DE102018106311A1 - Method and device for treating oil - Google Patents

Abstract

The invention relates to a process for treating oils, such as waste oil or crude oil, with which the oil is divided into fractions and impurities are separated, and in which the oil is fed to a one-tube reactor in which it is evaporated in a continuous process, and the generated gaseous oil, after leaving the monotube reactor, is fed to a cyclone separator wherein the higher boiling substances and the solids are separated from the vaporized oil. According to the invention it is proposed that hydrogen is supplied to the oil in the course of the monotube reactor in its liquid phase or its gaseous phase or in the transition phase between liquid and gaseous.

Description

The invention relates to a process for treating oil and especially waste oil or crude oil, with which the oil is divided into fractions and impurities are separated and in which the oil is fed to a one-tube reactor in which it is evaporated in a continuous process, and the generated gaseous oil, after leaving the monotube reactor, is fed to a cyclone separator wherein the higher boiling substances and the solids are separated from the vaporized oil. The process is suitable both for the treatment of crude oils and waste oils. It is therefore mainly spoken only of oils, but with both types of oil are to be understood.

In the course of the increasingly scarce oil deposits, it is necessary to recycle used oil in order to obtain reusable lubricants, raw materials or fuels. For this purpose, the waste oil is often heated in a boiler and then condensed to divide the oil into different fractions and to remove foreign matter. In particular, unwanted substances such as chlorine, sulfur or phosphorus compounds can be bound to precipitable solids by the thermal treatment of the oil. The batchwise heating has the disadvantage that the used oil is often brought to too high a temperature at which the cracking process begins. However, this is undesirable to obtain the desired properties, such as the lubricity of the oil.

From the DE 36 38 606 A1 It is known to heat the waste oil in a single-tube reactor. In this case, the temperature can be kept below the cracking temperature so that the properties of the oil obtained therefrom are maintained. The various fractions are fed out of the reactor via side strands.

From the DE 10 2014 118 486 A1 It is known to supply the waste oil to a single-tube reactor and then at least one cyclone separator to separate different fractions. Sodium hydroxide (NaOH) or potassium hydroxide (KOH) is added to the used oil before it enters the single-tube reactor to bind unwanted ester compounds.

The invention has for its object to provide a method for treating oils of the type described, in which the oil is freed on the one hand from impurities and processed to another.

The object is achieved according to the invention in that the oil in the course of the monotube reactor in its liquid phase or its gaseous phase or in the transition phase between liquid and gaseous reactive hydrogen (H ₂ ) is supplied. The reactive hydrogen may be supplied to the oil prior to entering the single-tube reactor. It is also alternatively or additionally possible that the hydrogen is supplied to the oil behind the inlet into the single-tube reactor before the evaporation. Then the hydrogen has a long residence time for the reaction with the oil. A supply in the gaseous phase of the oil is in a reactive state and heat losses are avoided. It may also be favorable if the hydrogen in the transition phase of the oil is supplied from liquid to gaseous. Also, the hydrogen can be supplied at several points of the single-tube reactor.

ausgetragen werden. Die Qualität des so behandelten Öls wird deutlich verbessert.Here, the invention utilizes the properties of the single-tube reactor to the extent that in the course of the rising temperature of the oil in the flow direction evaporates an ever-increasing amount. The roughness of the wall surface of the tube turbulent flow through the pipe and thus a good mixing is achieved, so that on the one hand, the hydrogenation of the oil is supported. On the other hand, pollutants and especially sulfur are bound by the supplied hydrogen and can be used as hydrogen sulfide (H ₂ S) according to the reaction equation $${\text{H}}_{\text{2}}+\text{S}\to {\text{H}}_{\text{2}}\text{S}\left(\text{gaseous}\right)$$

be discharged. The quality of the treated oil is significantly improved.

Due to the increasing evaporation of the oil in the flow direction, the volume and the flow velocity of the oil increase in the flow direction. At the end of the reactor, the oil can reach a flow rate of 1.0 to 2.0 times the speed of sound with a volume increase of the vaporized oil by a factor of 1,000. Furthermore, there is a negative pressure in the single-tube reactor, which may be less than 200 mbar. This condition is also called kinetic plasma. The reactions with the supplied hydrogen are thereby supported.

With this high flow rate, the vaporized and hydrotreated oil enters the cyclone separator, which has very good separation efficiency at this flow rate. In the course of the centrifugal movement of the oil vapor through the cyclone separator, possibly existing solid are separated. On the other hand, the oil vapor cools down, so that the higher-boiling components of the oil condense and are also separated. This is a treatment of the oil without major equipment required. The high speed, which is favorable for the cyclone separator, already exists behind the monotube reactor without further measures, so that the oil vapor can be passed directly into the cyclone separator.

