Chevron process

Cherts CHESS Chevrefeuille Chevrel phase Chevron-Gulf process Chevron process... 

The Chevron process was used in two U.S. plants, although it is no longer used. Cycle lengths tanged from 6—30 d, depending on catalyst age and OX content of the feed. Operating conditions were temperature of 370—470°C and space velocity of about 0.5/h. Addition of 5 wt % steam reduced disproportionation losses. 

Knowlton, H.E. Coombs, J. AUen, E. Chevron process reduces ECC/coker corrosion and saves energy. Oil Gas J. 1980, April 14. 

Chevron process -for xylenes [XYLENES AND ETHYLBENZENE] (Supplement) -for xylenes [XYLENES AND ETHYLBENZENE] (Supplement)... 

In the group of suspension processes, there are the jacket cooled and the directly (e.g., by inert gases) cooled processes. The Amoco process, on the one hand, and the Maruzen or Chevron process, on the other hand, are, according to Ransley (1984), representatives for such processes. Other developments are scrapes crystallizers according to the Humble-Oil, the Krupp-Harpen (see Ritzer 1973), or the Hoechst AG (DE-PS 1969) process which are used for the production of p-nitrochlorobenzene. These scraped surface crystallizers are in fact solid layer processes, but in the handling of the products—crystals in suspension—they have to be treated like suspension processes. A number of processes that feature a combination of a scraped crystallizer and suspension techniques will be discussed. 

Prior to introduction of the SHOP process a-olefins were produced by pyrolysis of waxes above 500 °C (e.g.. Chevron process) or by olefin oligomerization with triethylalmninium (Gulf process). However, both produce olefins that are less suited to market requirements [17]. 

The Chevron process has proved particularly effective in producing p-xylene by crystallization. Crystallization is carried out by direct cooling with CO2. Distilla-... 

Pressure crystallizer 2 Vacuum crystallizer 3 Mixing vessel 4 Melting vessel Figure 4.17 Flow diagram for p-xylene production by crystallization using the Chevron process... 

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