NL8101844A - PROCESS FOR HYDROGENATING TREATMENT OF CARBON-CONTAINING COMPOUNDS. - Google Patents

Description

S 5798-1 t *

P&C

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Process for the hydrotreating of carbon-containing compounds.

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The invention relates to a process for the hydrotreating of carbon-containing materials using "empirical" hydrates of certain alkali metal and sulfur-containing compounds.

Many methods are known for treating petroleum oils and the like with alkali metal compounds or sulfides.

For example, U.S. Patent 3,252,774 describes a process for cracking liquid hydrocarbons to form hydrogen-containing gases by contacting the feedstock with a melt of an alkali metal compound (eg, the sulfides) at temperatures between about 427 ° C. and about 982 ° C in the presence of steam.

US Patent 3,617,529 describes the removal of elemental sulfur from petroleum oil by contacting the oil at ambient temperature with an aqueous solution containing only sodium hydrosulfide or sodium hydrosulfide in combination with sodium hydroxide and ammonium hydroxide. The aqueous solution and the oil are separated and the aqueous solution is treated to free the sulfur from the polysulfides formed during the contacting step.

US patents 3,787,315 and 3,788,978 describe processes for desulfurizing petroleum oil. The oil is contacted with an alkali metal or alloy in the presence of hydrogen to form a sulfide, thereby desulfurizing the oil. The sulfide is separated from the oil by treatment with sulfur-hydrogen; the separated monosulfide is treated with a sodium polysulfide to form a lower sulfur polysulfide, which is then electrolysed to form sodium.

US Pat. No. 3,816,298 describes a two-step process for improving the quality (partial desulfurization, hydrogenation and hydrocracking) of heavy hydrocarbons (eg, residue material obtained under vacuum distillation) to liquid hydrocarbon products and a hydrogen-containing gas. In the first step, the supplied hydrocarbon material is contacted with a gas containing hydrogen and carbon oxide in the presence of one of the numerous possible catalysts, including alkali metal sulfides and hydrosulfides. The pressure should be more than approximately 1035 kPa (gauge pressure) and the average temperature approximately 370 ° - 593 ° C. According to one of 8101844 * *. .

- 2 - Examples, steam (as well as hydrogen and carbon oxides) with K 2 CO 2 as catalyst, is passed to the first step at an overpressure of about 2345 kPa and about 488 ° C. A by-product, solid carbonaceous material, is deposited on the catalyst and a portion of the catalyst is passed to the second step where it is contacted with steam, at kPa, an overpressure of about 1035 / and an average temperature above about 650 ° C.

U.S. Patent 4,003,823 describes another method for improving the quality of heavy hydrocarbons by contacting heavy hydrocarbons with alkali metal hydroxides at a hydrogen pressure of about 3447 - 34,470 kPa (gauge pressure) and a temperature of about 260 ° - 1093 ° C. Hydrogen sulfur can be added to the products withdrawn from the reaction zone to convert the alkali metal sulfides formed in the reactor into hydrosulfides as the first step of regenerating the alkali metal hydroxides.

US Pat. No. 4,018,572 describes a process for desulfurizing fossil fuels by contacting the material with an aqueous solution or melt of alkali metal polysulfide to form salts of higher sulfur which are decomposed around the lower polysulfides regenerate sulfur content.

Finally, US Pat. No. 4,119,528 describes another process for treating heavy carbonaceous feedstocks, wherein process involves potassium sulfide and a hydrogen pressure of about 3447 - 34,470 kPa (gauge pressure) and a temperature of about 260 ° -1093 ° C applied. The products are desulfurized low boiling oils and potassium hydrosulfide, which can be converted back to potassium sulfide. The potassium sulfide as such can be fed to the reactor or prepared in situ by reacting various potassium compounds with sulfur compounds, such as hydrogen sulfide. The potassium sulfide can also be prepared by reducing potassium compounds, such as the hydrosulfide or polysuldides, with reducing agents such as hydrogen. The sulfide can also be obtained by steam-treating potassium hydrosulfide at a high temperature. Preferably, a mixture of potassium and sodium sulfide is used, since the sodium sulfide acts as a "getter" for the hydrogen sulfide formed during the reaction which would otherwise react with the potassium sulfide to form "inactive" potassium hydrosulfide.

Methods for treating petroleum oils and the like with alkali metal compounds or sulfides are also described in U.S. Pat. Nos. 1,300,816, 1,413,005, 1,729,943, 1,938,672, 1,974,724, 2,145,657, 2,950,245, 3,112 .257, 3,185,641, 3,368,875, 3,354,081, 40 3,382,168, 3,483,119, 3,553,279, 3,565,792, 3,663,431, 3,745,109 and 4,007,109.

8101844 I 1 - 3 -

A problem which arises in the known processes, including the above mentioned, is that rigorous process conditions, for example high temperature and / or pressure, are necessary to obtain suitable products in high yield. This problem is now solved by the invention.

Surprisingly, it has been found that using an "empirical" hydrate detailed below in a hydrogenation treatment under only relatively mild process conditions, yields of suitable products are much higher than in any known hydrogenation treatment, including the above-mentioned processes. For example, the reaction temperature in the present process need not be higher than about 410 ° C and the pressure need not be above atmospheric. Since the conversion efficiency and yield of suitable products of the present process are surprisingly high and require less expensive process conditions, a reduction in cost can also be achieved.

