Hydrotreating moderate

OptiCAT-plus A process for regenerating hydrotreating catalysts. It uses a fluidized-bed pretreatment to control the initial exotherms found in regeneration, followed by a moderate heat soak to eliminate sulfur and carbon. Developed in the 1990s by the Criterion Catalyst Company. 

The installed capacities for hydrotreating distillates are predominantly moderate-pressure reactors (up to 3 MPa). Typical conditions used in today s commercial processes are summarized in Table IV (7). In the U.S., the Clean Air Act mandated that low-emission fuels will have to be developed for future use. Industry responded quickly, and by 1994 typical diesel fuels in the U.S. contained 0.05% S, with average cetane numbers of 42 and 31-37% aromatics. California imposed stricter standards, requiring 0.05% S and a minimum of 48 cetane with an emission that did not exceed that of a 10% aromatic fuel. This is the present standard for California Air Resources Board (CARB) certification. Through the development of improved processing and additives that lower emissions, Chevron was the... 

Insufficient activity of present catalysts to overcome the low-reactivity PASCs using existing moderate-pressure (<5 MPa) hydrotreating reactors... 

The natural material catalysts exhibit similar metal removal selectivity patterns as conventional hydrotreating catalysts. Vanadium removal activity is higher than that of nickel and overall activity increases with hydrogen pressure. Thus little change in intrinsic demetallation pathways is indicated with these materials. However, in contrast to CoMo/A1203, the nodule catalysts are only moderately active for HDS and essentially inactive for HDN. 

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. 

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... 

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 ... 

COMPARISON OP MODERATELY HYDROTREATED PRODUCTS PROM ILLINOIS H-COAL, WYODAK H-COAL,... 

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. 

Once the synthetic crude oils from coal and oil shale have been upgraded and the heavy ends converted to lighter distillates, further refining by existing processes need not be covered in detail except to note the essential character of the products. The paraffinic syncrude from oil shale yields middle distillates which are excellent jet and diesel fuel stocks. The principal requirements are removal of nitrogen to the extent necessary for good thermal stability of the fuels and adjustment of cut points to meet required pour or freeze points, limited by the presence of waxy straight-chain paraffins. The heavy naphtha from shale oil can be further hydrotreated and catalytically reformed to acceptable octane number, but with considerable loss of volume because of the only moderate content of cyclic hydrocarbons, typically 45-50%. On the other... 

The FCC process is the most common conversion unit in use today. As such, it is important to determine the performance of an FCC when feeding hydrotreated shale oil. The two 650° F+ feeds shown in Table VI were evaluated in an FCC pilot plant operating in a fixed fluidized-bed mode. The catalyst was withdrawn from an operating commercial FCC unit. It is a zeolite catalyst, CBZ-1, produced by Davison Chemical Division of W. R. Grace and Company and is moderately active as well as contaminated with metals. 

Under such conditions, the focus of retrofitting and revamping existing units will be optimizing middle-distillate production. Consequently, to meet higher quality requirements for middle distillates, E.U. refiners are projected to invest in hydrocracking capacity. Such investments may include standalone units and moderate conversion of units upstream of the FCC.15 Refiners will also raise hydrotreating capability. 

In this study subbituminous coals were liquefied and desulfurized effectively by hydrotreating with synthesis gas at moderate operating conditions In the presence of steam and anthracene oil used as a solvent. The data were compared when the same coals were liquefied with pure hydrogen under similar experimental conditions. Pyrltlc and organic sulfur present In these coals appear to be responsible for the formation of catalytic active form of Iron sulfide that functions as an effective hydrotreating catalyst (14). The presence of... 

Generally, configuration I is desired for such applications as hydrogen plants in petroleum refineries and for hydrocracking and hydrotreating. Configuration II would be the choice for applications where moderate conversions are necessary to keep some hydrocarbons in the product stream for further processing such as ammonia production plants. 

The process can be operated at moderate pressures, 50 - 70 bar at reactor outlet. Temperatures have to be low (below 320 °C) to achieve deep hydrogenation. Space velocities are low (below 0,5 hr ) if low product aromatic contents of e.g. 5 vol% are required. The first step of the process is not different from a typical diesel hydrotreating unit. Five different catalyst types in staged loading can be used to obtain the required desulfurization and hydrogenation level. Catalysts are only available under license. At the spring NPRA meeting of 1995 it was announced that 13 companies have taken a license. This impressive success is for an important... 

Model 1-6 is a new hydrodearomatization (HDA) catalyst developed by ICERP to be used in aromatics hydrogenation of gas oil blends. The catalyst has been obtained by a highly improved NiO dispersion on the promoted alumina support having a bimodale pore distribution with a total pore volume of minimum 45 cmVg. 1-6 has a good HDA activity under rather moderate hydrotreating conditions i.e. 60 bar total pressure and a remarkable sulphur resistance. 

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. 

Distillation/Hydrotreatment This technology is the most recent development, as in the KTI and Mohawk processes. After pre-treatment and thin-film distillation, the base oil fraction is hydrotreated under moderate conditions. A final distillation step gives a range of base oil streams of different viscosities with process yields of up to 90-95%. 

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