DE2613877C2 - - Google Patents

Description

It is known per se to use a two-stage lubricating oil Hydrogenation treatment of deasphalted waxy heavy To produce mineral oil fractions and subsequent dewaxing.

Such a process is described in FR-PS 20 01 873 described that at temperatures of 350 to 450 ° C, Pressing at least 50 kg / cm² and room flow velocities of at least 0.1 kg of oil per liter of catalyst each Hour. In the two treatment stages identical temperatures but different catalysts applied; the carrier material for the First stage catalyst hardly has acid functions, such as  e.g. B. alumina, while the catalyst support material second treatment stage is markedly acidic. From a Comparison of performed at different temperatures Test series A1 and B1 show that when using lower temperatures a higher lubricating oil yield contains, but then the viscosity index in undesirable Way descends.

The registration is therefore based on the task of a procedure for the production of lubricating oil with a low pour point, by means of which the yield is improved, in particular if the lubricating oils in question have high viscosity indices should have.

The task is solved by a method with the characterizing features of claim 1.

In the subclaims 2 to 5 are training of the method according to claim 1 specified.

A feed is used in the process according to the invention Distillate fraction used by vacuum distillation from one obtained by distillation at atmospheric pressure Residual oil fraction is obtained. The boiling range of a Such vacuum distillate is usually 350 to 550 ° C.

The inventive method is in the presence of hydrogen or hydrogen-containing gas in the first and second stage. Pure hydrogen can be used  but this is not absolutely necessary. A gas with a hydrogen content of 70 percent by volume or more is particularly suitable. In practice, it is preferably used one from a catalytic reformer originating gas containing hydrogen, since this gas is not only has a high hydrogen content, but also low boiling hydrocarbons, such as methane, and a low one Contains amount of propane.

The pressure in the first and second stages should not be below 50 kg / cm², otherwise the life of the catalysts is reduced and the risk of excessive aromatics content arises in the end product, which adversely affects the viscosity index affects. A pressure of more than 250 kg / cm² against it requires an expensive investment. Hence the pressure preferably between 100 and 200 kg / cm².

For the hourly space flow rate and the hydrogen / Oil ratio can be chosen very wide ranges will. Preferably the room flow rate should be however between 0.1 and 10 kg of oil per liter of catalyst per hour lie. A space flow rate of less than 0.1 kg of oil per liter of catalyst per hour makes at a given Degree of conversion the use of uneconomically large Reactors required while over 10 kg of oil per liter Catalyst per hour the degree of conversion remains very low. The hydrogen / oil ratio is preferably between 100  and 5000 liters under normal conditions (= liters at 1 bar and 0 ° C) per kg of oil. A very low H₂ / oil ratio has an effect unfavorable to the life of the catalyst while a very high H₂ / oil ratio at a considerable pressure loss leads in the catalyst beds, so that for the circulation of the hydrogen-rich gas a high pressure expenditure is required.

The catalyst support material preferably consists of first and in the second stage essentially from aluminum oxide. Mixtures of aluminum oxide and silicon oxide and in particular Mixtures of alumina and boron oxide are also available suitable, especially for the second stage, in which an acid adjusted catalyst is used.

Catalysts are particularly suitable for the first stage one or more metals from the groups nickel, cobalt, molybdenum and tungsten or their compounds contain, in particular combinations made of nickel or cobalt on the one hand and molybdenum or Tungsten, on the other hand. It is particularly preferred for the first Stage a catalyst made from nickel and tungsten (or compounds of these metals, especially their oxides) on one Carrier material consists of aluminum and boron oxide.

Often, the presence of phosphorus and / or fluorine in the First stage catalyst beneficial.

The liquid drain from the first stage can be removed  unwanted gas compounds, e.g. B. hydrogen sulfide, one Treatment are subjected (z. B. by adsorption of H₂S in an aqueous amine solution, e.g. B. a solution of diisopropanolamine). However, the entire liquid drain is preferred fed to the first stage of the second stage.

Pressure, hourly space flow rate and hydrogen / oil ratio in the second stage are preferably the same as in the first stage. However, the temperature T 2 in this stage should be between 350 and 390 ° C., ie always lower than the temperature T 1 in the first stage. As evidenced by the embodiment, the temperature difference between the two stages is z. B. 35 to 37 ° C.

In the second stage, an acidic catalyst should be used be used. This is understood to mean catalysts adsorption of dimethyl yellow (C₆H₅-N = N-C₆H₄-N- (CH₃) ₂) and other even weaker basic indicators a color change give what indicates the presence of an acidic medium.

Suitable carriers for the acidified catalysts are z. B. Compounds of silicon and aluminum oxide, such as silica / alumina cracking catalysts, compounds of silicon oxide and zirconium dioxide, compounds of Boron trioxide and aluminum oxide, compounds of boron trioxide and Silicon oxide and compounds of aluminum oxide and halogen,  such as aluminum oxide and fluorine, or aluminum oxide, silicon oxide and fluorine.

