1) distillation 2) conversion (전환 전화home.sogang.ac.kr/sites/sgpml/testmenu2/lists/b13... ·...

Chapter 2. Petroleum Refining

2. 석유정제 및 전환

1) Distillation2) Conversion (전환, 전화)3) Purification3) Purification

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1)Distillation (증류)•탄화수소의 혼합용액인 원유를 그 성분의 비점 또는 휘발도 차이를 이용•일정한 비점범위를 가지는 성분만으로 구성된 유분으로 분리하는 과정(straight-run process)(straight run process)

• 상압증류와 감압증류가 주로 사용됨

가) 탈염 (desalting)

• 원유에는 염화물, 황산염이 안정한 emulsion 상태로 존재① (염)산-장치부식① (염)산 장치부식② 석출 (고체침전) → 장치 blocking

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• micelle: aggregation of surfactant (5~6 nm)• CMC: micelle이 형성되는 농도

<CMC를 알 수 있는 방법>

Surfacetension Conductivity

C C C i C

- 화학 탈염범: 항 유화제 (alcohol 무기 화합물)로 emulsion 파괴

CMC Concentration C CMC Concentration C

화학 탈염범: 항 유화제 (alcohol, 무기 화합물)로 emulsion 파괴- 전기 탈염법: 고압 전기장으로 emulsion 파괴- 효율: 50 ~ 95%, 염분 > 15 g/1000 lit

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나) 상압 증류 (atmospheric P distillation or topping)

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• pipe still:pipe 속으로 원유가 보내져 가열압력이 걸려 있어 기화되지 않은 액상

• fractionator: (bubble tower, 증류탑)① flash zone: 상압에서 중질분을 제외하고 나머지는 기화① flash zone: 상압에서 중질분을 제외하고 나머지는 기화② tray zone: 45 ~ 90cm 간격의 수십 단의 trays

(기화/액화 반복)

fl 탑 상단 온도 조절 증류도 향상• reflux: 탑 상단 온도 조절, 증류도 향상

• stripper: 수증기 이용, 다량의 용매에 용해된 저비점 유분을 분리

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유분 b.p (℃) 탄소수 용도유분 b.p (℃) 탄소수 용도

gases -161 ~ 0.5 1 ~ 4 LPG, refining fuel

경질 naphtha(light distillate)

30 ~ 130 5 ~ 8석유화학 원료 (cracking)

blending for gasoline (low ON)

중질 naphtha중질 naphtha(light distillate)

80 ~ 170 7 ~ 12 catalytic reforming (ON 95)

등유 domestic fuel (실내등유)등유(kerosine)

150 ~ 280 9 ~ 19domestic fuel (실내등유)

보일러용, jet fuel, tractor fuel경유

230 350 14 23diesel fuel

(diesel or gas oil)230 ~ 350 14 ~ 23

central heating fuel 잔사유

> 350 > 17fuel for power station, ship, large

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(residue)> 350 > 17 heating installation



• 중유 (heavy or fuel oil, heavy distillate)y y① 잔사유에서 asphalt 제거 또는 윤활유 제조 후 잔사유 등에

등유 또는 경유 혼합② 산업용 연료:Bunker A → 소형보일러/선박② 산업용 연료:Bunker A → 소형보일러/선박

Bunker B → 중형Bunker C → 대형

③ B/C는 대도시 사용불가③ B/C는 대도시 사용불가(산업체 대형 또는 발전용 boiler용)

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다) 감압 증류 (vacuum distillation unit)

- 중질 유분을 고온에서 증류하면 열분해되어 품질과 수율이 저하- 가열관내 코크스 생성/부착에 따른 손상방지- 감압: 30~80 mmHg감압: 30 80 mmHg- 고비점 유분① vac. gas oil (VGO) → 중질유 분해 또는 LBO 제조② vac residue (VR) → 탈황시설② vac. residue (VR) → 탈황시설

상압 잔사유와 고비점 유분

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감압 증류 공정

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라) Steam distillation전압을 대기압 유지- 전압을 대기압으로 유지

- 수증기를 불어 넣으면 탄화수소의 분압 저하- 중질유의 비점이 강하하여- 낮은 온도에서 고비점 유분 유출이 가능

마) Azeotropic distillation바) E t ti di till ti바) Extractive distillation

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2) Conversion (전환, 전화)유분을 여러 방법으로 화학적 변화를 일으켜전보다 성능이 우수한 새로운 석유제품을 얻는 공정

