Al2O3, CoMo

石 油 学 会 誌

Sekiyu

Gakkaishi,

33,

(6),

413-417

413

(1990)

Catalytic Hydrocracking of Phenanthrene over NiMo/Al2O3, CoMo/Al2O3 Catalysts and Metal-loaded Y-Zeolites Kozo

UEDA,

Hisaji

MATSUI,

Res. & Dev. Center, Osaka

Chunshan

The

preliminary of

experiments 400℃

for

on

1h,

February

hydrocracking

with

and

Gas Co., Ltd., 6-19-9 Torishima,

(Received

temperature

SONG†1),

an

initial

of

hydrogen

Wei-Chun

XU*

Konohana,

Osaka 554

7, 1990) phenanthrene pressure

were of

7Mpa.

carried

out

Three

at

kinds

a reaction

of

metal-ion

exchanged Y-zeolites (NiH-Y, FeH-Y, LaH-Y) and H-Y zeolite were prepared and their catalytic behaviors were investigated. Two commercial catalysts (NiMo/Al2O3 and CoMo/Al2O3) were used as references. It was found that NiH-Y zeolite had the highest hydrocracking activity and conversion of phenanthrene reached 81%. At the same time, comparatively high yields of alkylbenzenes and alkylnaphthalenes were attained. H-Y and LaH-Y zeolites both gave similar results, attaining comparatively low conversion of 46%. FeH-Y zeolite showed lower activity but higher selectivity toward formation of partially hydrogenated phenanthrene. The order of conversion of phenanthrene and

the yields of benzenes

CoMo/Al2O3>FeH-Y. potential

1.

The

for the production

and

naphthalenes

results

of the

were

as follows:

present

of fine chemicals

from

study

of liquids

mainly

consisting

of

polynuclear aromatic compounds1) is evolved from coal conversion processes such as pyrolysis and gasification. It is desirable to produce more useful chemicals including two- and one-ring aromatic compounds from coal-derived liquids from the view-point of utilizing coal effectively and economically. For this purpose, catalytic conversion of polynuclear aromatic hydrocarbons has been challenged extensively. Recently, the hydrocracking of polynuclear aromatic hydrocarbons, such as anthracene, phenanthrene and pyrene, has been investigated relevant to coal liquefaction, using Lewis acidic metal halides2)-6), supported Mo and W catalysts and other unsupported catalysts7)-13). On the other hand, zeolytic catalysts have been widely used in FCC (fluid catalytic cracking)14), selective alkylation of alkylbenzenes15), hydrocracking of toluene16) and upgrading of heavy oil17). The catalytic effects on the hydrocracking of polynuclear aromatic hydrocarbons have also been investigated. For example, the study by Haynes et al.18) showed the possibility of using Ni-W loaded ultrastable Y-zeolytic catalyst for the hydrocracking of phenanthrene. Kikuchi et al. compared the catalytic behavior of zeolytic * To

whom

1) Present State

correspondence address:

University,

Fuel

should Science

be addressed.

Program,

The

that

hydrocracking

Introduction A large amount

NiH-Y>H-Y=LaH-Y>NiMo/Al2O3=

showed

Pennsylvania

石 油 学 会 誌

Sekiyu

Gakkaishi,

Y-zeolite

has

a high

catalysts with that of commercial hydrocracking catalysts, CoMo/Al2O3 and NiMo/Al2O3, on hydrocracking of phenanthrene, in the presence of hydrogen-donor solvent, using an autoclave19) and a flow system20). They found that the loading of La on H-Y zeolite is more effective on transferring hydrogen from tetralin to reactants. In spite of these, information on zeolytic catalysts for hydrocracking of polynuclear aromatic hydrocarbons is not yet adequate. The present work is focused on investigating the possibility of the zeolytic catalysts for hydrocracking of polynuclear aromatic hydrocarbons to produce more useful chemical feedstocks, such as two- or one-ring aromatic compounds. The preliminary experiments were carried out using phenanthrene as feedstock. Metal ions like La, Fe and Ni were loaded to Y-zeolite by ion-exchange method, and the catalytic effects on hydrocracking of phenanthrene were investigated. Commercial aluminasupported NiMo and CoMo catalysts were also examined for the purpose of comparison. 2.

