CS212241B2 - Fuel mixture - Google Patents

Abstract

This fuel mixture contains by weight 87.0 to 93% carbon, 5.0 to 11.0% hydrogen, 0.5 to 2.0% nitrogen, 0.1 to 3.0% oxygen and not more than 0.5% sulfur and is formed by a solid and/or semi-solid material containing by weight 87.0 to 93.0% carbon, 5.5 to 9.5% hydrogen, 0.3 to 3j0% nitrogen, not more than 1.5% oxygen and not more than 0.5% sulfur, prepared by a process in which a suspension consisting of coal and a hydrogen donor solvent is hydrogenated together with hydrogen in the absence of a catalyst in a first hydrogenation zone to form a coal-solvent suspension as an intermediate product, this coal-solvent suspension is deashed to form a coal-solvent solution, the coal-solvent solution is catalytically hydrogenated in a second hydrogenation zone to form a product which is separated at ambient pressure into a first liquid fraction with a boiling point of 100 to 375 °C, a second liquid fraction with a boiling point higher than that of the first liquid fraction, namely 200 to 525 °C, and a solid and/or semi-solid material, wherein at least the second part of the liquid fraction is recycled to the first hydrogenation zone, longer it is formed by low-boiling hydrocarbons with a boiling point of 100 to 375 °C at ambient pressure and containing by weight 85 to 93% carbon, 7.0 to 12.0% hydrogen, not more than 2.0% nitrogen, not more than 2.0% oxygen and not more than 3.0% sulfur, wherein the weight ratio of solid and/or semi-solid material to low-boiling hydrocarbons is 20:1 to 1.5:1.

Description

(54) Fuel mixture

This fuel mixture contains by weight 87.0 to 93% carbon, 5.0 to 11.0% hydrogen, 0.5 to 2.0% nitrogen, 0.1 to 3.0% oxygen and not more than 0.5% sulphur and is made up of a solid and/or semi-solid material containing by weight 87.0 to 93.0% carbon, 5.5 to

9.5% hydrogen, 0.3 to 3j0% nitrogen, maximum

1.5% oxygen and not more than 0.5% sulfur, prepared by a process in which a suspension consisting of coal and a hydrogen donor solvent is hydrogenated together with hydrogen in the absence of a catalyst in a first hydrogenation zone to form a coal and solvent suspension as an intermediate product, this coal and solvent suspension is deashed to form a coal solution in a solvent, the coal solution in a solvent is catalytically hydrogenated in a second hydrogenation zone to form a product which is separated at ambient pressure into a first liquid fraction with a boiling point of 100 to 375 °C, a second liquid fraction with a boiling point higher than that of the first liquid fraction, namely 200 to 525 °C, and a solid and/or semi-solid material, at least the second part of the liquid fraction being recycled to the first hydrogenation zone, longer being formed by low-boiling hydrocarbons with a boiling point of 100 to 375 °C at ambient pressure and containing by weight 85 to 93% carbon, 7.0 to 12.0% hydrogen, not more than 2.0% nitrogen, not more than 2.0% oxygen and not more than 3.0% sulfur, with a weight ratio of solid and/or semi-solid material to low-boiling hydrocarbons of 20:1 to 1.5:1.

2241

The invention relates to a fuel mixture consisting of a solid and/or semi-solid material prepared by hydrogenation of coal in the presence of a hydrogen donor solvent and low-boiling hydrocarbons with a boiling point of 100 to 375 °C.

Solvent refining of coal produces a solid and/or semi-solid material that cannot be easily converted to a lower viscosity fuel unless it is blended with a large amount of low-boiling hydrocarbon or hydrogenated. The disadvantage of hydrogenation is the high hydrogen consumption. Both blending with low-boiling hydrocarbon and hydrogenation are expensive processes.

Coal remains an important source of energy, and its processing into a fuel free of ash, sulfur, and other undesirable components is receiving constant attention.

The invention is a new fuel mixture containing by weight 87.0 to 93.0% carbon, 5.0 to 11.0% hydrogen, 0.5 to 2.0% nitrogen, 0.1 to 3.0% oxygen and not more than 0.5% sulfur, which is characterized in that it contains a solid and/or semi-solid material containing by weight 87.0 to 93.0% carbon, 5.5 to 9.5% hydrogen, 0.3 to 3.0% nitrogen and not more than 1.5% oxygen and 0.5% sulfur, which is preparable by a process in which a suspension consisting of coal and a solvent that is a hydrogen donor is hydrogenated with hydrogen in the absence of a catalyst in a first hydrogenation zone to form a coal-solvent suspension as an intermediate product, this coal-solvent suspension is deashed to form a coal-solvent solution, a solution of coal in a solvent is catalytically hydrogenated in a second hydrogenation zone to form a product which is separated at ambient pressure into a first liquid fraction with a boiling point of 100 to 375 °C, into a second liquid fraction with a boiling point higher than the first liquid fraction, namely 200 to 525 °C, and into a solid and/or semi-solid material, wherein at least a portion of the liquid fraction is recycled to the first hydrogenation zone, and further comprises low-boiling hydrocarbons with a boiling point of 100 to 375 °C at ambient pressure and containing by weight 85 to 93% carbon, 7.0 to 12.0% hydrogen and not more than 2.0% nitrogen, not more than 2.0% oxygen and not more than 3.0% sulfur, wherein the weight ratio of solid and/or semi-solid material to low-boiling hydrocarbons is 20:1 to 1.5:1.

