Download - Modification & Application of Borate Zirconia Catalyst

05 May 2006 MTech IIT KGP 1

MODIFICATION & APPLICATION OF BORATE ZIRCONIA CATALYST

Ranjeet Kumar04CH6022

Under the guidance of

Dr. Sonali SenguptaDepartment of Chemical engineering

IIT Kharagpur


Contents….

IntroductionLiterature surveyExperimentsMesoporous borate zirconiaCharacterizationConclusionReferences


Contents….



• Overall catalyst market is around $10 bn.• And revenue generated by processes using catalysts exceeds the catalyst market probably by factor between 100 and 1000, i.e. is somewhere between $1.000 and 10.000 billion

Fig: 1. Catalyst market total around $10 bn and its division into different application

Slight improvement in catalyst performance can lead to big saving in RM & energy.


Importance of Alkylation Reactions

Used in• Pharmaceuticals, Agrochemicals,

• Resins, Additives,

• Polymerization inhibitors, Antioxidants

• Petroleum refining


• Heavy environment pollution

• Troublesome product recovery & purification

• Catalysts cannot be reused

• Lower stability at higher temperature.

• Poor selectivity

• Use of expensive acid-resistant MOC

Alkylation reaction with solid catalysts are becoming emerging field in catalysis

Problems with Friedel-Craft alkylation---


Objective:- To search an environmental friendly process to produce ortho-alkylates

with high selectivity

>> OPTIONS ARE:-

ZEOLITES

CATION EXCHANGE REGINS

» unstable at higher temperature

ZIRCONIA CATALYST

» its high acidity favors C-alkylation.


Borate zirconia

• B2O3/ZrO2 catalyst (30mol% B) is reported as a superacid catalyst

suitable for isomerization of butane & pentanes.

• AlCl3 and borate zirconia had shown comparable performance for

Friedel-Craft acylation & beckman rearrangement of cyclohexanone

oxime.

• Comparable performance with heterogeneous catalysts like zeolite

H-beta and sulphated zirconia.


Contents….


IntroductionLiterature survey


Literatures on BZ

• No literature is available for preparation of ortho-xylene

using heterogeneous catalysts

• Activity & selectivity of zirconia based catalysts are very

sensitive to the method of preparation & heat treatments.

• Most of the studies have been carried out using large

quantities of the catalyst, and the effect of parameters

need to be addressed.


Contents….




ZrOCl2 + H2O. . ..

8 ZrOCl2 clear solution

Addition of NH3

8

Till pH = 10

Precipitate ofZr(OH)4

Zirconium hydroxide was filtered Washed with hot water

Zr(OH)4 was then dried

Immersed in boric acid solution Heated to dryness Calcined

Preparation of BZ


ZrOCl2 + H2O. . ..

8 ZrOCl2 clear solution

Addition of NH3

8

Till pH = 10

Precipitate ofZr(OH)4

Zirconium hydroxide was filtered Washed with hot water

Zr(OH)4 was then dried

Immersed in sulfuric acid solution filtered Dried Calcined

Preparation of SZ


Reactants Reaction hr. Catalyst % conversion of MeOH

Phenol +methanol

4 hours BZ 2.205

Phenol +methanol

8 hours BZ 14.186

Toluene +methanol

4 hours BZ 5.577

Two different systems of reactions were investigated in batch reactor :-1) Phenol + MeOH –

2) Toluene + MeOH –

Reaction temp was 250°C


Maximum temp attainable in this reactor is 300°C

Reactor set-up

Fig.- 1, reactor and controller


Fig.-2, stirrer & vessel

Reactor set-up…

Capacity of the vessel is 260 ml


• Alkylated product may increase by modifying reaction

conditions.

• Max temp is main constraint, reacton time may be

increased to get good result.

• Catalyst may be unsuitable for the desired reaction.

• Catalysts prepared above were microporous and may be

unsuitable for large molecule like benzene or phenol.

Microporous materials – pore size less than 2 nm (20 A°)

Reasons for low conversion may be


Mesoporous catalyst with wider opening may be more suitable for alkylation of phenol & toluene.