가 cracking가. cracking- gasoline 증산 (Standard Oil, 1912)- cracked gasoline, unsaturated HC 제조

나 R f i나. Reforming- high ON gasoline 제조, aromatics 제조

다. Others- isomerization, coking, (de)alkylayion,(de)hydrogenation, hydrotreating 등

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가. Cracking- 큰 분자에서 C5~C12의 (gasoline range) 분자 제조- Saturated HC → unsaturated HC (recently)- branched chain and aromatics 형성 (high ON)branched chain and aromatics 형성 (high ON)

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가. Cracking (계속)

- 반응① cracking of paraffin → paraffin + olefin

R-CH2-CH2-CH2-R´ → R-CH=CH2 + CH3-R´R CH2 CH2 CH2 R → R CH CH2 + CH3 R(olefin) (paraffin)

② dehydrogenation of paraffiny g pR-CH2-CH2-R´ → R-CH=CH-R´+ H2

③ isomerization of paraffinR-CH2-CH2-CH3 → R-CH-CH3

|CH33

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④ dealkylation of cycloparaffin(i th f hth i HC)(in the case of naphthenic HC)

+ CH =CH CH

CH2-CH2-CH3

+ CH2=CH-CH3

CH2 CH2 CH3

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- process

① thermal cracking (열 분해법)① thermal cracking (열 분해법) cracking under high P and T

high b.p HC → cracked gasolin(gas oil resid e) (lo b p)(gas oil, residue) (low b.p) low ON, 안정성 문제, 악취

② visbreaking process (viscosity breaking)g p ( y g)가솔린 제조가 주 목적이 아님(열 분해의 일종, P = 12 ~ 25 kg/cm2, T ~ 500 oC)

AR, VR의 점도저하 목적 AR, VR의 점도저하 목적(점도 낮은 경유 등 생산)

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③ delayed coking process 감압 잔사유 아스팔트 열 분해 찌끼유 감압 잔사유, 아스팔트, 열 분해 찌끼유

불포화 화합물 多 → 불안정

④ catalytic cracking ( >35% crude oil)④ y g ( ) largest volume catalytic process 등유 이상의 고비점 유분 → high ON gasoline

(gasoline 배합)(gasoline 배합) Catalysts

- 1936 ~ World War II: Houdry clay catalyst1950s ~ ’60s: synthetic silica alumina (FB)- 1950s ~ 60s: synthetic silica-alumina (FB)

- since then: riser catalytic unit (zeolite) high T & shorter contact time

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Fluidized Catalytic Cracking Process

H2 – C4

gas oil

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510 oC

Riser Catalytic Cracking UnitRiser Catalytic Cracking Unit

650 710 C650 ~ 710 oC

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⑤ hydrocracking (수소화 분해) catalytic cracking + hydrogenation purpose:

- hydrogenate coke precursor on the catalyst y g p yto minimize coke formation and long life of cat.

- convert objectionable S-, N-, O- compounds to volatile H2S, NH3and H2Oand H2O

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process1930’ 군사용 항공기 연료 (G / E l d)- 1930’s: 군사용 항공기 연료 (Germany / England)

(P > 20 MPa → uneconomic)- 1959: Standard Oil of California, dual function catalyst

(versatility of process)- modern process: to process high content of polycyclic aromatic compounds*g y yfor high ON gasoline (T = 200 ~ 400 oC, PH2 = 1 ~ 10 MPa)- vac. gas oil, deasphalted vac. residue, - heavy gas oil from coking, catalytic cycle oilheavy gas oil from coking, catalytic cycle oil

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mechanism① thermal cracking (free radical scission)

C : C C · + C ·

C : H C · + H ·C : H C + H

- olefin (특히 ethylene) 다량y- diolefin 비교적 많음- gas (C1, C2) 대량 생성, 방향족은 적게 생성- 반응성: paraffin/olefin > naphthene > aromatics반응성: paraffin/olefin naphthene aromatics

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ex) thermal cracking of n-decane (C10)) g ( 10)

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② catalytic cracking (ionic fission)C : C C + + C : -