The invention provides a method for the hydrotreating of the carbonaceous material with hydrogen, which method is characterized in that the carbonaceous material is treated in a reaction vessel with steam and an "empirical" hydrate of a sulfur-containing compound, namely an alkali metal hydrosulfide. , alkali metal monosulfide, alkali metal polysulfide or a mixture of two or more of these compounds.

None of the aforementioned U.S. patents disclose the use of "empirical" hydrates of alkali metal hydrosulfides, sulfides, or polysulfides for the hydrogenation treatment (eg, hydrogenation or hydrocracking) of carbonaceous materials by the present process, nor does the use derive these "empirical" hydrates from these references.

The term "carbonaceous materials" as used herein includes oils, slate, tar-containing sand, and the like, but not coal. Examples of these materials are crude oils, atmospheric pressure distillation resids (hereinafter referred to as residual oils) (cracked and uncracked), and residual oils obtained under vacuum (with "broken" (cracked) viscosity and non-"broken" viscosity) and non-35 petroleum oils. "Hydrogenating treatment" includes hydrogenation and hydrocracking. The name "empirical hydrates" is used here because these materials are apparently hydrates in that they contain bound or "associated" water released upon heating at certain temperatures.

The use of steam in the present process is essential 81 01844 4 - 4 because it maintains the above materials in their empirically hydrated (highly active) forms.

The present method provides many advantages. In addition to the aforementioned advantages, denitrogenation and demetallation take place during the hydrogenation treatment. Furthermore, depending on the conditions used in the process and the reactants used, desulfurization can also take place, see, for example, U.S. Patent 4,160,821, which describes a desulfurization process.

Also, the achievable efficiency and degree of hydrogenation treatment are very high. For example, according to a preferred embodiment, wherein hydrogen sulphide is also fed to a reaction zone in which a residual oil with an initial boiling point above 343 ° C is treated in one step, practically all products obtained boil at temperatures below 343 ° C. This shows the high degree of cracking achievable according to the invention under relatively mild conditions.

Other advantages of the present method are apparent from the description below.

Broadly speaking, according to the invention, carbon-containing material is contacted with an above hydrate. The carbon-containing material is usually used in the liquid phase, but research has shown that contact in the vapor phase can also be used. Steam is passed through the reaction mixture to keep the material used according to the invention in the empirically hydrated (highly reactive) form. (For carbon-containing materials with a high naphthenic acid content, the steam flow is kept to a minimum because water tends to decompose these materials; in these cases, hydrogen can also advantageously be supplied.) Free liquid water decomposes the hydrate and therefore, the reaction conditions should be chosen to avoid the presence of a significant amount of liquid water. Preferably, the conditions are chosen such that there is no free liquid water in the reaction zone.

The reaction mixture is heated to evaporate the treated product; steam and product are removed from the reaction zone, cooled and separated. If desired, the product can be collected in the form of a series of distillation fractions and the relatively heavy (high boiling) fractions are recycled for further treatment. The steam and the evaporated product need not be discharged continuously or at all; without periodic discharge, however, the pressure rises, causing the steam to condense. This decomposes the hydrate and stops the reaction. Therefore, it is preferable to remove vapor at least periodically; continuous removal is most preferred.

The treatment can be performed in almost any type of equipment.

For example, a "tank" can be used as a reactor. It is also possible to use a column reactor divided into a number of stages, which makes it possible to collect product fractions on top and as they flow. The present process can be carried out continuously or discontinuously and in one or more reaction steps. Is a "tank" reactor usually operated discontinuously? a multi-stage column is suitable for a continuous process.

In a preferred embodiment, hydrogen sulfide is also fed to the reaction zone and contacted with the reaction mixture. As a result, part of the hydrate is regenerated and a higher production is obtained. As explained below, hydrogen sulphide 15 is formed during the treatment and this hydrogen sulphide is discharged with the steam and evaporated product. It is therefore of great advantage if the discharged hydrogen sulphide is recycled to the reaction zone.

The reaction temperatures are relatively low, generally between about 40 ° C and 410 ° C. For certain materials (eg residues obtained by distillation under vacuum), practically no reaction takes place until the temperature is relatively high (eg 370 ° C). The pressure need not be above atmospheric, but construction considerations may require that higher pressures be used, for example, to reduce the diameter (and cost) of a column-type reactor. Whatever conditions are employed, they should not lead to condensation of a significant amount of the steam, and preferably no condensation of the steam takes place at all.

The materials used in accordance with the invention are the empirical hydrates of the hydrosulfides, monosulfides, and polysulfides of the elements of Group IA of the Periodic Table except hydrogen. The Francium and Cesium compounds are generally not used. The sodium, potassium, lithium and rubidium compounds are used more often.

The potassium, rubidium and sodium compounds are preferred, and the potassium compounds are most preferred. (In some cases, for example when using heavy Canadian crude oil, the sodium compounds are superior to the potassium compounds.) A material containing the empirical hydrates of three hydrosulfides, equivalent to 14% rubidium hydroxide, 29% potassium hydroxide and the balance sodium hydrosulfide ( based on the total of the two hydroxides and the hydrosulfide) has proved to be the most effective.

During the reaction, the material used according to the invention at low temperatures is in fact a mixture of the empirical hydrates of the hydrosulfide and sulfides (mono and poly) of any alkali metal used, and during the reaction conversion of these sulfur-containing forms takes place. place. (As the reaction temperature increases, some of these forms disappear as their decomposition temperatures are exceeded.) Therefore, the hydrate may be initially introduced into the reaction zone as the hydrosulfide hydrate or as one or more of the sulfide hydrates or as a mixture of the hydrosulfide. hydrate and sulfide hydrate. The empirical hydrates can also be prepared in situ, but they are preferably added in the form of the empirical hydrate. (Any of the alkali metal hydrosulfides and mono- and polysulfides may exist in the form of more than one empirical hydrate, and unless otherwise indicated, the name "empirical hydrate" used herein includes all hydrates.)