Experimental

In the present study, Y-zeolites were prepared

the metal-ion exchanged by mixing NH4-Y zeolite

(Shokubai Kasei Kogyo Co., SiO2/Al2O3=4.6) and 0.25M aqueous solutions of Ni(NO3)2, Fe(NO3)3, and La(NO3)3, respectively. The mixtures were agitated

at

85℃

ion-exchanged

U.S.A.

Ni-loaded

of phenanthrene.

Vol.

33,

for zeolites

No.

6,

1990

2h

and were

then washed

filtrated. with

The

distilled

414

Table

a): starting materials b): not measured

water, air

dried

at

at 500℃

calcining

120℃

for the

for preparation

for

4h.

H-Y

NH4-Y

1 Compositions

and

of metal-loaded

2h

and

then

zeolite zeolite

at

in

obtained

450℃

for

by 12h.

Two commercial hydrocracking catalysts of NiMo/ Al2O3 and CoMo/Al2O3 (from Shokubai Kasei Co., Japan) were also examined. The two catalysts were pretreated with 6% solution of CS2 in ndodecane

at 300℃

and

0.5MPa

hydrogen

for

400℃

at a heating for

1h.

rate

of

After

40℃/min

and

reaction,

the

Examined

of GC retention time of standard reagents. identification of isomers for some products conducted used

according

were

washed

to literatures. with

solvent

and

The dried

The was

catalysts at

100℃

for 1h in vacuum, followed by measurements for carbonaceous deposits by means of combustion method.

3h,

because presulfidation increases the yields of alkylbenzenes and alkyltetralins from hydrocracking of phenanthrene10). Table 1 shows the composition and properties of the catalysts. The amount of metals loaded was determined by inductively coupled plasma-atomic emission spectrometry. The surface areas of catalysts were measured by means of BET method, the acidic strengths of catalysts were measured by temperature programmed desorption technique with NH3 adsorbate21). Hydrocracking of phenanthrene (assay by GC> 98%, from Tokyo Kasei Kogyo Co., Ltd.) was carried out in a 100ml SUS-316 autoclave, equipped with magnetic stirrer, stirred at a speed of 130rpm. Typically, 4g of phenanthrene, 2g of catalyst and 10ml of n-heptane, which was used as reaction solvent, were added to the reactor. The reactor was pressurized to 5 or 7MPa of hydrogen, heated up to 400℃

of Catalysts

Y-zeolites

calcined

was

Properties

held

3.

Results

and Discussion

Typical gas chromatograms of the products from hydrocracking of phenanthrene are shown in Fig. 1. It is seen that numerous products were produced during hydrocracking of phenanthrene. In the present study, those are classified into the following groups: (1) C1-C4 gases; (2) C5-C7 aliphatics; (3) alkylbenzenes; (4) alkyltetralins and alkylindanes; (5) alkylnaphthalenes; (6) alkylbiphenyls; (7) unsym-octahydrophenanthrene and octahydrophenanthrene isomers; (8) sym-octahydrophenanthrene; (9) methylbenzoindanes; (10) tetrahydrophenanthrene; (11) dihydrophenanthrene; (12) phenanthrene; (13) alkylphenanthrenes; carbon deposit; and others (not determined).

(14)

at

reactor

was

quenched to room temperature with air blast. The gaseous products were collected and analyzed by gas chromatography. The content of the reactor was washed out with CH2Cl2 solvent and then strained. The liquid products, concentrated by evaporation, were analyzed quantitatively by a capillary gas chromatograph (Shimadzu GC-9A) equipped with flame ionization detector and a methylsilicone coated fused silica capillary column CBP-1,

0.25mm

temperature

(i.d.)×25m was

controlled

length. at

40℃

The for

column 5min

and Initial

then

heated

to 275℃

at a heating

rate

of 5℃/min.

The products were identified by capillary GC-MS (Shimadzu GCMS-QP1000) analysis. The major components were further confirmed with the aid 石 油 学 会 誌

Sekiyu

H2

CH2Cl2

Gakkaishi,

Fig.

pressure:

(GC

1

7MPa,

solvent),

Typical

Capillary

Products

Resulting

Phenanthrene

Vol.

33,

No.

