Ethylene-Steam Reaction Induced bv Ozonizer Discharae Thomas C. Ruppel, Paul F. Mossbauer, Michael F. Ferrer, and Daniel Bienstock Bureau of Mines, Pittsburgh Energy Research Center, U . S . Department of the Interior, Pittsburgh, Pa. 15213 In the presence of a Siemens ozonizer discharge, ethylene and steam react exothermally to produce a large number of gaseous and liquid products. The effect of molar ratio, space velocity, temperature, and reactor power on ethylene conversion was determined. The gaseous products consist of hydrogen, carbon dioxide, carbon monoxide, and traces of hydrocarbons. The liquid fraction is more complex. It contains at least 75 components, consisting of paraffins, olefins, and oxygenates. The oxygenates are largely ~ with alcohols. The total product consists of C1 through approximately C I molecules, Ce through Cs hydrocarbons and 1 -butanol predominating. The experimental data indicate that ethylene conversion increases with steam-ethylene molar ratio, electrical power, and temperature, and decreases with increasing flow rate. There is no reaction at any condition in the absence of a discharge.
NOVEL
techniques are being investigated by the Bureau of Mines to find new uses for coal or coal products. One technique under study uses an ozonizer discharge t o induce chemical reactions with industrial potential. Initially, the gas phase reaction of carbon monoxide and steam to produce carbon dioxide and hydrogen in the absence of a catalyst was investigated (Ruppel et al., 1969a). The effect of' 60-Hz input power, pressure, space velocity, and temperature on carbon monoxide conversion was determined. In the present paper, we report on the reaction of ethylene and steam in the electric discharge. From a chemical viewpoint, the ethylene-steam and
carbon monoxide-steam reactions are entirely different. Whereas the carbon monoxide-steam reaction yields carbon dioxide, hydrogen, and a trace of methane (less than l%), the products from the ethylene-steam reaction number a t least 88. This can be inferred from Reaction 1 and Figure 1. There were 13 gaseous and 75 liquid products detected in the experiment described, all of which cannot be seen in the reproduced gas chromatograms. Equipment and Procedure
The electrical discharge unit and operating procedure have been described (Ruppel et al., 1969a). Briefly,
Reaction 1 . Experiment 368 Product ComDosition Gas phase, Mole %
Feed Composition
50 mole % ethylene mole water
ozonizer discharge
69.9 10.2 4.9 2.6 2.1 2.1 1.8 1.6 1.2 1.1 0.9 0.7 0.7 0.1
Ethylene Hydrogen Butanes Ethane Carbon monoxide Pentanes Hexanes Butenes Propane Hexenes Pentenes Methane Propylene Carbon dioxide
liquid phase, -21°C cold trap
+5.1 mole Li; organics 94.9 mole % water
99.9 0.0202 lbihr 0.000882 lb mole/ hr 0.30 SCFH
0.00844 lb/hr 0.000277 lb mole/hr 0.099 SCFH
0.00970 lb/ hr 0.000392 lb mole/ hr
Ind. Eng. Chem. Prod. Res. Develop., Vol. 9, No. 3, 1970
369
I
1
' I
I
'
I
I
I
A
'original mixture
& in od x 40ft
Ucon LB-550 X column, 80-100 mesh a c i d washed chromosorb G Thermal conductivity detector 20 p I sample size Temperature programmed at 4 W m i n Helium carrier gas flow rote 40 m i / min at 50°C, 25 mt/min a t 180°C
7 4 pct by w t
Sensitivity x I
on
-J c
W
I
50
0
20
IO
30
TEMPERATURE, OC 40 50 T I M E , minutes
60
80
70
B
90
IO0
110
Paraffin froction
Sensitivity x 1-4
--
0
50 0
150
100 IO
20
180 hold
30
T E M P E R ATU R E , "C 40 50 TIME, minutes
60
70
00
90
100
110
Figure 1. Gas chromatograms of organic liquid product from ethylene-steam reaction in ozonizer discharge Experiment 368
a . Moss spectrometry b. Infrared spectroscopy
.f
e. Speculation
metered ethylene from a compressed gas cylinder is passed through a steam generator. The water in the steam generator is maintained at a precalibrated temperature, so that the resulting ethylene-steam flow rate and molar ratio meet the requirements of the experiment. The mixture enters a Siemens-type reactor, undergoes reaction, and leaves through a cold trap. The noncondensable gaseous product continues through a sample collection train of six gas collection bottles in series, and finally through 370
Ind. Eng. Chem. Prod. Res. Develop., Vol. 9, No. 3, 1970
/
c. Addition of known compound to mixture before sample injection
d. Retention time of known compound on same column
a wet-test meter for exit flow measurement. The cold trap is maintained a t -21°C by means of an ice-salt mixture. The Siemens-type ozonizer reactor, methods used for flow rate, and temperature measurements are described by Ruppel et al. (1969a). After the desired ethylene and steam flow rates were obtained and stabilized, the discharge was initiated. The gaseous product was analyzed by gas chromatography
.
