I n d . E n g . C h e m . Res. 1989, 28, 427-431
k = first-order reaction rate constant, cm/s 1 = diffusion length, cm n = shape factor ( n = 0, flat slab; n = 1, cylinder; n = 2, sphere) s = BET surface area, cm2/g t = time on stream, s u = dimensionless metals concentration w = weight of deposits, g/cm2 surface y = dimensionless distance from center of pellet z = dimensionless distance from center of micropore D = bulk diffusivity of metal bearing molecule, cm2/s LSV = liquid space velocity, l / s M = molecular weight of deposit sulfides, g/mol N = number of stirred tanks in series R = half-length of catalyst pellet, cm V = pore volume of catalyst, cm3/g Greek Letters
4 = dimensionless Thiele parameter, Ij(4k/dj”D,,J0.6 where j=m,M /3 = dimensionless parameter, VmdMo/VMdmo e = reactor void fraction p = density, g/cm3 8 = fraction of surface covered by deposits, w / w , A = ratio of molecule to pore diameter, dmOl/djwhere j = m, M 7 = macropore tortuosity Subscripts
d = deposits f = fresh or virgin i = index m = micropore mol = metal bearing molecule p = pellet s = saturation M = macropore R = reactor Superscript o = initial value Registry No. Co, 7440-48-4; Mo, 7439-98-7; V, 7440-62-2.
Literature Cited Ahn, B.-J.; Smith, J. M. Deactivation of Hydrodesulfurization Catalysts by metals deposition. AZChE J. 1984, 30, 739-746. Hensley, A. L.; Quick, L. M. Effects of catalyst properties and process conditions on the selectivity of resid hydroprocessing.
427
Presented at the AIChE National Meeting, Philadelphia, PA, June 1980. Hung, C.; Howell, R. L.; Johnson, D. R. Hydrodemetallation Catalysts. Chem. Eng. Prog. 1986, 3, 57-61. Kobayashi, S.; Kushiyama, S.; Aizawa, R.; Koinuma, Y.; Inoue, K.; Shimizu, Y.; Egi, K. Kinetic Study on the Hydrotreating of Heavy Oil. 1. Effect of Catalyst Pellet Size in Relation to Pore Size. Znd. Eng. Chem. Res. 1987,26, 2241-2245. Oyekunle, L. 0.; Hughes, R. Catalyst Deactivation during Hydrodemetalization. Znd. Eng. Chem. Res. 1987, 26, 1945-1950. Pereira, C. J.; Donnelly, R. G.; Hegedus, L. L. Design of Hydrodemetallation Catalysts. In Catalyst Deactivation; Petersen, E. E., Bell, A. T., Eds.; Marcel Dekker: New York, 1987. Pereira, C. J.; Cheng, W.-C.; Beeckman, J. W.; Suarez, W. Performance of the Minilith-A Shaped Hydrodemetallation Catalyst. Appl. Catal. 1988, 42, 47-60. Petersen, E. E.; Smith, M. C. Pore Size Distribution Effects on HDS/HDM Catalyst Activity. Prepr. Pap.-Am. Chem. SOC., Diu. Fuel Chem. 1985, 30, 36. Rajagopalan, R.; Luss, D. Influence of Catalyst Pore Size on Demetallation Rate. Znd. Eng. Chem. Process Des. Deu. 1979, 3, 459-465. Reid, R. C.; Sherwood, T. K. The Properties of Gases and Liquids; McGraw Hill; New York, 1966; pp 548-549. Shah, Y. T. Gas-Liquid-Solid Reactor Design; McGraw Hill: New York, 1979. Shimura, M.; Shiroto, Y.; Takeuchi, C. Effect of Catalyst Pore Structure on the Hydrotreating of Heavy Oil. Znd. Eng. Chem. Fundam. 1986,25, 330-337. Smith, B. J.; Wei, J. Catalyst Deactivation during the Hydrodemetallation of Nickel Porphyrin over CoMo/A120a. Presented at the AIChE National Meeting, Chicago, Nov 1985. Spry, J. C.; Sawyer, W. H. Configurational Diffusion Effects in Catalytic Demetallization of Petroleum Feedstocks. Presented a t the AIChE National Meeting, Los Angeles, Nov 1975. Takeuchi, C.; Fukul. Y.; Nakamura, M.; Shiroto, Y. Asphaltene Cracking in Catalytic Hydrotreating of Heavy Oils. 1. Processing of Heavy Oils by Catalytic Hydroprocessing and Solvent Deasphalting. Znd. Eng. Chem. Process Des. Dev. 1983,22,236-257. Tamm, P. W.; Harnsberger, H. F.; Bridge, A. G. Effects of Feed Metals on Catalyst Aging in Hydroprocessing Residuum. Znd. Eng. Chem. Process Des. Deu. 1981,20, 262-273. Turner, G. A. The Flow Structure in Packed Beds. Chem. Eng. Sci. 1958, 7, 156-165. van Dongen, R. H.; Bode, D.; van der Eijk, H.; van Klinken, J. Hydrodemetallization of Heavy Residual Oils in Laboratory Trickle-flow Liquid Recycle Reactors. Znd. Eng. Chem. Process Des. Dev. 1980,19,630-635. Wei, J. Catalyst Design, Hegedus, L. L., Ed.; Wiley: New York, 1987; pp 245-272.
