CS216083B1 - The process for the catalytic catalytic treatment of heavy hydrocarbon distillates - Google Patents

Abstract

The invention relates to a method for the hydrogenation catalytic processing of heavy hydrocarbon distillates into the basic components of lubricating oils and light hydrocarbon distillates. According to the invention, the hydrogenation catalytic reaction is carried out in a reactor in which the ratio of the height of the reaction space to the diameter of the reaction space is 40 to 1, and the ratio of the diameter of the reaction space to the diameter of the catalyst grains is at most 200. According to a preferred embodiment of the method according to the invention, a catalyst is used which consists of a catalytically inactive core and a catalytically active casing. Instead of the inactive core, the active casing can also be surrounded by a hollow space.

Description

The present invention relates to a method for catalytic processing of heavy hydrocarbon distillates into basic components of lubricating oils and distillates containing hydrocarbons.

By using this considered method, corresponding with respect to the state of the art and the conditions of the known method and the successful arrangement of the catalyst, in the reaction system, the basic components of lubricating oils with sufficient viscosity and a high viscosity index are produced in a high yield with simultaneous minimal gas formation and the necessary formation of qualitatively valuable fuels.

The essence of the method according to the invention is that the hydrocatalytic reaction is carried out in a reaction space in which the ratio of the height of the reaction space to the diameter of the reaction space is 40:1, while the quotient of the reaction space to the grain diameter is a maximum of 200,

For the production of highly valuable basic components of lubricating oils and distillates, the high-boiling fraction of crude oil is preferably subjected to hydrocatalytic processing under elevated pressure in a single-stage, preferably multi-stage process. /H. Klotzsche, P. Schnidt, D. Sachse» A technologie! változások fejlodése szénhidrogének hidro-krakkolásakor, Magyar Kémikusok Lapja XXXI, 257 až 260 /1976//.

'According to the current state of the art, catalysts are used for hydrogenation catalytic processing which consist of oxides and/or sulfides of the 6th and 8th subgroups of the periodic system of elements, supported on carriers, on alumina (natural) or alumina (natural) with proportions of silica, or possibly also supported on carriers doped with halogens, or multicomponent catalysts are used which consist of a hydrogen-elimination component, decationized, crystalline aluminosilicate and a heavy metal component or a component from hydrotreating consisting of oxides and/or sulfides of the 6th and 8th subgroups of the periodic system of elements, supported on alumina (natural) or on amorphous aluminosilicate and are produced for technical use by tabletting or pressing the starting material /K, Becker, H, D, Berrouschst et al.J Chemische Technik 29, 61 to 67 /1977//.

The hydrogenation-catalytic processing of, for example, petroleum distillates obtained by vacuum distillation for the production of highly valuable basic components of lubricating oils serves, on the one hand, in addition to the maximum removal of organic nitrogen and sulfur compounds as a result of the hydrogenation reaction, to reduce the content of aromatic hydrocarbon structures in the boiling temperature range of lubricating oil fractions, but on the other hand, it is also intended to act destructively on hydrocarbons in the boiling temperature range of the feedstock material in order to increase the viscosity-temperature behavior value (viscosity index).

Depending on the origin of the raw material, as well as the desired quality of the targeted product, single-stage or multi-stage technical processes are used.

In a single-stage process, the flexibility of the process is limited by the adherence to defined process parameters, corresponding to the operating characteristics of the catalysts used. The reaction courses to be activated by the catalyst cannot be optimally aligned in a single-stage system and the selectivity of the hydrogenation catalytic treatment is low due to secondary reactions.

This deficiency can be eliminated by multi-stage process control and the use of a combination of catalysts, specially optimized in accordance with the required product quality, while realizing higher flexibility and selectivity of the process with respect to the raw materials used and the final products produced. This technological solution has the disadvantage of increased investment costs and energy costs compared to the single-stage method of operation.

In all variants of the method and process for the hydrocatalytic treatment of heavy hydrocarbon distillates known from the prior art, a high catalyst surface area to catalyst volume ratio is required. Currently, strip-shaped catalysts with a catalyst diameter of up to 1.5 mm and smaller are used. In order to be able to smoothly technically control a large-scale process when using catalysts of these dimensions, reactors with a relatively large internal diameter are used, with the ratio of the reactor height to the reactor diameter being 10:1 to 20:5 1. This type of catalyst arrangement presents the main drawback of all hydrocatalytic methods for the treatment of high-boiling hydrocarbons. The removal of the reaction heat of the catalyst grains released from the exothermic reaction is technically possible only to a limited extent, so that thermal secondary cracking occurs, which is not influenced by the effect of the catalyst, and thus the yield of the desired lubricating oil fractions is reduced and the occurrence of gaseous hydrocarbons increases. This deficiency can be reduced by using catalysts with lower activity, reducing the conversion per pass, but at the same time the throughput of a given capacity device is significantly reduced.

The aim of the invention is to create a method for the hydrocatalytic treatment of heavy hydrocarbon distillates, by means of which high-quality lubricating oil fractions are obtained due to a significant increase in selectivity with respect to temperature-viscosity behavior (viscosity index) with sufficient hydrotreating in combination with an improved technological arrangement of the catalyst.

The object of the invention is to develop a process for processing heavy hydrocarbon distillates which is characterized by the use of a special reaction space corresponding to that necessary for the conversion of the catalyst and which allows the full use of the reactivity of the catalyst.

