K THUT XC TCCATALYST TECHNOLOGYTS. Nguyn Mnh Hun

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CHT XC TCtrong phn ng ha hc

N l g? Cc thnh phn ca n nh th no? N c tnh cht g? N c ch to nh th no?

Kim tra tnh cht ha hc v vt l ca n bng cc phng php g? Kim tra hot tnh nh th no? S dng l thuyt no cho phn ng ny? Chi ph? Pilot? Sn xut cng nghip?2

Vn

thc tin

L thuyt

iu ch

Xc tc

Chi ph?

Pilot?Nh my?Phn ng

nh gi xc tc

Phng php nghin cu tnh

Phng php nghin cu dng Thu nhn s liu

Hiu qu xc tc, ng hc, c ch phn ng

M ta vn tt ni dung hc phnHc phn ny bao gm:

L thuyt c bn v cht xc tc v qu trnh xc tc Xc tc cng nghip, cc giai on sn xut xc tc trong cng nghip Cc phng php hin i nh gi xc tc.4

Mc tiu ca hc phnSau khi hon tt hc phn sinh vin c kh nng:-

Nm vng kin thc c bn v k thut xc tc.

-

Lm c s nn tng hc tip cc mn chuynngnh.

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CNG + THI GIANBi tp Kim tra gia k

T1 T2 T3 T4 T5 T6 T7 T8 T9 T10Vai tr ca xc tc trong cng ngh ha hc Nghin cu tnh cht xp ca xc tc C s ca qu trnh xc tc Cc phng php nghin cu v nh gi xc tc Cc dng l phn ng trong phng th nghim Sn xut xc tc cng nghip6

iu ch xc tc

Ti liuSch tham kho

[1]. Charles N. Satterfields, Heterogeneous Catalysis in Industrial Practice, McGraw-Hill, Inc., 1991. [2]. Mukhlenov I.P., Dobkina E.I., Catalyst technology, Mir publishers, M. 1976. [3]. Mai hu Khim, Bi ging K thut xc tc, NXB HQG TP HCM, 2003

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Phng php nh gi mn hc

Seminar: dch bi bo

Thi gia hc phn

Thi kt thc hc phn8

Examples of Reactions w/o CatalysisOxygen in the air mixes with iron to form rust

Plants & animals decompose to oil & coal

1 week to several monthsHydrogen Peroxide forms a chemical reaction with your body

Millions of years

Seconds

Ways to Make Chemicals FasterTemperatureDisadvantage--Too hot!

PressureDisadvantage--Cause Explosions

Add other ChemicalsDisadvantage--Separate chemicals

Catalysts!!!!Disadvantage--Costly

CHNG 1: MT S VN CHUNG V XC TC

1.1 Lch s xc tc. Xc tc c s dng t lu

Nm 1836, Berzelius a ra t "xc tc" lnu tin. Ngy nay, 90% ngnh sn xut cng nghip thuc lnh vc ho hc phi dng xc tc11

CHNG 1: MT S VN CHUNG V XC TCMot so phan ng xuc tacPhn ng oxi ho kh 1.Oxi ho SO2 + 1/2O2 SO3 NH3 + O2 NO 2.Hydro ho N2 + 3H2 2NH3 CO + 2H2 CH3OH 3.Dehydro ho C4H10 H2 + C4H8 C4H6 4. Hydrat ho CH2=CH2 + H2O C2H5OH 5. Polyme ho nC2H4 [C2H4]n Sn phm Loi xc tc

H2SO4 HNO3 Amoniac Methanol Butadien Ru ethylic polyethylen

Pt, V2O5, Fe2O3 Pt, Pd, CoO,.. Fe(K2O, Al2O3, SiO2,..) ZnO + Cr2O3 + CuO + K2O Cr2O3: photphat Ni va Cr2O3 H3PO4 trn cht mang Al2O3 TiCl4 + AlR3(Ziegler-Naptha)12

(1850) Catalysis

(1875) Electrochemistry, Surface, TD and Instrumentation

( 1850) Tribology

(1925) Adsorption Science and Electron Emission

(1955) Surface Analytical Techniques

(1960) Microporous Solids

Development of Surface Chemistry and Catalysis Conceptually

(1975) Clusters and monomolecular films

during the last 200 years(1990) Nano & Mesoporous Materials Macroscopic level 1980 Molecular level 2000

Hetrogeneous CatalysisMilestones in Evolution-1

1814- Kirchhoff-starch to sugar by acid. 1817-Davy-coal gas(Pt,Pd selective but not Cu,Ag,Au,Fe) 1820s Faraday H2 + O2 H2O(Pt);C2H4 and S 1836- Berzelius coinsCatalysis;

1860-Deacons Process ;2HCl+0.5O2 H2O + Cl2;1875-Messel.SO2 SO3 (Pt); 1880-Mond.CH4+H2O CO+3H2(Ni); 1902-Ostwald-2NH3+2.5O2 2NO+3H2O(Pt); 1902-Sabatier.C2H4+H2 C2H6(Ni). 1905-Ipatieff.Clays for acid catalysed reactions; isomerisation, alkylation, polymerisation.

Milestones in Evolution-2

1910-20: NH3 synthesis (Haber,Mittasch) ; Langmuir 1920-30-Methanol syn(ZnO-Cr2O3); Taylor;BET 1930-Lang-Hinsh &Eley -Rideal models ;FTsyn;EO; 1930-50:Process Engg; FCC / alkylates;acid-base catalysis;Reforming and Platforming.

