US2339108A - Manufacture of hydrocarbon oils - Google Patents

Description

Jan. 11, 1944. M PIER ETAL MANUFACTURE 0F HYDROCARBON OIL Filed Nov. 9, 1940 All..

gulf

I I l l l I N n@ uw um 2, I@

Patented Jan. 11, 1944 MANUFACTURE F HYDROCARBDN OILS Mathias Pier, Heidelberg, and Walter Kroenig and Viktor Rank, Ludwigshafen-on-the-Rhine, lrmany; vested in the Alien Property Custo- Application November 9, 1940, Serial No. 365,016

In Germany July 20, 1939 i 6 Claims.

The present invention relates to a process for the manufacture of hydrocarbon oils.

We have found that liquid or fusible carbonaceous materials containing' asphalts and hence being difficult to work up, for example, by distillation or cracking4 or destructive hydrogenation, for example tars, mineral oils or products of the destructive hydrogenation of coals, tars or mineral oils or pressure extracts of coals containing asphalt, may without appreciable losses be transformed into products which may-easily be Worked up by distillation, cracking or destructive hydrogenation and are themselves useful as Diesel oils, lubricating oils or heating oils. The process consists in subjecting the initial materials containing asphalt to a cracking under mild conditions in the presence of hydrogen, so that an appreciable proportion of the constituents boiling above 325 C. in vacuo (12 millimeters mercury gauge), say from 20 to 60 per cent, are cracked into constituents boiling between 350 C. under atmospheric pressure and 325 C. in vacuo, and theamount of constituents boiling below v350 C. under atmospheric pressure is increased at the most by about per cent. This object is achieved by heating the initial materials under increased pressure, for example between 2 and 200 atmospheres or more, preferably between 3 and 100 atmospheres, in the presence or absence of hydrogen, while adding hydrogen after heating to temperatures above 400 C., as for instance between 420 and 470 C., for example in an amount of about 0.2 to about 6 cubic meters per kilogram of initial material, more particularly from l to 5 cubic meters or, if hydrogen be already present from the start, e. g., about 0.7 cubic meter per kilogram of initial material to avoid coking while heating, hydrogen must equally be added, for example in an amount of about 0.2 to about 4 cubic meters per kilogram of initial material, the temperature above 400 C. being maintained for a time until the above mentioned degree of cracking has been reached which may be ascertained, for example by investigating the boiling point curve of samples taken from the reaction mass. The materials are then separated into pitch and vaporous products without being treated with rening agents, or treated by sev,- eral of these ways.

The advantage of the process according to the present invention resides in the fact that, depending on the type of the initial material, Diesel oils, lubricating oilsand fuel oils may be produced without it being necessary to subject the products Areleased from pressure to a subsequent de-v structive hydrogenation or cracking, the oils being obtained in higher yields and superior quality than when producing them directly by distilla- .tion under mild conditions of the initial materials. Such a distillation is attended also with the production of a substantially larger amount of asphalt than the process according to this invention. If the-products obtained (after release from pressure) from the vapors by conf y densation are subjected to a destructive hydro-` genation or cracking treatment, much larger throughputs may be used and higher yields obtained and moreover the catalysts will display a better eciency and be active for a longer period of time than Without the heating under wax, as for example the heavy oil obtained from vapors escaping during the destructive hydrogenation. It is advantageous to add to the initial materials substances of a lower boiling point, for example middle oil, benzine, benzene or its lowboiling homologues which may be employed over again in a cycle. Products obtained in the process itself may also be added to the intial'materials, especially lighter oils. Additions 0f the said kind are not necessary if the initia1 materialv already contains sufficient amounts, for example 25 percent and more, of low-boiling fractions. An alternative procedure consists in removing low-boiling fractions ,rich in hydrogen which are contained in the initial-materials, as for example benzine, and replacing them kby low.. boiling hydrocarbons lower in hydrogen, as for examplebenzene. Itis of advantage to add to the initialmateria'l, before or during theheating, finely divided adsorption agents, as for example brown' coal low temperature coke, active charcoal, natural or lartincial silicates, bauxite or bleachingearths, as for example fullers earth. or silica gel Vor similar porous substances or/and metal "compounds, les,-

peciallygoxides," slphides, phosphates or halides from 2 to 200 atmospheres, advantageously in a tubular heater. Part of lthe heated materials may be returned to the heater in order to increase `the speed of ow therein, to avoid sedimentations and to save additional substances, as for exam ple brown coal low temperature coke.