~
. . ..
~
~
Sensitivity x
-9
5 ;
4
S
C Light olefin fraction
I a,
5
I L
O
4
Sensitivityx 8 5
I
-
C
-
L
u -
V
Sensitivity
9
XE
180h o l d
150
100-
50
TEMPERATURE, " C
0
20
IO
30
50
40 TIME,
50
150
100 IO
20
70
80
90
IO0
I IO
70
EO
90
IO0
I IO
180 hold T E M P E R A TURE,
0
60
minutes
"C
40 50 T I M E . minutes
30
I
60
.__----.
I
5
-l----~.--~------~
-_-
5 Oxygenate fraction iOPl sample size
0
0
0
c
Baseline
3
n
a,
t
TEMPERATURE, " C
0
IO
20
30
40
50
60
70
EO
90
IO0
110
T I M E , minutes
and mass spectrometry. The liquid portion was analyzed by analytical liquid chromatography, gas chromatography, infrared spectroscopy, and mass spectrometry. Results and Discussion
Characterization of Products. The primary characteristic of the ethylene-steam reaction in an ozonizer discharge
is the complexity of the product mixture. A complete material balance for one set of conditions (experiment 368) is given in Reaction 1. The organic liquid portion, immiscible with water, is characterized in Figure 1 and Table 1. Experimental results are given in Table 11. The five gas chromatograms indicate the complexity of the organic liquid product mixture and also provide Ind. Eng. Chem. Prod. Res. Develop., Vol. 9, No. 3, 1970 371
~~
Table I. Characterization of Organic Liquid Product
Experiment 368 Average molecular weight (ALC') 150 Bulk density (room temp.) g/cc 0.76 Molecular types present, wt cc Paraffinic (FIA and MSb) 26 Olefinic (FIA, MS, and I R ) a-olefin 29 Internal olefin 12 Branched a-olefin 4 Oxygenates (FIA, MS, and I R ) Alcohol 23 Ketone 7 Analytical liquid chromatography (Bombaugh et al , 1968). Fluorescent indicator analysis, ASTM D 1319-56T, and mass spectrometry. ' Infrared spectroscopy.