It was surprisingly found that the principle of dimensioning the reaction space of a completely new type, in conjunction with known catalyst systems, but primarily as a result of the use of a completely new type of catalyst system, leads to significantly better selectivity and activity in the hydrocatalytic processing of heavy hydrocarbon deethylates, while, with the full exhaustion of the performance characteristics of the catalyst, its geometric shape would be arranged in such a way that the engineering and technological limit parameters such as differential pressure and flow conditions would be maximally limited.

The hydrogenation catalytic reaction is carried out according to the invention in a reaction space in which the ratio of the height of the reaction space to the diameter of the reaction space is 40:1, preferably 60:1 to 80:1, whereby the ratio of the diameter of the reaction space to the diameter of the catalyst grains should reach a maximum value of 200, in order to keep the flow resistance of the reaction system within technically controllable values. In order to increase the degree of utilization of the catalyst with regard to the economical use of the catalytically active portion, a particularly advantageous variant of the method of using a catalyst is one which consists of a catalytically inactive core and a catalytically active coating, the wall thickness of which should preferably not exceed 3 mm and is produced, for example, by a known method of drawing or extrusion over a rigidly arranged mandrel.

The following examples are intended to further explain the principle of the invention without limiting it to these examples.

Two reaction systems A and B consisting of metering devices, heating of the feedstock and reaction hydrogen, a reactor with a catalyst, a separator system and condensation, of which reaction system A serves as a comparative reaction system with a ratio of the height of the reaction space to the diameter of the reaction space of 30:1 and reaction system B serves as a reaction system according to the invention, the ratio of its height of the reaction space to the diameter of the reaction space is 80:1. The results of examples 1 and 2 /reaction systems A and B/ - both were carried out using a catalyst corresponding to the state of the art - are summarized in the table. The table also shows the results of example 3 /reaction system C/, in which the catalyst according to the invention was used /catalytically active shell around a catalytically inactive core/ and the results of example 4 /reaction system D/. In contrast to Examples 1 to 3, in which the ratio of the reaction space diameter to the catalyst grain diameter was a maximum of 200, i.e. within the scope of the invention, Example 4 used a known catalyst for which the ratio of the reaction space diameter to the catalyst grain diameter was greater than 200, i.e. a maximum of 300.

In all examples, a distillate originating from the vacuum distillation of crude oil, containing sulfur, with the following physical and chemical characteristics was processed:

0.902

623 •5 specific gravity for 323 K /g/cnr/ boiling point K boiling point K sulfur % wt.

basic nitrogen compounds /mg/l/ aromatic carbon % wt.

806

1.63

277

17.0 was operated under the following hydrogenation catalytic process conditions:

Hydrogen partial pressure 10.0 MPa reaction temperature 673 K feed rate 1.0 v/v.h

-3 gas-product ratio 1000 m . m catalyst X-ray amorphous aluminosilicate with NiO and

WOj as hydrogenation active components

Catalyst composition /except for the inactive core of the catalyst used in example 3/ support X-ray amorphous aluminosilicate

Ni 2.0 wt.%

WO, Sat.

23.6% by weight

0.3% by weight

1.2 mmol/100 g

The following results were obtained»

Ύ.1 i ........... , . . i . . reactor system A /known/ B /p< C >according to the invention/ D catalyst known known according to the invention known ratio of reactor diameter to grain diameter catalyst / maximum 200 200 200 300 characteristic values of the reaction product specific gravity at 323 K /g/cn?/ 0.860 0.848 0.850 0.835 sulfur content % 0.20 0.04 0.04 0.02 basic nitrogen content mg/l 86 5 4 2 characteristic values of the reaction product fraction boiling above 693 K specific gravity at 323 K /g/cm2/ 0.858 0.849 0.853 0.838 sulfur content, % 0.15 0.02 0.03 0.02 basic nitrogen /mg/l/ 131 14 15 11 aromatic hydrocarbons, % 13.6 9.1 9.5 8.3 yield of this fraction after dewaxing, % 32 23 25 11 viscosity index 63 103 105 107

A comparison of Examples 1 and 2 shows that the reactor arrangement according to the invention significantly improves the hydrocracking and refining rates, while the aromatic content of the product is lower. A fraction with the desired viscosity index can be obtained from the product.

A comparison of Example 3 with Example 2 shows that the catalyst according to the invention substantially ensures hydrocracking, refining and aromatic removal, increases the yield of the desired product and improves the viscosity index. At the same time, the need for expensive, catalytically active metals is significantly reduced.

A comparison of examples 4 and 2 shows that by increasing the ratio of the reactor diameter to the catalyst grain diameter, the product quality improves somewhat, but the yield of the desired product decreases significantly, and secondary cleavage processes come to the fore.

Claims (2)

1. A process for the hydrotreating of hydrocarbon distillates into lubricating oil constituents and light hydrocarbon distillates, characterized in that the hydrotreating reaction is carried out in a reaction space in which the ratio of the reaction space height to the reaction space diameter is »40 s 1, the ratio of the reaction space diameter to the catalyst grain diameter is at most 200. 2. A process according to claim 1, wherein the catalyst consists of a catalytically inactive core and a catalytically active shell, respectively. from the empty part of the space and the catalytically active cover.