GB1599103A

GB1599103A - Synthetic liquid fuels

Info

Publication number: GB1599103A
Application number: GB10727/78A
Authority: GB
Original assignee: Electric Power Research Institute Inc
Current assignee: Electric Power Research Institute Inc
Priority date: 1977-05-23
Filing date: 1978-03-17
Publication date: 1981-09-30
Also published as: JPS53145811A; CA1116639A; DE2822487A1; ZA777508B

Description

(54) SYNTHETIC LIQUID FUELS (71) We, ELECTRIC POWER RESEARCH INSTITUTE, INC., a corporation organised and existing under the laws of the State of Washington, D.C., United States of America, of 3412 Hillview Avenue, Palo Alto, California, United States of America, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to an economical and efficient process employing coal, particularly sub-bituminous coal, as a fuel source for the production of distillate fuels and methanol.

There is a continuing interest in upgrading fuels, particularly coal, to provide fuels having a wide variety of applications and coming within specified standards, such as environmental standards and physical standards. Because of the relatively large supplies of coal, much attention has been focused on the use of coal to replace oil. Bituminous and sub-bituminous coal has only limited direct utility when mined. The coal contains substantial amounts of sulphur nitrogen and inorganic compounds such as calcium salts.

In order to fulfill environmental standards, it is necessary to remove substantial amounts of the sulphur and nitrogen. Since calcium and other inorganic compounds have no fuel value, they act to reduce the heat contents per unit weight of coal and are contaminants which must be removed from a combustion zone and may interfere with the proper operation of fuel combustion. In addition, in many generation operations it is desirous to have a liquid, rather than a solid fuel.

In any refining of coal to upgrade the coal to an acceptable fuel, it is essential that the system be economical and efficient and, whenever possible, provide at least a portion of the additional materials necessary for the processing. It is desirable to produce products which have high economic value in comparison to the original coal value.

Accordingly the present invention provides a process for upgrading coal which comprises hydro-liquefying coal, in the presence of a hydrogen solvent in a hydroliquefaction zone to produce a substantially gaseous effluent and a substantially liquid effluent containing 650"F light distillates, separating the liquid effluent into a light distillate fraction, a solvent fraction, a heavy distillate fraction and a vacuum residue slurry, pumping the vacuum residue slurry into a partial oxidation gasifier, transforming the residue to synthesis gas consisting essentially of carbon monoxide and hydrogen, removing the acid gases from the synthesis gas and reacting the synthesis gas to produce methanol or methane.

The ratio of hydrogen to carbon monoxide in the synthesis gas may be increased and a hydrogen rich gas recycled from the partial oxidation gasifier to the hydroliquefaction zone.

The solvent may be recycled to the hydro-liquefaction zone. A process is provided for the economic and efficient upgrading of coal to a clean, light distillate fuel, a heavy fuel and methanol. Coal is solvent refined under severe conditions, preferably in -a hydrogen environment, to provide a substantially liquid product, which is divided in a separation zone to a light distillate product, recycle solvent, a heavy fuel, and a vacuum residue slurry. The vacuum residue slurry provides an efficient feed for a partial oxidation production and can supply hydrogen to the above liquefier. Hydrocarbon contaminants in the synthesis gas feed are returned to the gasifier or otherwise processed for conversion to additional synthesis gas. The heavy fuel may be used for in-plant fuel requirements.Alternatively, the hydrocarbon gases may be used for in-plant fuel and the heavy fuel gasified with the vacuum residue.

The process of the present invention is concerned with the efficient and economical production of light distillate and methanol or methane. Coal, particularly bituminous or sub-bituminous coal, and preferably the latter, are employed as the raw material.

