CA1139700A - Treatment of coal liquids and coal bottoms - Google Patents

Abstract

(U.S. 969,361 etc,) ABSTRACT OF THE DISCLOSURE

Coal liquids are rendered compatible with petroleum liquids and the solubility of heavy fractions of coal (e.g., coal liquefaction bottoms) is obtained by selective oxygen alkylation and/or oxygen acylation by use of a phase transfer reagent and an oxygen alkylating and/or acylating agent.

Description

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BACKGRQUND OF T~IE INVENTION

2 1. Field of the_Invention

3 This invention is directed to improving the proper-4 ties of heavy coal fractions and, in particular, to increas ing the solubility of heavy coal fractions in common organic 6 solvents and petroleum liquids.
7 2. Description of the Pr_or Art 8 Processes for the liquefaction of coal and similar 9 carbonaceous solids usually involve contactlng the feed mat-erial with a hydrocarbon solvent and molecular hydrogen at 11 elevated temperature and pxessure. This results in partial 12 breakdown of the complex high molecular weight starting mat-13 erial into lower molecular weight hydrocarbon liquids and 14 gases. These are recovered from the liquefaction effluent, leaving a heavy liquefaction bottoms product which normally 16 boils in excess of about 1000F and generally contains sus-17 pended solid residues. The liquefaction bottoms may consti-18 tute 50% or more by weight of the total liquefaction products.
19 A major use of coal liquids, particularly high boiling coal liquids, could be in a fuel blend consisting of 21 both coal and petroleum liquids. Unfortunately, coal liquids, 22 such as those derived by hydrogenation processes, do not 23 appear to be compatible with petroleum liquids in that addi-24 tion of small amounts of the former to the latter causes precipitation.
26 Without subscribing to any particular theory, one 27 likely reason for this is that coal liquids are more polar 28 than petroleum liquids, due to the presenca of phenolic and 29 carboxylic functionalities. These polar functionalities cause intermolecular association between adjacent coal liquid 31 molecules and tend to hold the coal liquid molecules together 32 by a network of hydrogen bonds. Petroleum liquids, which 33 lack these polar functional groups, cannot participate in 34 the intermolecular association. As a result, segregation occurs, an~ the petroleum and coal liquids separate into 36 distinct layers.
., ~

1 A variety of different processes for upgrading 2 liquefaction bottoms have been proposed in the past. Exem-3 plary of these include pyrolysis of the bottoms that produce

4 gases, addi~ional hydrocarbon liquids and coke, followed by steam gasification of the coke to form hydrogen and carbon 6 monoxide for use as a ~uel; see e.g., U S. Patent 4,060!478.
7 Another process for upgxading liquefaction bottoms is dis-8 closed in ~ which discloses an acid-9 catalyzed C-alkylation or C-acylation of liquefaction pro-duct bottoms prior to recycling the bottoms fraction to the 11 liquefaction reaction ~one.
12 These various processes result in more efficacious 13 use of liquefaction bottoms. However, during subsequent coal 14 liquefaction process, phenols present in the coal are cleaved to produce water. In liquefaction processes employing hydro-16 gen, an excessive use of hydrogen thus occurs.
17 Solvent extraction of coal also leaves behind a 18 high molecular weight, insoluble fraction oE coal called 19 coal solubilization bottoms. Like liquefaction bottoms, this hea~y fraction is also the object of various upgrading pro-21 cesses in order to obtain incraased liquid yields.

