JPS58129091A - Coal liquefaction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to C5-482'C (
05-900'F) A method of coal liquefaction that increases the yield of liquid product (%).The present invention utilizes a selected combination of process conditions to increase the total liquid per unit feed slurry weight. The present invention relates to a coal liquefaction method that improves yield.

Background technology has been developed for this purpose. For example, U.S. Patent No. 3.8
No. 84.794 discloses a solvent-refined coal process for producing reduced or low ash hydrocarbonaceous solid fuel and hydrocarbonaceous distillate liquid fuel from a feedstock ash-containing feed coal, in which A slurry of feed coal and recycled solvent is passed through a preheater and subsequently dissolved in the presence of hydrogen, solvent, and recycled coal minerals, thus increasing the yield of liquid product. World economic and energy conditions demand such coal liquefaction processes in which the amount of liquid product per unit weight of coal processed is maximized to make the system competitive.

DISCLOSURE OF THE INVENTION In the present invention, we have discovered a coal liquefaction process that improves the total liquid yield (05-482°ClO3-900'')i'') per unit feed slurry weight. In the process of the present invention, a feed slurry consisting of a feed coal based on highly reactive feed coal, recycled molten coal of recycled normal solids, recycled mineral residues and recycled process solvent and hydrogen are combined into a coal liquefaction zone. wherein the feed slurry contains from about 10% to less than about 30% by weight of the feed coal mixture, based on the total weight of the feed slurry, and the feed slurry is brought into contact with the coal liquefier at about 0% by weight, based on the total weight of the feed slurry. The slurry is reacted for a nominal slurry contact time of from .5 hours to about 2.0 hours to about 30%
% to about 60% by weight, preferably about 40% or 45% to about 50% or 60% by weight of C,
-+82°C (C5-900°F) liquid yield is obtained. Surprisingly, in the coal liquefaction process of the invention, the total liquid production is greater than the selected coal concentration (and is operated at a fixed coal concentration of 35% by weight). The total liquid yield per weight is higher than the yield obtained by using a larger amount of feed coal in the slurry. Such increase in liquid yield per unit weight is greater even if the feed coal concentration in the feed slurry is reduced. Importantly, a net increase in liquid product per volume of slurry treated is achieved, for example when processing low reactivity feed coal.
This is surprising considering that the opposite effect occurs.

In the case of low reactivity feed coal, reducing the feed coal concentration in the feed slurry results in a very small increase in the liquid yield Q per unit weight of feed coal.

In this case, the result is a net reduction in liquid production per unit of feed slurry to be processed. Accordingly, the process of the present invention provides a relatively large amount of total liquid using a relatively small amount of feed coal.

As used herein, the term "highly reactive coal" refers to coals with a total organic sulfur content of 1.6% by weight or more (MF coal standard) and a pyrite sulfur content of 1.2% by weight or more (MF coal standard). , the total reactive maceral content (defined as vitrinite + vitrinite + ecdinite) is DMMF
It means a coal, preferably a bituminous type, with a capacity of more than 82% (on a mineral-free dry basis) and an average maximum reflectance of vitrinite + pseudovinyl-IJ units of less than 0.74. The term "highly reactive coal" refers to coals whose pyrite sulfur content is less than 1.2 wt. It also refers to coal having all the above-mentioned properties, except that it has been replaced with an external coal liquefaction catalyst.

As used herein, the term "mineral residue" means consisting of inorganic mineral matter and undissolved organic matter. Inorganic mineral materials, referred to herein as "ash," have not undergone a combustion process.

The “organic vacuum distillate” used here
The term cuum bottoms ) j is defined as (1
) insoluble organic matter in mineral residues and (2) soluble 482°C (900°
F1) means the whole with vacuum residue. When recovered as a product of a process, normally solid molten coal is referred to as "solvent refined coal." The term "distillate liquid" refers to organic materials within the full boiling range of 38 to 4828C (100 to 900'F), although such liquids need not exceed the full range. The term "process solvent" refers to a fraction of a distillate liquid that can serve as a process solvent, generally from about 1779°C to about 482°C (about 35°C).
0°F to about 900″F), preferably from about 232°C to
Boils within the range of about 450"F to about 900F.