It is favorable if the input of the cyclone separator is arranged directly behind the outlet of the monotube reactor. This will prevent flow losses. In particular, it is expedient if the working temperature of the cyclone separator essentially corresponds to the starting temperature of the monotube reactor. This can be achieved, for example, by arranging the cyclone separator in the same housing as the monotube reactor, so that the temperature there prevails in the cyclone separator. Thus, an undesirable or uncontrolled condensation of fractions of the oil vapor can be avoided, which can be fed to further processing. The separation cut can therefore be set very accurately.

Therefore, at the solids outlet of the first cyclone separator there is present as product a mixture of higher-boiling components and solids which could not previously be separated off. For example, this product can be used in bitumen production.

Through the clean gas outlet of the cyclone separator passes an oil vapor fraction with a lower boiling point. This fraction can be cooled and liquefied. The product is essentially free of solids and no longer has any higher boiling components.

It may further be provided that in the flow direction of the vaporous oil at least one further cyclone is connected in series behind the cyclone separator to divide the vaporized oil into different fractions. In particular, it is possible to provide a plurality of cyclone separators connected in series one behind the other, which operate at a different temperature in each case, so that certain fractions of the oil having different boiling temperatures and high purity can be produced. The oil fraction withdrawn at the solids outlet no longer has any solids or low-boiling constituents, since these have already been separated off in the preceding cyclone separator. Also, no higher-boiling constituents are included because they are still in the gas phase and are deducted via the clean gas outlet for further processing.

Behind the cyclone separator, the vaporized oil can be further divided and liquefied in a known manner in several condensation stages. Thus, different fractions of the oil are obtained in high quality and high purity.

It is useful if the oil is not heated above 380 ° C. As a result, an evaporation of the oil is achieved below the cracking temperature. The oil is therefore gently evaporated, and a splitting of the molecules does not take place. The desired properties of the thus treated oil are therefore maintained.

It can also be provided that additives are added to the oil supplied before evaporation. Additives such as potassium hydroxide (KOH) or sodium hydroxide (NaOH) may be added to bind the undesired ester compounds. Again, the long residence time until the later liquefaction of advantage.

In principle, it is advantageous if the oil is sedimented before being fed into the single-tube reactor. This removes coarse impurities and coarse solids from the oil. Contamination of the monotube reactor is therefore avoided.

Furthermore, the oil can be preheated to 120 ° C to 160 ° C prior to feeding into the single-tube reactor. As a result, volatile components and also water can be separated from the oil before the monotube reactor.

The apparatus for carrying out the method described above comprises a mono-tube reactor for vaporizing oil, the outlet of which is connected to the tangential mixture inlet of a cyclone separator, in which the solids and the higher-boiling components are removed from the vaporized oil. It is provided that in the flow direction in front of the monotube reactor and / or in the flow direction front region of the monotube reactor feed points for introducing hydrogen into the still liquid oil are present. This makes it possible to supply the still liquid oil required for the hydrogenation or pollutant treatment hydrogen. The feed points can be designed as static mixers, whereby a mixing of the hydrogen is supported with the still liquid oil.

Furthermore, it is possible for there to be at least one further feed point for NaOH or KOH upstream of the feed point for the reactive hydrogen in the flow direction. By means of these additives, the ester compounds can be bound in the waste oil.

The single-tube reactor can be made of a conventional steel tube having a rough inner surface, so that a setting turbulent flow. The reaction of the vaporized oil with the hydrogen is supported.

In the cyclone separator, the solids and higher boiling components are removed from the vaporized oil. Furthermore, it can be provided that the pure steam outlet of the first cyclone separator is connected to the tangential inlet of a further cyclone separator in which a lower temperature prevails than in the first cyclone separator and in which the oil condensing therein is separated. It can be arranged in series in this way several cyclone separator and connected to each other. The cyclone separators are operated with different and falling in the flow direction of the oil vapor temperatures. It can thus be formed a cascade, in their individual stages oil of certain boiling point fractions and can be deducted with high purity.

Instead of or in addition, known condensation stages can be present downstream of the cyclone separator in order to condense the oil vapor and to divide it into the desired fractions.

The invention is explained in more detail below with reference to the schematic drawing whose single figure shows the process scheme.