Received f o r reuiew May 11, 1988 Accepted November 28, 1988
Synthesis of Highly Calorific Gaseous Fuel from Syngas on Cobalt-Manganese-Ruthenium Composite Catalysts Tomoyuki Inui,* A k i r a Sakamoto, T a t s u y a Takeguchi, and Yoshiaki Ishigaki Department of Hydrocarbon Chemistry, Faculty of Engineering, K y o t o University, Sakyo-ku, K y o t o 606, J a p a n
To synthesize a highly calorific gaseous fuel from syngas, a composite catalyst system of Co-Mn-Ru supported on alumina calcined at 1060 “C was investigated by a continuous flow reactor under a pressure of 10 kg/cm2. In contrast to the Ni-based composite catalyst, the Co-Mn203-Ru catalyst converts syngas t o a methane-rich gas containing significant concentrations of Cz-C4 paraffins. Consequently, the Co-based catalyst yielded a highly calorific gaseous fuel directly from a coke oven gas. T h e pilot plant test was conducted by using a fluidized bed and confirmed satisfactory performance for more than 3000 h.
A coke oven gas was conventionally used as a city gas. Now in some countries, however, it is steadily being replaced by a natural gas of higher calorific value. To increase the calorific value, more than 10 vol % or about 30 0888-5885/89/2628-0427$01.50/0
carbon mol % C2-C4 hydrocarbons is added to the natural gas, the dominant component of which is methane. In a reaction near atmospheric pressure using CO methanation catalysts such as Ni and Ru, the major hydrocarbon 0 1989 American Chemical Society
428 Ind. Eng. Chem. Res., Vol. 28, No. 4, 1989
formed is limited to methane (Mills and Steffgen, 1973). Therefore, a higher calorific gas, including quite a high content of C2-C4 hydrocarbons, cannot be easily obtained, especially in high-conversion conditions. Moreover, the byproduct C02, owing to the progress of the shift reaction between CO fed and H 2 0 formed, often increases drastically with an increase of temperature. This reduces the utilization efficiency of the carbon source. The objective of this study was to develop a catalyst for converting a coke oven gas efficiently into a highly calorific gas which is comparable to the natural gas with added C&4 hydrocarbons. So far we have developed threecomponent composite catalysts composed of iron group metals-rare earth oxides-platinum group metals such as Ni-Laz03-Ru and Co-La203-Ru (Inui and Funabiki, 1978; Inui et al., 1979a, 1980), which exhibited very high activity for methanation from syngas and a gas mixture of carbon dioxide and hydrogen. The reason for the high activity was attributed to both effects of hydrogen spillover through the Ru part as the porthole and of a property of the oxide which could easily have a nonstoichiometric oxide. Such an oxide has the potential to assist surface transportation of oxygen-containing reactants. On the other hand, manganese oxide is known to have the ability of C-C chain propagation in Fischer-Tropsch reactions (e.g., Buessenmeier et al. (1977a,b), Dent and Lin (1978), Yang and Oblad (1978),Kolber et al. (1978),Kugler (19801, Vielstich and Kitzelmann (1981), Muller et al. (1982), Bruce et al. (1982), and Inui et al. (1989)). Therefore, in this study, the lanthanum oxide in the three-component catalyst was replaced by manganese oxide with the expectation of an increase in Cz-C4 hydrocarbon formation from syngas. As expected, the Co-Mnz03-Ru catalyst showed high activity with high stability for syngas conversion into methane containing large amounts of Cz-C4 hydrocarbons. The composite effects of the Co-Mnz03-Ru catalyst are discussed in light of the physical properties of the catalyst measured by XRD and CO adsorption methods. Then the result of a pilot plant test is also mentioned briefly.