6,

over

1990

Temperature;

p2: n-heptane

Gas from NiH-Y

(reaction

400℃,

Chromatograms Hydrocracking Zeolite

p1:

solvent)

of of

415

As it is well known, the hydrocracking reaction of phenanthrene does not proceed to any remarkable extent without catalyst because of the relatively lower reactivity. In the present study, the conversion was only 2.8% together with tetrahydrophenanthrene

Table

2

Product Catalysts

a): b): c):

as the main

Yields at 400℃

from

product

Hydrocracking for

1h

with

Initial

Phenanthrene Hydrogen

catalyst

being

pressure of 5MPa, Table 2. The promoted conversion together

in the case of

of an

no

over Pressure

the of with

NiMo/Al2O3, of

5MPa

used

Sekiyu

Gakkaishi,

Vol.

33,

No.

initial

reaction to a great phenanthrene have main products of

7MPa

R, R1 and R2 mean alkyl groups or hydrogen including cyclohexylphenylethane and cyclohexylbenzene including some unknown components with molecular ion mass of 182

石 油 学 会 誌

an

6,

hydrogen

as shown in the left column of use of NiMo/Al2O3 catalyst

CoMo/Al2O3 or

at

1990

and

Metal-ion

extent. The reached 40%, hydrogenated

Loaded

Zeolytic

416

phenanthrenes, i.e., both unsym- and sym-octahydrophenanthrenes, tetrahydrophenanthrene and dihydrophenanthrene. The yields of tetrahydrophenanthrene and dihydrophenanthrene reached 22.6%, while the yields of alkylbenzenes, alkyltetralins and alkylnaphthalenes (the products of hydrocracking) were 0.2%, 0.9% and 0.8%, respectively. When the initial hydrogen pressure was increased to 7MPa, the conversion of phenanthrene significantly increased to 68.4%. NiMo/Al2O3 catalyst afforded partially hydrogenated phenanthrenes as main products, and the major products of cracking were alkyltetralins, cyclohexylphenylethane, cyclohexylbenzene and alkylbiphenyls, together with small amounts of alkylnaphthalenes. The yields of alkylbenzenes, alkyltetralins and alkylnaphthalenes were higher than in the case of initial hydrogen pressure being 5MPa, reaching 1.5%, 4.4% and 1.8%, respectively. In any case, CoMo/ Al2O3 catalyst showed behavior similar to that of NiMo/Al2O3 catalyst, as shown in Table 2. Product distribution from hydrocracking of phenanthrene over metal-loaded zeolytic catalysts, at an initial H2 pressure of 7MPa, are shown in Table 2. The product distribution pattern was strongly influenced by kinds of loaded metals. The conversion of phenanthrene over H-Y zeolite (without metal loading) was only 47%. This is in fact lower than that in the case of NiMo/Al2O3 or CoMo/Al2O3 catalyst. Benzene, alkylbenzenes, naphthalene and methyl naphthalenes were obtained as major products of hydrocracking, together with C1-C4 gases. While the yield of alkyltetralins (0.7%) was very low, more than 10% of methyl and dimethyl phenanthrenes was formed with H-Y zeolite, which was probably due to transalkylation between alkylnaphthalenes and phenanthrene over the strong acidic catalysts. Loading La did not change the acidic strength of zeolite. The results with LaH-Y zeolite were very similar to those with H-Y zeolite under the present conditions, although loading La on Y zeolite increased the conversion of polynuclear aromatic hydrocarbons in the presence of hydrogendonor tetralin solvent19),20) On the other hand, loading Fe decreased the acidic strength of the zeolite to a great extent. FeH-Y zeolite showed significantly lower activity but different catalytic behavior as compared with H-Y and LaH-Y zeolites. The conversion of phenanthrene was suppressed to 20%, and the major products were dihydrophenanthrene (6.2%) and tetrahydrophenanthrene (4.6%), while alkylnaphthalenes was produced in a moderate amount (1.0%). The formation of alkylphenanthrenes (and 石 油 学 会 誌