The invention will now be explained by way of example with reference to the drawings.

As shown in the attached drawings, the dried highly reactive coal is sent to the slurry mixing tank 12 through line 10 and the highly reactive coal in the slurry mixing tank 12 is transferred to the normal solid recirculating molten coal flowing in line 14. and recycled mineral residue and recycled distillate solvent, such as from about 177°C to about 482°C (about 3
and a recycled distillate solvent boiling in the range of 50°F to about 900°F).

The resulting solvent-containing feed slurry mixture is a total feed slurry.
Contains SH).

This feed slurry is pumped through a reciprocating pump 18G, and recirculated hydrogen flows in from line 20 and
It is mixed with make-up hydrogen flowing in from the furnace 22, and then passed through a preheater tube 231 disposed inside the furnace 22.

The slurry is placed in a furnace 22 to begin the exothermic reaction of the process.
This is heated to a very high temperature and then sent via line 24 to reactor 26f. The reactant temperature at the preheater outlet can be adjusted to, for example, between about 700°F (371°C) and 404°C (404°C).
760°F). At this temperature, essentially all of the coal dissolves in the solvent Q and exothermic hydrogenation and hydrocracking reactions begin. Although the temperature increases gradually along the length of the preheater tube, the backmix reactor 26 is at a substantially uniform temperature throughout and the heat generated by the hydrocracking reaction within the reactor 26 (and thus the reaction For example, the body temperature is about 43
It rises to a range of 820'F to about 870°F.

Quenching hydrogen is passed through line 28 and is injected into reactor 26 at various points to control the reaction temperature.

The temperature conditions inside the reactor are, for example, about 430°C (806°C
F) to about 470°G (878°F), preferably about 44°F
0°C (824°F) to approximately 470°G (878'F),
49G 455℃ (851″F) ~ approx. 47
Temperatures can be in the range of 0°C (878°F).

The total slurry contact time of the slurry to be reacted is about 0.5 hours ~
Rub for about 2.0 hours, preferably about 0.8 hours to about 1.2 or about 1.5 hours. This contact time is the nominal contact time between the preheaters and the reaction conditions within the reactor zone.

The hydrogen partial pressure is approximately 105 kg7am2 (1,500psi
g ) ~ 280 kg/cm” (4,000 psig
), preferably about 140 kg/cm” (2,0
OOpsig) ~ approx. 210 kg/cm” (a,
o o o kg/CrIL"). The hydrogen partial pressure is defined as the product of the total pressure and the mole fraction of hydrogen in the feed gas. The hydrogen feed rate is approximately 2.0 kg/CrIL" per 100 parts by weight of feed slurry. 0 parts to about 4.0 parts by weight, preferably about 4 parts to about 6.0 parts by weight of hydrogen.

By reducing the highly reactive feed coal concentration in combination with other process conditions, the method of the present invention provides a
F) increases by about 1% to about 20% by weight, preferably from about 4% to about 15% by weight. Such a result is completely unexpected.

This is because it was previously unforeseeable that reducing the total weight of coal feeding the liquefaction sphere would increase the nominal net weight of liquid product per unit volume of slurry to be treated.

The reactor effluent is sent via line 29 to a gas-liquid separator 30. The gas-liquid separator 3o consists of a series of heat exchangers and gas-liquid separators that separate the reactor effluent into a non-condensable sludge stream in line 32, a condensed light liquid distillate in line 34, and a condensed light liquid distillate in line 56. Separate into product slurry. The condensed light liquid distillate from the separator is sent via line 34 to atmospheric fractionation column 86. The non-condensable gas in line 32 contains unreacted hydrogen, methane and other light carboxylic hydrogen (H2S and CO2), and the non-condensable gas is sent to acid gas removal unit 38 (which removes elemental sulfur). The sulfur is converted and the sulfur is removed from the process by line 4o. A portion of the purified gas is sent by line 42 to cryogenic unit 44 where most of the methane and ethane are removed as pipeline gas and the propane and butane are removed as LPG. Pipeline gas is passed through line 464 and LPG is passed through line 48G. The purified hydrogen in line 50 is mixed with residual gas from the acid gas treatment step in line 52. This is the process This is recycled hydrogen.