1950-70: Role of diffusion; Zeolites, Shape Selectivity; Bifunctional cata;oxdn cat-HDS; Syngas and H2 generation.1970- Surface Science approach to catalysis(Ertl) 1990 - Assisted catalyst design using : -surface chem of metals/oxides, coordination chemistry - kinetics,catalytic reaction engg - novel materials(micro/mesoporous/nano materials)

Dream Reactions Awaiting Catalyst Development( according to Jens Rostrup-Nielsen) CH4 + O2 CH3OH CH4 + 1/2O2 CO + 2H2 2CH4 + O2 C2H4 +2 H2O nCH4 CnH2n+2 + (2n-2) H2 Dimethyl ether C2H5OH H2 + O2 H2O2 2NO N2 + O2 2N2 + 2H2O+5 O2 4HNO3

CHNG 1: MT S VN CHUNG V XC TC1.2 c im chung ca tc dng xc tc1.2.1 nh ngha xc tc: Hin tng bin i tc phn ng ho hc hay kch ng chng do nhng cht m cui cng vn c phc hi gi l xc tc Cht gy nn s xc tc gi l cht xc tc 1.2.2 Hot ca xc tc: c o bng s bin i lng cht u tham gia phn ng trong mt n v thi gian v trn mt n v ca lng cht xc tc17

CHNG 1: MT S VN CHUNG V XC TC1.2.3 c trng chung ca tc dng xc tc: Nhit ng hc ca tc dng xc tc: xc tc ch c tc dng trong phm vi nhit ng hc cho php

V d: xt phn ng sau A=B A+Xt = Axt = B + xt G = - RT lnKcb: Kcb = k/k ( k, k: hng s tc ca phn ng thun v nghich)18

CHNG 1: MT S VN CHUNG V XC TC

Vn 1: Bn cht tc dng tng tc phn ng bi cht xc tc l g?

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CHNG 1: MT S VN CHUNG V XC TC

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CHNG 1: MT S VN CHUNG V XC TC

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Activation EnergyActivation Energy : The energy required to overcome the reaction barrier. Usually given a symbol Ea or GThe Activation Energy (Ea) determines how fast a reaction occurs, the higher Activation barrier, the slower the reaction rate. The lower the Activation barrier, the faster the reaction

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CHNG 1: MT S VN CHUNG V XC TC

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Activation EnergyCatalyst lowers the activation energy for both forward and reverse reactions.

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CHNG 1: MT S VN CHUNG V XC TCTnh chn lc ca xc tc: chn lc ca xc tc l t s tc to sn phm so vi tng tc bin i trn c s cht tham gia phn ng theo cc hng V d 1: Phn ng Fischer Trospch V d 2: phn ng xy ho NH3: 4NH3 + 3O2 = 2N2 + 6H2O 4NH3 + 4O2 = 2N2O + 6H2O 4NH3 + 5O2 = 2NO + 6H2O

+ 1300 KJ + 1100 KJ + 900 KJ

(a) (b) (c)

nh ngha: la chn ca mt cht xc tc theo mt hng nht nh bng tc hnh thnh sn phm chnh chia cho tng tc phn ng theo tt c cc hng.25

Bi tp 1Phn ng phn hy phenol: C6H5OH sn phm. Kt qu thc nghim theo ccbng bn di, cho bit R = 8.314 J.mol-1.K-1, tnh hng s vn tc k, n ca phn ng khi c v khng c xc tc, bit rng phng trnh ng hc phn ng theo phng trnh: -d[PhOH]/dt = k [PhOH]n. Xc nh mc gim nng lng hot ha khi s dng xc tc.

[PhOH] mol/L

Khng xc tc 20oC 1.65 2.01 2.46 3.10 3.67 4.48 5.50

Khng xc tc 30oC 3.25 4.10 4.96 6.11 7.27 9.08 10.80

C xc tc C xc tc 20oC 30oC 16.60 22.78 30.78 40.66 55.23 76.32 100.43 34.86 47.23 63.46 85.94 115.14 156.34 210.78

-d[PhOH]/dt (mol/L.s)

3.32 4.46 6.05 8.12 11.02 14.88 20.09

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CHNG 1: MT S VN CHUNG V XC TC1.3. Phn lai cht xc tc Qu trnh xc tc: ng th & d th. Chc nng xc tc: acid, base, oxy ha kh, kim lai, enzyme, Bn cht ha hc: acid, kim lai, oxt kim lai,

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CHNG 1: MT S VN CHUNG V XC TC1.4. Tm quan trng ca xc tc trong CN ha hc1.4.1. 85 90% cc qu trnh trong CN ha hc c s dng xc tc. a) b) c) d) e) Sn xut nhin liu trong cc nh my lc du. Sn xut ha cht trong cc nh my ha cht. Sn xut phn bn, cht do, Gim thiu nhim. X l nhim.

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CHNG 1: MT S VN CHUNG V XC TC1.4.2 Vai tr ca xc tc: Gim chi ph sn xut. Tng chn lc sn phm mong mun. Gim thiu nhim mi trng t qu trnh sn xut. Pht trin v khoa hc v cng ngh.

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CHNG 1: MT S VN CHUNG V XC TC1.4.3 Ha hc xanh.3C6H5CHOH-CH3 + 2CrO3 + 3H2SO4 3C6H5CO-CH3 + Cr2(SO4)3 + 6H2O chuyn ha: 42%. Sn phm ph: Cr2(SO4)3 & H2O C6H5CHOH-CH3 + O2 C6H5CO-CH3 + H2O (xc tc) chuyn ha: 87%.

Sn phm ph: H2O!

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