R ODM pV GASOLINE COMPONENTS 6 ] pQ WHFK Q ROy ...kkft.bme.hu/attachments/article/109/HP_6...

HYDROCARBON PROCESSING GASOLINE COMPONENTS

English version based on the presentation of

Prof. Dr. Jenő Hancsók, D.Sc.

held on 15.10.2014

[email protected]

Pannon University MOL Crude Oil and Coal Technology Department

MOL Ásványolaj- és

Széntechnológiai Intézeti

Tanszék

Vegyészmérnöki- és

Folyamatmérnöki Intézet

8200 Veszprém, Egyetem u. 10. Pf. 158.

Tel.: +36 88/624217 Fax.:+36 88/624520

Jenő Hancsók: Hydrocarbon processing, BME, 15.10.2014., Copyright 2

Motor gasolines

blending components additives

3 3

Motor gasolines

Blending components

Motor gasolines

Reformate

Alkylate

Isomerate

Oligomer gasolines

Straight rum gasoline

FCC gasoline

Hydrocrack gasoline

Alternative components

Gasolines

formed as

co-products

Ad

ditiv

es

Oxygenate

Jenő Hancsók: Hydrocarbon processing, BME, 15.10.2014., Copyright

4 4

Light naphtha isomerisation

5 5

Light naphtha isomerisation

Light naphtha (~30-40/45-82°C) isomerisation products

Light naphtha: C5-C6 hydrocarbons (C7

6 6

Goal of C5/C6 fraction isomerisation

Production of high octane light gasoline fractions

(ΔRON: 26-56 unit)

Sometimes pure isopentane production as feed for isoprene-

production


Kís

érle

ti o

ktá

nsz

ám

(K

OS

Z)

Forráspont, °C

-20

0

20

40

60

80

100

120

140

-20 0 20 40 60 80 100 120 140 160 180

többszörös elágazású

izoparaffinok

n-paraffinok

naftének

olefinek

aromások

7 7

Boiling point-RON correlation of different

hydrocarbon types


aromatics

olefins

n-paraffins

naphthenes

multi-branched

isoparaffins

Boiling point, °C

RO

N

8 8

Thermodynamics of C5/C6 paraffin

isomerisation

Paraffin hydrocarbon Reaction heat (25°C), kJ/mol

from n-pentane

2,2-dimethyl-propane -19,93

2-methyl-butane -8,04

from n-hexane

2,2-dimethyl-butane -18,39

2,3-dimethyl-butane -10,59

2-methyl-pentane -7,12

3-methyl-pentane -4,44


9 9

Equilibrium concentration of pentane and

hexane isomers


10 10

RON of C5 and/or C6 hydrocarbons equilibrium

mixtures (open chained)

60

70

80

90

100 150 200 250 300

Hőmérséklet, °C

Kís

érle

ti o

ktá

nszá

m .

C5-paraffinok

C5/C6-paraffinok

C6-paraffinok


Temperature, °C

RO

N

C5 paraffins

C6 paraffins

C5/C6 paraffins

11 11

Catalysts for C5/C6 paraffin isomerisation

Hydroisomerisation catalysts

Temperature of

favourable activity:

High

≥300°C

Pt(0,5-0,6)/g-Al2O3/F

F: 3-4%

Medium

200°C-300°C

Pt(0,3-0,5)/H-Y zeolite

Pt(0,3-0,5)/H-Mordenite

Low

≤200°C

Pt(0,3-0,4%)/Al2O3/chloride (7-10%)

Pt/sulphated metal-oxide

Mixed metal-oxide


12 12

General mechanism of n-C5/n-C6 paraffins

isomerisation on bifunctional catalysts

-H2 Diffúzió +H+

n-P n-O n-O n-C+

+H2 Diffúzió -H+

i-P i-O i-O i-C+

fémes

hely

savas

hely

krakk

termékek

-H2 Diffúzió +H+

n-P n-O n-O n-C+

+H2 Diffúzió -H+

i-P i-O i-O i-C+

fémes

hely

savas

hely

krakk

termékek

n-P: n-paraffin; n-O: n-olefin; n-C+:n-carbenium-ion;

i-C+: iso-carbenium-ion; i-O: iso-olefin; i-P: iso-paraffin


Diffusion

Diffusion

Metallic

site Acidic

site

Cracked

products

13 13

Classification of isomerisation processes

According to operation temperature:

Low (kb. ≤ 200°C)

Medium (kb. 200-300°C)

High (>300°C)

After 1990, only these

processes were implemented


14 14

Adventages of low temperature isomerisation

Feed and energy efficiency (CO2 ↓)

Higher isoparaffin yield

Higher RON (2-5 unit)

Lower hydrogen consumption (CO2 ↓)


15 15

Catalytic reforming

16

Catalytic reforming

Goal: production of high octane blending components and/or

production of hydrocarbon mixture suitable for individual aromatics

recovery

Feed: sulphur free( 1 mg S/kg) straight run and/or hydrocracking

and/or other gasoline fractions

16 Jenő Hancsók: Hydrocarbon processing, BME, 15.10.2014., Copyright

17

Main reactions I.

17

Dehidrogénezés Hőszínezet

cikloparaffin aromás H= +205 kJ/mol

+ 3 H2

sűrűség, g/cm

3 0,7694 0,8669

KOSZ: 73,8 119,7

paraffin olefin H= +90 kJ/mol + H2

sűrűség, g/cm

3 0,6838 0,7026

KOSZ: 0 89,8


Specific gravity, g/cm3

RON:


RON:


RON:

Dehydrogenation cycloparaffin aromatic

Reaction heat

18

Main reactions II.

18

Dehidrociklizáció H= +238 kJ/mol

+ 4 H2

sűrűség, g/cm

3 0,6838 0,8669

KOSZ: 0 119,7



RON:

Dehydrocyclisation

19

Main reactions III.

19

Izomerizáció H= -4,4 kJ/mol

n-paraffin i-paraffin

sűrűség, g/cm

3 0,6838 0,6871

KOSZ: 0 52,0

C5-cikloparaffin C6-cikloparaffin

sűrűség, g/cm

3 0,7913 0,7694

KOSZ: 100,4 73,8



RON:


RON:

Isomerisation n-paraffin i-paraffin

C5 cycloparaffin C6 cycloparaffin

20

Side reactions I.

20

Hidrokrakkolás

+ H2

+ H2

C1+

C2+

C3+

Hidrodezalkilezés

+ H2C1+


Hydrocracking

Hydrodealkylation

21

Side reactions II.

21

Alkilezés

+

Diszproporcionálódás

2 +

Kokszképződés


Alkylation

Disproportioning

Coke formation

22

Volume-yield correlation during different feed

(fixed bed process)


23

Catalysts for reforming

23

Megnevezés Relatív aktivitás

Króm-oxid 1

Molibdén-oxid 10

Pt/Al2O3/Cl (1953)

(Cl: 0,8-1,3%)

100

Többfémes (1967)

(Pt: 0,2-0,75%- és

Re, Sn, Ir, Ge, Rh: 0,01-től 0,3-0,5%-ig)

Stabilabb és

szelektívebb


Catalyst Relative activity

Chromium-oxide

Molibdenum-oxide

Multi metallic (1967) More stable

and

more selective

24

Process parameters

Temperature: 480 – 520 °C

Pressure: 5 – 20 bar

LHSV: 1,5 – 3,0 m3/m3h

H2/hydrocarbon molar ratio: 5:1 – 12:1


25

Industrial implementation of reforming

Reactors

number: 3-5

Fixed bed

(radial – lower pressure drop – or axial flow)

Moving bed (CCR – continuous catalyst

regeneration)

Construction material:

Resistant to reducing and oxidizing atmosphere

temperature: 550°C - ig

pressure: 5-25(35) bar


26

Conventional (fixed bed) reformer process


27

Continuous catalyst regeneration process


28

Product yield structure and characteristics


Products Yield, % Characteristics

Hydrogen rich gas 7-10 Hydrogen concentration 60-80 vol%

fuel gas (C1-C2) 1-3

propane 3-5

butene 5-8 ~50% i-butane

reformate 74-84

RON: 97-101

MON: 86-88

FBP: 20-40°C higher than the feed

aromatic content: >60%

specific gravity: 0,76-0,79 g/cm3

29 29

Alkylation

30 30

Chemistry of alkylation

Közvetlen eljárások

C3=

iC4 + C4=

C5=

Közvetett

C3=

iC4= + C4= + H2

C5=

*katalizátor: foszforsav szilárd hordozón, savas ioncserélő gyanták

**katalizátor: olefin hidrogénező (pl. Pd/Al2O3, NiMo/Al2O3)

Alkilátum

HF vagy H2SO4

Szupersavak szilárd hordozókon

katalizátor* katalizátor**


Direct processes

Indirect processes Alkylate

HF or H2SO4

Catalyst* Catalyst**

Catalyst*: phosphorous acid on solid support (acidic ion exchange resins

Catalyst**: olefin hydrogenation (e.g. Pd/Al2O3, NiMo/Al2O3

31 31

Chemistry of alkylation

Reactions:

Via tertiary carbenium ion, chain mechanism

Initiating step

e.g. proton addition onto isobutene in the presence of strong acid

Addition step

Chain producing reaction

Chain closing reaction C C CC

C C C

C

+

H++

C C C

C

C

C

C

C C C C

C

C C C

C

C

C

C

C C C C

C+

++

+

2,2,4-TMP

C C C

C

C C C

C

C C C

C

C

C

C

C++

+

C C C

C

C C C

C

+ H++


32 32

Thermodynamics of alkylation

Exothermic reactions

(-630)-(-480) kJ/kg alkylate (depending on the olefin)

Temperature favouring production of higher octane C7-C8 isoparaffins:

~ 10°C (H2SO4)

~ 35°C (HF)

Higher temperature polymerisation reaction

boiling range increases RON decreases


33 33

Process parameters of alkylation

Main goal: suppress the reaction of olefins with each other


Parameter HF H2SO4 Solid acid

Reactor temperature, °C 25-45 6-10 100-250

Pressure, bar 20 15 20-50

Isobutane: olefin ratio, vol%/vol% 15-20 10-15 5-8

Acid concentration, % 58-90 98-99 -

Acid in the mixture, % 50-70 50-75 -

Acid consumption, kg/t alkylate 0,4-0,7 35-150 -

34 34

Products of alkylation

Products

Isoparaffins with carbon number of the sum of the starting isoparaffin and olefin

Premium blending components

Aromatic content 0

Olefin < 0,1%

Good vapour pressure

High RON ( ≥ 93)

Low sensitivity [ +1 (-) +4 ]


35 35

Product composition and RON/MON of

different alkylation process products

0%

20%

40%

60%

80%

100%

HF H2SO4 Szilárd sav

C9+

C8

C6-C7

C5

95,7

94,2 95,6

93,6

97,0

93,2

KOSZ:

MOSZ:


Solid acid

RON:

MON:

36 36

Indirect alkylation

37 37

Alkylation and hydrogenation of isobutylene

and different butenes: octane number

comparison

Isobutylene reaction with …

Isooctane isomer RON MON

1-butene 2,2-dimethyl-hexane 72,0 77,5

1-butene 2,3-dimethyl-hexane 71,3 78,9

2-buttene 2,3,4-trimethyl-pentane 102,5 95,9

2-butene 2,3,3-trimethyl-pentane 106,0 99,4

2-butene 2,2,3-trimethyl-pentane 109,6 99,9

isobutene 2,2,4-trimethy-pentane 100,0 100,0


38 38

Theoretical scheme of process, using acidic

ion exchange resin catalyst


39 39

Oligomerisation

40 40

Oligomerisation

Gasoline blending components

- dimerisation of propene and/or butenes

Jet and diesel blending components

- oligomerisation of propene/butene/pentene

Petrochemical feedstock

- C7-C9 straight chain olefins (alcohol production)

