CN1087555A

CN1087555A - The catalyzer of ethene and the direct synthesizing styrene of benzene

Info

Publication number: CN1087555A
Application number: CN93107737A
Authority: CN
Inventors: 吕德伟; 李邦银
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 1993-06-30
Filing date: 1993-06-30
Publication date: 1994-06-08

Abstract

The invention discloses the catalyzer of ethene and the direct synthesizing styrene of benzene, it is by basic metal, alkaline-earth metal and rare earth metal, and elementary composition active constituent loading such as transition metal forms on the zeolite molecular sieve carrier.This catalyzer has alkylation and dehydrogenation simultaneously, at reaction pressure 0.1～1MPa, and 400～700 ℃ of temperature of reaction, benzene/ethylene ratio=(1.0～15.0)/1.0, air speed (gC ₂H ₄/ gCath)=0.2～2.0h ^-1Reaction conditions under, but high reactivity (C ₂H ₄Transformation efficiency can be up to 100%), highly selective (cinnamic selectivity can up to 65.2%) with ethene and benzene one-step synthesis vinylbenzene, both shortened technical process, can reduce investment again, cut down the consumption of energy.

Description

The catalyzer of ethene and the direct synthesizing styrene of benzene

The present invention relates to a kind of ethene and benzene one-step synthesis vinylbenzene catalyst for reaction.

Vinylbenzene is to produce plastics and elastomeric important source material, and producing cinnamic method at present both at home and abroad all is to adopt two step method, at first generates ethylbenzene by benzene and ethylene alkylation, generates vinylbenzene by ethylbenzene dehydrogenation again, promptly

The free energy △ G of the first step alkylated reaction wherein 0 ₍₁₎=-67.18KJ/mol be easy to carry out, but it is a strong exothermal reaction that catalyzer is easy to coking, the △ G of the second step dehydrogenation reaction 0 ₍₂₎=83.2KJ/mol, K _P2=2.61 * 10 ^-15, under the normal conditions, react and to carry out, but this reaction is thermo-negative reaction that elevated temperature helps the carrying out that react, and dehydrogenation reaction also to be subjected to the equilibrated restriction.Although adopt the liquid phase hydrocarbonylation to shift balance with employing negative dehydrogenation and membrane separation technique to this two-step reaction at present with the coking that overcomes catalyzer, balance is moved to generating cinnamic direction, these all are non-fundamental measures.The improvement of catalyzer and reaction process in recent years makes cinnamic production near the limit, therefore presses for research and development and produces cinnamic novel process.Reaction by benzene and the direct synthesizing styrene of ethene " single stage method " is feasible,

The △ G of " single stage method " 0 ₍₃₎=16.02KJ/mol is than the △ G of dehydrogenation reaction 0 ₍₂₎Much smaller, K _P3=1.56 * 10 ^-3K than dehydrogenation reaction _P2Much bigger, be easy to break through the equilibrated restriction, so " single stage method " reaction is more much easier than dehydrogenation reaction.By benzene and ethene " single stage method " directly the key of the reaction of synthesizing styrene be the research of catalyzer." single stage method " catalyst for reaction should have alkylating, and dehydrogenation functionality is arranged again.

The object of the invention provides a kind of ethene and direct synthesizing styrene catalyst for reaction of benzene " single stage method " of being used for, for a new route of synthesis is opened up in cinnamic production.

Catalyzer of the present invention is to load on the carrier with active constituent to form.Its carrier is a zeolite molecular sieve, and active phase composite is AaBbOx, and wherein A is a basic metal, alkaline-earth metal and thulium (as Li, K, Rb, Cs, Mg, La, elements such as Ce) one or more in, B are transition metal and III A, IV A, V A, and VI A family element (as V, Cr, Mo, W, Mn, Fe, Co, Ni, Pt and Bo, Sn, Pb, P, elements such as Bi) one or more in, the content of carrier is 10～90%wt usually, each element a, the relative content of b (based on carrier) is respectively a=0.1～10, b=0.1～20, the content commonly used of carrier is 40～80%wt, a, the best relative content (based on carrier) of b is respectively a=0.2～0.5, b=0.4～10.