The monotube reactor shown in the drawing 10 has a pipe 11 which extends helically from top to bottom. The pipe 11 is several 100 m long and in particular longer than 1,000 m. The length and the diameter are calculated and calculated according to the capacity of the processing plant. At its upper inlet in the drawing 12 becomes the pipe 11 fed with the oil to be treated. The oil can be pretreated and in particular sedimented and preheated. The inlet temperature can be for example 150 ° C.

The monotube reactor 10 is from below and thus against the flow direction 21 the oil to be treated heated. This can be done by a central heat source or by directly heating the helical tube. This can be designed to be double-walled. Such monotube reactors are basically known and therefore require no further explanation.

In the inflow 12 can still at least one feeder 13 provided by the additives, such as NaOH or KOH for the ester treatment of the oil, are added to the still liquid oil. The oil with these additives is continuously heated up to the boiling point during its movement through the monotube reactor.

Furthermore, there is a feeder 22 in the inflow 12 of the monotube reactor 10 provided by the reactive hydrogen (H ₂ ) is supplied to the still liquid oil. This hydrogen causes hydrogenation of the oil and repair of hydrocarbon chains.

Furthermore, in the treatment of waste oil whose sulfur content is reduced because the sulfur present with the hydrogen to hydrogen sulfide (H ₂ S) reacts, which can be discharged at a suitable point behind the monotube reactor.

Overall, the quality of the oil treated in this way in the single-tube reactor can be improved. The feeder 22 for the hydrogen is preferably located in the flow direction of the oil behind the feed 13 for the additives KOH or NaOH in the feed 12 of the monotube reactor.

Alternatively or additionally, it is possible to supply the hydrogen in the course of the single-tube reactor in the flow direction 21 provide further back. The dashed line shown in the drawing supply 22 ' is approximately in the range of the transition phase of the oil between liquid and gaseous. The feeder also shown in dashed lines 22 " is located in a region of the monotube reactor in which the oil is gaseous and thus particularly reactive. It can also be provided several feeds for the hydrogen in the course of the single-tube reactor.

The boiling temperature is about 350 ° C to 400 ° C depending on the composition of the oil. The vaporous oil passes through the monotube reactor to its exit 14 , The oil is not heated further, so that a cracking of the oil is avoided. Rather, the evaporation of the oil takes place in a gentle manner over a long residence time, so that there is sufficient time for the required chemical reactions for the treatment and hydrogenation of the oil. In particular, the process runs continuously.

Due to the roughness of the inner wall of the pipe 11 In addition, a formation of a turbulent flow thus gives us a better mixing and reaction of the supplied hydrogen 12 and the additives supplied 13 reached with the oil.

Due to the volume increase of the oil during evaporation, the flow rate continues to increase during continuous heating. During the transition to the gas phase flow velocities in the amount of 1.0 to 2.0 times the speed of sound (about 350 m / sec to 700 m / sec) can arise. In the vaporous oil are at the exit 14 still entrained solids and higher boiling components.

The exit 14 of the monotube reactor 10 is related to the tangential inlet 15 a centrifugal separator or cyclone 16 , Because the vaporous oil at very high speed out of the tube 11 and thus in the cyclone 16 a good separation of the solids contained in the oil vapor and the higher-boiling and thus still liquid components can be made from the oil vapor. The separated components pass over the conical cyclone wall 17 in the solids output 18 and are removed there. It is obvious that liquid components and already condensed oil are drawn off through the solids outlet. The product obtained here can be used for bitumen production.

The still gaseous component of the oil passes over the dip tube 19 to the clean gas outlet 20 , This product thus obtained is substantially free of solids and low boiling liquid components. It can be condensed and processed further.

Of course it is also possible to have several cyclones 16 to arrange in series one behind the other such that the clean gas output 20 a cyclone 16 with the tangential mixture input 15 the next cyclone 16 communicates. At the solids outlet 18 then processed oils with different boiling point fractions can be deducted. In the drawing is only the first cyclone 16 shown. The following cyclones always have the same effect and only have a different working temperature. Only the dimensions can change.

In the course of the passage of the vaporous oil through the cyclone, this will cool, so that gradually higher-boiling fractions are separated from the low-boiling fractions. After the first cyclone 16 the vaporous oil is already solids-free, so that the very pure oil of a certain boiling point fraction can be withdrawn at the respective solid outputs of the following cyclones.

It can be provided here that the cyclone is heated to a certain temperature, that is cooled or heated, so that the desired fraction can be deducted at the solids output. The required heat energy can be obtained in part from the waste heat when condensing the individual fractions. This waste heat can also be used to preheat the untreated oil.