In carrying out the process, a hydroliquefier is employed, whereby coal is contacted with hydrogen and solvent under severe conditions to produce high yields of light distillate. The gaseous fraction is taken overhead, and the hydrogen is preferably recycled to the hydroliquefier. The liquid fraction is transferred to a separation zone and divided into a light distillate fraction, a heavy distillate fraction, and a vacuum residue slurry. The light distillate fraction is a clean fuel. The heavy distillate fraction may be employed internally as a heat source, may be fed to the gasifier along with the vacuum residue slurry, may be further hydrocracked into light distillates, or stored and used for other purposes. The residue serves as a feed stock for a partial oxidizer gasifier which provides the synthesis gas feed stock for the methanol or methane production.Any hydrocarbon impurities from the preparation of methanol may be separated and returned to the gasifier, used as fuel gas, or steam-reformed to make additional synthesis gas.

The first stage of the process is the hydroliquefier. The hydroliquefier employs finely comminuted coal and a hydrogen donor solvent as a feedstock. Various processes for liquefying coal may be found in a wide variety of patents. See for example U.S. Patent Nos.

3,536,608 and 3,700,584.

In the present invention, various bituminous coals may be employed, but sub-bituminous coal is preferred, because it provides a high yield of light distillate, which is low in sulphur and nitrogen content. The comminuted coal will generally be less than one-quarter inch in diameter, more usually less than one-eighth inch, and preferably from 20 to 200 Tyler mesh, more preferably from 40 to 100 Tyler mesh. The size of the coal particles is not critical to this invention, and substantial variation is permitted.

The hydrogen donor solvent is primarily partially hydrogenated aromatic hydrocarbons.

Mixtures of hydrocarbons are generally employed, usually boiling in the range of from 260 to 425"C. Examples of suitable solvent components are tetralin, decalin, biphenyl and methylnaphthalene. Other types of solvents which may be added to the preferred solvents or may be present as part of the recycle stream are phenols such as phenol and cresol. The solvent may be hydrogen treated prior to introduction into the hydroliquefier to enhance the hydrogen donor capacity.

The operating conditions of the hydroliquefier are severe so as to enhance the production of light distillates. The hydroliquefier is normally operated at a temperature of from 700"F to 900"F, more usually from 825"F to 9000F and at a pressure of from 200 to 4,000 psig.

Reactor space rates is generally from 5 to 500 pounds of coal per hour per cubic foot of reactor volume, more usually from 5 to 40 pounds of coal per hour per cubic foot of reactor volume. Catalysts may be added, such as the oxides or sulphides of nickel, molybdenum and cobalt supported on a high surface area alumina or silica-alumina bar, normally however the process is noncatalytic.

The process may be carried out in the presence or absence of hydrogen. Where hydrogen is employed, the amount of hydrogen will generally vary from 5 to 50 scf per pound of coal.

The weight ratio of solvent to coal will generally be from 1:1 to 10:1, preferably from 1:1 to 3:1, and particularly preferred from 1.5:1 to 2:1.

The gas which exits from the hydroliquefier is a mixture primarily of hydrogen sulphide, carbon dioxide, water, methane, and hydrogen. By employing conventional scrubbing techniques, the hydrogen can be removed from the other gases and recycled to the hydroliquefier.

The substantially liquid effluent from the hydroliquefier is transferred to a separation zone, normally a distillation section, and preferably, one which includes a vacuum distillation column. The hydroliquefier effluent is divided into four fractions, a light distillate fraction, a solvent fraction, a heavy distillate fraction, and a vacuum residue slurry. Preferably, the separation is carried out in two stages where the distillate is divided into two fractions, the first fraction boiling up to 650"F and the second fraction boiling between 650"F and 950"F. The lower boiling fraction is then further separated into solvent and light distillate. The amount of vacuum residue slurry will be such that when gasified, as described below, will supply a substantial excess of gas over that which is required for the manufacture of make up hydrogen for the liquefier.

Based on the coal (dry ash free basis), the yield of light distillates may be from 15 to 45 percent by weight usually from 17 to 40 percent by weight and the stream of vacuum residue slurry may be from 40 to 80 percent by weight, usually from 44 to 75 percent by weight.