a partial analysis. Gas chromatogram A represents the original mixture, whereas B , C, D , and E represent fractions from a liquid-solid chromatographic analysis (ASTM, 1956) performed on the original mixture with silica gel as substrate and n-butylamine as eluent. The methanol extractant peak shown in Figure 1, E , arises from a methanol extraction of the oxygenate band in the chromatographic column. This band would not elute with n-butylamine and was examined by breaking the glass column and washing separately with methanol. The type separations from the chromatographic procedure were not complete, but the sharpness of the separations was satisfactory for the analyses desired. Several methods of peak identification were used, mass spectrometry and infrared spectroscopy being the most reliable. Mass spectrometric analysis consisted in trapping
a t -8O'C a component as it emerged from the exit of the gas chromatograph (Burrell Kromo-Tog Model KD) and then manually introducing the trapped component into the mass spectrometer (Consolidated Engineering Corp. Type 21-103). The other methods of identification depended upon the mass spectrometric and infrared results for their utility. I t can be seen from Reaction 1 and the gas chromatograms that the product from the ethylene-steam discharge reaction consists of C , through approximately c,, molecules with a preponderance of Ce through Cxhydrocarbons and 1-butanol. CI, Cli, and CI, hydrocarbons were detected by gas chromatography using FFAP as liquid phase and by mass spectrometry, but C I 1 is the practical termination point. The detection of Clr to C14hydrocarbons explains the average molecular weight value of 150 in Table I. An average molecular weight of 80 to 100 would be expected, due to the predominance of C6 to C, hydrocarbons. Apparently a large number of trace constituents, with molecular weights in the hundreds, are also produced in the discharge reaction. Ethylene polymerization is known to occur under the influence of a nondisruptive electrical discharge and is discussed in connection with Table IV. The finding of paraffinic, olefinic, and oxygenate molecular types in the organic liquid product mixture is not surprising for an electrical discharge-induced chemical reaction with an organic reactant. A complex product mixture is generally observed. The yields of hydrocarbons (71 weight 5)and oxygenates (30 weight 5)shown in Table I can be rationalized by considering the relative conversions of ethylene and steam. Single-pass ethylene and steam conversions of 55 and 16%, respectively, can
Table II. Experimental Results
10,000 Hz a.c. frequency, 1-atm pressure r.m.s. volt cm': E / P = 11.85 + 0.37 r.m.s. volt cm-' torr-' Reactor volume = 141 cm3except experiment 368, where volume = 153 cm'
EIN = (5.58 i 0.55") x
Expt. No.
% Ethylene Conversionb
Steam-Ethylene Molar Ratio
Space Velocity, HrC'
368 377 377A 377B 378 378A 378B 379 379A 379B 380 380A 380B 381 381A 381B 382 382A 382B 383 383A 383B 384 384A 384B 385
54.9 66.1 68.0 70.0 11.2 16.3 21.3 10.2 14.0 17.7 0 1.5 2.4 11.2 36.7 53.5 3.2 3.8 4.5 2.0 7.5 13.1 5.0 8.8 12.7 0
1.0 8.5 8.5 8.5 2.8 2.8 2.8 1.0 1.0 1.o 0.61 0.61 0.61 7.0 7.0 7.0 0.70 0.70 0.70 3.0 3.0 3.0 1.o 1.0 1.o 8.5
56 160 160 160 270 270 2 70 100 100 100 320 320 320 140 140 140 325 325 325 270 270 2 70 105 105 105 160
Standard deviation.
Temp,,
O
125 240 240 240 230 230 230 245 245 245 140 140 140 140 140 140 220 220 220 140 140 140 120 120 120 240
C
Secondary Power', Volt-Amperes
Secondary Voltage, R.M.S. Volts
350 380 420 460 380 420 460 380 420 460 380 420 460 380 420 460 380 420 460 380 420 460 380 420 460 0
7000 6390 6530 6670 6620 6920 7220 6790 7000 7210 7060 3780 7700 7100 7020 6940 6690 7160 7620 7260 7250 7240 7290 7500 7720 0
' r~conversion = [SCFH,, - SCFH,,.,)/(SCFH,,)] (100). ' Drawn by reactor.