For the pilot test with a fluidized bed (Inagawa et al., 19871, fine y-alumina particles of 60-pm average diameter were used as the catalyst support. A small amount of superfine alumina powder of size 1 km was mixed into a mixed solution of cobalt nitrate, manganese nitrate, and ruthenium chloride. This suspended solution was sprayed onto the support and dried. The support salts were decomposed in an air stream up to 500 "C and reduced at 400 "C in a hydrogen stream for 24 h. Characterization of Catalyst. To calculate the apparent surface area of the metallic parts of the supported catalysts, the amount of CO adsorbed on the reduced catalysts was measured by the conventional pulse method. Pretreatment for each sample was conducted in a hydrogen flow at 500 "C for 30 min. The surface area of the metallic part was calculated on the basis that chemisorbed CO occupied 13 A2 per CO molecule (Kokes and Emmett, 1960). XRD analysis of catalysts was carried out by the powder X-ray technique. A pattern was obtained with Cu K a radiation, using a Rigaku Denki Geigerflex-2025. Apparatus and Reaction Operation. The reaction was carried out in a continuous flow reactor system under 10 kg/cm2 at a temperature range from 180 to 300 "C. A stainless steel tube (6-mm i.d.) was chosen as the reactor. About a 1.5-mL portion of the catalyst was packed into the reactor tube. The space velocity based on standard volume of the reaction gas (Hz/CO/molar ratio = 3) was varied between 3800 and 6500 h-l. The pilot plant test was carried out with a fluidized bed reactor of 400-mm diameter and 13-m height. Catalyst particles amounting to 500 kg were loaded into the reactor. A gas mixture of a coke oven gas and CO from the CO generator was allowed to flow through the reactor under 8-10 kg/cm2. Part of the effluent gas was directly analyzed by Shimadzu's TCD-type gas chromatograph with MS-5A and Porapak-Q columns or by Hitachi's FID-type gas chromatograph with VZ-10 column. Each gas chromatograph was equipped with an integrator.
Experimental Section Catalyst. The alumina supports used were neobead C-5, 3.0-mm spherical particles manufactured by Mizusawa Chemical Co. Ltd., and ALO-4, pellets of 1.5 mm diameter and 10 mm length, presented from the Japan Catalysis Society as one of the reference catalyst supports. Both alumina supports were calcined at 1060 "C for 3 h to improve their performance for CO hydrogenation (Inui et al., 197913). Then three-component catalysts were prepared by the following procedures. First, the support was impregnated with an aqueous solution of RuC13.3H20. The impregnated support was dried at room temperature with gradual rolling. Then it was exposed to a vapor of 10% aqueous ammonia solution a t room temperature for 2 min (Inui et al., 1982). By this treatment, the ammonium complex was partly formed. This was heated to 350 "C to form an oxide. Second, a mixed solution of Co(N03)2.6H20and Mn(N03)2.6H20was poured onto the Ru catalyst while it was rolled. Finally, this was reduced in a stream of 10% Hz-90% N2 for 30 min at 400 "C. The single- or two-component catalysts were prepared in the same way. For example, for the Co-Ru catalyst, Co was supported on the Ru catalyst. When an additive such as Mo or W was combined with the catalyst, (NH4!6M07024-4H20 or (NH4)10W12041.5H20 was dissolved in the mixed solution of cobalt nitrate and manganese nitrate. These catalysts were made into tablets by a tablet machine and then crushed to 10-20 mesh to provide the reactions.