For example, in the potassium series, there are six sulfides of potassium, namely K_S, K_S_, KLS., K_S_ and K_S ,, and one hydrosulfide, KHS. The molecule Z ά -j ώ 4 Z b So that contains the largest number of sulfur atoms can be considered "saturated" with respect to sulfur (namely K ^ Sg), and the sulfides containing less sulfur are with respect to sulfur unsaturated.

For example, potassium monosulfide (I ^ S), crystallizes in the form of an empirical pentahydrate. Under reaction conditions at 162 ° C, the empirical pentahydrate decomposes to an empirical dihydrate, releasing 3 moles of water per mole of K 2 S, which decomposition is vigorous and observable. At 265 ° - 270 ° C, further decomposition takes place to a lower empirical hydrate, whereby water is released. Some hydrate water is likely to remain to or near the melting point of 948 ° C. The release of water at certain temperatures clearly proves the presence of bonded or "associated" water analogous to hydrate water.

In the present process, the hydrogenation and hydrocracking also include denitrogenation and demetallation. The nitrogen leaves the system as ammonia vapor. The metals removed include vanadium, nickel, cobalt and cadmium, and these remain in the material used according to the invention, which remains in the reaction zone. If feeding is also carried out or if the less sulfur-saturated empirical hydrates are used, desulfurization also takes place according to the present process.

By increasing the total ratio of sulfur to alkali metal 8101844 Λ Λ - 7 - in the reaction zone (including the sulfur in the carbonaceous material), the amount of cracking and desulfurization occurring is reduced. By lowering the ratio of sulfur to alkali metal, the degree of cracking and desulfurization are increased. If hydrogen sulfide is also supplied, the time of its addition also affects the degree of cracking. When the addition is started before the removal of all the liquid water (at about 110 ° - 135 ° C), the degree of cracking decreases; by starting the addition after this removal, the degree of cracking increases.

In the case of the potassium compounds, a total ratio of 0.5 / 1 (equivalent to 100% K 2 S) to 2.5 / 1 (equivalent to 100% I 2 S) can be used. For most carbonaceous materials is a more suitable range, however 0.55 / 1 to 1.5 / 1, the preferred range is 0.75 / 1 to 1/1, the limits of the preferred range can be considered as corresponding to (0.75 / 1) and K2S2 (VD. The preferred range for the sodium compounds is 0.55 / 1 to 1/1. Lower ratios may be required when using difficult to crack starting materials, for example residual oils obtained by vacuum distillation. If the ratio of sulfur to alkali metal of the combination of the empirical hydrate and the carbonaceous material is too low, elemental sulfur can be added, if this ratio is too high, a further amount of unsaturated hydrate can be added.

The amount of empirical hydrate used should be sufficient to provide adequate contact with the starting material and the desired degree of conversion. The maximum amount of starting material that can be treated with a certain amount of catalyst is not known, but it has been found that even 500 g of a residual oil obtained by vacuum distillation can be treated with 9.5 g of KHS (as empirical hydrate).

The empirical hydrates can be prepared by various methods.

For example, the preferred potassium compounds can be obtained as follows: First, sulfur in an excess of 15% can be added to potassium in a liquid ammonia-containing medium. This gives potassium sulfide hydrate (empirical hydrate). Then, a 55 part of the hydrate is reacted with a further amount of sulfur to obtain the empirical hydrate of the pentasulfide. The two hydrates are combined and used.

According to a second method, potassium hydroxide is dissolved in water and just enough of a low boiling alcohol (e.g. ethanol, 8101844-8-propanol-1) is added to effect the two-layer formation. For example, 1 gram of KOH can be dissolved in 2 gram of water. Sufficient alcohol (for example ethanol or a higher alcohol) is added to form two layers (the total volume is 160 ml or less), 5 and then elemental sulfur is added to bring the S / K ratio to the desired value .

This second method gives almost exclusively empirical hydrates of sulfides and not of the hydrosulfide. The little hydrosulfide that is formed remains in the alcohol layer, and the water layer contains only sulfides. The sulphides in the water layer have been used successfully in hydrotreated tests. This shows the suitability of the sulfides.

According to the third (and preferred) method, potassium hydroxide is dissolved in an alcohol in which KOH is soluble, after which the solution is contacted with hydrogen sulfide. The alcohols are usually primary alcohols; methanol and ethanol are preferred since KOH is more soluble in these alcohols than in higher alcohols.

The resulting mixture contains potassium hydrosulfide in the form of empirical hydrates. (This method can also be used to prepare the rubidium compounds. Sodium hydrosulfide is not prepared in this way; instead, commercially available flakes of empiric hydrate of NaHS can be directly introduced into the reaction zone.)

For example, the preparation of the empirical hydrate of potassium hydrosulfide according to the preferred method is carried out as follows: Two 1 liter calibrated cylinders are each filled with slightly less than 600 ml of ethanol, and 3 grams of potassium hydroxide are dissolved in each cylinder. A source of hydrogen sulfide is connected to the first cylinder to introduce B 2 S near the bottom of the solution of KOH in ethanol. The vapor fed from the top of the first cylinder is passed to a second cylinder 30 and introduced near the bottom into the solution contained in this cylinder.

