Catalytic hydrodesulphurization

Within the framework of the Kyoto Protocol on atmospheric pollution, the European Union has imposed a maximum sulphur content of 50 ppm for fossil fuels, to be lowered to 10 ppm by 2009 (Fig. 8). The U.S. Environmental Protection Agency (EPA) has imposed limits of 30 ppm for petrol and 15 ppm for diesel fuel. With current catalytic hydrodesulphurization technology it is very difficult to satisfy these limits. One of the most promising alternatives is the use of room-temperature ionic liquids (RTILs). Although these substances were once prohibitively expensive, their prices have already begun to fall and should continue to do so. 

Catalytic Hydrodesulphurization of a Petroeum Residue in a Batch Recycle Trickle Bed Reactor, Chem. Eng. Sci. (1984) 1051-1061. 

Residues (petroleum), heavy coker and light vacuum Residues (petroleum), catalytic reformer fractionator Residues (petroleum), hydrodesulphurized atmospheric tower Residues (petroleum), topping plant, low sulphur Residues (petroleum), heavy coker gas oil and vacuum gas oil Residues (petroleum), thermal cracked... 

Clarified oils (petroleum), hydrodesulphurized catalytic cracked... 

Distillates (petroleum), hydrodesulphurized intermediate catalytic cracked Distillates (petroleum), hydrodesulphurized heavy catalytic cracked... 

Correlations between catalytic activity and a variety of bulk properties of semiconductors have been reported (i) the average band gap of III-V and II-VI semiconductors and activity towards hydrogenation of isopropanol (ii) enthalpy of oxides and their activity towards oxidation of propylene and (iii) number of d-electrons (and crystal field stabilization energy) or 3rf-metal oxides and their activity towards N2O decomposition. The last correlation, due to Dowden (1972), is important since it provides a connection between heterogeneous catalysis and coordination chemistry of transition-metal compounds. A correlation between the catalytic activity of transition-metal sulphides towards hydrodesulphurization of aromatic compounds and the position of the transition metal in the periodic table has been made by Whittingham ... 

Figure 8.19 Catalytic activity of transition-metal sulphides for hydrodesulphurization of dibenzothiophene. (After Whittingham Chianelli,...

The objective of the present work is to classify the catalytic performances of unsupported transition metal sulphides (TMS) for these different reactions dehydrogenation of a sulphur containing molecule without sulphur elimination, hydrodesulphurization and hydrogenation. 

Hydrodesulphurization Catalysts Based on Mo or W. - In this Section structural studies of Mo- and W-containing catalysts (unsupported and supported, without and with promoters) and relations between catalyst composition and structure and catalytic properties are reported. Work on sulphides of other metals and on the kinetics and mechanism of hds is reported in the following two Sections. 

Hydrogen is an important feedstock for many essential chemical and petroleum industries such as ammonia, methanol, hydrocracking, hydrogenation of edible oil, hydrodesulphurization, reduction of iron ores and fuel cells. The catalytic steam reforming of natural gas is the most economical process for the production of hydrogen and syngas. Steam reforming of natural gas (mainly methane) is a complex... 

This review paper is concentrated on problems in scaling-up multiphase catalytic fixed bed reactors such as trickle-bed or packed bubble column reactors, in which two fluid phases (gas and liquid) pass concurrently through a bed of solid (usually porous) catalyst particles. These types of reactors are widely used in chemical and petrochemical industry as well as in biotechnology and waste water treatment. Typical processes are the hydrodesulphurization of petroleum fractions, the butinediol syntheses in the Reppe process for synthetic rubber, the anthrachinon/hydrochinon process for H202 production, biochemical processes with fixed enzymes or the oxidative treatment of waste water under pressure. 

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