372 Ind. Eng. Chem. Prod.
Res. Develop., Vol. 9, No. 3, 1970
Kva-hr' per Lb Ethylene Converted
53.4 87.5 93.1 98.3 125 95.9 79.7 193 158 136 1900 429 261 418 176 119 151 140 131 974 218 132 487 256 184
...
be calculated from the material balance associated with Reaction 1. Assuming that some of the ethylene underwent reaction independently of the steam, the hydrocarbonoxygenate ratio is roughly equivalent to the ethylenesteam conversion ratio. This calculation can be carried somewhat beyond the limits of its reliability by stating that 1 7 5 of the ethylene was converted to other hydrocarbons independently of the steam. A gas chromatogram, analogous t o Figure 1, A, was obtained using a flame ionization detector. More than 75 components could be counted, compared with approximately 65 in Figure 1, A . A thermal conductivity detector was used in obtaining the gas chromatograms in Figure 1 to permit the trapping of individual components for mass spectrometric identification. The water fraction was analyzed by mass spectrometry and found to contain more than 99'; water, C 1 through C6 alcohols accounting for 0.64'; of the impurities. The organic liquid product in Reaction 1 consists of 5.1 mole 5 of the -21" C cold trap contents. This quantity, nevertheless, is equivalent t o 50% by weight of the total products on an ethylene-free and water-free basis. Since the single-pass ethylene conversion was 54.9% for experiment 368 in Table 11, and 50 weight 5% of the product consists of organic liquid, 27 weight 75 of the ethylene feed is converted to liquid products. Effect of Process Variables on Ethylene Conversion. As part of a larger program to delineate the effect of process variables on product characteristics, the effect of steamethylene feed molar ratio, space velocity, and temperature on ethylene conversion was determined. The data were analyzed by means of a linear hypothesis statistical empirical model (Mendenhall, 1968). With this model, it is assumed that the conversion of ethylene is dependent on all variables studied to the first power only and on interaction or cross terms between the variables. The dependent variable could be chosen from any measured product characteristic; we chose the per cent conversion of ethylene. The following regression equation resulted from this model:
C2H4converted = 6.040 + 1.752(MR) O.O1942(Sv) + 0.006024(T) + 0.03596(MR)(T)0.01811(MR) ( S V ) (1) where
M R = steam-ethvlene feed molar ratio S V = space velocity, hr-', flow rate/reactor volume (STPI T = temperature, o C . The standard error of estimate of Equation 1 is 2.5. Equation 1 represents the experimental data of Table I1 a t 420 volt-amperes secondary power. Secondary power does not appear as a variable in the regression equation, because ethylene conversions obtained a t 380, 420, and 460 volt-amperes secondary power were not obtained from experiments carried out in a randomized sequence. This could, and did in a test equation including secondary power, lead to spurious regression coefficients for terms containing secondary power. As seen in Table 11, molar ratio, space velocity, and temperature were randomized with respect to sequence. Randomization eliminates any apparent correlation of independent variables. However. Table I1 indicates that ethylene conversion increases with power drawn by the reactor.
Table Ill. Ethylene Conversions Calculated from Equation 1
10,000 Hz a.c. frequency; 1-atm pressure; 420 volt-amperes drawn by reactor Ethylene Conversion
Oh
12.0 14.1 1.5 3.5 15.5 25.8 5.5 15.2
Steam-Ethylene Molar Ratio
Space Velocity Hr
100 100 300 300 100 100 300 300
Temp., ' C
100 200 100 200 100 200 100 200
The effect of steamlethylene molar ratio, space velocity, and temperature on ethylene conversion can be easily seen from Table 111, which was calculated from Equation 1.