The following total reaction takes place: H2S + KOH -> KHS + H20.

This reaction proceeds so rapidly that if the H 2 S flow is too low, the solution in each of the cylinders is drawn into the vapor supply tube. The gas flow to the first cylinder is stopped as soon as H2S flows freely to the second cylinder, any precipitate formed in the first cylinder is dissolved and the temperature of the first cylinder has fallen to a value below 22 ° C. At this time, the first cylinder contains high quality 8101844-9 hydrate (empirical dihydrate of potassium hydrosulfide (KES.2H ^ 0) in ethanol) and this cylinder should be taken out of the system and closed with a stopper.

A representative discontinuous process for treating the carbonaceous material of the invention using the preferred potassium compound prepared by the preferred method is as follows (the carbonaceous material is petroleum oil): The oil is fed to the reaction vessel and continuously introduces nitrogen (or other inert gas) into the oil to stir the oil while it is being heated. (Instead of gas stirring, mechanical means such as a magnetic stirrer can be used.) If elemental sulfur is needed to increase the sulfur / alkali metal ratio, this elemental sulfur can be added to the oil at this point. The mixture used according to the invention (empirical dihydrate of potassium-15 hydrosulfide in ethanol) is then added. (Instead, the extra sulfur can be added to this mixture instead of the oil.) The temperature is raised to about 130 ° C and steam is introduced. The steam flow need not be stronger than the flow sufficient to create bubbles visible on the surface of the oil. If the steam stirs sufficiently, the introduction of nitrogen can be stopped.

The overhead obtained vapor is continuously discharged and this vapor contains the alcohol and water from the above mixture, steam, hydrogen sulfur from the reaction, and both evaporated and non-condensable hydrocarbon products of the treatment (assuming the initiation temperature of the reaction has been reached). The stream discharged from above is cooled with cooling water and the condensate obtained is fed to a liquid-liquid separator. The non-condensed vapor can be sent to a cold trap (for example from about -51 ° C) to recover further hydrocarbon products.

As the temperature of the oil mass in the reactor rises, several overhead products are isolated in the overhead fraction system. The nitrogen introduced into the oil begins to remove the alcohol and water from the hydrate as vapor almost immediately as the hydrate is added (at about 40 ° C). At a temperature of 90 ° C, the first drops of a separate hydrocarbon layer are visible in the liquid-liquid separator. For this purpose, the light hydrocarbons formed (for example, compounds with 3, 4, 5 and 6 carbon atoms) have already appeared as top fractions and at least a part of these have been dissolved in the 8101844 * 10 alcohol in the separator.

At a temperature of 135 ° C, the distillation of the alcohol and water from the hydrate-containing mixture is practically complete. The water-alcohol layer in the separator is preferably discharged and recirculated to the steam generator providing the steam. As a result, the light hydrocarbons are eventually returned to the reaction vessel and the further formation thereof is suppressed. Instead, one can separate the water and the alcohol and only recycle the water to the steam generator. This avoids "impacts" in the reaction vessel caused by the re-evaporation of the recycled alcohol.

The temperature of the oil can be continuously increased or kept at one or more temperatures (after the steam flow starts at about 130 ° C). Maintaining a low temperature for a long period of time favors the formation of lighter products, but also leads to more "stripping" of the heavy starting material from the reaction zone by the steam.

Table A below sets forth the cumulative amounts of products isolated in the liquid-liquid separator when treating a light crude with 11.75 wt% hydrogen using a potassium-containing empirical hydrate with an S / K ratio -things of 1/1, which oil had been kept above 140 ° C for 15 minutes at any stated temperature.

TABLE A

Temperature Isolated cumulative products as 25 oil mass percentage of supplied oil_

Up to 140 ° C approx. 24 wt.% 180 ° C approx. 38 wt.%

220 ° C

270 ° C approx. 59% by weight

320 ° C

340 ° C approx. 96% by weight

The residue in the reaction vessel was less than 2% by weight of the starting oil. During this test, about 4.7 g of product were isolated in a cold trap at a temperature of about -51 ° C.

35 It has been found that regardless of which light petroleum oil (with the exception of those having a high naphthenic acid content) treated in a discontinuous system without the addition of hydrogen sulfide, the hydrogen, nitrogen and sulfur contents of different product fractions are within certain ranges . Table B below lists these expected values. (The "fraction below 140 ° C" is the hydrocarbon material that is insulated while the oil mass temperature is below 140 ° C; the "140 ° - 170 ° C fraction" is the material that is isolated when the oil mass temperature is 140 ° - 170 ° C, etc.)

5 TABLE B

Product fraction Quantity of element in product fraction__ (temp, oil mass) Hydrogen Nitrogen Sulfur

Below 140 ° C 13.8-14.1% less than 0.05% less than 0.05% 140p - 170 ° C 13.4-13.6% less than 0.05% 0.07% 10 170 ° - 270 ° C 13% 0.1% 0.36-0.48% 270 ° - 340 ° C 12.4-13.0% 50% of initial 2/3 of initial value

Many variations in the process are possible. One or more of the product fractions can be recycled to the reactor for further cracking. For example, it is possible to recycle all product fractions isolated at mass temperatures above 140 ° C and to isolate substantially only a 140 ° C net product.