Preparation of catalysts method of the present invention is as follows: (1) zeolite molecular sieve is used NH earlier under 50～100 ℃ ₄Cl is exchanged into NH ₄The type zeolite is used the NH of 5%～10%wt usually ₄Cl is exchanged into NH by liquid-solid ratio 2/1～10/1 ₄The type zeolite got H type zeolite in 3～5 hours then 110 ℃ of oven dry down, and 400～550 ℃ of following roastings; (2) with pickling process with active constituent loading on H type zeolite, after the drying again under 400～700 ℃, 3～18 hours zeolite catalysts that get product of roasting in the air atmosphere.

Catalyzer of the present invention is used for ethene and the cinnamic reaction of benzene one-step synthesis, at reaction pressure 0.1～1.0MPa, and 400 ℃～700 ℃ of temperature of reaction, benzene/ethene=(1.0～15.0)/1.0, air speed (gC ₂/ H ₄/ gCat.h)=0.2～2.0 h ^-1Reaction conditions under, C ₂H ₄Transformation efficiency can be up to 100%, cinnamic selectivity can be up to 65.2%.

Catalyzer of the present invention has alkylation and dehydrogenation functionality simultaneously, is used for ethene and benzene synthesizing styrene, can directly synthesize in " step ", thereby opened up a new way for vinylbenzene is synthetic, not only but shortened process reduces investment cost, but also can cut down the consumption of energy.

Further specify the present invention by the following examples.

Example 1, this routine carrier HZSM-5 zeolite molecular sieve, the activity of such catalysts component contains Mg, La, P, Fe element.Earlier the NaZSM-5 zeolite molecular sieve is used 10%wt NH down at 95 ℃ ₄Cl gets NH 3 times by liquid-solid ratio 5/1 exchange ₄ZSM-5,110 ℃ of oven dry down, 550 ℃ of following roastings obtained the HZSM-5 zeolite in 5 hours, with (the NH of capacity then ₄) H ₂PO ₄The aqueous solution place beaker with the P(of load 10%wt based on HZSM-5), in addition with the OMg(NO of capacity ₃) ₂6H ₂The O aqueous solution also place beaker with the Mg(of load 5%wt based on HZSM-5), the La(NO of capacity ₃) O ₃XH ₂O(La ₂O ₃Content is 40%) aqueous solution also is added in the beaker, with the La(of load 0.5%wt based on HZSM-5), again with (NH ₄) ₃Fe(C ₂O ₄) ₃3H ₂The O aqueous solution also is added in the beaker with load α-Fe ₂O ₃, 10%wt(is based on HZSM-5), adding the volume that water makes steeping fluid volume and carrier simultaneously is 1: 1.The good back of dipping 110 ℃ dry down, 650 ℃ of following roastings 12 hours, catalyzer gets product.Contain 4.8%wt Mg in the catalyzer, 0.48%wt La, 9.5%wt P, 9.6%wt α-Fe ₂O ₃(based on carrier HZSM-5).

Example 2, this routine carrier HZSM-5 zeolite molecular sieve, the activity of such catalysts component contains Mg, La, P, Fe, Pt, Sn element.Its preparation process is with example 1, and steeping fluid is except using (NH ₄) H ₂PO ₄, Mg(NO ₃) ₂6H ₂O, La(NO ₃) ₂XH ₂O, (NH ₄) ₃Fe(C ₂O ₄) ₃3H ₂Outside the O, the Platinic chloride that also adds capacity with the Pt(of load 0.4%wt based on HZSM-5), also add an amount of SnCl simultaneously ₄5H ₂O is with the Sn of load 0.5%wt, and adding water at last, to make the volume of steeping fluid and the volume ratio of carrier be 1: 1, after dipping is good, 110 ℃ dry down, and 650 ℃ of following roastings 12 hours, catalyzer got product.Contain 4.8%wt Mg in the catalyzer, 0.46%wt La, 9.6%wt P, 9.8%wt α-Fe ₂O ₃, 0.38%wt Pt, 0.49%wt Sn(is based on carrier HZSM-5).