An inspection of Table I11 shows that steam-ethylene molar ratio and temperature have a positive effect on conversion, whereas space velocity exerts a negative effect. According to Table 11, maximum conversion of ethylene within the range of Equation 1 was found in experiment 377A. The experimental value of 68.0% compares with a value of 67.7 obtained by calculation. Regions of interest suggested by the equation and Table I11 would be high steam-ethylene molar ratio, low space velocity, and high temperature. No ethylene was converted to gaseous or liquid products in the absence of an electrical discharge in experiment 385. These conditions matched those yielding the highest ethylene conversion, experiment 377. Thus, there is no thermal reaction a t these conditions and the discharge supplies the energy necessary for reaction. The authors' previous investigation (Ruppel et al., 1969a), using the water-gas shift reaction ( H 2 0+ CO = H2+ COJ, indicated that the discharge is necessary in that case also, and further that the quartz walls of the ozonizer are probably not involved. By analogy, it appears that the ethylenesteam reaction in an ozonizer discharge is also a homogeneous gas phase reaction. We have obtained some preliminary experimental results a t 60-Hz a x . frequency. With identical conditions, except frequency, the gaseous and liquid product characteristics appear to be identical. However, the product yield is less. This variable will be studied further in future experiments. The over-all ethylene-steam reaction exothermic. The heat of reaction is sufficient t o keep Le reaction temperature above the condensation point I' steam. In practice, sectional heating and cooling were employed. The discharge by its nature has a tendency to localize, producing hot spots. These areas could become the sites for arc formation, with subsequent quartz reactor perforation and failure. A relatively even and stable discharge was obtained with the judicious intermittent use of small cooling fans and sectional heaters. Mechanistic Details of Product Formation. While the product arising from the discharge-induced reaction of ethylene and steam consists of a complex mixture of paraffins, olefins, and oxygenates, it is worthwhile to speculate on the mode of formation of the products. Since it is difficult to describe any such chemical reaction mechaInd. Eng. Chem. Prod. Res. Develop., Vol. 9, No. 3, 1970
373
nistically, we limit ourselves to relatively simple and reasonable mechanisms. The following equations provide a reasonable means for formation of the observed products. ALCOHOLS ( ~ - B I J T A NPREDOMINANT) OL
H?O
+
~
discharge
Ha
*CH,--CH?-OH
+ OH.
.CHL(CH?-CHZ),CH?-OH + He * CH 3 (CHr--CH?) ,,CHr--OH The above mechanism could be modified by introducing a hydrogen atom first and a hydroxyl radical last.
PARAFFINS (HEXANE PREDOMINANT)
CH?=CH? + He
+ nCHL=CHr
CH~-(CH?-CH?),-CHZ.
+
CH,(CHI-CH?),CH?-OH
+
CHj-CHZ.
+ H.
-
CH?--(CH,-CHj),--CH
Table IV. Survey of Other Ethylene Reactions in Nondisruptive Electrical Discharges Reoction Reoctonts
374
Products
Conditions
Investigator
Ethylene
Acetylene Butadiene 1-Butene Ethane 1-Hexene Hydrogen Methane Liquid + solid products
I
Vondisruptive discharges near atmospheric pressure
Andreev (1938) Balandin et al. (1934) Dem’yanov and Pryanishnikov (1926) Eidus (1938) Eidus and Nechaeva (1940) Fujio (1930) tJovitschitsch (1908) Mignonac and De St. Aunay (1929) Stratt,a and Vernazza (1931, 1933) Szukiewicz (1933) Vernazza and Stratta (1931)
1.68 ethylene 5.00 air
Acetaldehyde Carbon dioxide Diformyl peroxide Ethyl alcohol Ethylene oxide Formaldehyde Hydrogen Methane Methanol Propargyl alcohol Water
Ozonizer, atmospheric pressure
Sugino et al. (1965)
1 ethylene 5 air
Carbon dioxide Water
Ozonizer, near atmospheric pressure
Vernazza and Stratta (1930)
1 ethylene 1 air
Carbon monoxide Formaldehyde Hydrogen Methanol Paraformaldehyde Water Other liquid products
Ozonizer, atmospheric pressure, 10,000 Hz A.c. frequency
Ruppel et al. (1969b)
2 ethylene 1 nitrogen
Acetylene Hydrogen cyanide Liquid + solid products
“Silent discharge” near atmospheric pressure
Miyamoto (1922)
Ethylene Carbon dioxide
Carbon monoxide Hydrogen Methane Liquid saturated hydrocarbons
Ozonizer, 1:4 to 4:l ratios
Vernazza and Stratta (1930)
1 ethylene 1 carbon dioxide
Butanes Butenes Carbon monoxide Ethane Hexanes Hydrogen Pentanes Pentenes Liquid products
Ozonizer, atmospheric pressure, 10,000 Hz A.c. frequency
Ruppel et al. (1969b)
Ind. Eng. Chem. Prod. Res. Develop., Vol. 9, No. 3, 1970
3
The hydrogen atom addition in the last reaction could be replaced with the alkyl radical attack on a hydrocarbon. This would produce a paraffin and another alkyl free radical. HIGHER OLEFINS AND HYDROGEN( ~ - H E X E N PREE DOMINANT)
CH?=CH,
discharge
CH,=CH. + H.
