US1988019A - Production of hydrocarbons of high boiling point range - Google Patents

Description

M. PIER 1,988,019 PRODUCTION OF HYDROCARBONS OF HIGH BOILING POINT RANGE Jan. 15, 1935.

2 Sheets-Sheetl Filed April 5, 1929 K EQNW kuN v wn 1 l w! n lun Nm mw E S QL INVENTOR mcd'hias' Pie? 'LLL% W' AT ORNEYS M. PIER Jan. 15, 1935.

PRODUCTION OF 'HYDROCARBONS OF HIGH BOILING POINT 'RANGE 2 Sheets-Sheet 2 Filed April 5. 1929 INVENTOR MaTums 'PHER BY 3 E AfioRNEY S.

Patented Jan. 15, 1935 UNITED STATES PRODUCTION OF HYDROCABBONS OF HIGH BOILING POINT RANGE Mathias Pier, Heidelberg, Germany, assignor, by

mesne assignments, to Standard-I. G. Company, Linden, N. 1., a corporation of Delaware Application April 5, 1929, Serial No. 352,929 In Germany May 18, 1928 'lClaims.

This invention relates to improvements in the production of hydrocarbons of high boiling point range from coal, shale and other bituminous solid carbonaceous materials. These materials are classified on page 64 of Asphalt and Allied Substances by Abraham, 3rd ed. as solid pyrobituminous materials, in which language they will be referred to in the appended claims.

I have found that the carbon content of bi-- I pressure, and then by subjecting preferably directly the products extracted from the initial material to a treatment with reducing gases under such conditions in respect of temperature and pressure and only for such a period of time that no substantial decomposition to products of lower boiling point occurs. No substantial decomposition when employed in the present application, means that if a decomposition takes place at all not more than percent of the extracted product v shall be decomposed. The duration of treatment consequently depends on the particular temperature. employed and is the shorter the higher this temperature is selected. It further depends somewhat on the nature of the materials to be extracted and of the extracting solvents employed. In any case the period of time allowable may easily be determined from the reaction products and is to be lowered when the latter contain more than 10 per cent'of decomposed products. with reference to the extracted products. The conditions alsovary according to the nature of the initial material and of the catalyst, if employed. The extraction produces constituents of very high boiling point, which constitute valuable initial products for lubricating oils, and which can be produced in suflicient amount to meet large demand for lubricating oils.

Hydrogen need not be added in the extraction 0 treatment.

The extraction products may be reduced in the presence of the solid residues, or after separation therefrom.

The temperature employed for the reduction pounds at an elevated temperature and. under treatment should be kept below the decomposition temperature of the hydrocarbons; as a rule it ranges between 200 and 430 0., preferably between 300 and 400 C. The pressures maintained in this stage of operation range between 50 and 1000 atmospheres. The reduction treatment can be performed, with particular'advantage, by means of hydrogen, or gases containing the same, such as mixtures of carbon monoxide and hydrogen, under pressure. The hydrogen can also be used in the nascent state, or the oper- 10 ation can be conducted with other reducing agents, such as sulphuretted hydrogen. It is, preferable to operate in the presence of a catalyst which facilitates the reduction, for example, a catalyst immune frompoisoning by sulphur or a catalyst having an alkaline reaction.

The operation may be conducted, with advantage, in stages, that is to say, for example, by extracting solid wax in the first stage, for example, with benzene at a low temperature and sep arating off the wax and then, in the second stage, extracting the high boiling substances, at a somewhat higher temperature, with an oil, boiling between 300 and 350 centigrade, obtained by the destructive hydrogenation of coal. The dura-. tionof the extraction in each stage varies with the nature of the solvent employed. Thus for instance in the example given the treatment in the first tage of the extraction with benzene may be ca ried out for one hour and the treatment in the second stage for two hours. The said high boiling substances are then subjected separately to the treatment with hydrogen for the production of lubricating oils. The further the extraction is carried in the first stage, the more valuable are the lubricating oils obtained.

In this manner, the troublesome separation of the lubricating oils from the solid wax is avoided to a large extent.

'Apparatus for carrying out the process in accordance with the present invention are further illustrated diagrammatically in the accompanying drawings, in which Fig. 1 shows a one stage extraction and Fig. 2 shows a two stage extraction.

The following examples will further illustrate the nature of the said invention which however is not limited thereto.