23 In accordance with the present invention, function-24 alities having weakly acidic protons in coal liquids and heavy coal fractions or bottoms are treated by a process 26 selected from the group consisting of alkylation and acyl-27 ation (sometim~s referred to herein as oxygen or O-alkylation 28 and oxygen or O-acylation). Weakly acidic protons include 29 phenolic, carboxylic and mercaptan functionalities. The O-alkylation or O-acylation is conveniently carried out by 31 use of a phase transfer reagent and an alkylating or acylating 32 agent. The phase transfer reagent, which is recyclable, is 33 by way of example a quaternary ammonium or phosphonium base 34 (R4QOR"), where each R is the same or different group sel-ected from the group consisting of C1 to about C20 alkyl and 36 C6 to about C20 aryl; Q is nitrogen or phosphorus; and R"

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1 is selected from the group consisting o hydrogen, C1 to 2 about C10 alkyl, aryl, alkylaryl, arylalkyl and acetyl. The 3 alkylating and acylating agents are represented by the form-4 ula R'X where R' is a Cl to C20 al~yl or acyl group and X is a leaving group selected from the group consisting of halide, 6 sulfate, bisulfate, acetate and stearate, wherein X is attach-7 ed to a primary or secondary carbon atom.
8 O-alkylated Gr O-acylated coal liquids and heavy 9 coal fractions evidence increased solubility in common organic solvent and are more compatible with petroleum liq-11 uids than those not so treated.
12 The process disclosed herein may be advantageously 13 employed with any coal liquid of bottom, regardless of deri-14 vation.
~ETAILED DESCRIPTION OF THE INVENTION
. .
16 Coal liquids and heavy coal fractions (bottoms) are 17 those materials derived from coal by a variety of processes 18 including hydrogenation and donor solvent reactians involving 19 a distillation to remove coal liquids. Coal liquefaction bottoms, though only a by-product of the liquefaction process, 21 constitute an undesirably large fraction of the total lique-22 action products. Exemplary of the solvent hydrogen donor 23 liquefaction process is that described in U.S. Patent 3,617,513.
24 Coal solubilization bottoms are those residues de-rived from coal by a variety of solvent extraction processes.
26 Exemplary of the solvent extraction process is that described 27 in U S. Patent 3,607,716, which discloses supercritical gas 28 extraction.
29 The alkylation or acylation process disclosed herein may be advantageously employed with any heavy coal fractions, 31 re~ardless of derivation. As used herein, the terms "coal 32 bottoms" and "heavy fractions" are synonymous and relate to 33 coal residues derived by coal treatment processes such as 34 liquefaction, solubilization and the like. Certain gasifi-cation processes yield a by-product tar, which is also a coal 36 residue contemplated for treatment by the process of the ~L3~

1 invention.
2 By the process of the invention, functionalities 3 containing weakly acidic protons in the -treated material 4 are chemically altered. For example, acidic proton-contain-ing groups such as phenolic and carboxylic, which are very 6 polar functional groups are converted to relatively non-polar 7 ethers and esters, respectively. The chemical transformation 8 may be represented as follows:
9 Ar-OH + R'X ~ ~ Ar-OR' Ar-COOH + R'X ~---~ Ar-COOR' 11 where R' is a Cl to about C20 alkyl or acyl group.
12 The O-alkylation or O-acylation of coal liquids or 13 coal bottoms by reagents which are in liquid solution is 14 greatly influenced by the use of a phase transfer reagent.
lS Such a reagent has both a lipophilic and a hydrophilic por-16 tion and is capable of transferring a basic species, -OR", 17 from an aqueous phase to either a solid or liquid organic 18 phase, where R" is either hydrogen or a carbon-bearing func-19 tionality. The phase transfer reayent may be generated cata-lytically, in which case the process is termed a phase trans-21 fer catalysis, which is a well-known reaction; see, e.g., 22 Vol. 99, Journal of the American Chemical Societx, pp. 3903-23 3909, (1977). Alternatively, the reagent may be generated 24 in a separate step, then used in the alkylation or acylation reaction. If this latter reaction is employed, then the 26 active form of the reagent may be regenerated in a subsequent 27 step. In either case,-the overall chemical transformation 28 on the coal bottoms is the same. A generalized mechanistic 29 scheme for this transformation is shown below.
+- + - ~ _ 31 _~ R4QX + M:OR" - R4QOR" + M:X
32 ~_ _ +
33 Coal-H + R4QOR" Coal-QR4 + R"OH
34 _ + +_ = + R4QX

