Moderate severity hydrotreating

Case 5A uses moderate severity hydrotreating without further downstream cracking conversion to produce motor gasoline and No. 2 heating oil as shown in the alternate arrangement of Figure 8. This case was included to give some idea of the... 

REFINING SRC-II OIL BY MODERATE SEVERITY HYDROTREATING TO PRODUCE 50,000 BARRELS PER CALENDAR DAY OF MOTOR GASOLINE PLUS NUMBER TWO HEATING OIL DOE CONTRACT EF-76-C-01-2315 ... 

Selective ring conversion of a raffinate can also be a very effective route to improved basestock properties. This is dramatically illustrated by comparing the profiles of a Group I basestock made from conventional separations-based processing with a Group II basestock derived from a similar raffinate, but converted by a moderate severity hydrotreating type process, RHCTM. 

HYDROTREATING OF SCR-II WITH AGED ICR 113 CATALYST AT MODERATE SEVERITY 750°F—1750 PSIA H2... 

If the SRC-II is hydrotreated at an intermediate or moderate severity, further processing will be necessary to upgrade the product to specification transportation fuels. A number of pilot plant tests have been made to determine the conditions and to demonstrate the feasibility of these processing steps. 

At moderate severity, the hydrotreating catalysts foul, as shown in Figure 3 by the rise in nitrogen content of the products versus time. In commercial operation, the catalyst temperature would be raised and the product nitrogen content would be held constant. Commercial run lengths appear feasible, even at moderate severity. 

A severe hydrotreating plant will have a flow scheme similar to the hydrofinishing unit shown in Fig. 1.11. Hydrocracking is a highly exothermic reaction, so cold hydrogen must be injected at several points in the catalyst bed to moderate the temperature rise. Operating conditions are severe, with pressures of 100-180 bar and reaction temperatures of 350 20°C. 

The most facile reactions in a hydrotreating or hydrocracking enviromnent involve the removal of sulfur and nitrogen. These species are present in both aliphatic and ring stmctures, and at moderate severity conditions essentially complete ejection can be achieved of even the most refractory of these heteroatoms, such as those embedded in stmcturally... 

Naphtha Hydrotreating - At both the moderate and intermediate severities, it is necessary to further hydrotreat the naphtha before it can be fed to a bimetallic reforming catalyst. Table VII summarizes results of further hydrotreating of... 

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