Another variation is the regeneration of the empirical hydrate. The hydrogen sulfide is isolated in the vapor stream removed from the reactor and the potassium compounds remaining in the reactor are treated. To isolate it into the vapor stream, the overhead fraction from the reactor is passed through a cooling water chiller as previously described, after which the uncondensed material is passed through alcohol as a washing liquid to remove the lighter hydrocarbons as it hinder isolation of the hydrogen sulfide in the next step. (The alcoholic wash solution can be recycled to the steam generator.) The residual gas stream, containing H 2 S, is then fed to a solution of alkali metal hydroxide in alcohol, which solution removes the hydrogen sulfide in the gas stream by generating regenerated empirical hydrate of the alkali metal hydrosulfide or sulfide in the same manner as in the preferred method of preparing fresh hydrate. It is desirable to use a multi-stage H 2 S scrubber in which the final step vaporous effluent contains no hydrogen sulfide.

In order to recover the potassium in the reactor (insofar as potassium-containing hydrates are used) and to regenerate the hydrate, the solid in the reactor, which is formed by polysulfides and metal compounds formed during the reaction, is removed therefrom and about 3 moles of water per mole of potassium are added to form an aqueous solution. If desired, alcohol is added in a volume less than or equal to the volume of the aqueous solution. The alcohol stabilizes the hydrate precursors during the subsequent treatment. Then, the mixture is cooled to a temperature below 22 ° C, causing some alkali metal hydroxide to form, and hydrogen sulfide, which may be recycled H 2 S from an operating reactor, is bubbled through the mixture to cool to keep the temperature below 22 ° C. This causes sulfur to precipitate, and the liquid to separate from the solid.

The liquid is then heated to expel most of the water and alcohol (if used), leaving a melt of a potassium-containing empirical hydrate.

In the case of potassium compounds, when heated to a temperature of 105 ° - 110 ° C under an aqueous atmosphere, a melt of an empirical hydrate containing about 35% by weight of bound water remains. Then the melt is dissolved in just enough low boiling alcohol (preferably methanol or ethanol) to form a saturated solution. (Thinner solutions can be used, but this requires more energy to evaporate the surplus of alcohol.) In the case of potassium compounds, at the ambient temperature about 150 ml of methanol or a slightly larger amount of ethanol is required to make 1 gram To solve KHS. Hydrogen sulfide is bubbled through the solution at a temperature above 60 ° C, resulting in a solution of empirical hydrate in alcohol. After this, the solution is ready for use in a reactor for hydro-generating treatments; however, it is desirable to use the solution first to wash the hydrocarbon products. This clarifies the distillates, removes the free sulfur contained therein and improves the efficiency of the hydrate.

In a preferred embodiment, hydrogen sulfide is fed to the reactor. It apparently suppresses the decomposition or deactivation of the hydrate, and as mentioned above, the degree of cracking tends to increase or decrease depending on when the H 2 S flow starts. The minimum amount and the maximum amount of hydrogen sulphide that can be used advantageously are not yet known.

The invention is further illustrated in the following non-limiting examples.

EXAMPLE I

164.5 g of a Texas crude oil, 2 g of elemental sulfur and 40 ml of a solution of 15.2 g of KHS and 7.6 g of water (the water bound in an empirical dihydrate) were added. ) in methanol in a flask; the contents were stirred by introducing nitrogen below the liquid surface, near the bottom of the flask. The flask was heated by a heating jacket and steam from a steam generator was introduced into the liquid in the flask. Steam introduction was started when the temperature of the liquid mass was about 120 ° C.

The vapor discharged from above was fed to a condenser operating with cooling water; the condensate was collected in a flask.

During the operating state, methanol-water condensate from the water-cooled cooler was periodically returned to the steam generator. The hydrocarbon condensates at different temperatures of the oil mass (fractions) were periodically removed and analyzed. The non-condensed vapor was passed through a solution of 0.5 mole KOH in 100 ml methanol (practically removing all H 2 S), through a water washer (removing methanol) and then through a bath of isopropanol and solid carbon dioxide (to remove some light hydrocarbons). The crude oil and product fractions analyzes are given below.

20 _analysis_

Material Quantity Hydrogen Nitrogen Sulfur

Crude oil 164.5 g 12.11% 0.14% 1.51%

Fraction below 140 ° C 29.4 g 13.87% <0.05% 0.05% 140-170 ° C Fraction 16.6 g 13.6% <0.05% 0.07% 25 170-275 ° C fraction 25.7 g 13.1% 0.07% 0.8% 275-340 ° C fraction 45.0 g 12.3% 0.1% 1.1%

The reaction flask contained no carbonaceous residue and the cold trap condensate totaled 22 ml.

The data shows that hydrogenation, denitrogenation and desulfurization take place in this process. All product fractions contain a greater amount by weight of bound hydrogen, a lesser amount by weight of bound nitrogen and a lesser amount by weight of bound sulfur than the crude oil. (The cold trap distillate was not analyzed but obviously had a higher percentage of bound hydrogen than the crude oil.)

EXAMPLE II

200 g of an Alaskan crude oil were treated using the method of Example I, except that steam was introduced at 135 ° C and no cold fall was generated 8101844 * 14 - uses. Crude oil and product analyzes are set forth below (the flask contained practically no oil residue).