The heating may be effected with hydrogen being' present already from the start. However,

the hydrogen may also be added during or after the heating, but not later than when the temperature above 400 C., at which the treatment is to be carried through, has been reached. Should there be deiiciency in hydrogen at this temperature, its partial pressure is to be increased, for example by adding hydrogen once or several times. the total pressure being also changed, if Y desired.

By a preferred method of practicing the process accordingl to the invention the materials, after being heated in a tubular heater. are conveyed to an enlarged vessel, for example a column, without release of pressure. care being taken that the partial pressure of hydrogen prevailing in this latter vessel is higher than that prevailing in the heater. This is achieved, for example, by

agents of the aforesaidkind, preferably at moderately elevated temperatures, or with chemical reiining agents, as for example sulphuri'i acid, or subjected to a rening destructive hydrogenation or a treatment with selective solvents, as for example liquefied normally gaseous hydrocarbons and/or selective solvents having a preferen tial dissolving power for cyclic compounds.

The process has provedespecially useful in pretreating carbonaceous materials which'are to be subjected to a catalytic destructive hydrogenation, for which purpose the efllucnt vapors together with the hydrogen contained therein may be passed over hydrogenating and/or cracking catalysts under a high pressure at temperatures of between 350 and 550 C. This destructive hydrogenation maybe carried out as a cracking destructive hydrogenation, whereby low-boiling hydrocarbons are obtained, or as a so-called low temperature destructive hydrogenation, whereby lubricating oils and valuable Diesel oils are ob-n tained. The vaporous products may also be cracked into products of lower boiling point in the presence of hydrogen which is not consumed thereby. For this'purpose there are used smaller quantities of hydrogen than are usual for thedestructive hydrogenation. In such cracking treatment, the catalyst may be moved through the cracking space either in the samev direction as, or preferably in counter-current to, the vapors to be cracked. It is sometimes of advantage to eilect a mild destructive hydrogenation after cracking, the cracking products being thus refined to a large extent.

introducing hydrogen into the vessel at one or several points or shortly before the entry oi the preheated materials. The materials may also be slightly released from pressure before entering the enlarged vessel; for example the pressure may be about 20 per cent lower than thefpressure initially prevailing. The temperature in the adjoining vessel may be by about 10 to 50 C. lower than' in the heating tubes. The vapor space of the enlarged vessel is advantageously equipped with baiilefplates, bell trays or Raschig rings and/or suchsubstances, as for example bauxite, silica gel or active charcoal. In this manner, with a proper choice ot the temperature there may easily be accomplished a separation into vaporous products containing heavy oil which leave at the upper end of the vessel, and pitchy residues which are discharged at` the lower end.

Besides hydrogen, other gases, as for example steam, gaseous hydrocarbons or gases containing the same, as for example cracking gases, iurthermore oxides of carbon or nitrogen, may be added. It is especially advantageous to carry out the pressure heating under such condition that the quantity of the pitchy residue, which is usually solid at ordinary temperature and fusible, amounts to about 3 to 15 per cent and that the heavy oil contained in the vapors, which boils above 350 C. under a pressure o! 780 millimeters,

still contains at least 3 per cent of constituents boiling above 325' C. under apressure or 12 millimeters. When working in this manner the et nuent vapors still contain resins and asphalte which, however, have a lower molecular weight 'I'he following example illustrates how the present invention may be carried out in practice,

' but the invention is not restricted to this example.

.Example Referring to the accompanying drawing which illustrates a plan for carrying out the present invention a Germanmineral oil is admitted through feed pipe I and freed from constituents boiling up to 200 C. by distillation in still 2. The distillation residue contains 35 per cent of a traction vboiling up to 350 C. under atmospheric pressure.

- The fraction boiling above 350 C. contains 60 gram of oil, admitted through line 4, while adding than the asphaltic constituents of the initial ma- 7c in the subsequent together with the brown coal producer ashes added In'theupper part of the vessel l 92 per centoftheinitialmaterialusedpassesintnthevaporousstate. Itcontains4 percentottheV .constituentsboilingupto350. Thewastedue toros-mation ot gas amounts to per cent. The

fraetionsboilingabove C. containonly C.

rigidly arrangedeor ilnely divided adsorption Il withdrawn through' line Il 7 per cent of pitch percentetccnstituentsboillngabovem under a pressure of vl2 milimeters (mercury gauge).

