Mean hydrocracking

MITI is currently undergoing research to develop technology for the recycling of non-flammable plastics such as those used in business machines and computers. Their National Institute for Resources and Environment plans to decompose, without the production of harmful substances, non-flammable polymers by means of liquid phase hydrocracking, and to recover from them light oils such as benzene, toluene and xylene. The key to the technology, it is claimed, lies in the development of a catalyst which will be able to combine hazardous substances such as bromine and chlorine contained in the waste plastics. 

EFFECT OF VARIOUS MEANS OF INCORPORATING SULFPR ON HYDROCRACKING... 

As a means of preparing high percentages of diesel fuels with good quality from the hydrocracked oil, a batch distillation of the oil was made in a packed laboratory distillation column in which a first fraction was removed at a corrected column head... 

The activation energy for adsorption of hydrocarbons on nickel is about 40 kJ/mole (76) and the activation energy for hydrocracking is in the range 160-200 kJ/mole (77). This means that below the temperature, Tp, at which Ta > rn, i.e. rp > 0, gum formation takes place. To ensure trouble free operation the prereformer must operate within the temperature window of T < T < Tc. 

The LC-Fining process is a hydrocracking process capable of desulfurizing, demetallizing, and upgrading a wide spectrum of heavy feedstocks by means of an expanded bed reactor. Operating with the expanded bed allows the processing of heavy feedstocks, such as atmospheric residua, vacuum residua, and oil sand bitumen. 

At high temperatures Sasol tests have shown that the slurry bed has a lower conversion than the fixed fluidized-bed (FFB). At these high temperatures the wax is hydrocracked, ie, there is a negative wax production. To avoid this, the reactor temperature has to be lowered which, of course, means a further drop in conversion. It is not possible to load as much catalyst per unit reactor volume in a slurry phase reactor as in a normal FFB reactor. This gives the latter system an intrinsic advantage. (Increasing the catalyst content of a slurry increases its viscosity, hence the bubble size increases, resulting in a shorter gas residence time.)... 

With present technology it is entirely possible to process the bulk of the crude oil into petrochemicals, and several approaches to this problem have been considered. In this study we consider the approach in which ethylene is produced by conventional steam cracking and the heavy residual petroleum fractions are converted into steam cracker charge by means of residue hydrocracking through the H-Oil process. 

Examples of thermal processes in which incompatibility might occur are the visbreaking process and the hydrocracking process. The visbreaking process is a means of reducing the viscosity of heavy feedstocks by controlled thermal decomposition. However, the process is often plagued by sediment ( sludge ) formation that must be removed if the products are to meet fuel oil specifications. 

Figure 1 shows the effect of nR/nA (or of nR since nA is here constant) on the initial activity of the RHZSM5 samples in acetone transformation. Like in hydrocracking the initial activity Ao first increases with nR/nA and for a certain value of nR/nA remains constant. This means that then the limiting step of acetone transformation does not occur on the piatinum sites and is therefore cataiyzed by the acid sites. 

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