CH?=CH, + He CH,=CH* + Ha + H . CH,-CH,* CH,=CH? + He CH:j-CH?* + CHe=CHZ CHr-CH?-CH?-CH?. 4
4
4
CH:j--CH?--CH,-CHZ * + CH?= CH * -+ CH:q---CH?-CH,-CH?-CH CH,---CH,-CH,--CH,
* +
CH,-CH,-CH
CH,,-CH?-CH*--CH3 + C,H,=CH. CH:;-CH?-CH(CHs)-CH
= CH?
S-CH,
-+
= CH,
C.H.,--CH,- --CH(CH,)--CH=CH? CH:,--C H 2- C (CHs) =CH---C H,
(1930), Ruppel et al. (1969b). Vernazza and Stratta and the authors also investigated the ethylene-carbon dioxide system. Ethylene plus nitrogen was studied by Miyamoto (1922). The ethylene-nitrogen-propane system in a glow discharge was investigated by Hinde and Lichtin (1969) for the purpose of elucidating the mechanism of olefin reactions with active nitrogen. Most of the above citations were concerned with ozonizer discharges a t or around atmospheric pressure; however, the a x . frequencies employed varied greatly. The above investigations are qualitatively summarized in Table IV. I n practically all cases, the reactions in Table IV did not proceed to completion. The residence time was too short for the complete reaction of feed material. Factorially designed experiments are in progress to determine simultaneously the effect of a.c. frequency, molar ratio, field strength--gas density, space velocity, and temperature on several measurable product characteristics. Following these experiments it should be possible, within the limitations of the chemistry involved, to produce product with specified characteristics.
+
HYDROGEN (PREDOMINANT GASEOUS PRODUCT)
HLO
-----i
discharge
He
CH?=CH, + He 2H. H,
-+
+ OH* CH,=CH*
+ H . + Ha
--i
The appearance of odd-membered paraffins, olefins, and alcohols in the product gas and liquid suggests the formation of the methylene radical in the discharge. Kunugi et al. (1969) give an estimated large activation energy of. 167 kcal per gram mole for the formation of the methylene radical from ethylene. While it is very short-lived, reacting with the first particle it encounters, its low concentration should be high for such a reactive moiety, because it is produced by ethylene, one of the most abundant species in the discharge. A single attack by a methylene radical will ultimately produce an odd-membered product. Other mechanistic interpretations concerning organic compounds in nondisruptive electrical discharges are given by Thomas et al. (1941), Wiener and Burton (1953), Kawahata et al. (1964), Borisova and Eremin (1968), d’Engheim et al. (1968), Sonoda et al. (1968), LeGoff and Vuillermoz (1969), Hiraki (1969), and Suhr and Weiss (1970). Hinde and Lichtin (1969) and Ruppel et al. (1969a,b) also discuss reaction mechanisms in electrical discharges. Kunugi et al. (1969) present kinetic and mechanistic interpretations of thermal reactions of ethylene. Comparison with Other Ethylene Reactions
A patent was granted to den Hertog and Bruin (1954) concerning the production of alcohols from olefins by electrical discharge. Similar systems have been studied by others. The decomposition and polymerization of ethylene in nondisruptive discharges were studied by Andreev (1938), Balandin et al. (1934), Dem’yanov and Pryanisnikov (19261, Eidus (1938), Eidus and Nechaeva (1940), Fujio (1930), Jovitschitsch (1908), Mignonac and De St. Aunay (19291, Stratta and Vernazza (1931, 1933), and Szukiewicz (1933). The ethylene-air system was investigated by Sugino et al. (1965), Vernazza and Stratta