Results and Discussion Synergistic Effect in Co-Mn-Ru Three-Component Catalyst. The catalytic activity of each single-, two-, and three-component catalyst of Co-Mn-Ru combination was compared by the varying reaction temperature under 10 kg/cm2 and at a space velocity 6000 h-' with a feed gas of 75% Hz and 25% CO. The result is shown in Figure 1. On the 10 wt % Co single-component catalyst, CO was converted above 220 "C, and CO conversion reached the 100% level at around 300 "C. The activity of 2 wt % Ru catalyst exhibited ca. two-thirds that of the Co catalyst, for the whole temperature range. The activity of 6 wt % Mn203catalyst was minor even a t 300 "C. When the Mn component was combined with Co or Ru, the activity decreased markedly. On the other hand, when Ru was combined with Co, the activity increased dramatically, and complete CO conversion was achieved a t lower temperature, above 240 "C. Such a synergistic effect was also observed when Ru was combined with Co-Mn, and CO was converted completely at 280 "C. The major product was methane, and it occupied 60-80 carbon mol %, irrespective of the kind of catalyst. Distribution of the hydrocarbon products containing above two carbon atoms obeyed the Schulz-Flory distribution law, as mentioned later. The only product other than hydrocarbons was COz, and its selectivity was below 20 carbon mol % . The dependences of CO conversion and space-time yields of methane, C2-C4 hydrocarbons, and COz on temperature are shown in
Ind. Eng. Chem. Res., Vol. 28, No. 4, 1989 429 5
4 c L
&
\
3
7
P
v
E 2 v)
d
V
u
N
1
0 180
200
220
240
260
280
300
Temperature ( O C )
Figure 1. Dependence of CO conversion on temperature for syngas conversion on various catalysts: Hz/CO = 3; SV = 6000 h-l; P = 10 kg/cmP; ( 0 )10% Co/Alz03, (A) 6.0% MnzO3/AlZO3,(0) 2.0% Ru/ AlzO3, (0) 10% C d . O % Mn203/A1203, ).( 10% Co-2.0% Ru/A1203, (A)6.0% Mnz03-2.0%Ru/AlZOs, (V) 10% C0-6.0% Mnz03-2.0% Ru/A1203.
-
40
L
Temperature("C) Figure 3. Dependence of STY of Cz-C4 on temperature for syngas conversion on various catalysts: Hz/CO = 3; SV = 6000 h-'; P = 10 kg/cm2; (0)10% Co/Al20,, (A) 6.0% Mn203/A1203,(0) 2.0% Ru/ Al2O3, (0) 10% CO-6.0%MnZO3/AlzO3, ).( 10% C0-2.0% Ru/AlzO3, (A) 6.0%" MnZOa-2.0%Ru/Al2O3, (V) 10% C0-6.0% Mnz03-2.0% Ru/AlZOp
1
f
7 30 7
8
v
>
=,
20
d 8 U
10
Co-Mn Mn- Ru Mn
0 180
200
220
240
260
280
300
Temperature( "C) Figure 2. Dependence of STY of methane on temperature for syngas conversion on various catalysts: Hz/CO = 3; SV = 6000 h-l; P = 10 kg/cm2; (0)10% Co/Alz03, (A) 6.0% MnZO3/Al2O3, (0) 2.0% Ru/A1203, (0)10% Co-6.0% Mnz03/A1203,(m) 10% Co-2.0% Ru/Al2O3, (A) 6.0% Mnz03-2.0% Ru/AlPO3, (V) 10% Co-6.0% Mnz03-2.0% Ru/AIzO3.