Sekiyu

Gakkaishi,

carbon deposit) was greatly suppressed over FeH-Y zeolite. Interestingly, some increase in acidic strength of the zeolite was observed when Ni was loaded, as shown in Table 1. NiH-Y zeolite (Table 2) showed the highest hydrocracking activity among the catalysts examined. The conversion of phenanthrene increased greatly to 81% and afforded higher yields of benzenes, especially toluene. Not only alkylnaphthalenes, but also alkyltetralins and methylindanes, were obtained as two-ring hydrocracked products, with NiH-Y zeolite. The yields of alkylbenzenes, alkyltetralins and alkylnaphthalenes were 6.9%, 4.4% and 6.3%, respectively. At the same time, formation of hydrocarbon gases were also significantly promoted. Finally, analyses of the used catalysts showed considerable deposition of carbonaceous substances over H-Y, LaH-Y and NiH-Y zeolytic catalysts, which have strong acidity. On the contrary, extensive carbonaceous deposition did not occur on the lower acidic FeH-Y zeolytic catalyst, as observed in the hydrocracking of toluene16). Since the critical diameter of phenanthrene molecule size

is 7.9Å18),

of

Y-zeolite

which

(about

is similar 8Å),

to

hydrocracking

the

pore re-

actions might occur on the external surface of the zeolytic catalysts rather than in the micropores and, therefore, the zeolites did not show any molecular sieve effects, as pointed out by Haynes et al.18). It could be considered that the acidic catalyst promoted the hydrocracking reactions, whereas metals like Ni, loaded on acidic catalyst, would accelerate the hydrogenation reaction. In the present study, the conversion of phenanthrene and the yields of benzenes and naphthalenes took the following order: NiH-Y>H-Y=LaH-Y>NiMo/ Al2O3=CoMo/Al2O3>FeH-Y.

In conclusion,

NiH-Y

zeolite

prepared

in the

present study showed the highest activity among the zeolytic catalysts, and the activity of NiH-Y zeolytic catalyst has exceeded that of the commercial NiMo/Al2O3 or CoMo/Al2O3 catalysts. Niloaded Y-zeolite unambiguously demonstrated high potential for the production of fine chemicals from hydrocracking of phenanthrene. Some problems such as carbonaceous deposits on catalysts and others will be carried over for further study. Acknowledgment The authors would like to thank Dr. T. Masuda, Faculty of Engineering, Kyoto University, Japan, for his aid in the measurements of acidic strength of the catalysts.

Vol.

33,

No.

6,

1990

417

1913. 12) Lemberton, J.-L., Guisnet, M., Appl. Catal., 13, 181 (1984). 13) Wu, W.-L., Haynes Jr., H. W., Am. Chem. Soc. Div. Petrol. Chem. Prep., 20, (2), 466 (1975). 14) Nishimura, Y., Ogata, M., Kagaku Kogaku, 50, 604 (1986). 15) Yashima, T., Sekiyu Gakkaishi, 31, (3), 185 (1988). 16) Hidaka, S., Iino, A., Nita, K., Maeda, Y., Morinaga, K., Yamazoe, Y., "New Developments in Zeolite Science and Technology", ed. by Murakami, Y., Iijima, A., Ward, J., Kodansha Elsevier, (1986), p.329. 17) Nita, K., Kameya, M., Noguchi, Y., Seiyama, K., Sekiyu Gakkaishi, 32, (3), 122 (1989). 18) Haynes Jr., H. W., Parcher, J. F., Helmer, N. E., Ind. Eng. Chem., Process Des. Dev., 22, 401 (1983). 19) Kikuchi, E., Shibahara, N., Tsunoda, A., Morita, Y., Sekiyu Gakkaishi, 27, (4), 369 (1984). 20) Kikuchi, E., Tsunoda, A., Morita, Y., Sekiyu Gakkaishi, 27, (4), 296 (1984). 21) Hashimoto, K., Masuda, T., Takagi, Y., Shokubai, 29, (6), 406 (1987).

References

1) Collin, G., Ullmann-Terr und Pech, 22, 411 (1981). 2) Zielke, C. W., Struck, R. T., Evans, J. M., Costanza, C. P., Gorin, E., Ind. Eng. Chem., Process Des. Dev., 4, 151 (1966). 3) Kikkawa, S., Nomura, M., Murase, K., Sekiyu Gakkaishi, 19, (10), 863 (1976). 4) Nakatsuji, Y., Kubo, T., Nomura, M., Kikkawa, S., Bull. Chem. Soc. Jpn., 51, 618 (1978). 5) Salim, S. S., Bell, A. T., Fuel, 63, 469 (1984). 6) Song, C., Ono, T., Nomura, M., Bull. Chem. Soc. Jpn., 62, 630 (1989). 7) Qader, S. A., J. Inst. Petrol. (London), 59, 178 (1973). 8) Shabtai, J., Veluswamy, L., Oblad, A. G., Am. Chem. Soc. Div. Fuel Chem. Prep., 23, (1), 107 (1978). 9) Sapre, A. V., Gates, B. C., Ind. Eng. Chem., Process Des. Dev., 20, 68 (1981). 10) Song, C., Hanaoka, K., Ono, T., Nomura, M., Bull. Chem. Soc. Jpn., 61, 3788 (1988). 11) Ogata, E., Hatakeyama, K., Kameya, Y., Chem. Lett., 1985,

