Effective Control of Molecular Transformations in ... 14th Sympo/02 Abdo 04 UOP... · UOP 4349B-13...

$: Effective Control of Molecular Transformations in ... 14th Sympo/02 Abdo 04 UOP... · UOP 4349B-13 Reactions of Naphthenes Refractory and difficult to convert once formed Side chains$
Molecular Transformations in Hydrocracking

Effective Control of Molecular Transformations in Hydrocrackers

for Clean Fuels Production

Suheil Abdo, Ph.D.

UOP LLC

© 2004 UOP LLC. All rights reserved. UOP 4349B-1

Worldwide Refining Trends

� Continued growth in oil demand

� Diesel growth exceeding gasoline

� Fuel oil demand declining � Shift to more sour crudes

GasolineGasoline2%2% DieselDiesel

2.8%2.8%

Fuel OilFuel Oil--0.5%0.5%

Refined Fuels Refined Fuels Demand GrowthDemand Growth

1.6% Oil Demand Growth1.6% Oil Demand Growth

Increasing Demandfor Conversion capacity

UOP 4354A-2


European Fuel Specification Trends

Diesel Off Road

Diesel On Road

Gasoline

< 10500-2000

84550/10

5111.0

2

Density, kg/m3Sulfur, ppm Cetane NumberPolycyclic Aromatics, wt%, maxBio Diesel, % by E-content

< 1035

5.75

50/10352

Sulfur, ppmAromatics, vol%Bio gasoline, % by E-content

2009+2005

Sulfur, ppm

On Road and Off Road Diesel Harmonization Impacts LCO Utilization

UOP 4354A-3

845< 1051

Review5.75

The Technology Challenge How to Meet the Needs

� Understand the chemistry and how to control it– Removal of sulfur and nitrogen – Rearrangement and cracking of carbon