Forward path >>>

Pore size Type of material

< 2 nm microporous

>2 nm & < 50 nm mesoporous

>50 nm macroporous

Table - 2,IUPAC definition for materials on the basis of pore size


Contents….




Literatures on Mesoporous zirconia catalyst

• No literature is available on mesoporous borate zirconia.

• Mesoporous sulphated zirconia and other mesoporous catalysts are

reported and are useful for alkylation reactions. [7], [8], [9], [11].


Contents….



Preparation of Mesoporous BZ

• Co-operative nucleation of molecular inorganic solution (I), with

surfactant molecules (S).

• Two different surfactants were selected for searching/standardizing

the preparation method ---

1) sodium lauryl sulfate (C12H25NaO4S) (SLS)

2) tetradecyltrimethylammonium bromide (C17H38BrN)

(TTBr or Cetrimide)Acid percolation in mesoporous materials, neutral templating are other methods for mesoporous catalyst preparation


In this case I = Zirconium Oxychloride + Water + Borax S = SLS / TTBr + Water

Steps of preparation: - a) preparation of solution

b) aging

c) filtration

d) washing

e) calcinations/extraction

More the hours of aging better is the catalyst

Preparation of Mesoporous BZ


Trials for standardizing the preparation method

Zr : SLS : B : H2O SA m2/g

1 0.3 0.05 500 75.53

1 0.3 0.05 750 NA

1 0.3 0.05 1000 83.26

1 0.3 0.05 1250 NA

1 0.3 0.05 1500 86.70

Trial 1:-


Zr : SLS : B : H2O SA m2/g

1 0.2 0.05 500 37.00

1 0.2 0.05 750 43.80

1 0.2 0.05 1000 NA

1 0.2 0.05 1250 NA

1 0.2 0.05 1500 85.53

Trial 2 :-

Since the range of surface area was not so wide so Zr : Sufactant : B : H2O :: 1 : 0.3 : 0.05 : 1000 was taken as base for further trials.


• Trials were done by changing surfactant, instead of SLS,

cetrimide was used.

• Instead of calcinations extraction of aged precipitate with

ethanol plus sodium acetate solution was done.

• Aging hours were increased from 72 hours to 120 hours.

• Instead of making one solution of S & I, two separate

solutions were prepared and mixed drop wise.


Contents…



Elemental analysis of prepared catalyst

Energy Dispersive X-Ray Spectrometer (EDS) was done in CRF lab –

>>Test confirmed the presence of Zr, O.

It failed to detect the presence of B.

>>> Presence of B was confirmed by Atomic Absorption Spectrometry


XRD

XRD of MBZ

0

50

100

150

200

250

0 1 2 3 4 5 6 7 8 9 10

2 theta

Fig.:- XRD pattern of MBZ shows a peak at 3°.


pore dia, nm Pore vol, ml/g % Pore vol, ml/g %

Under 6 0.02806 41.89 0.02301 37.91

6-8 0.00561 8.37 0,00559 9.21

8-10 0.00308 4.60 0.00318 5.24

10-12 0.00347 5.18 0.00274 4.51

12-16 0.00379 5.66 0.00368 6.06

16-20 0.00384 5.73 0.00424 6.98

20-80 0.01455 21.72 0.01484 24.45

Above 80 0.00459 6.85 0.00342 5.64

TOTAL 0.06699 100 0.06069 100

Adsorption

Reading from pore size analyzer

Desorption


Adsorption isotherm

The adsorption isotherm is type IV IUPAC classification with hysteresis, which Indicate a mesoporous material.


Surface area & pore size distribution

Apparatus used was – Coulter’s SA3100 for SA & pore size

analysis.

SMARTSORB-90 for SA

Mesoporous Microporous

SA – 310 m2/g 85-115 m2/g

Pore volume – 0.23 cm3/g 0.09-0.12 cm3/g>>> An excellent surface area (310 m2/g) was obtained by using separate

solution of S ( Cetrimide ) & I, 72 hr aging, and extraction.


• Reaction was carried out in a flow reactor at 450°C over MBZ

catalyst, reactants were toluene and methanol.

• Reaction mixture was analyzed in GC, retention time of

product confirmed presence of o-xylene.

•Conversion of methanol was about 30%.