The new fuel mixture according to the invention is suitable as a fuel for energy production instead of heating oil prepared from crude oil. It can be prepared in an economical manner.

Generally, a slurry containing coal and a hydrogen donor solvent is hydrogenated together with hydrogen in the absence of a catalyst in a first hydrogenation zone under the conditions shown in Table 1.

Table 1

Hydrogenation conditions in the absence of a catalyst

General field

Advantageous field

Temperature, °C 343 until 510 399 until 482 Pressure, kPa 3,447 up to 34 470 6,894 until 13,888 Weight ratio solvent/coal 0.5/1 until 10/1 1/1 until 4/1 Weight ratio hydrogen/coal feed 0.01/1 until 0.30/1 0.05/1 until 0.10/1 Hydrogen purity, % mole 85 until 100 95 until 97 Delay, hours 0.1 until 5.0 0.5 until 2.0

Hydrogenation of the slurry in the absence of a catalyst produces a coal-solvent slurry as an intermediate product. Ash and/or other undissolved materials are separated from the coal-solvent slurry intermediate product to produce a solvent-coal solution. This coal-solvent solution is catalytically hydrogenated in a second hydrogenation zone. The catalytic hydrogenation conditions are given in Table 2.

Table 2

Catalytic hydrogenation conditions

General field Beneficial field Temperature, °C 260 to 538 399 until 454 Pressure, kPa 3,447 to 68 940 6,894 up to 27 576 Hourly space velocity fluids introduced volume/volume catalyst/hour 0.3 to 10 1.0 until 4 Hydrogen flow rate kmol hydrogen/m^ of feed 25 to 190 60 until 90

Any catalyst suitable for the hydrogenation of coal may be used. A preferred catalyst comprises hydrogenation components selected from the group consisting of metals of groups VI and VIII, their oxides and sulfides, supported on a support other than a zeolite, the catalyst being promoted by metals of group IVB. Examples of catalysts particularly suitable for the process of the invention include metal combinations of nickel, titanium and molybdenum, nickel, cobalt and molybdenum, and nickel and tungsten on alumina as a support.

The product formed by catalytic hydrogenation can be separated by any method known in the art, in particular by distillation at ambient pressure into a) a first liquid fraction with a boiling point of 100 to 375 °C, in particular 150 to 325 °C, b) a second liquid fraction with a boiling point higher than that of the first liquid fraction, namely 200 to 525 °C, preferably 250 to 475 °C, and c) a solid and/or semi-solid material. The elemental analysis of a typical solid and/or semi-solid material, which is a necessary component of the new fuel mixture according to the invention, is given in Table 3.

Table 3

Analysis of solid and/or semi-solid material

General range % by weight

Preferred range % by weight

Carbon 87.0 until 93.0 88.0 until 92.0 Hydrogen 5.5 until 9.5 6.5 until 8.0 Nitrogen 0.3 until . 3.0 0.8 until 2.0 Oxygen 0.0 until 1.5 o,’ until 1.0 Sir 0.0 until 0.5 0.0 to 0.2

The solid and/or semi-solid material may be mixed with low boiling hydrocarbons having a boiling point of about 100 to 375°C, preferably having a boiling point of 150 to 325°C at ambient pressure. A typical elemental analysis of such low boiling hydrocarbons is given in Table 4.

Table 4

Analysis of low-boiling hydrocarbons

General range % by weight

Preferred range % by weight

Carbon 85.0 Hydrogen 7.0 Nitrogen 0.0 Oxygen 0.0 Sulfur 0.0

until 93.0 88.0 to 91 .0 until 12.0 8.5 until 1 1 .0 until 2.0 0.1 until 0.7 until 2.0 0.1 until 0.7 until 3.0 0.0 until 0.3

Generally suitable low boiling hydrocarbons which may be used in accordance with the invention include, for example, fuel oil, kerosene, jet fuel, diesel, gasoline, light fractions of oil from bituminous shale and light fractions obtained from coal hydrogenation. Particularly preferred low boiling hydrocarbons are the so-called first liquid fraction with a boiling point of 100 to 375 °C, preferably 150 to 375 °C. The elemental analysis of this first liquid fraction is given in Table 5.