skeleton – Selective utilization of hydrogen

� Utilize materials/catalysis knowledge to effect the right chemistry

UOP 4349B-3


Evolution from Macro Scale to Molecular Scale

Old - Physical Properties

� Distillation

� API gravity

� Smoke point

� Cloud point

New – Molecular Definition

� Individual compounds or classes

UOP 4349B-4

Example:Typical LCO Properties

Nitrogen 100Nitrogen 100--750 wppm750 wppm

Diesel Boiling Range Diesel Boiling Range TT--95>36095>360°°CC

High in AromaticsHigh in Aromatics-- ~80%~80%

Low Cetane Low Cetane -- ~15~15--2525

Sulfur 0.2Sulfur 0.2--1.5 wt1.5 wt--%%

UOP 4354A-7

Density 920Density 920--980 kg/m980 kg/m33

SR Distillate77%

4.5%4.5%8.5%8.5%

HDCHDCDieselsDiesels

Coker/Coker/VisbreakerVisbreakerDistillateDistillate

LCOLCO10%10%


LCO Feed LCO Feed

NonNon--polar P

araffins, n

aphthenes, olefin

s

polar Paraffin

s, naphthenes, o

lefins

Higher C no. single

Higher C no. single--rin

g aromatics

ring aromatics

Naphthalene

CC1010 11-- ring arom

atics

ring aromatics

Xylenes

C1 naphthalene

Indane

C2 naphthalene

nn--C16

C16

3-ring aromatics

22--ring aromaticsring aromatics

Boiling Point S

eparation

Boiling Point S

eparation

Polarity Separation

Polarity SeparationUOP 4349B-5

Hydrocracked Hydrocracked Product Product

NonNon--polar P

araffins, n

aphthenes, olefin

s

polar Paraffin

s, naphthenes, o

lefins

Higher C no. single

Higher C no. single--rin

g aromatics

ring aromatics

Naphthalene

CC1010 11-- ring arom

atics

ring aromatics

Xylenes

Toluene

C1 naphthalene

Indane

C2 naphthalene

nn--CC1616

3-ring aromatics

22--ring aromaticsring aromatics

Benzene

Boiling Point S

eparation

Boiling Point S

eparation

Polarity Separation

Polarity SeparationUOP 4349B-6


100100 300300 500500 700700 90090000

1010

2020

3030

4040

5050

00

1010

2020

3030

4040

5050

1010

2020

3030

4040

5050

6060

1010

2020

3030

4040

5050

6060

HDS Reactions

� H2S moderate inhibitor to HDN and Hydrogenation

� More refractory species prevalent in cycle oils

� Most refractory sulfur sterically hindered

� Incomplete conversion in R-1 of little consequence to downstream HC

ProductProduct

Sulfur SignalSulfur Signal

Carbon SignalCarbon Signal

FeedFeed

100100 300300 500500 700700 900900secondsseconds

--101000

101020203030404050506060

Co

un

tsC

ou

nts

--101000101020203030404050506060

001010202030304040505060607070

00101020203030404050506060

Co

un

tsC

ou

nts

7070

Co

un

tsC

ou

nts

Co

un

tsC

ou

nts

secondsseconds

S

UOP 4349B-9

Beta substitutedBeta substituted--DibenzothiopheneDibenzothiopheneFamilyFamily

Sulfur SpeciesSulfur Species

SS

ThiophenesThiophenesBenzothiophenesBenzothiophenes

Mercaptans, SulfidesMercaptans, Sulfides

DibenzothiophenesDibenzothiophenes

Most Difficult SpeciesMost Difficult Species

--DiDi--BetaBeta--DibenzothiophenesDibenzothiophenes

Reactivity of Sulfur Species

RR

RR--

RR

--RR

UOP 4349B-10


HDN Reactions

� Critical for catalyst activity and life

� Slip managed to balance HDT and HDC catalyst life

� Basic nitrogen easier than non-basic

� Rxns are hydrogenation limited

� NH3 by-product poisons acid sites

7070

8080

9090

100100

8080 9090 100100

Total Conversion, %Total Conversion, %

Basic Basic NitrogenNitrogen

NonNon--BasicBasicNitrogenNitrogen

Con

vers

ion

by T

ype,

wt%

Con

vers

ion

by T

ype,

wt%

NHNH

NN

UOP 4349B-11

Nitrogen SpeciesNitrogen Species

AminesAmines

Pyridines and QuinolinesPyridines and QuinolinesNon-Basic

IndolesIndoles, , PyrrolesPyrroles, Carbazoles, Carbazoles

--AnilinesAnilines

Reactivity of Nitrogen Compounds

Basic

NN

Example SpeciesExample Species

NN

UOP 4349B-12


00 11 22 33 44 55 66

Reactions of Aromatics

� Outer rings hydrogenated first� Ring opening and dealkylation

of multi-rings leads to high quality products

� Hydrogenation highly exothermic� Subject to equilibrium limitations� Side chains slow hydrogenation

00101020203030404050506060707080809090

100100

Rel

ativ

e H

ydro

gena

tion

Rat

e R

elat

ive

Hyd

roge

nati

on R

ate

Alkyl Chain LengthAlkyl Chain Length

UOP 4349B-13

Reactions of Naphthenes

� Refractory and difficult to convert once formed� Side chains are cleaved off before ring opening� In equilibrium with aromatics� Require strong acidity to open rings� Multi-ring naphthenes boil significantly lower

than their aromatic analogs

+++

+++

R1R1 R2R2 R2R2 R1R1

R1R1 R1R1 R1R1

UOP 4349B-14


+++R1R1 R2R2

Formation of Heavy PolynuclearAromatics (HPNA)

Diels-Alder Condensation Side Chain Cyclization

Both pathways promoted by deficient hydrogenation function

HPNAs accumulate in the recycle oil due to low reactivity

R2R2

R1R1

R1R1 R2R2

UOP 4349B-19

Reactions of Paraffins

� Reaction rates proportional to chain length

� Inverse dependence on H2 pressure

� Cracking rates promoted by higher acidity

0123456

789

nn--CC88 nn-- CC1212 nn--CC1616

Rates Constants Rates Constants Relative to CRelative to C88

UOP 4349B-15


Reaction Environment Varies between Reactors

LPGLPG

OffOffGasGas

LNLN

HNHN

MUMUGasGas

LPS

HC

Feed Feed

Unconverted OilUnconverted Oil

FractionationFractionation

RGRGCompressorCompressor

HPS

HDCHDT

1st Stage1st Stage

High NHHigh NH33 /High H/High H22SS DieselDiesel

RR--11

RR--22

2nd Stage2nd Stage

Low NHLow NH33 /High /High oror Low HLow H22SS

HDC

RR--33

UOP 4349B-7

Molecular Evolution in the Hydrotreating Reactor

AromaticsAromaticsSulfurSulfur NitrogenNitrogen

R2R2

R1R1

R2R2

R1R1

R2R2

R1R1

NHNH22

NN NN NHNH

SS--SS

SS

SH

SS

SSSS

SS

NN

NHNH

R1R1

R1R1

R2R2

R1R1

R2R2

R1R1

R2R2

R1R1

NHNH33 HH22SS

NHNH33 HH22SS

NHNH33 HH22SS


Molecular Evolution in the Hydrocracking Reactor

NHNH33 HH22SS

R1R1

R2R2

R1R1

R1R1

R1R1

R2R2

R1R1

R1R1

R2R2

R1R1

Alkyl AromaticsAlkyl Aromatics ParaffinsParaffinsAromatics/NaphthenesAromatics/Naphthenes