Without any further processing, the residue from the separation zone is employed as a feedstock for a partial oxidizer gasifier. This type of gasifier which produces synthesis gas has been described extensively in patent literature. Various special techniques may be employed as described in U.S. Patent Nos. 3,528,930, 3,816,332 and patents cited therein.

Therefore, only a brief description of the process is provided herein.

The residue, containing ash, is fed to the partial oxidizer and reacted with oxygen and steam in a closed reaction zone at an autogeneous temperature of from 1,800"F to 3,0000F, usually from 2,200 F to 2,800 F. The residue and steam are generally preheated to 5000F and usually at least 600"F. The reactor zone pressure is generally from 600 to 1,000 psig, although a pressure of up to 3,000 psig can be used.

The products from the gasifier are principally carbon monoxide and hydrogen, together with small amounts of carbon dioxide, methane and entrained carbon. The entrained carbon may be removed by conventional methods and the gas stream transferred to a methanol synthesizer.

The hydrogen-to-carbon monoxide ratio of the above gas is then altered to increase the proportion of hydrogen by conventional means. The acid gases are removed.

In the hydrogen-to-carbon monoxide ratio altering process, the synthesis gas is contacted with water under conditions such that carbon monoxide reacts with the water to produce hydrogen and carbon dioxide. The hydrogen rich stream is then split, a portion may be employed as make-up hydrogen for the liquefier and the remaining portion combined with the gasifier stream to provide at least the stoichiometric requirements for methanol or methane production, 2 and 3 molar proportion respectively.

While various processes for the synthesis of methanol may be employed, the preferred process is that of U.S. Patent No. 3,888,896. In this process the methanol synthesis is carried out in a liquid medium. Polyalkylbenzenes are used as a liquid medium and boil from 100"C to 250"C, although other liquids may also be included. The reaction temperature employed ranges from 200"F to 950"F, usually from 400"F to 750"F, with pressures from 200 to 100,000 psia, usually from 500 to 3,500 psia. Normally, hydrogen will be in excess of the stoichiometric requirement, usually not more than 5, more usually not more than 4 times stoichiometric.The flow rate of reactants will generally be from 0.1 to 10 pounds of feed per pound of catalyst per hour more usually from 0.5 to 5 pounds of feed per pound of catalyst per hour.

Any conventional methanol forming catalyst may be employed, for example, a copper, chromium or zinc catalyst as described in U.S. Patent No. 3,326,956.

The methanol stream which exits from the methanol synthesizer is generally contaminated with low molecular weight volatile hydrocarbons. These may be readily separated from methanol and the hydrocarbons returned to the gasifier. Alternatively, where the stoichiometry does not provide for complete reduction of the carbon monoxide, the unconverted reactants in the exiting gas stream may be employed directly for generation of electric power or for fuel. Alternatively, a side stream may be taken from the gasifier effluent to be used for the direct generation of electric power. In addition, the hydrocarbon purge from the methanol unit may be steam reformed to make synthesis gas, which may be then cycled to the methanol synthesis unit, rather than recycling the hydrocarbon purge to the gasifier unit.

The methanol produced from excess gasification products will generally be from 35 to 80%, usually from 40 to 60% of the total heating value of the fuel products.

Alternatively the methanol synthesis unit may be replaced by a methane synthesis unit, so that methane rather than methanol is prepared, which may then be used as a fuel.

The invention is further illustrated in the accompanying Drawing which is a flow diagram of a process in accordance with the present invention.

Coal (2) and recycle solvent (30) are slurried together in slurry preparation section (4), the coal being relatively dry and in finely comminuted form. The slurry is mixed with fresh hydrogen (825 and recycle gas (23) at preheater (6). Heated products (7) flow to liquefier (8). Liquefier product (9) is separated into vapour products (14) and liquid products (12) in hot vapour/liquid separator (10). The liquid product (12) is fed to a vacuum still (13). The vapour products (14) are cooled and flow to a separator (20) wherein fixed gases (21) are separated from water (19) and condensed hydrocarbons (26).