Table 5

General range % by weight

Preferred range % by weight

Carbon 87.0 until 93.0 88.0 until 91.0 Hydrogen 7.0 until 12.0 8.5 until 11.0 Nitrogen 0.0 until 2.0 0.1 until 0.7 Oxygen 0.0 until 2.0 0.1 until 0.7 Sulfur 0.0 until 0.5 0.0 until 0.3

The solid and/or semi-solid material is mixed with the low-boiling hydrocarbons by methods well known in the art. The components are mixed until a homogeneous product is obtained. The weight ratio of the solid and/or semi-solid material to the low-boiling hydrocarbons is about 20:1 to 1.5:1, with a weight ratio of 10:1 to 2:1 being preferred.

The elemental analysis of the homogeneous product is given in Table 6.

Table 6

General range % by weight

Preferred range % by weight

Carbon 87.0 until 93.0 88.0 until 91.5 Hydrogen 5.0 until 11.0 6.0 until 9.0 Nitrogen 0.5 until 2.0 0.8 until 1.5 Oxygen 0.1 until 3.0 0.2 until 1.5 Sulfur 0.0 until 0.5 0.0 until 0.2

The product according to the invention is suitable as a fuel for energy production instead of heating oil prepared from coal and crude oil.

The invention is illustrated in the following examples.

Example 1

Coal containing ash from the Pittsburg and Midway Coal Company Colonial Mine was used for the experimental work. The coal has the following composition.

Table7

Analysis of coal-containing ash (based on dry matter)

% by weight Carbon 71.8 Hydrogen 5.0 Nitrogen 1.3 Oxygen 7.9 Sulfur 3.7 Ash 10.3

Coal is dissolved in a solvent essentially defined in Table 6 of the above-mentioned Czechoslovak patent together with hydrogen under hydrogenation conditions in the absence of a catalyst as set forth in Table 8 in a first hydrogenation zone to form a slurry of coal and solvent as an intermediate product.

Table 8

Hydrogenation conditions in the absence of a catalyst

Temperature, °C 450

Pressure, kPa 10,755

Solvent/coal weight ratio 2.14/1

Mass ratio of hydrogen/introduced carbon 0.08/1

Delay, hours 1

Ash and/or other insolubles are separated from the coal-solvent suspension by filtration under the conditions given in Table 9, to form a coal-solvent solution. The analysis of the coal-solvent solution is given in Table 10.

Table 9

Filtration conditions

Filter temperature, °C

Filter pressure, kPa

Pressure drop, kPa

Knife feed, mm/min

Drum speed, min/rpm Base coat Pre-coat

229 1 206

207 0.254 1.0 to 1.5

Fibra F10-11C and Celite 545 Celite 535

Table 10

Analysis of coal solution in solvent

% by weight Carbon 89.3 Hydrogen 6.3 Nitrogen 1.2 Oxygen 2.5 Sulfur 0.7 Ash 0.04

A solution of coal in a solvent is catalytically hydrogenated by passing the solution over a specific catalyst under specific reaction conditions listed in Table 11.

Table 11

Catalyst composition and reaction conditions of catalytic hydrogenation

Catalyst'

Temperature, °C

Pressure, kPa

Hourly liquid space velocity ml feed/ml catalyst/hour

Hydrogen flow rate kmol hydrogen/m-^ feed

0.5% by weight nickel 1.0% by weight cobalt 8.0% by weight molybdenum

427 20 700

2.0

75.2 'The metals are deposited on alumina with a surface area of 185 m^/g, an average pore size of 18.8 nm and a pore volume of 0.66 ml/g.

After catalytic hydrogenation, the product is separated by distillation under a trough into a) a first liquid fraction boiling at about 191 to 288 °C, b) a second liquid fraction boiling at about 288 to 396 °C, and c) solid and/or semi-solid material. The analysis of these products is given in Table 12.

Table 12

Analysis of liquid fractions and solid and/or semi-solid product (mass)

First liquid fractions carbon 89.3 % boiling point 191 to 288 °C hydrogen 9,θ % nitrogen 0.4 % oxygen 0.4 % sulfur 0.06 % Second liquid fraction carbon 90.6 % boiling point 288 to 403 °C hydrogen 8,’ % nitrogen 0.5 % oxygen 0.4 % sulfur 0.1 %

212241 6 continued table 12

Solid and/or semi-solid material carbon hydrogen nitrogen oxygen sulfur 89.3% 7.0% 1.3% 0.8% 0.1% Solid and/or semi-solid material, defined in table 12, with mixes with low-boiling hydrocarbons, as defined in Table 12 as the first liquid fraction. The mixture has characteristics listed in table 13. Table 13 Mixture of solid and/or semi-solid material and first liquid fraction Mixture number 1 Mixture number 2 Solid and/or semi-solid material % by weight (A) 82 75 First liquid fraction % by weight (B) 18 25 A/B ratio 4.6 3.0 Saybolt viscosity furol, seconds at 99 °C 180 58 % by weight % by weight Carbon 89.3 89.3 Hydrogen 7.5 8.2 Nitrogen 1.1 ’,1 Oxygen 0.7 0.7 Sulfur 0.1 0,’

