that this combination of methanol synthesis and methanol-to-gasoline catalysts enables the direct formation of ethylene and propylene. The influence of the addition of alkaline metals, of the reaction temperature and of the space velocity on the production of alkenes shows that alkanes are obtained by hydrogenation of the corresponding alkenes. 

Individual polycyclic aromatic hydrocarbons (PAH) were measured for 18 light-duty vehicles representing 1978 through 1981 model-year production cars for the European and US market. In detail, the test fleet included the following classes 1) gasoline non-catalyst vehicles, 2) gasoline catalyst vehicles, 3) diesel vehicles, 4) neat methanol vehicles with and without a catalyst, and 5) methanol-gasoline blend vehicles. 

About 1.2-1.4% Acoke forms on residue catalysts compared with about 0.7- 0.8% on gasoline catalysts. The distribution of Acoke for both types of feed is shown in Table 5.12. Most of the increase is associated with contaminant and feed coke. 

For example, in the case of light Arabian crude (Table 8.16), the sulfur content of the heavy gasoline, a potential feedstock for a catalytic reforming unit, is of 0.036 weight per cent while the maximum permissible sulfur content for maintaining catalyst service life is 1 ppm. It is therefore necessary to plan for a desulfurization pretreatment unit. Likewise, the sulfur content of the gas oil cut is 1.39% while the finished diesel motor fuel specification has been set for a maximum limit of 0.2% and 0.05% in 1996 (French specifications). 

The crankcase of a gasoline or diesel engine is in reality a hydrocarbon oxidation reactor oil is submitted to strong agitation in the presence of air at high temperature (120°C) furthermore, metals such as copper and iron, excellent catalysts for oxidation, are present in the surroundings. 

Catalytic cracking is a key refining process along with catalytic reforming and alkylation for the production of gasoline. Operating at low pressure and in the gas phase, it uses the catalyst as a solid heat transfer medium. The reaction temperature is 500-540°C and residence time is on the order of one second. 

Automobile Automobilebumpers Automobile catalysts Automobile emissions Automobile finishes Automobile gasolines Automobiles... 

---