____analysis_

Material Quantity Hydrogen Nitrogen Sulfur 5 Crude oil 200 g 12.04% 0.23% 1.5%

Non-condensable 74 g materials

Fraction below 140 ° C 38.4 g 13.99% <0.05% <0.05% 140-180 ° C Fraction 20.1 g 13.77% <0.05% 0.07% 10 180-343 ° C fraction 59.1 g 12.8% 0.1% 0.9%

EXAMPLE III

175 g of crude oil from Trinidad were treated with 30 ml of a solution of 11.4 g of KHS and 5.7 g of water (bound in the empirical hydrate) in methanol. Because of its high naphthenic acid content, this oil is subject to deterioration in quality by water. Therefore, a minimal amount of steam was used (the steam generator was kept at 99 ° C at ... sea level) and gaseous hydrogen was also supplied. The analyzes of the crude oil and of the products are given below.

_Analysis_ 20 Material Quantity Hydrogen Nitrogen Sulfur

Crude oil 175 g 11.83% 0.32% 1.43 -%

Fraction below 180 ° C) 33 vol.% 13.01% 0.05% 0.24%

Hydrocarbons in oil ^ "^ 12.89% 0.06% 0.55% alcohol-water condensate) 25 180-240 ° C fraction 21 vol.% Of 12.39% 0.06%. 0.58% • crude oil

Residue in flask 20% by volume of 11.87% 0.31% 1.43% crude oil

Due to the construction of the equipment used, the hydrogen could not be introduced close enough to the bottom of the reaction flask to contact the material closest to the bottom; therefore the residue was 20%.

EXAMPLE IV

150 g of a light Arabian crude, 2 g of elemental sulfur and 40 ml of a solution of 15.6 g of KHS and 7.8 g of water (bound in the empirical hydrate) in methanol were charged into a reaction flask, and the mixture was charged run the test in the manner described in Example I, except that the addition of steam at 130 ° C was started. The analyzes of the crude oil and the isolated products are listed below.

8101844 - 15 - _Analyse_

Material Hydrogen Nitrogen Sulfur

Crude oil 12.25% 0.1% 1.8%

Fraction below 140 ° C 13.8% <0.05% 0.09% 5 140-170 ° C fraction 13.5% <0.05% 0.12% 170-270 ° C fraction 13.1% 0, 07% 2.3% 270-330 ° C fraction 12.8% 0.11% 0.8%

EXAMPLE V

In a reaction flask, a residual oil obtained by direct distillation under vacuum (obtained with an initial boiling point under vacuum of 593 ° C) and a solution of KHS in methanol (0.47 g KHS / ml solution) was introduced. Heating was started and the contents of the reactor were stirred with nitrogen from the ambient temperature to 70 ° C, at which point the nitrogen supply was stopped and steam supply was started.

The experiment was stopped when the temperature of the mass of the residual oil had reached 400 ° C, at which time the amount of residue remaining in the flask was 51% of the initially added amount. The analyzes of the starting material and of the two distillates are given below.

^ _Analysis_ e-r · -—- Hydrogen Nitrogen Sulfur

Residual oil 10.51% 0.52% 3.83%

Fraction below 110 ° C 12.01% 0.22% 2.61% 110-40Q ° C Fraction 11.41% 0.21% 2.96%

EXAMPLE VI

The residual oil of Example V obtained by direct distillation under vacuum was again treated with KHS, using hydrogen in this example to stir the system from ambient temperature to 240 ° C. Steam introduction started at 170 ° C. The run was stopped at 425 ° C, at which point the amount of coking material remaining in the reactor was 9% of the amount of residual oil initially added. The analyzes of the residual oil, of the two distillates collected and of the residue in the flask are given below.

35 8101844 * «- 16 - _Analse_

Material Hydrogen Nitrogen Sulfur

Residual oil 10.51% 0.52% 3.83%

Fraction below 360 ° C 12.17% 0.13% 2.41% 5 360-425 ° C Fraction 12.29% 0.11% 1.95%

Residue in flask and coolant wash liquid 6.67% 0.23% 2.46%

Chromatographic analysis of the non-condensed gas stream showed that this stream contained 30.52% hydrocarbons of the following composition 10:

Compound (s)% Hydrocarbon in gas stream

Methane 59%

Ethane + ethylene 21%

Propane + propene 6% 15 Butanes 6%

Pentans 2%

The remainder of the gas flow (69.48%) is believed to be air in the gas chromatography tube. The condensed distillates were very light and no heavier than No. 2 or diesel fuel. Furthermore, in the absence of precipitate in the effluent gas scrubber containing an alcoholic solution of KOH, it was found that little or no carbon dioxide had formed in the reactor.

EXAMPLE VII

150 ml of another residue of oil obtained by vacuum distillation and 22 ml of one solution of an empirical hydrate of KHS in methanol (0.477 g of KHS per ml of solution) were placed in a reaction vessel and heated. Nitrogen was stirred from the ambient temperature to 190 ° C, at which point the nitrogen supply was stopped and the steam supply started (superheated at 140 ° C). A single distillate was collected and kept at 100 ° C to expel water. The hydrocarbons that did not distill with the water are referred to as the "100 ° - 425 ° C fraction" and the hydrocarbons that did distillate as the "fraction below 100 ° C". The analyzes of the residual oil, of the two hydrocarbon products and of the residue in the flask are given below:> 8101844 - 17 - Analysis_

Material Quantity Hydrogen Nitrogen Sulfur

Residual oil 150 ml 10/85% 0.44% 2.91%

Fraction below 100 ° C 27 ml 12.92% 0.07% 1.03% 5 1Q0-425 ° C Fraction 110 ml 12.08% 0.25% 2.26%

Residue in flask 20 g 3.02% 1.25% 4.47%

EXAMPLE VIII

Example VII was repeated except that hydrogen was used instead of nitrogen from the ambient temperature to the final temperature of 425 ° C. At the end of the test, the same amount of residue (20 g) remained in the flask. The analyzes of the residual oil and of the single distillate are given below.