In the single-tube reactor 10 can at the exit 14 a temperature of about 380 ° C - 400 ° C are present. In the first cyclone 16 There is a similar working temperature of 375 ° C - 395 ° C, in the second cyclone, a temperature of, for example, 240 ° C to 260 ° can be set. The third cyclone has a temperature of 200 ° C - 220 ° C. Thus, the individual fractions of the evaporated oil can be separated very accurately.

It is also possible to provide behind the cyclone one or more condensation stages in which the vaporized oil condenses with different boiling points at different temperatures. This can also be done in a conventional manner, a separation into different fractions.

The gaseous hydrogen sulfide produced by the reaction with the hydrogen is preferably due to a discharge due to the low boiling point 23 discharged behind the last cyclone separator or the last condensation stage.

In the drawing is the Zylkonabscheider 16 below the monotube reactor 10 shown. In fact, it is convenient if the entrance 15 the cyclone is directly at the exit 14 of the monotube reactor connects. The cyclone separator 16 is then located next to the monotube reactor, so that only a short pipe run is in between. Also, the cyclone separator may be disposed in the same housing as the single-tube reactor to different temperatures in the cyclone separator and at the reactor outlet 14 to avoid.

With this device and the method thus possible, oil can be processed without the risk of cracking. The oil has retained its original properties and is essentially acid free. Different fractions with different boiling points can be separated from each other.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3638606 A1 [0003]
• DE 102014118486 A1 [0004]

Claims (14)

Process for treating oils, such as waste oil or crude oil, with which the oil is divided into fractions and impurities are separated, and in which the oil is fed to a single-tube reactor (10), in which it is evaporated in a continuous process, and the gaseous oil produced after leaving the monotube reactor (10) is fed to a cyclone separator (16), in which the higher-boiling substances and the solids are separated from the evaporated oil, characterized in that the oil in its liquid phase in the course of the monotube reactor or its gaseous phase or in the transition phase between liquid and gaseous hydrogen is supplied. Method according to Claim 1 , characterized in that the hydrogen is supplied to the oil before entering the single-tube reactor. Method according to Claim 1 or 2 , characterized in that the supplied oil before evaporation NaOH or KOH is added. Method according to one of Claims 1 to 3 , characterized in that the oil is sedimented prior to feeding into the single-tube reactor. Method according to one of Claims 1 to 4 , characterized in that the oil is preheated to 120 ° C to 160 ° C before being fed into the single-tube reactor. Method according to one of Claims 1 to 5 , characterized in that the vaporized oil is fed to the cyclone separator (16) immediately after the one-tube reactor (10). Method according to one of Claims 1 to 6 , characterized in that in the cyclone separator (16) behind the monotube reactor (10) substantially the same operating temperature prevails as the temperature of the vaporized oil at the reactor outlet (14). Method according to one of Claims 1 to 7 , characterized in that in the flow direction (21) of the vaporous oil in series behind the cyclone (16) at least one further cyclone separator is switched at a lower temperature than in the preceding cyclone separator to divide the vaporized oil into different fractions. Apparatus for carrying out the method according to one of the preceding claims, comprising a single-tube reactor for vaporizing oil, the outlet of which is connected to the tangential mixture inlet (15) of a cyclone separator (16), in which the solids and the higher-boiling components are removed from the vaporized oil be characterized in that in the flow direction in front of the monotube reactor and / or in the flow direction front region of the monotube reactor at least one supply point (22) for introducing reactive hydrogen in the still liquid oil are present. Device after Claim 9 , characterized in that at least one further feed point (13) for NaOH and / or KOH is present in the flow direction in front of the feed point for the reactive hydrogen. Device after Claim 9 or 10 , characterized in that the cyclone separator (16) directly adjoins the outlet (14) of the monotube reactor (10). Device according to one of Claims 9 to 11 , characterized in that the cyclone separator (16) is arranged in the same housing as the monotube reactor (10). Device according to one of Claims 9 to 12 , characterized in that behind the monotube reactor (10) and behind the clean gas outlet (20) of the cyclone separator (16) at least one further cyclone separator is connected in series, the clean gas outlet of the preceding cyclone separator being connected to the tangential mixture inlet of the following cyclone separator, in which a lower temperature prevails than in the preceding cyclone separator and in which the oil condensing therein is separated by the respective solids outlet of the cyclone separator. Device according to one of Claims 9 to 13 , characterized in that in the flow direction behind the monotube reactor (10) and behind the Zyklonabscheider (16) at least one discharge (23) for discharging the hydrogen sulfide formed in the course of treatment is provided.

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