Hydrocracker Mild

Mild hydrocracking prepares the feedstock for catalytic cracking or for the conventional lubricant production scheme. 

Table 10.18 presents some useful data on the mild hydrocracking process and resulting products. 

Typical Feedstocks composition, performance and product properties from mild hydrocracking. I... 

British Coal Corp. is developing a gasoline-from-coal process at a faciUty at Point of Ayr (Scotiand). This process involves treatment with Hquid recycle solvents, digestion at 450—500°C, filtration to separate unconverted residues, and separation into two fractions. The lighter fraction is mildly hydrotreated, and the heavier one is hydrocracked (56). 

More severe hydrotreating, such as mild hydrocracking at an H2 partial pressure of >6.9 MPa (1000 psig) and temperature of >400° C, can stiU further reduce sulfur content in the FCC feed. Mild hydrocracking of a 25° API VGO reduced the sulfur content of the FCC feed 98%, from 1.7 wt % to 0.03 wt % (40). This reduction can be expected to lower the SO content in the FCCU regenerator flue gas by about 90%. 

Basic to establishing whether power recovery is even feasible, let alone economical, are considerations of the flowing-fluid capacity available, the differential pressure available for the power recovery, and corrosive or erosive properties of the fluid stream. A further important consideration in feasibihty and economics is the probable physical location, with respect to each other, of fluid source, power-production point, and final fluid destination. In general, the tendency has been to locate the power-recoveiy driver and its driven unit where dictated by the driven-unit requirement and pipe the power-recoveiy fluid to and away from the driver. While early installations were in noncorrosive, nonerosive services such as rich-hydrocarbon absorption oil, the trend has been to put units into mildly severe seiwices such as amine plants, hot-carbonate units, and hydrocracker letdown. 

This work is a contribution to the understanding of the effect of spillover hydrogen in a type of catalyst of considerable industrial importance, namely that composed of transition metal sulfides and amorphous acidic solids. This is typically the case of sulfided CoMo supported on silica-alumina used for mild hydrocracking. 

Dieselmax A petroleum cracking process which combines mild hydrocracking with thermal cracking to maximize the production of middle distillate without using more hydrogen than hydrocraking alone. Developed by UOP. 

MHC Unibon [Mild hydrocracking] A mild hydrocracking process for desulfurizing gas oil and converting it to lower molecular weight hydrocarbons, suitable for further processing by catalytic cracking. Developed by UOP. 

Figure 6-14 Integration of the mild residuum hydrocracking (MRH) process into a refinery.

Figure 6-15 Variation in product yield in the mild resid hydrocracking (MRH) process.

An example of how feedstock composition can influence the variation in product distribution and quality comes from application of the ABC (asphaltene bottoms cracking) hydrocracking process to different feedstocks (Tables 6-18, 6-19, 6-20, and 6-21) (Takeuchi et al., 1986 Komatsu et al., 1986). A further example of variations in product distributions from different feedstocks comes from the Mild Resid Hydrocracking (MRH) process (Table 6-22 Figures 6-14 and 6-15) (Sadhukhan et al., 1986). In addition, different processes will produce variations in the product slate from any one particular feedstock (Figure 6-14) and the feedstock recycle option adds another dimension to variations in product slate (Tables 6-23 and 6-24) (Munoz et al., 1986). 

The Axen s mild hydrocracking process combines an ebullated-bed, mild hydrocrack-... 

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