The vaporous fractions are passed, through line I 2 and pump I4, together with 3 cubic meters of hydrogen per kilogram of oil, admitted through linev|3 over a catalyst arranged inchamber I5 and consisting of nickel sulphide and tungsten sulphide at a temperature of 340 C. under a pressure of 250 atmospheres and subsequently over a catalyst arranged n chamber I6 and consisting of molybdenum oxide, zinc and magnesium oxide, the temperature being slowly raised from 360 to 450 C. by means of heater I1 while passing the fractions over the latter catalyst cham ber I 6.

The products thus obtained as passed through line I8 and fractionating tower I9. They may consistto the extent of 80 per cent of a fraction boiling up to 36.0 C., this fraction consisting of 25 per cent of benzine-like products boilingl up to 200 C. and 75 per cent o! Diesel oil boiling from 200 to 360 C. The fractions having a higher boiling point are recycled through line 20.

What we claim is:

1. The process of producing a hydrocarbon oil from a hydrocarbon mixture containing asphalt which comprises heating the Iinitial material to a temperature above 400 C. under pressures ranging from 2 to 200 atmospheres, adding hydrogen after heating, in an amount of 0.6 to 6 cu. m. per kilogram of initial material, maintaining the initial material without appreciable consumption of hydrogen at a temperature above 400 C. until a substantial portion of the fraction boiling above 325 C. under a pressure oi about 12 millimeters is cracked into a fraction boiling between 350 C. under atmospheric pressure and 325 C. under a pressure of about 12 millimeters while the fraction boiling below 350 C. under atmospheric pressure is augmented at the most by about 10 per cent, and separating the reaction product into pitch and vapors substantially without release from pressure and substantially without cooling.

2. In the'process as claimed in claim 1, Working in the presence of a solid adsorption agent.

3. The process of producing a hydrocarbon oil from a hydrocarbon mixture containing asphalt which comprises heating the initial material to a temperature above 400 C. under pressures- C. under a pressureof about 12 millimeters is cracked into a fraction boiling between 350 C.

under atmospheric pressure and 325 C. under a pressure oi about 12 millimeters while the fraction boiling below 350 C. under atmospheric pressure is augmented at the most by about 10 per cent, and separating the reaction product into pitch and vapors substantially without release from pressure and substantially without cooling.

4. The process of producing a hydrocarbon oil from a hydrocarbon mixture containing asphalt which comprises heating the initial 4material to a temperature between 420 and 470 C. under pressures ranging from 2 to 200 atmospheres, adding hydrogen after heating, in an amount of 0.6 to 6 cu. m. per kilogram of initial material, maintaining the initial material without appreciable consumption of hydrogen at the said temperature until a substantial part of the fraction boiling above 325 C. under a pressure of about 12 millimeters is cracked into a fraction boiling between 350 C. under atmospheric pressure and 325 C. under a pressure of about 12 millimeters while the fraction boiling below 350 C. under atmospheric pressure is augmented at the most by aboutlO per cent, and separating the reaction product into pitch and vapors substantially without release from pressureand substantially Without cooling.

5. The process of producing a hydrocarbon oil from a hydrocarbon mixture containing asphalt which comprises heating the initial material to a temperature above 400 C.' under pressures ranging from 2I to 200 atmospheres in an elongated, comparatively narrow heating zone, passing the heated product into an enlarged adjoining reaction space maintained at substantially the same temperature, adding hydrogen in an amount of 0.6 to 6 cu. m. per kilogram of initial material, maintaining the initial material without appreciable consumption of hydrogen at a temperature above ,400 C. until a substantial part of the fraction boiling above 325 C. under a pressure of about 12 millimeters is cracked into a fraction boiling between 350 C. under atmospherio pressure and 325 C. under a pressure oi about l2 millimeters while the fraction boiling below 350 C. under atmospheric pressure is augmented at the most by about 10 per cent, and separating the reaction product in the enlarged reaction space into pitch and vapors substantially without release from pressure and substantially without cooling.

6. In the-,process claimed in claim 5 heating the initial material in the elongated heating zone in the presence of hydrogen suiiiclent in amount to prevent coking while heating and adding iurther hydrogen in an amount from about 0.2 to about 4 cubic meters per kilogram of initial material in the adjoining enlarged reaction space.

MATHIAS PIER. WALTER KROENIG. VIKTOR RANK.

Images