Overhead products (24) from the vacuum still (13) are mixed with the condensed hydrocarbons (26) and these are fed to an atmospheric fractionation section (28). Three products are taken from the atmospheric fractionation, namely: 400 x 950"F recycle solvent (30), heavy fuel (32) and net clean distillate product (34).

The vacuum still may be operated to leave this cut in the vacuum bottoms (i.e., slurry feed (36) to gasifier (42)).

The fixed gases (21) from the separator (20) are split partially into recycle gas (23) and purge gas (22). Purge gas stream (22), will be produced in an amount so that the build up of impurities in the liquefier feed gas can be controlled and the desired partial pressure of hydrogen in the liquefier provided. Purge gas stream (22) will contain hydrogen as well as hydrocarbon gases, carbon monoxide, carbon dioxide, hydrogen sulphide and other impurities. This stream may be admixed with gasifier output (50) or may alternatively be used as a source of fuel gas.

The vacuum residue slurry (36) and optionally purge gas stream (46) are fed to partial oxidation gasifiers (42) along with oxygen (40) and steam (44). Synthesis gas consisting principally of carbon monoxide, hydrogen and acid impurities CO2, H2S, COS) is the gasifier output (50). The acid gas impurities are removed in section (56). It may be desired to concurrently remove hydrocarbon impurities if a physical absorption system is used for acid gas removal. If this is done, part or all of stream (48) is removed as a stream from block (56) rather than from the methanol synthesis purge (46). A portion of clean gas stream (62) is shifted to form relatively pure hydrogen in blocks (68) and (72). A portion of hydrogen (82) is returned to the coal liquefaction section.The remainder of gas (66) is remixed with unshifted gas to form methanol synthesis gas feed (76). The split between streams (62) and (64) is chosen to be such that methanol synthesis gas feed (76) has a molar ratio of H2 to CO of approximately 2:1. The hydrogen and CO are converted to methanol in block (78) from which impurities emerge as stream (46) and the alcohol product as stream (80).

In the above description, it should be understood that the key process steps have been described conceptually and that one skilled in the engineering design of process plants would recognize engineering alternatives for carrying out the same process steps. In particular, it is important to the overall economics of the process to efficiently recover energy (heat) from steams being cooled and to use this energy to offset other process requirements. The particular choice of such items will be apparent to one skilled in the art.

In the process of the present invention, coal is transformed into a number of high quality fuels and chemicals by means of an economical and efficient process. Rather than using the coal directly in a gasifier to produce carbon monoxide and hydrogen, the process first hydroliquefies the coal under severe conditions, so as to give a high yield of light distillate fraction. In addition, the process provides hydrogen for the hydroliquefaction of coal and fuel for operation of the plant. The vacuum residue, which is a pumpable slurry at elevated temperature, is employed for the production of synthesis gas and ultimate production of methanol. Alternatively, the process can be easily modified to produce methane rather than methanol.A key feature of the process is the coproduction of distillates and methanol (or alternatively methane) in significant high yields The process can easily accommodate an increased yield of methanol is this is desired. The slurry feed to the gasifier (36) is capable of accepting additional solid hydrocarbons, such as coal, while still maintaining its slurry character. A substantial quantity of coal, equal to 30% or more by weight of stream (36), may be added. This is demonstrated in Example 4, below.

The process of the present invention upgrades the hydrogen and carbon values of coal to provide useful fuels and chemicals. The various products derivable from coal are integrated into a single system to produce a spectrum of products, which either may be used internally or provide high grade fuels or raw materials for further processing.

The invention is further illustrated in the following Examples.