_Analysis__

Material Hydrogen Nitrogen Sulfur 15 Residual oil 10.85% 0.44% 2.91%

Distillate 12.19% 0.17% 1.95%

EXAMPLE IX

160 ml of the residual oil of Examples VII and VIII obtained by vacuum distillation and 25 g of dry, commercially available NaHS flakes (technical grade) were placed in a reaction flask. This material is inherently in the form of empirical hydrate. Methanol was introduced into the steam generator. It was stirred with hydrogen and steam started to be supplied at 220 ° C. The analyzes of the residual oil and of the single distillate are given below.

.25 _Analysis_

Material Hydrogen Nitrogen Sulfur

Residue 10.85% 0.44% 2.91%

Distillate 12.07% 0.18% 2.53%

EXAMPLE X

A cracked residue oil and an alcoholic solution of the empirical hydrate of KHS (0.47 g of KHS per ml of solution) were placed in a reaction flask. Nitrogen was stirred from the ambient temperature to 190 ° C, at which point the nitrogen supply was stopped and the steam supply started. At the end of the test, 13.3% of the residual oil (in non-coked form) was found to remain in the flask. The single distillate was kept at 100 ° C to evaporate the condensed water. The hydrocarbons evaporated with the water were recovered and dried and are indicated below as the "fraction below 100 ° C". Analyzes of the residual oil and of the two products 8101844

* V

- 18 - are given below.

'_Analysis_

Material Hydrogen Nitrogen Sulfur

Residual oil 10.45% 0.53% 3.33% 5 Fraction below 100 ° C 12.55% <0.05% 1.91%

Fraction above 100 ° C 11.84% 0.2% 2.57%

EXAMPLE XI

Example X was repeated, except that hydrogen was used instead of nitrogen from the ambient temperature to the final temperature of 450 ° C, with minimal amounts of steam. The analyzes of the residual oil and of the three distillates are given below.

_Analysis_

Material Quantity Hydrogen Nitrogen Sulfur

Residual oil - 10.45% 0.53% 3.33% 15 Fraction 1 20% of total 12.66% 0.08% 2.12% distillate

Fraction 2 30% of total 11.98% 0.15% 2.34% distillate

Fraction 3 50% of total 11.6% 0.25% 2.2% distillate

EXAMPLE XII

Example XI was repeated, except that commercially available technical grade NaHS flakes were introduced directly into the reactor and methanol in the steam generator instead of using the alcoholic solution of KHS. The NaHS flakes are inherently in the form of empirical hydrate. "The analyzes of the residual oil and of the two distillates are given below.

_Analysis_

Material Hydrogen Nitrogen Sulfur 30 Residual oil 10.45% 0.53% 3.33%

Fraction 1 12.36% 0.07% 1.99%

Fraction 2 11.79% 0.18% 2.12%

EXAMPLE XIII

125 ml of a cracked desulfurized residual oil, 1.8 g of elemental sulfur and 25 ml of a solution of the empirical hydrate of KHS in ethanol (0.24 g of KHS per ml of solution) were placed in a flask with flat bottom, which flask rested on a heated plate and contained a magnetic stir bar. The contents of the vessel were quickly stirred and heated to 120 ° C to expel the ethanol and water from the hydrate solution and heating continued. Steam was introduced at 130 ° C with steam 8101 844-19 - and steam supply was continued until the final temperature of 325 ° C. The analyzes of the residual oil, of the two distillates and of the residue in the flask are given below.

_Analysis__ 5 Material Quantity Hydrogen Nitrogen Sulfur

Residual oil 125 g 9.08% 0.45% 1.81%

Low temperature. fraction 57 ml 11.94% 0.06% 0.70%

High temp. fraction - 9.77% 0.35% 1.91%

Residue in flask - 8.75% 0.43% 1.91%

EXAMPLE XIV

Hydrogen sulfur was also added to a two-stage reactor to treat a residual oil obtained by vacuum distillation. In the first reaction stage, a vertical, cylindrical vessel with a total volume of about 1 liter and fitted with a heating jacket, 50 ml of a solution of empirical dihydrate of potassium hydrosulfide in methanol (0.38 g KHS / ml solution) were introduced. In the second reaction stage, a round flask equipped with a heating jacket, 25 ml of the solution of the hydrate were introduced. The S-gas fed to the first stage was introduced through a manifold below the surface of the liquid 20 and near the bottom of the vessel. Likewise, vapor fed above the first stage was introduced into the second stage below the surface of the liquid contained therein through a distribution tube. Second stage vapor was cooled and partially condensed in a water-cooled unit.

At the start of the run, several hundred grams of the residual oil obtained by distillation under vacuum was heated (to allow the residual oil to flow) and placed in a feed vessel located directly above the first stage reactor. Some of the residual oil was allowed to enter this reactor, and both reactors were heated. At the same time, the supply of steam, nitrogen and hydrogen sulphide into the first stage reactor was started. The H2S flow could not be measured, but was estimated at 3 grammes / hour. As the temperature in the first stage rose, the methanol and the water of the empirical hydrate added with the solution of the hydrate distilled and entered the second stage, which was at a temperature of 110 ° C to prevent condensation of water herein.