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1 The phase trans~er reagent is preferably a quater-2 nary base represented by the formula R4QOR" where each R is 3 the same or different group selected from the group consist-4 ing of Cl to about C20, preferabl~ Cl to C6 alkyl and C6 to about C20, preferably C6 to C12 aryl group; Q is nitrogen or 6 phosphorus, preferably nitrogen; and R" is selected from the 7 group consisting of hydrogen, Cl to about C10, preferably C
8 to C6 alkyl, aryl, alkylaryl, arylalkyl and acetyl group;
9 more preferably a Cl to C4 alkyl group and most preferably hydrogen. The phase trans~er reagent may be generated by 11 reacting thecorresponding quatexnary salt R4Q~ with a metal 12 base MOR" where X is selected from the group consisting of 13 halide, sulfate, bisulfate, acetate and stearate. Preferred 14 is when ~ is a halide and selected from the group consisting of chlorine, bromine and iodine, more preferably chlorine.
16 M is selected from the group consisting of alkali metals, 17 more preferably sodium and potassium. As shown above, the 18 quaternary ~ase is then reacted with the acidic groups on 19 the coal which in turn is reac~ed with at least one alkyl-ating or acylating agent represented by the ~ormula R'X where-21 in R' is selected from ~he group consisting of Cl to about 22 C20 alkyl or acyl group and X is as previously defined, as 23 long as X is attached to a primary or secondary carbon atom.
24 Preferably R' is an inert hydrocarbon--that is, a hydrocarbon group containing only hydrogen and carbon, although hydrocar-~6 bon groups containing other functionality may also be suit-27 able for use herein, even though less desirable. It will be 28 noted that the acidic proton H (hydrogen atom) is usually 29 located on phenolic groups in higher rank coals and on car-boxylic groups for lower rank coals. The acidic proton may 31 also be located to a lesser extent on sulfur, nitrogen, etc.
3~ Phase transfer reagents such as quaternary ammonium 33 base (R4QOR") are very effective in the O-alkylation and O-34 acylation of coal bottoms. These O-alkylation and O-acylation reactions are successful because the -OR" portion of the mole-36 cule is soluble in an organic medium. When this base is :' .

~397~

l present in such a medium, it is not solvated by water or 2 other very polar molecules. As an unsolvated entity, it 3 can react as a very efficient proton transfer reagent. For 4 example ~Coal)-OH ~ OR" - r- (Coal)-O + R"OH
6 This unsolvated base (also known as a "naked hydroxide" when 7 R" is hydrogen) can have a wide variety of counter ions.
8 Although the counter ion may be a quaternary ammonium or 9 phosphonium species as previously discussed, other examples of counter ions useful in the practice of the invention in-ll clude "crown ether" complexes of a salt containing the OR'I
12 anion and clathrate compounds complexed with a salt contain-13 ing the OR" anion. Salts represented by MOR", where M is as 14 given above, when complexed with crown ethers, for example, have been previously demonstrated to evidence a reactivity 16 similar to that found for R4QOR" compounds.
17 In one embodiment of the process of the invention, 18 a two-phase solid/liquid or liquid/liquid system comprising l9 the coal bottoms or coal liquids in liquid suspension is formed. If coal bottoms are heated they may be ground to 21 a finely divided state and contain particles less than about 22 1/4 inch in size, preferably less than about 8 mesh NBS sieve 23 size, more preferably less than about 80 mesh. The smaller 24 particles, of course, have greater surface area and thus alkylation or acylation will proceed at a faster rate. Con-26 sequently, it is desirable to expose as much coal surface 27 area as possible without losing coal bottoms as ~ust or fines 28 or as the economics of coal grinding may dictate. Thus, 29 particle sizes greater than about 325 mesh are preferred.
Also, in the case of coal liquids, a three-phase system com-31 prising the coal liquid and aqueous phase, together with a 32 petroleum liquid, may be employed.
33 Although not necessary, a solvent may be added if 34 desired. The solvent may be used to dissolve alkylated or acylated carbonaceous product or to dissolve alkylating or 36 acylating agent (especially if the agent is a solid and is ~3~