Example 1 - Hydroliquefaction Sub-bituminous coal (l) from the Wyodak Mine located in Campbell Country Wyoming (Wyodak - Anderson Seam) was liquefied in a continuous apparatus with conditions and yields as follows: Coal Analysis Moisture, W% 6.4 Proximate, W% (dry) Ash 7.0 Volatile Matter 46.5 Fixed Carbon 46.5 Ultimate, W% (dry) Carbon 67.8 Hydrogen 5.0 Nitrogen 0.8 Sulphur 0.8 Ash 7.0 Oxygen (by difference) 18.6 Heating Value (dry basis) 11,480 Btf/pound.

(l) Johanson, Edwin, Solvent Refining of Wyodak, Illinois 6, and Black Mesa Coals, EPRI RP 389 (vol. 2), Electric Power Research Institute, Palo Alto, California, February 1976 (Data quoted are Run 177-114) RUN NUMBER 22 13B Run Conditions Coal Space Rate lb of dry coal 32 32 hr - Ft3 Recycle Solvent to Coal, wt 2 2 Temperature, F 840 835 Pressure, psig (pure H2 feed gas) 2500 2000 Type of reactor Perfectly mixed flow Yields, Weight % of MAF"' Coal CO2 8.25 5.84 CO .61 1.77 C1 x C3 9.10 5.70 C4 x 350"F 8.23 8.28 350 x 650 F 11.53 8.81 650 x 950"F 10.01 13.08 + 950 F Residuum Coal 36.99 34.94 MAF Unconverted Coal 7.38 13.19 H2O 10.66 10.66 NH3 .24 .13 H2S .50 .47 Total (100+ Hydrogen reacted) 103.50 102.87 (1'Moisture and ash free Properties of Products W% C 4 x 350 F % Sulphur 0.09 % Nitrogen 0.06 350 x 650 F % Sulphur 0.40 40 % Nitrogen 0.30 Example 2 - Gasification of Hydroliquefaction Vacuum RESIDUE SLURRY Vacuum residue slurries from hydroliquefaction processing Wyodak Coal (2) were gasified in a Texaco partial oxidation gasifier.Summarized results are as follows: Cold Gas Efficiency - 85% (Gross heating value of the synthesis gas as a fraction of gross heating value of the feed) SCF of Oxygen Oxygen Consumption - 0.270 SCF of O2 SCF of CO + H2 Example 3 - Integration of Liquefaction and Gasification and Methanol Synthesis Based on the above, Examples 1 and 2, the following yields were projected for their combination in accord with Figure 1 (Run 22 of Example 1), wherein streams 48 and 54 were null.

(2)Robin, Allen M., Hydrogen Production from Coal Liquefaction Residue, EPRI AF-233 Final Report, Electric Power Research Institute Yields, per 100 Btu net (lower) heating value of coal.

C4 x 350"F Distillate 12.8 Btu (LHV) 350 x 650"F Distillate 17.3 Btu (LHV) 650 x 950"F Distillate 15.5 Btu (LHV) Methanol 34.6 Btu (LHV) Total 80.2 OXYGEN REQUIRED 0.05 SCF For comparison, if methanol were produced from coal directly by partial oxidation, with feed in a water slurry, the products would be approximately 55 to 60 Btu of methanol LHV) per 100 Btu of feed coal (LHV), and the oxygen consumption would be more than twice as high.

In both of the above cases, the internal plant fuel requirements have not been considered. The net plant fuel requirements are about equal for the two cases.

The advantages of the process of the present invention with regard to plant efficiency are thus readily apparent.

Example 4 - Addition of Coal to Vacuum Bottoms The following data illustrates the fluidity of vacuum residues from processing of sub-bituminous coal and mixtures of that coal with the vacuum residue at 6000F Vacuum Residues - 0.4 poise 30% Coal/70% Vacuum Residues - 11.0 poise WHAT WE CLAIM IS: 1.A process for upgrading coal which comprises hydroliquefying coal in the presence of a hydrogen donor solvent in a hydroliquefaction zone to produce a substantially gaseous effluent and a substantially liquid effluent containing 650"F light distillates, separating the liquid effluent into a light distillate fraction, a solvent fraction, a heavy distillate fraction and a vacuum residue slurry, pumping the vacuum residue slurry into a partial oxidation gasifier, transforming the residue to synthesis gas consisting essentially of carbon monoxide and hydrogen, removing the acid gases from the synthesis gas, and reacting the synthesis gas to produce methanol or methane.