Example 1' With reference to Figure l, brown coal is made into a paste with anoil boiling between about 300 and 350 C. obtained by the destructive hydrogenation of coal and containing practically no lubricating oil constituents. The mixture thus obtained is introduced through the pipe a into a preheater b in which it attains a temperature of about 380 to 400 C. and is then continuously introduced at into the extraction vessel d under a pressure of about 200 atmospheres and at from about 380 to 400 C. without any special addition of hydrogen. The velocity of flow of the treated mixture is so selected that each unit remains in the said reaction vessel for about one hour. By this treatment, about 60 per cent of the coal is extracted and brought into solution. Without separating the solid residues from the liquid products the entire reaction product containing the solid coaly constituents in a finely divided state is mixed with hydrogen which is introduced at f at thejunction e and is then passed through the preheater g. The preheated mixture is passed over a rigidly arranged molybdenum zinc catalyst m in a second high pressure reaction vessel h at about 200 atmospheres pressure and about 400 C. At this temperature no substantial clecomposition of this product into lower molecular compounds, but only a saturation with hydrogen, takes place. On account of the fact that the solid coaly particles are contained in the treated mixture in a finely divided state no difiiculties are encountered when passing the said mixture over rigidly arranged catalysts. It is preferable not to remove said solid particles before introducing the material into the catalytic chamber h, since by an intermediate separating operation, for example by filtering or centrifuging, the materialsmust'be cooled and released from pressure, which would result in losses of energy. In case, however, it isdesired to obtain the wax separately from the lubricating yielding substances itis preferable to employ a low boiling extracting agent, such as benzene, to remove the solid partly extracted coaly matter from the products issuing from vessel d by means of a filter or centrifuge (not shown) connected with said vessel and to cool the extract, in order to precipitate the extracted montan wax. The residual coaly matter is'passed on with a heavier oil and, if desired, after a further extracting treatment such as effected in vessel (1, is supplied to the junction e, where it is mixed with hydrogen, and then, after being preheated in preheater a, treated inthe hydrogenating vessel It. The products issuing from the said vessel pass into the stripping vessel 7' in which they are removed from the hydrogenating gas. The said gas passes of!v at n and may be returned to the process. Thereaction products obtained after cooling in the cooler k are drawn oil. at l and contain about 25 per cent of the coal employed in the form of valuable lubricating oils. The lubricating oil has-the character of a heavy engine oil, with a flash pointer from 180 to 200 C., and the viscosity 10 Engler at 50 C. 1 I

The operation may also be carried out by separating the high boiling liquid products from the mixing oil and the solid residues after the extraction, and then subjectingthe liquid products to a further treatment with hydrogen under a pressure of 200 atmospheres, or if desired up to 1000 atmospheres (preferably in the presence of catalysts). Under the latter conditions, lubricating oils, which are still richer in hydrogen, are obtained.

Example 2 With reference to Figure 2, bituminous brown coal is supplied from bunker 1 and made up into troduced from vessel 3. The mixture is then pumped by means of pump 4 from this mixing vessel into the preheater 5 and from thence passed into the first extraction vessel 6 which may be kept under ordinary or slightly elevated pressure. In this vessel an extract containing from about 5 to 15 per cent of the carbon in the coal is obtained. The materials having undergone extraction are passed from vessel 6 into cooler 7 in which they are cooled to a temperature at which the montan wax extracted from the coal still remains liquid. The cooled products are then conveyed to the drum filter 8 in which the solid coaly matter is separated from the extract. This extract is then cooled in drum filter 9 to a temperature at which the waxes separate out as forexample a temperatureof about 20 below zero centigrade. The parts remaining liquid are led into the distillation column 10 in which the benzene is distilled oil. The distilled benzene is condensed in cooler 11 and thereupon recycled to vessel 3 from which it may be withdrawn for the extraction of further amounts of coal. The portion of the liquid products in vessel 10 remaining undistilled is withdrawn at the bottom thereof and may be employed for any suitable purpose, if desired after a careful non-splitting hydrogenation. The waxes separated in the drum filter are collected in vessel 12 in which they are again liquefied and thereupon "purified in the hydrogenation vessel 13 by treatment,with hydrogen at an elevated temperature and under pressure so that no splitting of the materials under treatment takes place. The purified liquid waxes are collected, after cooling (not shown), in the collecting vessel 14. The coaly matter separated in the drum filter 8 is passed into the bunker 15 from which it is conveyed into ,the mixer 16. Heavy oil from a destructive hydrogenation process issuing from vessel 1'7 is employed for making up into a paste the said coaly matter in mixer 16. The paste thus obtained is then pumped by means of pump 18 into the extraction vessel 19 in which it is tr'eated at a temperature of from about 380 to 400 C. and under a pressure of 200 atmospheres until on the average from about 40 to 50 per cent of the carbon originally present in the coal has been extracted in the form of bituminous substances. The products leaving the said extraction vessel 19 are passed into the cooler 20 and from thence into the drum filter 21 in which the extracted materials are separated from the liquid matter. This liquid matter is subjected to distillation in the column 23 maintained under reduced presure. The lower boiling constituents are evaporated and leave the column at 24. Those of the higher boiling constituents which are still evaporated but condensed again by the cooling coil 25 are withdrawn as a liquid at 26. This a portion is pumped by means of pump 27 into the hydrogenating vessel 28 in which by careful reduction with hydrogen in the presence of catalysts it is converted into a valuable engine oil.