l comparatively insoluble in water). The solvent may also be 2 used to provide ~or more efficient mixing. Many of the 3 common organic solvents may be employed in any reasonable 4 amount, depending on the desired result.
The phase transfer reagent that is used must dis-6 solve in or be suspended in both phases so that it has inti-7 mate contact with both the organic and aqueous phases. Dur-8 ing the course of the reaction, the phase transfer reagent g will partition itself into both of these phases. Quaternary bases are one class of compounds useful as phase transfer ll reagents in the practice of the invention and are given by 12 the formula R4QOR", where R is an alkyl or aryl group having 13 at least one carbon atom, and preferably 1 to 20 carbon atoms, 14 and more preferably l to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, preferably 6 to 12 carbon atoms.
1~ The lower number of carbon atoms is pre~erred, since such 17 compounds are more water soluble and can be removed ~rom the 18 alkylated or acylated coal bottoms by simple water washing.
l9 The R groups may be the same or different. Examples of R
groups include methyl,butyl, phenyl and hexadecyl.
21 Examples of quaternary bases useful in the practice 22 of the invention include the following:
23 1. Tetrabutylammonium hydroxide (C4Hg)4NOH
24 2. Benzylhexadecyldimethylammonium hydroxide~
25 (C6H5cH2)(cl6H33)(cH3)2NO
26 3. Tetrabutylphosphonium hydroxide (C4H9)4POH
27 4. ADOGEN 464, (C8-C10)4NO~ ~ADOGEN 464 is a 28 trademark of Aldrich Chemical Co., Metuchen, NJ~.
29 The metal base used to convert the quaternary salt to the corresponding base is an alkali metal or alkaline 31 earth metal base such as NaOH, KOH, Ca(OH)2 or NaOCH3. The 32 use of an alkoxide, for example, permits use of the corres-33 ponding alcohol in place of water, which may provide an 34 advantage of treating coal bottoms under conditions where water is not desired.
36 In choosing the alkylating and acylating reagent, ~L~39~

1 two considerations must be weighed. First, it is desired 2 to add longer chains to the coal liquids or bottoms which 3 render the product more petroleum-like, and therefore, more 4 soluble in organic solvents and more compatible with petro-leum liquids. On the other hand, shorter chains render the 6 alkylated or acylated coal liquids or bottoms more volatile.
7 Second, shorter chain materials are also less expensive and 8 still improve solubility.
9 In the case of O-alkylation, the carbo~ to which the leaving group is attached may be either a primary or 11 secondary carbon atom. Primary carbon halides have been 12 found to react faster than the corresponding secondary 13 halides in a phase transfer or phase transfer catalyzed 14 reaction on carbonaceous materials and are accordingly pre-ferred. While the balance of the carbon-bearing functional 16 group may, in general, contain other moieties, such as hetero-17 atoms, aryl groups and the like, bonding of the carbon-18 bearing functional group to the phenolic or carboxylic oxy-19 gen is through either an sp3 hybridized carbon atom (alkyl-ation) or an sp2 hybridized carbon atom (acylation). Further, 21 a mixture of alkylating or acylating agents or a mixture of 22 both may advantageously be employed. Such mixtures are 23 likely to be generated in coal-treating plants in other 24 processing steps and thus provide a ready source of alkyl-ating and/or acylating agents. Examples of alkylating and 26 acylating agents useful in the practice of the invention 27 include ethyl iodide, isopropyl chloride, dimethyl sulfate, 28 benzyl bromide and acetyl chloride.
29 While alkylating and/or acylating agents are em-ployed in the practice of the invention, alkylating agents 31 are preferred for the following reasons. First, alkylating 32 agents are readily prepared from their hydrocarbon precursors.
33 For example, alkyl halides may be easily prepared by free 34 radical halogenation of alkanes, which is a well-known pro-cess. When a system containing more than one alkylating or 36 acylating agent is used, the hydrocarbon precursor is pref-~g~