Example 3, ethene and the cinnamic reaction of benzene one-step synthesis, catalyst system therefor is example 1 catalyzer.Catalyzer activates 2 hours under 550 ℃ earlier in air atmosphere, be 500～600 ℃ in temperature of reaction, and reaction pressure is normal pressure (0.1MPa), and benzene/ethylene ratio is 10/1, air speed (gC ₂H ₄Under/gCat.h)=1.0 reaction conditions, C ₂H ₄Transformation efficiency be 100%, toluene, ethylbenzene, cinnamic selectivity are respectively 7.7%, 61.8%, 30.5%.

Example 4, ethene and the cinnamic reaction of benzene one-step synthesis, catalyst system therefor is example 2 catalyzer.Catalyzer activates 2 hours under 550 ℃ earlier in air atmosphere, be 500～600 ℃ in temperature of reaction, and reaction pressure is normal pressure (0.1MPa), and benzene/ethylene ratio is 10/1, air speed (gC ₂H ₄Under/gCat.h)=1.0 reaction conditions, C ₂H ₄Transformation efficiency be 100%, toluene, ethylbenzene, cinnamic selectivity are respectively 6.3%, 28.5% and 65.2%.

The table I is the performance of each preformed catalyst.

The table I

Catalyzer composition/carrier	C ₂H ₄Transformation efficiency	Selectivity
					Toluene	Ethylbenzene	Vinylbenzene
		0.50%La,9.6%Fe ₂O ₃/HZSM-5	85.3%	3.4%				77.8%	18.8%
0.64%La,0.32%Cs, 9.6%Fe ₂O ₃/HY	62.8%				9.2%	64.4%	26.4%
		4.8%Mg,0.48La,9.5%P, 9.6%Fe ₂O ₃/HZSM-5	100%	7.7%				61.8%	30.5%
4.8%Mg,0.46%La,9.6%P, 9.8%Fe ₂O ₃,0.38%Pt, 0.4%Sn/HZSM-5	100%				6.3%	28.5%	65.2%

Claims

1, the catalyzer of ethene and the direct synthesizing styrene of benzene, the carrier that it is characterized in that catalyzer is a zeolite molecular sieve, and active phase composite is AaBbOx, and wherein A is a basic metal, alkaline-earth metal and thulium (Li, K, Rb, Cs, Mg, La, the Ce element) one or more in, B are transition metal and III A, IV A, V A, VI A family element (V, Cr, Mo, W, Mn, Fe, Co, Ni, Pt and Bo, Sn, Pb, P, Bi element) one or more in, each element a, the relative content of b (based on carrier) is respectively a=0.1～10, b=0.1～20, and the content of carrier is 10～90%wt.

2, by the described catalyzer of claim 1, the content commonly used that it is characterized in that carrier is 40～80%wt.

3, by claim 1,2 described catalyzer is characterized in that each element a, and the best relative content (based on carrier) of b is respectively a=0.2～5, b=0.4～10.

4, a kind of method for preparing the described catalyzer of claim 1 is characterized in that:

(1) zeolite molecular sieve is used NH earlier under 50～100 ℃ ₄Cl is exchanged into NH ₄The type zeolite becomes H type zeolite 400～550 ℃ of following roastings then;

(2) with pickling process active constituent is loaded on the H type zeolite that above-mentioned (1) obtain, again under 400～700 ℃, roasting gets the finished product zeolite catalyst in the air atmosphere after the drying.

5,, it is characterized in that zeolite molecular sieve is following to 5%～10%wt NH at 50～100 ℃ by the described method for preparing catalyst of claim 4 ₄Cl is exchanged into NH by liquid-solid ratio 2/1～10/1 ₄The type zeolite.

6, the described catalyzer of claim 1 is used for the reaction of ethene and the direct synthesizing styrene of benzene, it is characterized in that reaction pressure is 0.1～1MPa, and temperature of reaction is 400～700 ℃, and benzene/ethylene ratio is (1.0～15.0)/1.0, air speed (gC ₂H ₄/ gCat.h)=0.2～2.0h ^-1