The final product is collected in vessel 29. The portion of the liquid products not distilled in vessel 23 represents heavy oil which by way .01 pipe 30 is recycled into the vessel 17 and from thence may be employed for pasting up further amounts of coaly matter supplied from bunker 15. Devices 31', 32, 33 and 34 represent pressure release valves. The solid matter separated in the drum filter 21 is collected in vessel 22 and may be further extracted with heavy oil fractions at an elevated temperature and under higher pressure as for example 1000 atmospheres and more by which means up to about 70 per cent and more of the carbon originally present in the form of hydrocarbon products can be recovered. The extract is subjected to conversion into high boiling lubricating oils by a reduction treatment with hydrogen.

Example 3 1000 parts of a bituminous brown coal are extracted with benzene and then with a heavy oil from a destructive hydrogenatiomin the manner described in example 2. The extract obtained in an amount of from 260 to 330 parts is then subjected to a cautious reducing treatment with hydrogen at a temperature of 380 C., under a pressure of 800 atmospheres and in the absence of catalysts. In addition to about 50 parts of gas oil and high boiling residual oils a valuable engine oil is obtained in a yield of from 50 to 100 parts. The remainder of the initial material may be worked up as described in Example 2.

What I claim is: I

1. A process for producing lubricating oils which comprises subjecting solid pyrobituminous material to an extraction at a temperature below 400 C. and under an levated pressure with an organic liquid having substantially the same solvent action on the initial material as benzene has at a temperature below 400 C. for such a time as to efiect a substantial extraction of soluble constituents and then subjecting the constituents extracted from the initial material to the action of reducing gases at an elevated temperature below 400 C. and under an elevated pressure suitable for the hydrogenation of said constituents for such a periodof time as to cause a saturation of said constituents without appreciable splitting thereof into lower boiling prodnets.

2. The process according to the preceding claim in which the organic liquid employed for the extraction is an oil boiling between 300 and 350 C. obtained by the destructive hydrogenation of coal.

3. The process according to claim 1 in which the organic liquid employed for the extraction is an oil boiling between 300 and 350 C. obtained by the destructive hydrogenation of coal and the extraction is carried out at a temperature between 380 and 400 C. and under a pressure of about 200 atmospheres.

4. The process according to claim 1 in which the extraction is carried out in stages in the first of which the material is extracted with benzene at a low temperature below 400 C., and in the second of which the extraction is carried out at a higher temperature below 400 C. and under an elevated pressure with an oil boiling between 300 and 350 C. obtained by the destructive hydrogenation of coal 7 5. The process according to claim 1 in which the treatment with reducing gases is carried out in the presence of a catalyst immune from poisoning by sulphur and under a pressure between 200 and 1000 atmospheres.

6. A process for producing lubricating oils which comprises subjecting'solid pyrobituminous material to an extraction at a temperature between 380 and 400 C. and under a pressure of about 200 atmospheres with an oil boiling between 300 and 350 C. obtained by the destructive hydrogenation of coal for such a time as to efiect a substantial extraction of soluble constituents and then subjecting the constituents extracted from the initial material to the action of hydrogen at an elevated temperature below 400 C. under a pressure between 200 and 1000 atmospheres and in the presence of a catalyst immune from poisoning by sulphur for such a period of time as to cause the saturation of said constituents without appreciable splitting thereof into lower boiling products.

7. A process for producing lubricating oils which comprises subjecting solid pyrobituminous material to an extraction in stages in the first of which the material is extracted with benzene at a low temperature below 400 C., and in the second of which the material is extracted at a temperature between 380 and 400 C. and under a pressure of about 200 atmospheres with an oil boiling between 300 and 350 C. obtained by the destructive hydrogenation of coal, the separate extractions being carried out for a sufliclent length of time to effect a substantial extraction of soluble constituents from said initial material and then subjecting the constituents extracted from the initial material to the action of hydrogen at an elevated temperature below 400 C. under a pressure between 200 and 1000 atmospheres and in the presence of a catalyst immune from poisoning by sulphur for such a period of time as to cause a saturation of said constituents without appreciable splitting thereof into lower boiling products.

' MATHIAS PIER.

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