1 erably a product stream of a certain cut derived from coal 2 and petroleum processing and the like. This stream may con-3 tain minor amounts of components having various degrees of 4 unsaturation which are also suitable for reacting with the phenolic and carboxylic groups herein, as long as X (as pre-6 viously deined) is attached to an alkyl or saturated carbon 7 atom in the resulting alkylating or acylating reagent.
8 Second, acylating reagents are susceptible to hydrolysis.
9 Since water is present due to the nature of the inventive process, some loss of acylating agent may occur by hydrolysis.
11 In contrast, alkylating reagents do not evidence the same 12 susceptibility to hydrolysis.
13 If the O-alkylation or O-acylation is carried out 14 by a catalytic process, then the quaternary salt, metal base and alkylating or acylating agent are mixed directly with 16 the coal liquid or an aqueous slurry of coal bottoms. The 17 quaternary salt catalyst may be present in small amounts, 18 typically about 0.05 to 10 wt. ~ of the amount of coal bot-19 toms used; however, greater amounts may also be employed.
The metal base and the alkylating or acylating agent must 21 be present in at least stoichiometric quantities relative 22 to the number of acidic sites ~phenolicl carboxylic, etc.) 23 on the coal liquid or bottoms, but preferably an excess of 24 each is used to drive the reaction to completion. Advan-tageously, a two-fold excess of metal base and alkylating 26 or acylating agent is employed; however~ a greater excess 27 may be employed. A~ter the reaction, the excess quaternary 28 base and quaternary salt catalyst may be removed from the 29 coal liquid or bottoms by ample water washing ~or recycling.
Excess metal base will also be extracted into the water wash, 31 and it may be reused. Excess alkylating or acylating agent 32 may be conveniently removed from the treated coal material 33 by fractional distillation or by solvent extraction with 34 pentane or other suitable solvent and may be reused.
To cap off all acidic protons in typical coal liquid 36 or bottoms employed in the catalytic process, less than about ~L~IL3~

1 2 days are required for 100~ conversion, employing only a 2 51iqht excess of alkylating or acylating agent on -80 mesh 3 coal bottoms or on coal liquids under atmospheric pressure 4 and ambient temperature. A greater excess of alkylating or ~ acylating agent will reduce the reaction time considerably.
6 A faster alkylation or acylation reaction may be 7 obtained in a number of ways, one of which is to add the 8 phase transfer reagent (R4QOR"~ directly to the coal liquid g or bottoms rather than to form this reagent in situ with the reaction in which coal fractions are alkylated or acylated.
11 ~hen this is done, substantially complete conversion of all 12 the phenolic and carboxylic groups is achieved in a matter 13 o~ minutes. The amount of quaternary base added ranges from 14 about stoichiometric proportions to about 10 times the total number of acidic sites on the coal liquid and/or bottoms 16 which are capable o undergoing alkylation or acylation. As 17 before, the quaternary salt that is generated in the alkyl-18 ation or acylation step may be recovered and recycled by 19 reacting it wlth fresh metal base to regenerate the quater-nary base. By employing this two-step process, there is no 21 contact between metal base and the coal bottoms, and the 22 reaction is essentially complete in abouk one hour.
23 In another embodiment, a blend of coal llquids -and 24 petroleum liquids and the alkylating or acylating agent is contacted with an aqueous solution containing the phase trans-26 fer reagent. The alkylation or acylation may be performed 27 catalytically or non-catalytically, employing the procedures 28 outlined above.
29 The temperature at which the reaction is carried out may range from ambient to the boiling point of the mat-31 erials used. Increased temperature will, of course, speed 32 up the reaction rate.
33 The reaction mixture may be stirred or agitated or 34 mixed in some fashion to increase the interface or surface area between the phases, since there can be aqueous, organic 36 liquid and/or solid coal bottoms phases present.