NHNH33HH22SSR2R2R1R1

R1R1 R2R2

R1R1 R2R2

R1R1

RR

RR

RR

Reactions are faster in the second stage, without NHReactions are faster in the second stage, without NH33

Approaches to Controlling Chemical Transformations

Catalyst

� Acid

� Metal

� Porosity

� Stacking

Process

� Flow scheme design

� Hydrotreating severity

� Hydrocracking severity

� Temperature

� Pressure and hydrogen availabilit

UOP 4349B-20


Metal

Metal

Acidity

SecondaryCrackingProducts

+H2

SecondaryCracking

-H2

IsomerizedProducts

+H2

Isomerization

Feed

PrimaryCrackingProducts

+H2

PrimaryCracking

Ideal Non-Ideal

Hydrocracking Mechanism is Bifunctional

UOP 4349B-21

+ +t y p e A

t e r t i a r y

s e c o n d a r y

+

t e r t ia r y

+

t e r t ia r y

+t y p e B 1 +

+t e r t ia r y

t y p e B 2+

s e c o n d a r y

+

t y p e C ++

s e c o n d a r y

+

t y p e D

s e c o n d a r y

s e c o n d a r y

++

+

p r im a r y

Paraffin Cracking Requires Range of Acid Site Strengths

Increasing Acid S

trength

J. Weitkamp, ACS Symp. Ser., 20, 1(1975).


Catalyst Design Elements

� Acid function– Amorphous and zeolitic– Strength and distribution

of acid sites� Hydrogenation function

– Ring opening selectivity– Activity for low P service

� Control residence time at active sites– Porosity and channel

dimensions– Catalyst shape and size

MesoporesMesopores

TEM Photo of Stabilized Zeolite

MicroporesMicropores

UOP 4349B-22

Adjustment of Pore Geometry and Active SitesAdjustment of Pore Geometry and Active Sites

UZM-9 8 MR 4.1 A

UZM-5 8 MRUZM-4 12 MR <-> 8 MR

New UOP New UOP

ZeoliticZeolitic MaterialsMaterials


0.0

5.0

10.0

15.0

20.0

25.0

30.0

0 93 204 316 427 538 649

Average Boiling Point, °C

Wt%

by

GC

in t

he

Liq

Pro

du

ct (

50 °

F c

ut)

LCO Feed

Catalyst A; Net Conv = 48.1

Catalyst B; Net Conv = 48.6

Catalyst C; Net Conv = 49.2

Catalyst D; Net Conv = 47.1

Cracking Pattern Adjusted by Selection of Catalyst Cracking Pattern Adjusted by Selection of Catalyst

Product Simulated Distillation Differential PlotProduct Simulated Distillation Differential Plot

Cat A

Cat B

Cat C

Feed

Cetane Increases by Opening Rings

P = 1200 psig LHSV = 1.5 hr

-1

H2/Oil = 4500 SCF/B30

32

34

36

38

360 366 371 377 382 388 393 399 404

Temperature, deg C

Cet

ane

Ind

ex

Cat D Cat E Cat F

Increasing Ring O

pening Function


Application Example

LCO Processing

CHCH33

CHCH332 H2 H22

3 H3 H22

CHCH33

�� LCO UpgradeLCO Upgrade�� Gasoline & DieselGasoline & Diesel

HH22

HH22

CHCH33

HH33CC

Higher Higher CetaneCetaneand Better and Better StabilityStability

CHCH33

CHCH33

CHCH332 H2 H22

2 H2 H22

CHCH33

2 H2 H22CHCH33

CHCH33

CHCH33

BTX FeedstockBTX FeedstockNew Feed SourceNew Feed Source

CHCH33M/AM/A

CHCH33

Naphtha CrackerNaphtha CrackerFeed PretreatmentFeed Pretreatment

M/AM/A

CHCH33

CHCH33

HH33CC

CHCH33

CHCH33

CHCH33

HH33CC

HH33CC

Higher Ethylene and Higher Ethylene and Propylene YieldsPropylene Yields

Ring OpeningRing OpeningOpportunitiesOpportunities

UOP 4197G-20


LCO Hydroprocessing Options

Full Conversion Full Conversion HydrocrackigHydrocrackigNaphthaNaphtha

Direct BlendingDirect BlendingDiminishing OptionDiminishing Option

HydrotreatingHydrotreatingQuality IssuesQuality Issues

ULSD and High Octane Gasoline ULSD and High Octane Gasoline Blend StocksBlend Stocks