Conclusions
The ethylene-steam reaction holds potential engineering applications. I t is novel, exhibits good reactivity from a technical viewpoint, can be carried out under mild conditions, and produces a myriad of alcohols, olefins, and paraffins. I t is a mixture analogous to crude petroleum, Fischer-Tropsch synthesis product, and the product from the destructive distillation of coal, but its chemical constitution is novel. Since electrical power is a t present a relatively expensive form of power, the ethylene-steam reaction product is not as attractive as the above feed stocks as a source of raw materials. However, if a compound, boiling range fraction, or mixture of alcohols or olefins could be found which appears to be worth marketing, the product may prove to be a useful source of synthetic organic chemicals. Literature Cited
American Society for Testing and Materials, 1916 Race St., Philadelphia, Pa., ASTM D 1319-56T, “Fluorescent Indicator Analysis,” 1956. Andreev, D. N., Bull Acad. Sci. U R S S , Classe Sci. Math. Nut., Ser. Chim. 1938, 1039; C A 33, 6575 (1939). Balandin, A. A., Eidus, Y. T., Zalogin, N. G., Compt. Rend. Acad. Sci. U R S S 4, 132 (1934); C A 29, 6154 (1935). Bombaugh, K. J., Dark, W. A., King, R. N., Res./Deuelop. 19, No. 9, 28 (1968). Borisova, E. N., Eremin, E. N., “Organic Reactions in Electrical Discharges,” N. S. Pechuro, Ed., pp. 52-7, Consultants Bureau, New York, 1968. Dem’yanov, N. Y., Pryanishnikov, N. D., J . Russ. Phys. Chem. SOC.58, 472 (1926); C A 21, 3344 (1927). d’Enghien, A.-P, Vrebosch, J., Van Tiggelen, A,, Bull. SOC.Chim. Fr. 6,2315, 2321 (1968). den Hertog, H. J., Bruin, P., U. S. Patent 2,672,440 (1954). Eidus, T. Y., Bull. Acad. Sci. U R S S , Classe Sci. Math. Nut., Ser. Chim. 1938, 737; C A 33, 3269 (1939). Eidus, Y. T., Nechaeva, N. N., Bull. Acad. Sci. U R S S , Classe Sci. Chim. 1940, 153; CA 35, 3540 (1941). Fujio, C., Bull. Chem. SOC.Japan 5, 249 (1930); CA 24, 5644 (1930). Hinde, P. T., Lichtin, N. N., Aduan. Chem. Ser. No. 80, 250 (1969). Ind. Eng. Chem. Prod. Res. Develop., Vol. 9,No. 3, 1970 375
Hiraki, T., Bull. Chem. Soc. Japan 42, 470, 2993 (1969). Jovitschitsch, M. A., Monatsh. 29, 1, 5 (1908); C A 2, 1418 (1908). Kawahata, M., Fraser, J. C., Coffman, J. A., Amer. Chem. Soc., Diu. Fuel Chem., Preprints 8, 33--41 (1964); C A 64, 3254 (1966). Kunugi, T., Sakai, T., Soma, K., Sasaki, Y., Ind. Eng. Chem. Fundam. 8, 374 (1969). LeGoff, F., Vuillermoz, B., J . Chim. Phys. 66, 403 (1969). Mendenhall, W., “Introduction to Linear Models and the Design and Analysis of Experiments,” pp. 48-61, 93-6. Wadsworth Publishing Co., Belmont, Calif., 1968. Mignonac, G., De St. Aunay, R. V., Compt. Rend. 189, 106 (1929); CA 23, 4668 (1929). Miyamoto, S., J . Chem. Sac. Japan 43, 2 1 (1922); CA 16, 2248 (1922). Ruppel, T. C., Mossbauer, P. F., Bienstock, D., Aduan. Chem. Ser., No. 80, 214 (1969a). Ruppel, T. C., Mossbauer, P. F., Bienstock, D., unpublished results, 1969b. Yamamoto, S., Okumura, K., Noda, S.,TsutSonoda, N., sumi, S.,Aduan. Chem Ser. No. 76, 352 (1968). Stratta, R., Vernazza, E., Ind. Chim. (Rome) 6,133 (1931); C A 25, 4186 (1931).