~L3~

l The reaction is carried out at ambient pressure, 2 althou~h low to moderate pressures (about 2 to 20 atmos-3 pheres) may be employed along with heating to increase the 4 reaction rate.
Once the reagents and solvent if any are removed 6 from the alkylated or acylated coal liquid or battoms, infra-7 red analysis may be conveniently used to determine that all 8 the hydroxyl groups having been alkylated or acylated. If 9 the added alkyl or acyl group is IR-active, then the appear-ance of the appropriate infrared frequency is observed.
ll Other well known analytical methods may also be employed if 12 desired. The ultimate analysis of percent C, H, N, S and O
13 is altered in a fashion which is consistent with the expected 14 change due to the added alkyl or aryl substituent. For example, the increase in the H/C ratio of O~methylated coal 16 bottoms from Illinois No. 6 coal indicates that 3.S methyl 17 ~roups per 100 carbon atoms are added to the coal bottoms.
18 The H/C ratio in the untreated coal bottoms of Illinois No.
19 6 coal is 0.754 and the H/C ra~io after methylation by the process of the invention is 0.790. The thermo~ravimetric 21 analysis of the methylated coal bottoms shows a significant 22 increase in volatile organic content over the untreated coal 23 bottoms (48% versus 38%~.
24 If coal liquids are treated the increase in the H/C
ratio of O-methylated coal liquid derived from Illinois No.
26 6 coal indicates that 3.5 methyl groups per 100 carbon atoms 27 are added to the coal liquid. The H/C ratio in the untreated 28 coal liquid derived from Illinois No. 6 coal is 1.004 and H/C
29 ratio after O-methylation by the process of the invention is 1.037. The treated coal liquids become more soluble in com-31 mon organic solvents. For example, the solubility (20C) of 32 O-methylated coal liquids in cyclohexane increases to 63%
33 from 11% for untreated coal liquids.
34 The alkylated and acylated coal li~uids formed by the process of the invention are compatible with petroleum 36 liquids, as indicated by the increased solubility of alkylated 37 and acylated coal liquids in petroleum liquids. Blends of ~39`'7D~

l coal liquids treated in accordance with the invention and 2 petroleum liquids evidence increased stability~
3 Coal bottoms treated in accordance with the inven-4 tion may be recycled through the liquefaction, gasification, solubilization, etc., processes from which they were derived.
6 Liquid products derived are more compatible with petroleum 7 liquids than those derived from coal bottoms not so treated.
8 The solvent extractability of the coal bottoms is greatly 9 increased after it is O-alkylated or O-acylated. For example, Illinois No. 6 coal bottoms become more soluble in common ll organic solvents after oxygen-methylation, as shown in Table 12 I below.
13TABLE_I
14Maximum Solubility (at 1_atm)_ (DMMF) 15Toluene Tetrahydrofuran 16Illinois #6 Coal Bottoms 22 60 17O-methylated Illinois #6 18coal bottoms 95 95 19Coal liquids which are derived by so~vent extraction of coal bottoms treated in accordance with the invention 21 evidence both improved quality and increased quantity over 22 coal liquids derived from untreated coal.

2~ Example 1 - Phase Transfer Catalyzed Alkylation A coal liquid derived from Illinois No. 6 coal by 26 Exxon's donor solvent process was treated as follows:
27 In a 250 ml round bottom flask which was flushed 28 with nitrogen and equipped with a mechanical stirrer were 29 added the following components: 5.0 g of coal liquids (650-1050F, derived from Illinois No. 6 by hydrogen donor solvent 31 liquefaction), 0.25 g of tetrabutylammonium iodide (as re-32 ceived from Aldrich Chemical), 50 ml of toluene (spectrograde 33 from Matheson, Coleman and Bell, purged with nitrogen), 35 ml 34 of 20% aqueous solution of NaOH (purged with nitrogen) and 11.0 g of iodomethane (added dropwise with vigrous stirring).
36 A nitrogen atmosphere was maintained for 5 days, until the ~3~