Liquid slurry from gas-liquid separator 30 is passed through line 561. The liquid slurry contains distillate liquid, normally solid molten coal, and catalytic mineral residues. The flow in line 56 is 2
The two main streams 58 and 60 are of the same composition as the flow in line 56.

In fractionation column 36, the slurry product from line 60 is distilled at atmospheric pressure, with an overhead naphtha stream via line 62#, a middle distillate stream via line 64, and a bottoms stream via line 66.
Take it out. The naphtha flow in line 62 represents the net naphtha yield from the process.

The bottoms stream in line 66 is sent to vacuum distillation column 68.

The temperature of the feed liquid to the fractionator is usually maintained at a sufficiently high level G that no additional preheating is required other than the start-up operation.

A mixture of fuel oil from the atmospheric column in line 64 and heavy distillate recovered from the vacuum column via line 70 is the primary fuel oil product of the process and is removed via line 72. The flow in line 72 is between 193 and 482°c (a
so~900°F) distillate liquid, a portion of which is sent to line 73
The solids concentration in the feed slurry can be adjusted by recirculating the feed slurry from the feed slurry mixing tank 12G. The recycle stream in line 78 is recirculated to allow for changes in the ratio of solvent to total recycle (thus providing flexibility in the process). The ratio in line 58 is not fixed. Also, recirculation in line 73 improves slurry pumpability. Indicates the net yield of distillate liquid from the process.

The bottoms from vacuum column 68 consists of all the normal solids of the process, molten coal, undissolved organic matter, and mineral matter;
The distillate liquid or hydrocarbon gas is essentially free of carbon. This bottoms can be discharged through line 76Q and treated as required. For example, U.S. Pat.
59,236, this bottoms stream can be sent to a partial oxidation gasifier (not shown) to produce process hydrogen. The following description is made with reference to what is disclosed in this US patent. A portion of the vacuum column bottoms (VTB) can be recycled directly to mixing tank 12 if desired.

Next, the present invention will be explained using Example Q.

Example Tests were conducted to demonstrate the method of the invention.

The feed slurry for each test was made by mixing dry, powdered high-reactivity coal and low-reactivity coal, respectively, with liquid solvent and recirculated slurry to form the feed slurry.

Typically, low-reactivity coals, such as bituminous coal types, have a total sulfur content of less than 3.5% by weight (IF coal standard) and a total reactive maceral content (vitrinite + pseudo-vitrite + Exginite) is less than 82 capacitance in DMMF, and the average maximum reflectance of vitrinite+pseudovitrinite is greater than 0.74.

The particular feed coal used had the properties shown in the table below.
lysis), all are expressed as weight percent based on anhydrous feed coal.

Table 1: Blacksville Ireland Characteristics (Blacksville) Coal (
Ireland) Carbon elemental analysis, weight % Carbon 71.10 71.74 Hydrogen 5.22 5.13 Nitrogen
1,55 1.00 chlorine
0.0? 0.11 oxygen (difference)
7.04 5.88 Sulfur
8.08 4.48 Ash content 1
1.94 11.71 Sulfur Form Pyrite 1.65 2.07
Sulfate 0.04 0.01 Organic 1.89 2.40 Total
3.08 4. +8 petrographic analysis bit 73,2
80.2 EXGINIT
7.6 4.2 Totally reactive macerals 8
0.8 84.4 Average maximum reflectance 0.
80 0.66 ll tank reactor (O3T) where feed slurry was continuously stirred with hydrogen through a tubular preheater
R)
455 under a total pressure of 7cm” (2000psi)
The reaction was carried out at a temperature of °C. At this time, pure hydrogen was used at a ratio of 4 parts by weight per 100 parts by weight of slurry supplied. The reactor effluent was separated and analyzed to determine the yield of product per unit time. The conditions used in each test and the test results are shown in the table below (Standard: Reactor (processed slurry 454k
g (10001b) 7 hours).

