Hydro-treating

Nowadays, based on the amount of processed material, hydrotreating is the largest process in heterogeneous catalysis. On the basis of catalysts sold per year, hydro-treating ranks third after automotive exhaust and fluid catalytic cracking [R. Prins, V.H.J. de Beer and G.A. Somorjai, Catal. Rev.-Sci. Eng. 31 (1989) 1]. 

Hydrogen production has commercial roots that go back more than a hundred years. Hydrogen is produced to synthesize ammonia (NH3), for fertilizer production, by combining hydrogen with nitrogen. Another major use is hydro-formulation, or high-pressure hydro-treating, of petro-... 

Alternatively, vegetable oil can be upgraded to a fuel with similar properties as BTL by hydro-treating. For optimum use of vegetable oil, dedicated diesel engines are required. 

Alternatively, refined vegetable oil could be converted to a fuel similar to BTL by hydro-treating, e.g., in a refinery. Rapeseed cake, which is produced as a by-product, is assumed to replace animal fodder, i.e., from imported soybeans. Alternatively, the rapeseed cake can also be converted to biogas. 

As FAME or hydro-treated vegetable oil are typically blended with conventional diesel fuel from crude oil, they do not require a separate fuel distribution infrastructure to the filling station. 

Catalytic processes (finid catalytic cracking, catalytic hydrocracking, hydro-treating, isomerization, ether manufacture) also create some residuals in the form of spent catalysts and catalyst fines or particulates. The latter are sometimes separated from exiting gases by electrostatic precipitators or filters. These are collected and disposed of in landfills or may be recovered by off-site facilities. The potential for waste generation and hence leakage of emissions is discussed below for individual processes. 

One of the commercial benefits of this route is the value of the coproducts, tertiary butyl alcohol (TBA) when isobucane is used, and styrene when ethylbenzene is used. TBA also can be easily hydro-treated back to isobutane if a recycle stream for PO manufacture is more advantageous. 

A new illustration of this approach is given in this paper with the hydroprocessing of chloronitrobenzenes over the sulfided industrial hydro-treating catalysts, CoO-MoOj/y-Al 203 HR 306 and NiO-MoOj/y-AlHR 348 from Procatalyse. These catalysts have been shown to differ in their hydrogeno-lysis rather than in their hydrogenation properties (ref.2). 

Catalytic hydrodemetallation studies with vanadyl naphthenates have been reported by West (1984). The instability of these compounds makes them relatively poor models for mechanistic studies. At typical hydro-treating conditions, a homogeneous noncatalytic demetallation route and a heterogeneous catalytic route contribute to overall metal removal. 

As the trend toward utilizing heavier petroleum feedstocks continues, the hydro-treating processes used to upgrade such stocks become increasingly important. Difficulties are encountered in the development of catalysts with high resistance to deactivation. Another important challenge is that of designing three-phase reac-... 

Co-Mo-alumina catalysts (16). The selection of four hydrotreated samples for analysis, termed reactor-samples 1 through 4 reflects the following considerations. The variations in hydro-treating conditions presented in Table I should not drastically... 

In a previous paper ( 8), we presented results of hydro-treating SRC-II process product at several severities, and preliminary cost estimates were given. In the present chapter, previous results are summarized and results of further downstream processing pilot plant studies are presented, together with process engineering studies and updated cost estimates. More details of this study are given in a DOE report. (9)... 

The SRC-II process is one of several coal liquefaction processes currently under development in programs funded by the Department of Energy (DOE). Product from this process is a distillate that is relatively attractive as a feed for conversion to transportation fuels. Essentially all of the nitrogen, sulfur, and oxygen can be removed in a single catalytic hydro-treating stage to yield a naphtha that is an excellent feed for a catalytic reformer and a middle distillate fraction that is a... 

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