Figures 2, 3, and 4, respectively. The space-time yield (STY) is expressed as moles of the product per liter of catalyst per hour. As shown in Figure 2, the dependence of both methane STY's for Co and Ru catalysts was almost the same. For the cases of Co-Ru and Co-Mn-Ru catalysts, at the temperatures where CO conversion reached 10070,the methane STY's attained plateau levels and the STY'Sslightly increased above these temperatures. As for the Co-Ru catalyst, the C2-C4 STY showed the maximum value a t 240 "C and markedly decreased above that temperature (Figure 3). On the other hand, for CoMn-Ru, the STY increased with an increase of CO conversion and attained a plateau level which was higher than the maximum STY for the Co-Ru catalyst a t the temperature range of 100% CO conversion. As shown in Figure 4, the COz STY'S for Co-Ru and Co-Mn-Ru catalysts increased below 280 "C with an increase of reaction temperature. Above 280 "C, however, the STY's decreased, which shows that COBwas hydrogenated to methane at the temperature range of 100% CO conversion. The Schulz-Flory plot for Co-Mn-Ru and Co-Ru catalysts is shown in Figure 5. The carbon chain growth
Temperature("C) Figure 4. Dependence of STY of COPon temperature for syngas conversion on various catalysts: H2/C0 = 3; SV = 6000 h-l; P = 10 kg/cm2; (0)10% Co/Alz03, (A) 6.0% MnzO3/Al2O3,(0) 2.0% Ru/ AlZO3, (0) 10% Co-6.0% MnPO3/Al2O3, ).( 10% Co-2.0% Ru/AlZO3 (A) 6.0% Mnz03-2.0% Ru/AlP03(V)10% C0-6.0% Mnz03-2.0% Ru/A1203.
probability (a)of the Schulz-Flory equation (Henrici-OlivB and OlivB, 1976) for the products on the Co-Mn-Ru catalyst was much higher than that of the Co-Ru catalyst, indicating that the Mn ingredient promotes carbon chain growth. The metallic surface areas measured by CO adsorption for various catalysts are shown in Table I with their catalyst performances. Evidently, the catalysts that had larger metallic surface areas exhibited higher CO conversions indicating that the syngas conversion occurred at a more reduced catalyst surface. From XRD measurements (Figure 6), it is elucidated that Ru exists as the metallic state (20 = 44.0"). The peak of Mn or manganese oxide was absent. This shows that Mn is highly dispersed, and Co exists as CoA1204(20 = 36.8O) and/or Co304 (20 = 42.8"), which are, however, absent for the Co-Ru catalyst. This shows alloying of Co-Ru for the Co-Ru catalyst, and for the Co-Mn-Ru catalyst, Mn retards alloying of Co-Ru. In order to determine the effect of metal concentration, syngas conversion was carried out on the Co-Mn-Ru