- high purity light olefins (e.g. ethylene → 1-butene → 1-octene)


41 41

Feedstocks and preconditioning

Feedstocks

FCC C3-C4-C5 olefins

thermal cracking (viscosity breaking, delayed coking) light olefins

Steam reformer C3-C4-C5 olefins

Preconditioning

Hydrogen-sulphide removal: with amine scrubbing

Mercaptans removal: caustic washing

Basic materials removal (e.g. ammonia): water washing


42 42

Mechanism of olefin oligomerisation

Via carbenium ion intermedier, which is formed during the reaction of the olefin and strong acid.

Proposed dimerisation scheme of propene:

This intermedier is highly reactive, so it will rapidly react with an other propene molecule, forming a new carbenium ion

Proton transmission (to an other propene)

Similarly, from butene and propene-butene mixtures first C7 and C8 olefins will be formed, later C9, C12, C16 olefins.


Strong acid

43 43

Thermodynamics of catalytic oligomerisation

Exothermic reaction (-920, -1450 kJ/kg, butene, propene

respectively)

Necessary to cool the reaction mixture


44 44

Catalysts for oligomerisation

Heterogeneous catalytic processes

Phosphorous acid on inert support (e.g. SiO2)

zeolite

Ion exchange resins

Homogeneous catalytic processes

Nickel and titan-coordination complex + aluminium-alkyl

Ion liquids


45 45

Heterogeneous catalytic processes

Temperature 150-200°C

Pressure 10-70 bar


46 46

Scheme of polymerisation gasoline production

(on solid catalyst)

Hűtővíz Hűtővíz

Kisnyomású

vízgőz

C3=-C4

=

alapanyag

C3=

visszavezetés

C3=

Propánmentesítő Butánmentesítő

C4=

Polimerbenzin

Kvencs

Kisnyomású

vízgőz fejlesztés

Nagynyomású

vízgőz Reaktor

Kisnyomású

vízgőz


Reactor

Quench

Depropanizer

Propene

recirculation

Debutanizer

C3-4 olefin

feed

Polimerysation gasoline

47 47

Catalytic polimerisation: yield and quality

Feed Value

Propene, % 21,4

Butene, % 36,3

Polymerisation gasoline

Yield, % 52,9

Specific gravity, g/cm3 0,735

RON 95,5


48 48

Oxygenates

49 49

Oxygenates

Alcohols

Ethers


50 50

Ether type gasoline blending components

MTBE ETBE TAME

Boiling point, °C 55,2 71,7 86,1

Ignition point, °C -28 -19 -11

Oxygen content, % 18,2 15,7 15,7

RON 118 118 110

MON 100 102 97

Solubility in water

comp. in water, v/v %

water in comp., v/v %

4,3

1,4

2,0

0,6

0,6

0,6


51 51

Isobutene containing hydrocarbon streams

Catalytic cracking (15%)

Steam cracking (45%)

Isobutane dehydrogenation (48%)

n-butene isomerisation (17%)

Fischer-Tropsch synthesis C4 fraction (12 – 20%)

( ) – izobutene content


52 52

MTBE synthesis

Catalyst: acidic ion exchange resin

Exothermic, reversible reaction (-37 kJ/mol)

Process parameters

methanol/isobutene mol ratio: 1,1-1,2:1

temperature: 50-90°C in main reaction area, 40-60°C in the finishing reaction area

pressure: 7-20 bar

LHSV: 4-6 h-1

CH3

C CH2

CH3

CH3

OH

CH3

C

CH3

CH3

O CH3+


53 53

Scheme of the conventional MTBE synthesis


54 54

Ether production


55

Thank you for your attention!

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