Reaction with MBZ

.>>>>


Flow reactor

>>>>>

preheater

reactor

condenser


conclusions

• Surface area of prepared catalyst is 310 m2/g, it is highest among

mesoporous zirconia catalysts.

• Conversion of methanol is about 30% which may be increased by

searching optimum reaction conditions.

• Large pores will allow the use of bulky oxidants in fine chemical

preparation.

• Catalyst has shown its activity in alkylation reaction.

• It may open a path to produce many fine chemicals.


[1] Sonali Sengupta, G. D. Yadav, Yogeeta B. Jadhav (2003), “Novelties of kinetics and mechanism of liquid–liquid phase transfer catalysed reduction of p-nitroanisole to p-anisidine”, Chemical Engineering Science, vol 58 , p 2681-1689.

[2] Sonali Sengupta, G. D. Yadav, Yogeeta B. Jadhav, (2003), “Selectivity engineered phase transfer catalysis in the synthesis of fine chemicals: reactions of p-chloro- nitrobenzene with sodium sulphide”, Journal of molecular Catalysis A: Chemical, vol 200, p 117-129.

[3] Kusum M. Malshe, Pratap T. Patil, Shubhangi B. Umbarkar, Mohan K. Dongare (2004), “Selective C-methylation of phenol with methanol over borate zirconia solid catalyst”, Journal of Molecular Catalysis A : Chemical, vol 212, p 337–344.

[4] Ullman’s Encyclopedia of Industrial chemistry, vol. A 19, fifth ed.,(1989), p313.[5] S. Velu, C.S. Swamy, (1996), “Selective C-alkylation of phenol with methanol over

catalysts derived from copper-aluminium hydrotalacite”, Applied Catalysis A : General, vol 145, p 141-154.

[6] Takako Funamoto, Takamasa Nakagawa, Kohichi Segawa, (2005), “Isomerization of n-butane over sulfated zirconia catalyst under supercritical conditions”, Applied Catalysis A:General, vol 286, p 79-84.

[7] Yin-Yan Huang, Timothy J. McCarthy, Wolfgang M.H. Sachtler(1996),”Preparation and catalytic testing of mesoporous sulfated zirconium dioxide with partially tetragonal wall structure” Applied Catalysis A:General, vol 148 (1996) p 135-154.

References


[8] Yinyong Sun, Lina Yuan , Shengqian Ma, Yu Han, Lan Zhao, Wei Wang, Chang-Lin Chen, Feng-Shou Xiao(2004), Improved catalytic activity and stability of mesostructured sulfated zirconia by Al promoter, Applied Catalysis A: General, vol 268, p 17-24[9] Cornelia Breitkopf , Arnd Garsuch, Helmut Papp (2005), “Structure– activity relationships for sulfated zirconias — comparison of mesoporous samples based on organic precursors”, Applied Catalysis. A: General, vol 296, p 148-156.[10] Huiyuan Gao, Jerry Y. S. Lin, Baoquan Zhang (2005), “Electroless plating synthesis, characterization & permeation of Pd-Cu membranes supported on ZrO2 modified porous stainless steel”, Journal of Membrane Science, Vol 265, Issues 1-2, p 142-152[11] Yinyong Sun, Lei Zhu, Huijuan Lu, Runwei Wang, Sen Lin, Dazheng Jiang, Feng-Shou Xiao (2002), “Sulfated zirconia supported in mesoporous materials”, Applied Catalysis. A: General,vol 237 p 21–31.[12] Daniela Terribile, Alessandro Trovarelli,*, Jordi Llorc, Carla de Leitenburg, Giuliano Dolcetti (1998) “The preparation of high surface area CeO2±ZrO2 mixed oxides by a surfactant- assisted approach”, Catalysis Today, vol 43, p 79-88.[13] G. Pacheco , E. Zhao , E. Diaz Valdes, A. Garcia, J.J. Fripia (1999), “Microporous zirconia from anionic and neutral surfactants”, Microporous and Mesoporous Materials, vol 32 p 175–188.[14] Debra J. McIntosh, Ronald A. Kydd(2000), “Tailoring the pore size of mesoporous sulfated Zirconia” Microporous and Mesoporous Materials, vol 37, p 281–289

References…..


Thanks