430 Ind. Eng. Chem. Res., Vol. 28, No. 4, 1989 Table I. Metallic Surface of Various Catalysts and Their Performance of Syngas Conversion" metal product distribution, C wt % surface area, catalyst m2/g CO conv, % CH4 CZ c3 + c4 c5+ 12.2 1.8 0.60 86.3 74.2 7.5 10% Co/A1203 6.0% Mn203/A1203 0.00 5.3 68.8 8.1 3.3 0.0 0.31 49.3 78.9 7.0 12.0 0.9 2.0% Ru/A1203 9.6 0.0 0.26 13.6 75.6 4.4 10% Co-6.0% Mn203/A1203 1.07 100.0 79.7 3.2 2.4 1.8 10% C0-2.0% Ru/A1203 0.18 9.5 55.6 9.1 22.9 9.6 6.0% Mn203-2.0% Ru/A1203 12.0 6.1 1.22 98.7 58.9 7.1 10% C0-6.O% Mnz03-2.0% Ru/Al2O3
COP 4.3 19.8 1.2 10.4 12.9 2.8 15.8
" P = 10 kg/cm2; T = 230 "C; SV = 6000 h-'; Hz/CO = 3; support, Neobead C-5 calcined at 1060 "C. Table 11. Syngas Conversion on the Co-Mn-Ru Catalysts with Various Metal Loadings" product distribution, C wt % catalyst 4.6% Co-0.1% Mn203-0.35% Ru 11%co-4.4% Mnz03-0.67% Ru 11% co-4.4% Mnz03-0.67% Rub 10% Co-6.0% Mnz03-2.0% Ru
H2/C0
SV, h-I
temp, "C
COconv, %
CH,
Cz
C 3 + C4
C5+
COP
2.6 3.3 3.3 3.0
3800 6500 6500
240 240 220 289
94.0 100.0 75.0 100.0
56.1 71.6 55.3 54.3
7.7 9.2 7.7 11.2
3.8 10.1 18.0 18.8
2.0 5.1
31.5
9.2 9.6
9.8 6.1
6000
4.0
" P = 10 kg/cm2; support, JRC-ALO-4 calcined at 1060 "C. *Calcined at 850 "C for 3 h in a stream of 10% Hz/N2. Table 111. Ssnnas Conversion on the Co-Mn-Ru Catalysts with Mo or W" catalyst 10% 10% 10% 10%
C0-2.0% Mo0,-4.0% Mnz03-2.0% Ru
Co-6.0% MoO,-2.0% Ru Co-2.0% wo3-4.0% Mn203-2.0% Ru c0-0.5% wo3-5.5% Mn203-2.0% RU
temp, "C
CO conv, %
CH4
260 260 250 240
90.9 78.9 77.7 100.0
45.7 55.9 51.5 53.9
product distribution, C wt % C3 + C4 C,+ C2
COP
21.7 20.7 22.9 20.0
14.2 4.9 11.7 10.3
7.3 7.9 6.7 7.1
11.1 10.6 7.2 8.7
"HP/CO = 3; P = 10 kg/cm2; SV = 3000 h-l; support, Neobead C-5 calcined at 1060 "C. 0
~
~~~~
Temp.("C)
Co-Mn-Ru
240 280 300 0
A
0
Co-Ru
-1
--.
0
z z E
v
cn 0 7
-2
-3 1
2
3
4
5
6
N
30
35
40
45
50
55
50
Figure 5. Schulz-Flory plots for the Co-Mn-Ru and Co-Mn catalysts: the Schulz-Flory distribution, log ("IN) = log (InZa) + N log a;N , number of carbons in chain; mN,weight fraction of oligomers; a,probability of chain growth.
Figure 6. XRD patterns for various catalysts support JRC-ALO-4 calcined at 1060 "C.