The first stage reaction started at about 370 ° C. During the course of the test, the temperature in the first stage rose from 370 ° C to 390 ° C and in the second stage from 110 ° C to 270 ° C. During the test, 8101844 -> t - 20 - a total of 286 g of residual oil were introduced, and less than 10 g were left in the first stage at the end. The analyzes of the residual oil obtained by vacuum distillation, the product remaining in the second reaction stage and the product collected from the water-cooled unit are given below.

_analysis_

Material Quantity Hydrogen Nitrogen Sulfur

286 g 10.04% 0.64% 2.02% residual oil 10 2nd stage product 57.1 g 11.22% 0.42% 1.48%

End product 186.5 g 12.99% 0.50% 1.19%

The final product had an initial boiling point of 23 ° C and a peak distillation temperature of 118 ° C. The amount of non-condensed vaporous product was estimated to be about 35 g. The product of the second stage and the final product for the vacuum residue oil 15 had a specific gravity of resp. 0.95 and 0.777, compared to a specific gravity of 6.0 ° API at 60 ° F. The metal contents are listed below in parts per million (ppm); "NA" means not detectable.

_Analysis_ 20 Material Na V K Fe Ni

Residual oil obtained under vacuum 2.6 102 2.3 24 62

2nd stage product 0.35 NA 2.9 NA NA

Final product 1.6 NA 46 0.93 NA

. 25 ·. , ·. .. .. .. ... EXAMPLE XV. ..

Slate oil was treated in the first stage reactor of Example XIV using a solution of the empirical hydrate of KHS in methanol, steam and nitrogen, but no H 2 S. The analyzes of the slate oil, the products and the residue in the reactor are given below.

_Analysis_

Material Quantity Hydrogen Nitrogen Sulfur

Slate oil 200 g 9.90% 1.45% 6.23%

Fraction below 280 ° C 22 g 10.33% 1.16% 6.85% 35 280-300 ° C Fraction 35 g 10.59% 0.95% 6.80%

Residue 100 g 8.33% 1.47% 5.76%

The amount of non-condensed volatile materials totaled about 43 g. The metal contents are given below (unless otherwise stated, these amounts are given in parts per million (ppm); "NA" 40 means undetectable).

8101844 - 21 - _Analysis_

Material Na V K Fe Ni Ca

Slate oil 11 124 64 106 86 1223

Fraction below 280 ° C 1.2 5 5 NA 20

5 280-300 ° C fraction 0.61 19 4.6 NA NA

Residue 21 56 2.89% 34 565 -

EXAMPLE XVI

A heavy crude with a specific gravity of 0.994 (ca. 15.6 ° C) was treated with empirical hydrate, steam and hydrogen sulfide using the apparatus and method of Example XIV, except that the reactor from the second step was not used and 100 ml of the empirical hydrate solution was used. One product was obtained at 370 ° - 390 ° C. The crude oil and product analyzes are given below. At the end of the run, less than 2% of the crude oil remained in the reactor.

_Analysis_

Material Hydrogen Nitrogen Sulfur

Crude oil 10.80% 0.40% 4.42%

Product 11.69% 0.13% 3.15% 20 The product had a specific gravity of 0.907 (about 15.6 ° C), a starting boiling point of 110 ° C and an end point (97% recovered) of 360 ° C. The metal contents are given below (the amounts are expressed in parts per million (ppm); "NA" means undetectable).

__Analysis_ 25 Material Na V K Fe_ Ni

Crude oil 5 203 3 6 99

Product 0.06 NA NA 0.66 NA

The invention is not limited to the above-described embodiments, since numerous modifications are of course possible within the scope of the invention.

8101844

Claims (13)

A process for the hydrotreating of carbon-containing material, characterized in that the carbon-containing material is treated in a reaction vessel with steam and an empirical hydrate of a sulfur-containing compound, namely an alkali metal hydrosulfide, an alkali metal monosulfide or an alkali metal polysulfide or a mixture of two or more of these compounds. 2. Process according to claim 1, characterized in that steam is introduced into the reaction vessel after the contents of the vessel have been heated to a predetermined temperature, which steam keeps the sulfur-containing compound in the form of its empirical hydrate, A method according to claim 1 or 2, characterized in that the alkali metal is sodium, lithium, potassium or rubidium. 4. Process according to claims 1-3, characterized in that the alkali metal hydrosulfide in the vessel is potassium hydrosulfide and / or sodium hydrosulfide. 5. Process according to claims 1-4, characterized in that hydrogen sulphide is also introduced into the vessel. 6. Process according to claims 1-4, characterized in that hydrogen sulfide formed in the reaction vessel is isolated and recirculated thereto. Process according to claims 1-6, characterized in that the temperature of the mass of the carbon-containing material in the reaction vessel is about 40 ° - 410 ° C and the vessel has an approximately atmospheric pressure. 25 8. Process according to claims 1-7, characterized in that hydrogen is also introduced into the reaction vessel. 9. Process according to claims 1-8, characterized in that elemental sulfur is introduced into the reaction vessel to adjust the ratio of sulfur to alkali metal. Process according to claims 1-9, characterized in that the alkali metal is in an alcohol solution. Process according to claim 10, characterized in that the alcohol used is methanol, ethanol or propanol-1. 12. Process according to claims 1-11, characterized in that sulfur-hydrogen and hydrocarbon-containing vapor is discharged from the reaction vessel and the hydrocarbon is isolated from the discharged vapor. Process according to claims 4-12, characterized in that potassium hydrosulfide is used with a sulfur / potassium ratio in the reaction vessel of 0.55 / 1 to 1.5 / 1. 8101844