1 reaction was assumed to be com~lete. The layers were sep-2 arated in a separatory funnel~ The organic layer was washed 3 eleven times with 150 cc portions of water to remove caustic 4 and catalyst. The toluene and residual iodomethane were stripped off under vacuum at 100C.
6 The solubility (20C) of coal liquid vacuum gas oil 7 increased from 11% to 63% in cyclohexane after phase transfer 8 catalyzed O-methylation in cyclohexane solvent.
9 A one to two order of magnitude increase in solu-bility of the O-methylated (versus untreated) coal liquid 11 vacuum gas oil in a petroleum liquid~ which was a desulfuri-12 zed Aruba high viscosity fuel oil, was observed.
13 ~ - Phase Transfer Catalyzed Alkylation 14 The followi1lg reactions were carried out on various coal liquids employing the reagents in the amounts indicated 16 shown in the following Table.

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~" o~o o~O
~r o o o\o ,1 ~r 1` o o Lf) O
~1 ' q C.~ H ` ` lo a~ 10 H H r-l ~:q X
C~
h \o`Po\C\O .
~ ~ O ~1 r-lr~ I r-l uq .~1 .,_1 Z 0 ~ ~

I¢ -- d~ rl r-l ~ r-l O o\Oo\O O ~--1 ~., ~
~ ~ ~ O

~ ~ ~ O ~ O 0 ~
~ u~
p:; ~: ~ rl ~4 ~ C) ~ r-l r-l a~ t.) U~r-l ~I r~r~ lr~l ~ (~1 U~
O ~ ~ O ~ .~
a) u, E 1 13 rl ~i ~1 ~ ~) ~ ~ri U~ r~
I¢ ~ ~rl ~ E~ (d .~ O O o O ` V
U~ ~ aJ O
~ri ,a ~ ~,a 1--1 a~ Q~
tn ~ t~ a) ~ IJ

~1 E3 ~ Ei ~
!~] ~ ~ rj_~ ~ ~1 3 t) o t~ V U V V N
O ,~ ~ri O U~ O ~7 ~i ri ~r r i ~ rj Q
q ~N ~ r _ _ _ X O ri I ~ i ~:1 _ _ r i ~ ~ ~ U') ~O ~ ~ ~ O ~1 r~ ~1 9L3L3~

1 Ex mples 6-14 - Phase Transfer_Catalyzed Alk~lation 2 Coal liqueaction bottoms derived from Illinois No.
3 6 and Wyodak coals are treated employing the reagents and 4 amounts set Eorth in Table II below. In each case, the reac-tants were mixed together for 1 to 2 days at ambient temp-6 erature.

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p cr~ c) ~1 ~ ~ o ~ ~ ~7 o o ~ o u~
1:~ C`l Ci~ p~ O ~D O h 1` O U~ H ~ c~l H C`l r l ^ ^ N :~
~ ~ '~ ~ ~ ~ ~ ~ ~) ~\ ~ t:C h _~ o O O O o O O O O C~ C`! O C~

~ 3 O P ~ O ~ ~ ~ O O ~ ~ ~ O
u~ c~ z z z z æ z z; z z; z æ z z z ~ ~,i Z ~ ~ Z ~
C~ I .,~ o ~ V o ~ o o o ~ o~ ~

H ~ ~ ~U O
~9 ~ c c c ~3 c ~' 5 ~ ~ 3 C c~ o ~

~ e co ~ ~ ' O
o ~ ~ ~ , O
o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~o o e ,~ ~ 3 e c e e e e ~ e e e e e e ~ e e 0, ~ e ~,, ~d ~ o ~oa o ,~ ~ ~ ~ ~o ~ ~ ~rl O~rl ~rl a~ ~ 3 3 o ~ 1 ~
_ :1~3~