NewNew

LCOLCO

LCO Unicracking TechnologyLCO Unicracking Technology

Severe Hydroprocessing Is Required to Upgrade LCO 6400 ppm

Easy Sulfur

4 MDBT4 MDBT

4,6 DMDBT4,6 DMDBT 231 ppm231 ppm

56 ppm56 ppm

989 ppm989 ppmDifficult Sulfur


Exploit the Chemical Nature of LCO

RR

XX

XXDesir

edDesir

ed

RR

RR

RR

RR

RR

RR

RR

RR

RR

RR

RR

RRRR

Hydrogenatio

n

Hydrogenatio

n

& crack

ing

& crack

ing

UOP 4354A-22

Diesel RangeDiesel Range Gasoline Gasoline RangeRange

HCTM 190 New CatalystTailored for LCO Unicracking Process

UOP 4349C-22

Hydrogen rich dieselHydrogen rich diesel

Hydrogen lean gasolineHydrogen lean gasoline

Selective HydrogenationSelective Hydrogenation

Longer run lengths atLonger run lengths atlow pressure operationlow pressure operation

Higher ActivityHigher Activity


LCO Unicracking TechnologyLCO Unicracking TechnologyDiesel Blend Stock QualityDiesel Blend Stock Quality

DensityDensity

Cetane IndexCetane Index

Sulfur, ppmSulfur, ppm

Feed CIFeed CI

Conversion, wtConversion, wt--%%860860870870880880890890900900910910920920930930940940950950

Den

sity

, Kg/

mD

ensi

ty, K

g/m

33

� Density and Cetaneimprove with conversion

� Sulfur meets ULSD specs

00

1010

2020

3030

4040

5050

Cet

ane

Cet

ane

or S

ulfu

r,

or S

ulfu

r, p

pmppm

Feed DensityFeed Density

Gasoline Yield, Gasoline Yield, wtwt--%%

Gasoline Aromatic wtGasoline Aromatic wt--%%

LCO Unicracking TechnologyLCO Unicracking TechnologyGasoline Yield and QualityGasoline Yield and Quality

4040

5050

6060

7070

8080

9090

Gas

olin

e Y

ield

, wt

Gas

olin

e Y

ield

, wt --

%%

00

1010

2020

3030

4040

5050

Gas

olin

e A

rom

atic

s, w

tG

asol

ine

Aro

mat

ics,

wt --

%%

Conversion, wtConversion, wt--%%

� Gasoline aromatics do not change with conversion

� Product flexibility


Not a simple Answer –

What is the Best LCO Option ?Hydrotreating or LCO Unicracking

Best Option is a function of:� Refinery Configuration� Product Specifications� Pricing

LCO UnicrackingLCO Unicracking

HydrotreatingHydrotreatingULSDULSD

LCOLCO

ULSD and High Octane ULSD and High Octane Gasoline Blend StocksGasoline Blend Stocks

Fuel OilFuel Oil

GasolinePool

FuelOil

ULSD Pool

LCO Upgrading Case Study

�About 75% of hydrotreated diesel required downgrading

HydrotreatingHydrotreating

25%25%

75%75%



GasolinePool

FuelOil

40%40%ULSD Pool

LCO Upgrading Case Study

�About 75% of hydrotreated diesel required downgrading

�Gasoline and diesel products blended into the EuroIV pool

�Higher value product


LCO Unicracking LCO Unicracking ProcessProcessUnicrackingUnicracking

60%60%

25%25%

75%75%

LCOLCOHydrotreatingHydrotreating

The Future

� Hydrocracker requirements increasingly defined at the molecular level

� Hydrocracker role more critical in clean fuels production

� Optimum design and operation will be aided by expanding knowledge

UOP 4349B-28

Effective Control of Molecular Transformations in ... 14th Sympo/02 Abdo 04 UOP... · UOP 4349B-13...

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Transcript of Effective Control of Molecular Transformations in ... 14th Sympo/02 Abdo 04 UOP... · UOP 4349B-13...