Catalyst For Alkylation Of Benzene Research Articles

Highly active and stable immobilized aluminium chloride catalyst for alkylation of benzene with 1-dodecene

An AlCl3 catalyst immobilized on g-Al2O3with meso- and macro-pore bimodal structure was prepared and studied in the alkylation of benzene with 1-dodecene in a suspension bed reactor. The catalyst exhibited high activity, selectivity and stability during 1000 h running, with a 1-dodecene conversion of more than 95%, monoalkylbenzene selectivity of 92%, and 2-phenyldodecane (2-Ph) selectivity of nearly 42%.

Activity and stability investigation of [BMIM][AlCl 4] ionic liquid as catalyst for alkylation of benzene with 1-dodecene

[1-butyl-3-methylimidazolium][tetrachloroaluminate] ([BMIM][AlCl 4]) ionic liquid was used to catalyze the alkylation of benzene with 1-dodecene to synthesize LAB, linear alkylbenzenes. The batch reaction performances were investigated using the orthogonal experimental method. It showed that the most important factor that governed the conversion of olefin and selectivity of LAB was reaction temperature. Moreover, the effects of molar ratio of AlCl 3 in ionic liquid to 1-dodecene and that of benzene to 1-dodecene on its conversion and selectivity are obviously in different degrees. The reaction temperature, molar ratio of benzene to 1-dodecene and the amounts of catalyst compared with the traditional reaction technologies were decreased. Further, the experimental results demonstrated that the ionic liquid catalyst had higher activity at 25 °C even if the molar ratio of AlCl 3 in ionic liquid to 1-dodecene and that of benzene to 1-dodecene were 0.07 and 8, respectively. Then, a continuous flow reactor equipped with a special bell type of settling–separating–discharging device was proposed. In this way the in situ separation of product mixtures from ionic liquid was realized and the stability of ionic liquid catalyst for the alkylation reaction was tested. A considerably longer running time of catalyst and higher efficiency were attained in the reactor adopted.

Propane as alkylating agent for alkylation of benzene on HZSM-5 and Ga-modified HZSM-5 zeolites

Abstract Alkylation of benzene with propane has been studied under continuous-flow condition at atmospheric pressure. Ga-modified HZSM-5 zeolites have shown to be very efficient catalysts for alkylation of benzene with propane. Toluene and ethylbenzene are formed as major products and cumene and n-propylbenzene are also produced at low reaction temperatures in small amounts. The product formation pathways on HZSM-5 and Ga-modified HZSM-5 have been discussed and suggest that acid-catalyzed cracking of propane predominates on HZSM-5, leading to the formation of toluene and ethylbenzene. Over Ga-modified HZSM-5, a bifunctional pathway is noted and cracking of propane and propane dehydrogenation are controlled by Lewis (Gax+)/Bronsted (H+) acid sites ratio. The effect of oxidative and reductive treatments on catalytic activity has been studied and shown that the catalytic activity and the selectivity to toluene of the Ga-modified HZSM-5 zeolite catalysts are enhanced after H2/O2 treatment due to the increase in gallium dispersion.

Alkylation of benzene with 1- dodecene over usy zeolite catalyst: Effect of pretreatment and reaction conditions

Catalytic activity, stability and selectivity of USY zeolite catalyst for alkylation of benzene with 1-dodecene were investigated using a continuous fixed bed high pressure microreactor. It is found that the catalytic activity and stability depend closely on the pretreatment temperature of catalyst and reaction conditions. The best result was obtained at 120 °C and 3.0MPa with 8 molar ratio of benzene to 1-dodecene, and 4 h-1 weight hourly space velocity of reactant over the catalyst with the pretreatment temperature of 500 °C. Under this condition, the reaction conversion was nearly 100% and no deactivation was observed within the employed 50 h of time on stream with the selectivity of 2-phenyldodecene being 22%.

Effect of water in the performance of the “solid phosphoric acid” catalyst for alkylation of benzene to cumene and for oligomerization of propene

The solid phosphoric acid catalyst has been utilized industrially for a long time for the synthesis of cumene by benzene alkylation, as well as for the oligomerization of propene to liquids utilized for gasoline blendings. This paper describes the effect of the water content in the feedstock on the catalytic performance of the solid phosphoric acid catalyst, both in terms of activity/selectivity and of the overall life. The water was found to affect the activity strongly in the case of the propene oligomerization, the highest activity was achieved in the case of complete hydrolysis of the P 2O 5/H 2O, constituting the active phase of the catalyst, to the ortho-phosphoric acid. In the case of the benzene alkylation, instead, complete hydrolysis led to a decrease in both the activity and the selectivity to alkylaromatics. However, the main influence of water was on catalyst lifetime: more than 200 ppm water in the feed led to a quick destruction of the catalyst, with loss of the mechanical properties. This phenomenon was found to be due to the hydrolysis of the main catalyst components, the silicon phosphates. A remarkable improvement in lifetime of the solid phosphoric acid catalyst was achieved by making the system more resistant to hydrolysis through a modification in the preparation procedure.

Influence of reaction products on stability and activity of catalyst for alkylation of benzene by propylene

It has been of interest to study the timewise course of the process under conditions simulating a multisectional reaction zone, i.e., with increasing quantities of products from the interaction of benzene and propylene. The experiments were performed in a flow unit with a tubular reactor (catalyst charge 100 cm/sup 3/) at a temperature of 200-210/sup 0/C pressure 2.5 MPa, and feedstock space velocity 2 h/sup -1/. The decrease in propylene conversion with the passage of time was compensated by increasing the temperature to 280/sup 0/C. The catalyst was a cation-substituted Y zeolite (SiO/sub 2//Al/sub 2/O/sub 3/ = 4.4), molded without binder, with respective contents of Na/sub 2/O, Ln/sub 2/O/sub 3/, and CaO 0.57%, 15.8%, and 2.3% by weight. The starting materials were benzene in Grade kh.ch. (chemically pure) and propylene (purity 99.9% by weight) in a mole ratio from 7/1 to 8/1. In the course of these studies, isopropylbenzene and polyalkylbenzenes were added to the feed in various amounts. The composition of the liquid phase of the feed is shown.

Polyfunctional catalyst for alkylation of benzene with ethylene

Polyfunctional catalyst for alkylation of benzene with ethylene