As can be seen from Table 2, in tests 1 and 2 using highly reactive feed coal, the feed coal concentration was reduced to 454 kg/hour (1000/b/hour) of the feed slurry [as opposed to 136 kg/hour].
97 hours (a o o tb/hour) to 113 to 9
/hour (250I!b 7 hours).

This corresponded to reducing the feed coal concentration from 30% to 25% by weight. As a result, C5-482℃ (C,
-900°F) The net weight of the liquid product is +z, lky/
(92,9/'b/hr) to ++, 41 cg/hr (97,9/'b/hr). 'Thus, reducing the total coal weight fed to the liquefaction reactor by 17 inches resulted in a 5% increase in the total production weight of nominal liquid product. In other words, using less coal (more liquid was produced).

In contrast, tests 3 and 4 using low-reactivity feed coal gave exactly the opposite results. The net liquid product produced is 39.I
JiiJ/hour (86,3/b/hour) to 33.2k
g/hour (7a, aI!b/hour) Q decreased. Therefore, for a low reactivity coal, a 1796 reduction in the total coal weight fed to the liquefaction reactor resulted in a 15 inch reduction in the total production weight of nominal liquid product.

[Brief explanation of drawings]

The accompanying drawing is a flow sheet of an example of the method of the present invention. 10... Line, 12... Slurry mixing tank, 14
．． 16...Line, 1B...Reciprocating pump, 20゜2
1... Line, 22... Furnace, 23... Preheater tube,
24 line, 26... reactor, 29... line, 3
0... Gas-liquid separator, 32.34... Line, 86.
...Atmospheric pressure fractionation column, 38...Acidic gas removal device, 40.4
2...Line, 44...Cryogenic equipment, 46.48,5
0゜52.56...Line, 58.60...Main flow (line), 62,64,66...Line, 6B
...Vacuum distillation column, 70, 72, 73.76... line.

Claims (1)

[Claims] 1 C per unit feed slurry weight, -482°C (C5-
900° F.) Coal liquefaction process to increase liquid yield, where the total organic sulfur content is greater than 1.6% by weight on an anhydrous coal basis and the pyritic sulfur content or equivalent is greater than 1.6% by weight on an anhydrous coal basis. .2% by weight or more, the total reactive maceral content (Bil-IJ Nipper + Pseudovitrinite + Exinite) is more than 82% by volume on a mineral-free dry basis,
Feed slurry based on highly reactive coal with an average maximum reflectance of vitrinite + pseudovitrite less than 0.74, normal solids recycled molten coal, recycled mineral residues and recycled process solvents and hydrogen are reacted in a coal liquefaction sphere, with the concentration of the highly reactive feed coal being about 10% to less than about 30% by weight based on the weight of the total feed slurry, and the feed slurry being heated for about 0.5 hours to less than about 30% by weight of the total feed slurry. About 0.3 parts by weight to about 0.6 parts by weight of 0.5-482° C. (0.5-482° C.) per part by weight of feed coal reacted with a nominal slurry contact time of about 2.0 hours.
, -900°F), and then the total liquid production is at least as high as that achievable under the same conditions at a coal concentration greater than the selected coal concentration and less than 35% by weight coal concentration. A coal liquefaction method characterized by operating at a selected coal concentration such that: Approximately 15% by weight of the above supplied slurry or the total slurry weight
The method of claim 1 containing about 28% by weight of said feed coal. Approximately 20% by weight of the above supply slurry or the total slurry weight
3. The method of claim 2 containing about 28% by weight of said feed coal. Approximately 20% by weight of the above supply slurry or the total slurry weight
4. The method of claim 3, wherein the feed coal contains about 26 gw [1%] of said feed coal. 5. The hydrogen partial pressure in the coal liquefaction sphere is approximately 105%.
am” (1500p, sig) ~ approx. 28 ok
7 cm" (4000 pslg). a. The method of claim 1, wherein the contact time of the slurry is from about 0.8 hours to about 1.5 hours. 7 7. The method of claim 6, wherein the contact time of the slurry is about 0.8 hours to about 1.2 hours.