Stratta, R., Vernazza, E., Ind. Chim. (Rome) 8, 698 (1933); C A 27, 5254 (1933). Sugino, K., Inoue, E., Shirai, K., Koseki, T., Gomi, T., Nippon Kagaku Zasshi 86, 1200 (1965). Suhr, H., Weiss, R. I., 2 . Naturforsch. 25B, 41 (1970). Szukiewicz, W., Rocz. Chem. 13, 245 (1933); C A 27, 4487 (1933). Thomas. C. L., Egloff, G., Morrell, J. C., Chem. Rev. 28 (l), 1 (1941). Vernazza, E., Stratta, R., Ind. Chim. (Rome) 5, 137 (1930); C A 24, 5644 (1930). Vernazza, E., Stratta, R., Ind. Chim. (Rome) 6, 761 (1931); C A 26, 1198 (1931). Wiener, H., Burton, M., J . Amer. Chem. Soc. 75, 5815 (1953).
RECEIVED for review February 2, 1970 ACCEPTED June 26, 1970 Symposium on Chemicals from Coal, Division of Fuel Chemistry, 158th Meeting, ACS, New York, N.Y., September 1969. Reference to a company name is made to facillitate understanding and does not imply endorsement by the U.S. Bureau of Mines.
Carbon Black Feedstock from l o w Temperature Carbonization Tar Donald C. Berkebile, Harold N. Hicks, and W. Sidney Green Ashland Oil,Inc., Ashland, K y . 41101
IN
1966, Ashland Oil initiated a modest coal liquids research program aimed a t accumulating basic technology and providing a basis for more extensive studies. Discussions with the FMC Corp. established that it would supply tar from its low temperature carbonization (LTC) pilot plant for experimental work. The FMC LTC unit was constructed under sponsorship of the Office of Coal Research (OCR). This program is designated as CharOil-Energy-Development (Project COED), The COED process utilizes multiple-stage, fluidized-bed pyrolysis with increasing stage temperatures to drive off the volatile matter a t controlled rates and temperatures, so that a high percentage of the coal is converted to gas and condensable oil products. Coal is crushed and dried and fed to the first-stage vessel, where it is fluidized in hot recycle gases generated from combustion of some of the product gas or char. The coal then proceeds from the first stage, which is nominally a t 600”F, to the subsequent stages where it is subjected to increasing temperatures of 850”, lOOO”, and 1600°F.Heat for the second and third stages comes from burning some of the char with oxygen in the fourth stage. The gases from the 376 Ind.
Eng. Chern. Prod. Res. Develop., Vol. 9, No.
3, 1970
fourth stage flow countercurrent to the solids through the third stage to the second stage, from which most of the volatile products are collected. A small percentage of the volatiles comes from the first stage. A small amount of char is recycled t o the third and second stages to provide some of the heat necessary to maintain the vessel temperatures. The volatile products from the pyrolysis are condensed and separated. The Project COED tar feedstock for all work described in this paper was derived from Illinois No. 6 coal. The primary object of Ashland’s tar research program was to produce carbon black feedstock from all or a portion of the LTC coal liquids. This approach would require minimal processing and utilize heretofore unmarketable fractions of the coal liquids. Secondly, emphasis was placed on converting the fractions unsuitable for carbon black feedstock into products compatible with normal refinery operations. Others have tried many techniques to upgrade LTC tar, including coking, thermal cracking, and hydrogenation. Products ranging from coke to gasoline with some intermediate chemicals are commonly reported in the liter-