~ 17 -l In the case of CLPP bottoms, 3.5 alkyl groups were 2 added to each lOO carbons in the sample. The H/C ratio of 3 each sample increased in accordance to the chain length of 4 the alkyl group added. The O-alkylated bottoms evidenced greater volatility and solubility in a variety o~ solvents 6 and were more hydrogen rich and less viscous than the un-7 treated bottoms.
8 A comparison between untreated coal liquefaction 9 bottoms and O-methylated coal liquefaction bottoms gave the results shown in Table III below.

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U~
~1 U~
m $ o o ~ I co ~ o o

5~ O-~l U

~ ~ OU~ OO
E1 d ~1 ~ ~I CO ~ D ~1 0 o al ~ `I
~ U ~ O
H ~C .~

,__ Z UU
Z ~ , ~ Q~ a H _ _ ~
~ a~
U O ~ ~ O ~
~ O Ul Q~
~ ~) ~ .,J N
U ~_) n~ ~ O X -- --~ o~ o\ E~ E~
~ I` co ~ ~ ~-1 ~3~

1 Table III shows a dramatic decrease in the soften-2 ing point and viscosity of coal bottoms, which improve pro-3 cessability. Phase transfer alkylation increases the vola-4 tile organic portion of liquefaction bottoms and lowers the boiling range (Ti and Tf~. Thus, more usable volatile organic

6 coal bottoms are recovered by distillati.on.

Claims (11)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method for improving the properties of coal liquids and coal bottoms, by oxygen-alkylation and/or oxygen-acylation, which method comprises contacting the coal liquids or coal bottoms with a solution comprising:
(a) at least one quaternary base represented by the formula R4QOR" where each R is the same or different group select-ed from the group consisting of C1 to about C20 alkyl and C6 to about C20 aryl; Q is nitrogen or phosphorus; and R" is selected from the group consisting of hydrogen, C1 to about C10 alkyl, aryl, alkylaryl, arylalkyl and acetyl; and (b) at least one compound represented by the formula R'X where R' is a C1 to C20 alkyl or acyl group and X is selected from the group consisting of halides, sulfates, bisulfates, ace-tates and stearates; wherein X is attached to a primary or second-ary carbon atom.

2. The method of claim 1 wherein R" is a C1 to C4 alkyl group or hydrogen, R is the same or different C1 to C6 alkyl group, R1 is a C1 to C4 inert hydrocarbon and X is selected from the group consisting of chlorine, bromine and iodine.

3. The method of claim 2 wherein X is chlorine, R' is a methyl group, and Q is nitrogen.

4. The method according to claim 1, 2 or 3 wherein the amount of quaternary base ranges from about a stoichiometric amount to about 10 times the total number of acidic sites of the coal liquid or coal bottoms.

5. The method of claim 1, 2 or 3 wherein R'X is present in at least a stoichiometric amount relative to the number of acidic sites of the coal liquid or coal bottoms.

6. The method of claim 1 wherein a quaternary salt re-presented by the formula R4QX is reacted with an alkali or alka-line earth metal base represented by the formula MOR" to form the corresponding quaternary base, wherein M is an alkali or alkaline earth metal.

7. The method of claim 1 wherein the reaction is carried out catalytically.

8. The method of claim 7 wherein the amount of quaternary salt is a catalytic amount ranging from about 0.05 to 10 wt. % of the coal.

9. The method of claim 6 wherein the quaternary base is formed separate from the alkylation or acylation reaction.

10. The method of claim 6 which is repeated at least once.

11. A composition of matter selected from the group con-sisting of coal liquids and coal bottoms wherein the hydrogen atoms of substantially all of the hydroxyl and carboxyl groups of the coal liquids and coal bottoms, have been replaced with a group selected from the group consisting of Cl to C20 alkyl and acyl groups.