要

旨 NiMo/Al2O3,

CoMo/Al2O3触

媒 お よ び 各 種 金 属 担 持Y型

ゼ オ ラ イ ト上 に お け る

フ ェナ ン トレン の接 触 水 素 化 分 解

上 田 耕 造,

松 井 久 次,

宋

春 山 †1), 許

維 春

大 阪 ガ ス 株 式 会 社 開 発 研 究 所, 554大 阪 市 此 花 区 酉 島6-19-9 †1)(現住 所) Fuel Science Program, The Pennsylvania State University,

石 炭 の 水 素 化熱 分 解 で は多 環 芳 香 族 化 合 物 を主 成 分 とす る 多

触 媒 を 用 い る と70%弱

U.S.A.

の 転 化 率 で 主 生 成 物 と して水 素 化 フ ェ

量 の 液 状 生 成 物 が 得 られ る。 こ れ らの 液 状 生 成 物 の ア ップ グ

ナ ン ト レ ン 類 と テ ト ラ リ ン類 を 生 成 し た。H-YとLaH-Y型

レー デ ィン グ に よ り付 加 価 値 の 高 い1∼2環

ゼ オ ラ イ ト を 用 い る と 転 化 率 が46∼47%に

の芳香族化合物 を

な り,

生 産 す る こ とは石 炭 利 用 の経 済 性 向 上 に対 して 非常 に 重要 で あ

ゼ オ ラ イ トの 場 合 に は そ の 活 性 が 低 く転 化 率 が20%に

る。 本 研 究 で は, コー ル ター ル中 の 含 有 量 が 高 い フ ェナ ン トレ

っ た。 こ れ に 対 し てNiH-Y型

ンの 接 触 水 素 化 分 解 反 応 を, 初 期 水 素 圧7MPa,

ナ ン ト レ ン 転 化 率 を 与 え,

FeH-Y型

400℃,

反応 時 間1時

反応 温 度

に,

間 で 行 い, 従 来 検 討 の 少 ない 金 属 担 持Y

(Fig.

1)。 比 較 の た め に, 市 販 の 工 業 用 水 素 化 分 解 触 媒 で あ る

物

NiMo/Al2O3とCoMo/Al2O3を

=CoMo/Al2O3>FeH-Yの

用 い た 反 応 生 成 物 は, GCお

よ り同 定 ・定 量 分 析 した。Table

2に 各 反 応

り,

高 い 水 素 化 分 解 活性 を示 す と と も

1)。 フ ェ ナ ン ト レ ン の 転 化 率 お よ び1∼2環

の

収

率

は,

順 に 増 加 し た。 こ れ ら の 結 果 よ

本 研 究 で 調 製 し たNiH-Yゼ

オ ラ イ トは 多 環 芳 香 族 化 合 物

の生 成 物 分 布 を示 す。 フ ェ ナ ン トレ ンの 水 素 化 分 解 反 応 は, 無 触 媒 の場 合 に は ほ と ん ど進 行 しな い が, NiMoとCoMo担

可 能 性 が あ る こ と が 分 か っ た。

芳 香 族 化 合物 製 造 の 触 媒 と して の

Keywords Phenanthrene,

Hydrocracking,

Hydrogenation,

石 油 学 会 誌

Sekiyu

Supported

Gakkaishi,

catalyst,

Vol.

33,

No.

芳香族化合

NiH-Y>H-Y=LaH-Y>NiMo/Al2O3

の 水 素 化 分 解 に よ る1∼2環

持

とどま 上 のフェ

付 加 価 値 の 高 い ナ フ タ リ ン 類 や ベ ン ゼ ン 類 を 多 く生 成 し た

型 ゼ オ ラ イ トの 触 媒 と して の 可 能 性 に つ い て調 べ た (Table

よ びGC-MSに

ゼ オ ラ イ トは80%以

Ion-exchanged

6,

1990

zeolite,

Acidity