catalysts with various metal loadings (Table 11). The selectivity of C2-C4 hydrocarbons for higher loading catalyst was twice as large as that for the lower one. When the high concentration catalyst was reduced in a H2stream with stream a t 850 "C, the CO conversion decreased slightly; however, the selectivity of Cz-C4 was as high as 25.7%. This shows that metal is sintered by the hightemperature treatment; thereby CO methanation on Co metal was controlled. Then higher hydrocarbons were formed. When the Mn content was increased, the selec-
tivity of C2-C4 was the highest (30.0%). In order to decrease the methane selectivity, Mo or W was added to the Co-Ru and Co-Mn-Ru catalysts (Table 111). When Mo was added to the Co-Ru catalyst, the methane selectivity decreased. When Mo or W was added to the Co-Mn-Ru catalyst, methane selectivity considerably decreased and C2-C4 increased with the coexistence of Mn. SNG Synthesis from the Coke Oven Gas by the Pilot Plant. A long-term operation with the pilot plant
28 ( d e g )
Znd. Eng. Chem. Res. 1989,28,431-437 Table IV. Change i n Gas Composition (Volume Percent) i n t h e Pilot P l a n t after CO addition after reaction after PSA composition COG 25.40 2.53 53.07 H2 57.57 9.65 0.00 0.00 co 6.45 0.16 3.40 2.74 COZ 2.56 26.00 45.60 85.53 CH, 26.60 3.55 5.13 10.23 c2-c4 3.62 3.73 1.49 2.85 2.91 N2
test was carried out using 20 wt '70 Co-20 wt % Mn203-0.1 wt % Ru/AlZO3catalyst prepared by the spray-drying method. The reduction conditions were set a t SV of 1000 h-l, 260 "C, and 8 kg/cm2. A coke oven gas (Hz/CO = 8.9) was arranged by addition of CO from a CO generating plant and provided as the reaction gas having a Hz/CO volumetric ratio 5.5. As shown in Table IV, CO was converted completely, and after the unreacted Hz, COz, and Nzwere reduced by pressure-swing adsorption (PSA) plants, the content of Cz-C4 in the gas became 10.2%. The catalyst life was confirmed at least 3000 h without any deactivation. The scattering of catalyst from the reactor during the long-term reaction was 1% . The product gas produced by this process generates 10 020 kcal/ (N m3) of combustion heat and only 4 vol % LPG required to adjust the city gas calorie (11OOO kcal/ (N m3)),reducing the necessary amount by about one-third compared with the conventional methanation process. Registry No. Co, 7440-48-4; MnPO3,1317-34-6; Ru, 7440-18-8; CO, 630-08-0; CH,,74-82-8; Cz, 74-84-0; C3,74-98-6; Cq, 106-97-8; C02, 124-38-9.
Literature Cited Bruce, L.; Hope, G.; Turney, T. W. Light Olefin Production from CO/H2 over Silica Supported Fe/Mn/K Catalysts Derived from a Bimetallic Carbonyl Anion, [Fe2Mn(CO)12]-.React. Kinet. Catal. Lett. 1982,20, 175-180. Buessenmeier, B.; Frohning, C. D.; Horn, G.; Kluy, W. (Ruhrchemie A.-G.) Ger. Offen, DE 2518964; Chem. Abstr. 1977a, 86,124093~. Buessenmeier, B.; Frohning, C. D. Horn, G.; Kluy, W. (Ruhrchemie A.-G.) Ger. Offen. DE 2536488; Chem. Abstr. 1977b, 87,41705~. Dent, A. L.; Lin, M. Cobalt-based Catalysts for the Production of C2-C4 hydrocarbons from Syngas. Prepr. Pap-Am. Chem. SOC.,
431
Diu. Fuel Chem. 1978,23, 502-512. Henrici-Oliv6, G. Oliv6, S. The Fischer-Tropsch Synthesis: Molecular Weight distribution of Primary Products and Reaction Mechanism. Angew. Chem. 1976,88, 144-150. Inagawa, H.; Yasumaru, J.; Usugi, Y.; Taki, K.; Ito, M.; h i , T. COG ta SNG by Co-MnzO3-Ru/Al2O3 Catalyst. Proc., Regional Symp. Petrochem. Tech. '87, Bangkok 1987, CA-3-CA-11. Inui, T.; Funabiki, M. Methanation of Carbon Dioxide and Carbon Monoxide on Supported Ni-La203-Ru Catalyst. Chem. Lett. 1978, 251-252. Inui, T.; Funabiki, M.; Suehiro, M.; Sezume, T. Methanation of C02 and CO on Supported Ni-based