DE3323572C2 - Process for the further processing of hydrogenation residue from the hydrogenation of heavy oils - Google Patents

Abstract

In a process for the further processing of hydrogenation residue obtained in the hydrogenation of heavy oils, the hydrogenation residue and the catalyst contained in it are added to the bottom phase of a coal hydrogenation plant and hydrogenated together with coal. The hydrogenation residue can be introduced directly into the sump phase of the coal hydrogenation plant or it can be used as a grind oil for the coal.

Description

The invention relates to a method for the further processing of heavy oils during the hydrogenation resulting hydrogenation residue.

Due to the development of the general raw material situation, those in the petroleum processing are increasing or subjected to a further hydrogenation treatment of the heavy oils occurring directly during the production process, to increase the proportion of light and middle distillates. In addition, the hydrogenation of Coal growing interest.

In the hydrogenation of heavy oils, the progression of the hydrogenation reactions becomes the one present in each case Heavy oil residue is always a reaction carrier. In order to obtain as many recoverable distillates as possible, therefore the hydrogenation conditions, d. H. Temperature, pressure, addition of catalyst and residence time, matched to the reactivity given towards the end of the hydrogenation be. In particular, the residence time must be extended disproportionately.

If the hydrogenation process is carried out optimally, optimally in terms of high distillate gain The shortest possible residence time, low temperatures and pressures, must be based on a substantial proportion of the njr distillates which can be obtained under severe hydrogenation conditions and which are present in the hydrogenation residue in is usually gassed, remain and thus get lost.

Optimal process management also requires a certain excess of hydrogenation catalyst, so that at the end of the reaction path there is still a sufficient hydrogenation effect to prevent dehydrogenation of the products produced, for example coke formation, to be avoided. The excess catalyst remains in the hydrogenation residue and is also lost.

The object of the present invention is to provide a process for the further processing of hydrogenation indicate hydrogenation residue obtained from heavy oils, which avoids these disadvantages.

According to the invention, this object is achieved in that the hydrogenation residue is transferred to the bottom phase of a carbohydrate hydrogenation given and hydrogenated together with coal.

The catalyst contained in the hydrogenation residue is not separated off, but together with the Hydrogenation residue fed to the sump phase of the carbohydrate hydrogenation.

The residue from the heavy oil hydrogenation can admittedly directly into the hydrogenation reactor for carbohydrate hydrogenation be initiated. Advantageously, however, it is at least partially used as a grind oil, in addition to from the Carbohydrate grind oil obtained in-house, for which charcoal is also used

In the process according to the invention, it is no longer important to obtain as far as possible all of the recoverable distillates as early as the hydrogenation stage for the heavy oil. The heavy oil hydrogenation can therefore take place under optimal conditions in terms of pressure, temperature and residence time. The distillates remaining as potential in the hydrogenation residue are now split off in the sump phase of the coal hydrogenation.
Appropriately, in the hydrogenation of

heavy oils, the hydrogenation conditions are set so that the reactivity of the hydrogenation residue obtained corresponds to the reactivity of the coal used
This procedure of adapting the reactivity of the residue of a first hydrogenation stage, in which a raw material which is easier to hydrogenate is used, to the reactivity of a raw material that is more difficult to hydrogenate and to hydrogenate it together with this in a second hydrogenation stage under correspondingly more stringent conditions, can generally also be used with others Combinations of raw materials are used. For example, heavy oil or lignite tar can be used in the first hydrogenation stage and a heavy oil or tar pitch which is more difficult to hydrogenate can be used in the second hydrogenation stage.

The further hydrogenation of the residue obtained in the oil stage in the sump phase of the carbohydrate hydrogenation proves to be particularly advantageous because the catalyst contained in the residue is also used for the hydrogenation of carbons has sufficient activity. This allows the addition of catalyst directly to the Reduce the swamp phase of the carbohydrate hydrogenation. on the other hand the heavy oil hydrogenation can be carried out without loss if there is an excess of catalyst. The return

The oil level also contains a lot of hydrogen. In addition to its use as a grind oil for the coal, it therefore also acts as a hydrogen donor.
If you wanted to feed the hydrogenation residue to a gasification unit when a heavy oil hydrogenation plant was operated on its own, hardly any slag would be produced since the heavy oil contained little or no inert components. The heavy metals contained in petroleum residues are therefore produced as dust from the gases produced or when the gases are cleaned in the washing water, so that additional expensive process steps are required to remove the heavy metals.

When gasifying the residue from the carbohydrate hydrogenation, on the other hand, a glass-like ash falls into which the heavy metals contained in the coal are firmly enclosed. This ash is insoluble and therefore safe suitable for deposit.

The further hydrogenation according to the invention of the residue from the oil hydrogenation together with coal in the coal sump phase and subsequent gasification of the residue from the coal hydrogenation are now even the heavy metals originally contained in heavy fuel oil in the ashes are environmentally neutral involved.

Claims (3)

Patent claims: 1. Process for the further processing of the catalytic hydrogenation of heavy oils Hydrogenation residue, characterized in that that the hydrogenation residue together with the catalyst contained in the hydrogenation residue added to the sump phase of a coal hydrogenation plant and hydrogenated together with coal. 2. The method according to claim 1, characterized in that the hydrogenation residue is at least partially is used as a grinding oil for the coal. 3. The method according to any one of claims 1 or 2, characterized in that the reactivity of the hydrogenation residue is adapted to the reactivity of the coal used.