Example 2

The procedure is the same as described in Example 1, except that the hydrogenation conditions are as follows:

Temperature, °C 427

Pressure, kPa 10,300

Hourly liquid space velocity ml feed/ml catalyst/hour 2

The hydrogen flow rate kmol hydrogen/m^ feed is 75.2 and the weight ratio of solid and/or semi-solid material (boiling point above 454 °C) to low-boiling hydrocarbons is 2.7:1. The final product obtained has the properties shown in Table 14.

Table 14

Properties of the mixture of solid and/or semi-solid material and the first liquid fraction

Mixture number 3 Solid and/or semi-solid material % by weight (A) First liquid fraction 73 % by weight (B) Saybolt viscosity 27 furol, seconds at 99 °C 75 % by weight Carbon 90.8 Hydrogen 7.1 Oxygen 1.3 Nitrogen ’,3 Sulfur 0.1 Example 3 The procedure is the same as described in the example 1, except that the conditions of catalysis tical hydrogenation are as follows: Temperature, °C 427 Pressure, kPa Hourly liquid space velocity ml feed/ml catalyst/hour Hydrogen flow rate 20,700 1 kmol hydrogen/m3 feed 75.2 Solid and/or semi-solid material (o boiling point above 389 °C) is mixed with first liquid fractions. The mixture has the characteristics listed in table 15. Table 15 Properties of a mixture of solid and/or semi-solid material and the first liquid fractions Mixture number 4 Mixture number 5 Mixture number 6 Solid and/or semi-solid material % by weight (A) First liquid fraction 89 87 82 % by weight (B) 11 13 18 A/B ratio Saybolt viscosity 8.1 6.7 4.6 furol, seconds, at 99 °C 180 70 30 % by weight Carbon 89.6 89.6 89.6 Hydrogen 7.6 7.6 7.8 Nitrogen 1.2 1.2 Oxygen 0.4 0.4 0.4 Sulfur always less than 0.04

Claims (6)

SUBJECT OF THE INVENTION 1. A fuel mixture containing by weight 87.0 to 93.0% carbon, 5.0 to 11.0% hydrogen, 0.5 to 2.0% nitrogen, 0.1 to 3.0% oxygen and not more than 0, Sulfur, characterized in that it contains a solid and / or semi-solid material containing 87.0 to 93.0% by weight of carbon, 5.5 to 9.5% of hydrogen, 0.3 to 3.0% of nitrogen, 1,5% oxygen and not more than 0,5% sulfur, obtainable by a process in which a slurry composed of coal and a hydrogen donating solvent is hydrogenated together with hydrogen in the absence of a catalyst in the first hydrogenation zone to form a slurry of coal and solvent such as the coal-solvent solution is catalytically hydrogenated in a second hydrogenation zone to give a product which is separated under ambient pressure to a first liquid fraction of boiling point 100 DEG-375 DEG C., to a second liquid fraction boiling above a first liquid fraction, i.e. 200 to 525 ° C, and to a solid and / or semi-solid material, wherein at least a second portion of the liquid fraction is recycled to the first hydrogenation zone for longer comprising low boiling hydrocarbons boiling at 100 to 375 ° C at ambient pressure 85 to 93% by weight of carbon, 7.0 to 12.0% of hydrogen, not more than 2.0% of nitrogen, not more than 2.0% of oxygen and not more than 3.0% of sulfur, the ratio by weight of solid and / or semi-solid material to low boiling hydrocarbons is 20: 1 to 1.5: 1. 2. The fuel mixture of claim 1, wherein the weight ratio of the solid and / or semi-solid material to the low boiling hydrocarbons is from 10: 1 to 2: 1. 3. The fuel mixture of claim 1, wherein the low boiling hydrocarbons have a boiling point of 150 to 325 [deg.] C. at ambient pressure. 4. The fuel composition of claim 1, wherein the low boiling hydrocarbons are selected from the group consisting of fuel oil, kerosene, jet fuel, diesel, naphtha up to 193 ° C, light shale oil fraction, and light fractions obtained in the hydrogenation of coal. 5. The fuel mixture of claim 1, wherein the low boiling hydrocarbons are a first liquid fraction having a boiling point of 100 to 375 [deg.] C. 6. The fuel mixture of claim 1, wherein the low boiling hydrocarbons are a first liquid fraction boiling in the range of 150 to 375 [deg.] C.