composite Catalysts. J . Chem. Soc., Faraday Trans. I 1979a, 75, 787-802. Inui, T.; Funabiki, M.; Takegami, Y. Simultaneous Methanation on CO and C02 on Supported Ni-based composite Catalysts. Znd. Eng. Chem. Prod. Res. Dev. 1980,19, 385-388. Inui, T.; Kuroda, T.; Takeguchi, T.; Miyamoto, A. Selective Conversion of Syngas to Olefins and Aromatic-rich Gasoline on FeMn-Ru Containing Composite Catalysts. Submitted for publication in Appl. Catal., 1989. Inui, T.; Sezume, M.; Miyaji, K.; Takegami, T. Pronounced Improvement of Methanation Activity by Modification of the Pore Structure of the Catalyst Support. J . Chem. SOC.,Chem. Commun. 1979b, 873-874. Inui, T.; Suehiro, M.; Saita, Y.; Miyake, Y.; Takegami, Y. Enhancement of Methanation Activity by Ammonia-water Vapor Treatment at the Stage of Catalyst-Salt Supported on a Carrier. Appl. Catal. 1982,2, 389-398. Kokes, R. J.; Emmett, P. H. Chemsorption of CO, C02, and N on Ni 1960, 82, 1037-1041. Catalysts. J. Am. Chem. SOC. Kolbel, H.; Ralek, M.; Tillmetz, K. D. Feedstock for Chemical Industry by Selective Fischer-Tropsch Syntheses. Proceedings of the 13th Intersociety Energy Conversion Engineering Conference, San Diego, C A Society of Automotive Engineer, Inc.: Warrendale, PA, 1978; Vol. 1, pp 482-486. Kugler, L. Synthesis of Light Olefins from CO and H2. Prepr. Pap-Am. Chem. SOC.,Diu. Fuel Chem. 1980,25, 564-569. Mills, G. A.; Steffgen, F. W. Catalytic Methanation. Catal. Rev. 1973, 8, 159-210. Miiller, K.; Deckwer, W. D.; Ralek, R. Fischer-Tropsch Synthesis on Polyfunctional Manganese/Iron-Pentasil Zeolite Catalysts. Studies Surf. Sci. Catal. 1982,12, 267-274. Vielstich, W.; Kitzelmann, D. Japan Pat. Showa-56-25117; Chem. Abstr. 1981, 94, 86946~. Yang, C. H.; Oblad, A. G. Catalytic Synthesis of Light Olefinic Hydrocarbons from CO and H2 over Some Iron Catalysts. Prepr. Pup-Am. Chem. SOC.,Diu. Fuel Chem. 1978,23, 513-520. Receiued for review May 6, 1988 Accepted December 12, 1988
Kinetics of Triaminoguanidine Nitrate Synthesis C h a n - Y u a n Ho,* Tai-Kang L i u , and Wen-Hai W u Chung S h u n Institute of Science a n d Technology, P.O. Box 1-4, Lungtan, Taiwan, Republic of China
A kinetic study was performed on the synthesis of triaminoguanidine nitrate (TAGN) from guanidine nitrate, hydrazine, and ammonium nitrate in an aqueous solution. The reaction rate (-rH) was found to be equal to the sum of the rate of two independently occurring second-order irreversible reactions, namely, the main reaction between hydrazine and guanidine nitrate t o form TAGN and the neutralization reaction between hydrazine and ammonium nitrate t o form hydrazine nitrate. T h e parameters of the apparent kinetic model of these two reactions were derived from individual experiments following NH3 off-gas evolution rate. A reaction mechanism was attempted to elucidate the apparent kinetic model of the main reaction. Moreover, the validity of this model for reactor design was proved by good agreement of conversion between continuous stirred tank reactor experiments and simulation predictions. Triaminoguanidine nitrate (TAGN), one of the important propellant ingredients, has been used primarily as an oxidizer in cool-burning gun propellants for rapid fire weapon systems (Kaye, 1980a,b). It can be prepared by
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the following methods: (a) dicyandiamide method (Satriana et al., 1966), (b) cyanamide method (Sauermilch, 1964, 1969), (c) calcium cyanamide method (Satriana et al., 1974), and (d) guanidine nitrate method (Morton et al., 1981; Frick and Hoffman, 1951; Sauermilch, 1964; Haury, 1976). Among the diversified chemical routes, 0 1989 American Chemical Society