2. A process as claimed in Claim 1, wherein the ratio of hydrogen to carbon monoxide in the synthesis gas is increased and a hydrogen rich gas is recycled from the partial oxidation gasifier to the hydroliquefaction zone.

3. A process as claimed in Claim 1 or Claim 2, wherein the solvent is recycled to the hydroliquefaction zone.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

Example 2 - Gasification of Hydroliquefaction Vacuum RESIDUE SLURRY Vacuum residue slurries from hydroliquefaction processing Wyodak Coal (2) were gasified in a Texaco partial oxidation gasifier. Summarized results are as follows: Cold Gas Efficiency - 85% (Gross heating value of the synthesis gas as a fraction of gross heating value of the feed) SCF of Oxygen Oxygen Consumption - 0.270 SCF of O2 SCF of CO + H2 Example 3 - Integration of Liquefaction and Gasification and Methanol Synthesis Based on the above, Examples 1 and 2, the following yields were projected for their combination in accord with Figure 1 (Run 22 of Example 1), wherein streams 48 and 54 were null.

(2)Robin, Allen M., Hydrogen Production from Coal Liquefaction Residue, EPRI AF-233 Final Report, Electric Power Research Institute Yields, per 100 Btu net (lower) heating value of coal.

C4 x 350"F Distillate 12.8 Btu (LHV)

350 x 650"F Distillate 17.3 Btu (LHV)

650 x 950"F Distillate 15.5 Btu (LHV) Methanol 34.6 Btu (LHV) Total 80.2 OXYGEN REQUIRED 0.05 SCF For comparison, if methanol were produced from coal directly by partial oxidation, with feed in a water slurry, the products would be approximately 55 to 60 Btu of methanol LHV) per 100 Btu of feed coal (LHV), and the oxygen consumption would be more than twice as high.

In both of the above cases, the internal plant fuel requirements have not been considered. The net plant fuel requirements are about equal for the two cases.

The advantages of the process of the present invention with regard to plant efficiency are thus readily apparent.

Example 4 - Addition of Coal to Vacuum Bottoms The following data illustrates the fluidity of vacuum residues from processing of sub-bituminous coal and mixtures of that coal with the vacuum residue at 6000F Vacuum Residues - 0.4 poise 30% Coal/70% Vacuum Residues - 11.0 poise WHAT WE CLAIM IS: 1.A process for upgrading coal which comprises hydroliquefying coal in the presence of a hydrogen donor solvent in a hydroliquefaction zone to produce a substantially gaseous effluent and a substantially liquid effluent containing 650"F light distillates, separating the liquid effluent into a light distillate fraction, a solvent fraction, a heavy distillate fraction and a vacuum residue slurry, pumping the vacuum residue slurry into a partial oxidation gasifier, transforming the residue to synthesis gas consisting essentially of carbon monoxide and hydrogen, removing the acid gases from the synthesis gas, and reacting the synthesis gas to produce methanol or methane.
2. A process as claimed in Claim 1, wherein the ratio of hydrogen to carbon monoxide in the synthesis gas is increased and a hydrogen rich gas is recycled from the partial oxidation gasifier to the hydroliquefaction zone.
3. A process as claimed in Claim 1 or Claim 2, wherein the solvent is recycled to the hydroliquefaction zone.
4. A process as claimed in any one of claims 1 to 3, wherein yield of light distillates