The suitable for the catalyst in the second stage or preferably used metals (or metal compounds) and their combinations are the same as in type and quantity in the first stage. Particularly advantageous catalysts for Use in the second stage is nickel and tungsten (or their connections, e.g. B. nickel and tungsten oxides) on one Aluminum oxide / boron oxide carrier material and fluorinated nickel and tungsten (or their compounds, e.g. nickel and tungsten oxides) on a silica / alumina support.

According to a preferred embodiment, in the first and the second stage of the method according to the invention are the same Catalysts used.

When the pour point of the liquid drain from the second stage is still too high, you can outgrow the process as such. However, lower boiling is preferred before dewaxing Components removed, e.g. B. by distillation. Preferably before dewaxing, all connections with one Boiling point up to 400 to 450 ° C away.

Dewaxing can be done in any way e.g. B. by adding a suitable liquid, e.g. B. a Mixture of methyl ethyl ketone and toluene, the mixture obtained cool to about -20 ° C and then remove the solid wax.  

However, the dewaxing is preferably carried out catalytically Ways by using the liquid to be dewaxed with a Contacted catalyst in the presence of hydrogen. To the Suitable catalysts include metals or metal compounds of Groups VI and VIII of the Periodic Table of the Elements on a crystalline mordenite support. For example Platinum, palladium and tungsten are suitable for this.

Pressures from 40 to 120 kg / cm² are suitable for dewaxing, Temperatures from 300 to 400 ° C, in particular from 300 to 350 ° C, as well as room flow velocities of 0.1 to 2 kg of oil each Liters of catalyst per hour.

If desired, the catalytic dewaxing step can proceed be topped with low-boiling ingredients to remove, and / or with a suitable extracting agent, e.g. As sulfur dioxide or sulfolane, extracted to aromatics to remove.

example

A waxy distillate with a boiling range of 430 up to 550 ° C, made from Middle East crude oil, is used together with Hydrogen at a pressure of 140 kg / cm², a room flow rate of 0.8 kg of oil per liter of catalyst each Hour and a hydrogen / oil ratio of 1750 Nl / kg about two successive reactors, each with a catalyst bed headed.  

Each of the two reactors contains a catalyst as follows Composition:

57.5% AL₂O₃ - 6% B₂O₃ - 30% WO₃ - 6.5% NiO.

However, the temperatures in the two reactors are different. Table I shows the yield of lubricating oil with a viscosity index of 95 in percent by weight, based on the total weight of the liquid effluent from the second reactor, which by topping at 430 ° C and catalytic dewaxing is obtained. With catalytic dewaxing liquid discharge of the second reactor (after topping at 430 ° C) at a pressure of 60 kg / cm², a room flow rate of 0.5 kg per oil per liter of catalyst per hour and at one Temperature of 315 ° C over a catalyst of 10 percent by weight Tungsten (in oxidic form) on synthetic mordenite headed.

Appropriate tests are carried out at different temperatures carried out.

Table I

As Table I shows, the highest yields of lubricating oil with a viscosity index at a temperature of  about 395 ° C in the first reactor and at temperatures between 360 and 390 ° C in the second reactor. With falling temperature the yield decreases in the second reactor.

Claims (5)

1. A process for the production of lubricating oil with a low pour point, wherein in two stages a deasphalted, wax-containing mineral oil fraction in the presence of hydrogen at temperatures from 350 to 450 ° C., pressures of at least 50 kg / cm² and space disturbance speeds of at least 0.1 kg oil per liter of catalyst per hour contacted with catalysts which contain one or more metals and / or metal compounds of groups VI and VIII of the Periodic Table of the Elements on an aluminum oxide-containing support material, and optionally dewaxed all or part of the process from the second stage, characterized in that that a vacuum distillate with a boiling range between temperatures of 350 to 550 ° C in the first stage at a temperature of T 1 from 390 to 450 ° C is contacted with the catalyst that in the second stage at least part of the liquid effluent from the first stage in the composition obtained there at a temperature T 2 of Feeds 350 to 390 ° C and contacted there with an acidic catalyst, and that the catalysts in both stages 10 to 30 parts by weight of one or more metals and / or metal compounds of group VI and 2 to 15 parts by weight of one or more non-noble metals and / or contain metal compounds of group VIII. 2. The method according to claim 1, characterized in that for the catalysts in the first and / or second stage a carrier material is used which contains boron oxide.   3. The method according to claim 1 and 2, characterized in that catalysts are used in the first and second stages that contain nickel and tungsten compounds. 4. The method according to claim 1 to 3, characterized in that the same catalysts are used in the first and second stages will. 5. The method according to claim 1 to 4, characterized in that the entire liquid flow from the first stage with the Second stage catalyst is contacted.