comprises from 15 to 45% of the coal (dry ash free basis), and the yield of vacuum residue slurry comprises from 40 to 80% of the coal, and wherein methanol is produced from excess gasification products and amounts to from 35 to 80% of the total heating value of the fuel products.
5. A process as claimed in any preceding claim wherein the coal is sub-bituminous coal.
6. A process as claimed in any preceding claim wherein a 650 to 9500F net heavy oil product is included in the vacuum residue slurry.
7. A process as claimed in any preceding claim wherein the convention of carbon monoxide and hydrogen to methanol is incomplete, and the unconverted carbon monoxide and hydrogen are burned for the generation of electric power.
8. A process as claimed in any of claims 1 to 7, wherein the amount of gasifier feed slurry is increased by mixing coal therewith.
9. A process as claimed in claim 8, wherein the gasifier feed contains up to 30% coal (by weight).
10. A process as claimed in any of claims 1 to 9, wherein the hydroliquefaction of the coal takes place at a temperature of from 700"F to 900"F.
11. A process as claimed in claim 10, wherein the hydroliquefaction of the coal takes place at a temperature of from 825"F to 900"F.
12. A process as claimed in any of claims 1 to 11, wherein the hydroliquefaction of the coal takes place at a pressure of from 200 to 4,000 psig.
13. A process as claimed in any of claims 1 to 12, wherein the hydroliquefaction reactor space rate is from 5 to 500 pounds of coal per hour per cubic foot of reactor volume.
14. A process as claimed in claim 13, wherein the hydroliquefaction reactor space rate is from 5 to 40 pounds of coal per hour per cubic foot of reactor volume.
15. A process as claimed in any of claims 1 to 14, wherein the hydroliquefaction step employs a catalyst.
16. A process as claimed in claim 15, wherein the catalyst is an oxide or sulphide of nickel, molybdenum or cobalt supported on a high surface area alumina or silica alumina bar.
17. A process as claimed in any of claims 1 to 16, wherein hydrogen is employed in the hydroliquefaction step in an amount of from 5 to 50 scf per pound of coal.
18. A process as claimed in any of claims 1 to 17, wherein the weight of solvent to coal in the hydroliquefaction zone is from 1:1 to 10:1.
19. A process as claimed in claim 18, wherein the ratio of solvent to coal in the hydroliquefaction zone is from 1:1 to 3:1.
20. A process as claimed in claim 19, wherein the ratio of solvent to coal in the hydroliquefaction zone is from 1.5:1 to 2:1.
21. A process as claimed in any of claims 1 to 20, wherein the temperature in the partial oxidation gasifier is from 18000F to 30000F.
22. A process as claimed in claim 21, wherein the temperature in the partial oxidation gasifier is from 2200"F to 2800"F.
23. A process as claimed in any of claims 1 to 22, wherein the pressure in the partial oxidation gasifier is from 600 to 1000 psig.
24. A process as claimed in any of claims 1 to 23, wherein the methanol synthesis is carried out in the presence of polyalkylbenzenes boiling at a temperature of from 100"C to 2500C.
25. A process as claimed in any of claims 1 to 24, wherein the methanol synthesis is carried out at a temperature of from 200"F to 950"F.
26. A process as claimed in claim 25, wherein the methanol synthesis is carried out at a temperature of from 400"F to 7500F.
27. A process as claimed in any of claims 1 to 26, wherein the methanol synthesis is carried out at a pressure of from 200 to 10,000 psia.
28. A process as claimed in claim 27, wherein the methanol synthesis is carried out at a pressure of from 500 to 3500 psia.
29. A process as claimed in any of claims 1 to 28, wherein a copper, chromium or zinc catalyst is used in the methanol synthesis step.
30. A process as claimed in Claim 29, wherein the flow rate of reactants in the methanol synthesis is from 0.1 to 10 pounds of feed per pound of catalyst per hour.
31. A process as claimed in Claim 30, wherein the flow rate of reactants in the methanol synthesis is from 0.5 to 5 pounds of feed per pound of catalyst per hour.
32. A process as claimed in Claim 1 substantially as herein described with reference to Example 3.
33. A process as claimed in Claim 1 substantially as herein described with reference to the accompanying drawing.
34. Methanol whenever produced by a process as claimed in any preceding claim.