C : H C + + H : -

- 프로필렌, 부틸렌 다량 생성- C3 ~ C6 branched (iso-) paraffin

방향족 많고 di l fi 거의 없음- 방향족 많고 diolefin 거의 없음- 반응성: olefin > paraffin ~ naphthene > aromatics

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ex) catalytic cracking of n-decane (C10)

stablestable

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ex) isomerization by catalytic cracking

1) n-butane

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2) n-butylene in the presence of H+

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열분해와 접촉분해의 비교

Thermal Cracking Catalytic Cracking

ethylene propyleneGas

ethylene(C1, C2 다량)

propylene(C4 paraffin, olefin)

more paraffin Main

productmore olefin

than paraffin

pthan olefin

분지 지방족 다량(특히 C3 ~ C6)

방향족 적음 많음

코크스/타르 석출 다량 적음

Diolefin 비교적 많음 거의 없음

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② visbreaking process (viscosity breaking)- 가솔린제조가 주 목적이 아님(열분해의 일종, P = 12 ~ 25 kgf/cm2, T ~ 500 oC)- AR, VR의 점도저하 목적(나프타와 분해경유 소량 생산)

③ delayed coking process 감압 잔사유 아스팔트 열분해 찌끼유- 감압 잔사유, 아스팔트, 열분해 찌끼유

- 가스오일 이상의 경질유와 cokes 부생- 불포화 화합물 다량 → 불안정

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정유사 정제능력 (2009)

SK(유공)

LG-Caltex(럭키 Group)

인천정유(한화 Group)

S-Oil(쌍용정유)

현대 Oil Bank(현대정유)

설립년도 1962.10 1967.05 1968.09 1976.01 1965

가동개시 1964.04 1969.06 1971.06 1980.05 1965.03

부산공장소재지 울산 여천 인천 온산

부산대산 (1989)

시설능력(천BPSD)(천BPSD)

초기

2000

35

810

60

600

50

275

60

443

50

310

기타사업

내용

석유화학

윤활유윤활유 발전 윤활기유 윤활유

합작선

(철수년도)

GULF

1980

Caltex

-

Union Oil

1983ARAMCO

쌍용양회 합작

Shell

1977

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시장점유율 39.1 28.7 10.4 12.5 5.8



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2. 석유정제 및 전환Chapter 2 Petroleum Refining

나. Reforming나 g• gasoline range molecules are reconstructed or

reformed without change in their C numbers to improve fuel qualityg p q y(high ON의 개질 가솔린)

• principal source of aromatic chemicals (BTX)by dehydrogenation of both straight chain and cyclic aliphatics

• feed stock: a large quantity of straight chain paraffin

(15 75% ON < 50%)(15~75% , ON < 50%)and a small amount of branched chain paraffin,naphthene, olefin, and aromatics

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Octane Numbers (ON) of Pure HydrocarbonsParaffins :

n-Butane 113

n-Pentane 62

n-Hexane 19

n-Heptane 0

n-Octane 19

2-Methylhexane 41

2,2-Dimethylpentane 89

2 2 3-Trimethylbutane 1132,2,3 Trimethylbutane 113

Naphthenes (cycloparaffins) :

Methylcyclopentane 107

1,1-Dimethylcyclopentane 96

Cyclohexane 97

Methylcyclohexane 104

Ethylcyclohexane 43

Aromatics :Aromatics :

Benzene 99

Toluene 124

1,3-Dimethylbenzene 145

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Isopropylbenzene 132

1,3,5-Trimethylbenzene 171

Iso-octane (2,2,4-trimethyl pentane) 100



ON of HC

① 동일계 HC: b.p 낮을 수록 ON↑(1 t 91 1 h 76)(1 pentene 91; 1 hexene 76)

동일 탄소수 HC: aromatics > naphthene > olefin > paraffin

② paraffin: 측쇄가 많을수록 ON↑

③ olefin: 2중 결합이 분자 중앙에 있을 수록 ON↑

④ iso-paraffin > olefin > n-paraffin④ iso paraffin > olefin > n paraffin

⑤naphthene and aromatics: 측쇄가 길수록 ON↓

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Process

① thermal reforming경질 olefin이 많은 가솔린과 다량의 가스 발생경질 olefin이 많은 가솔린과 다량의 가스 발생 고분자의 HC가 절단되어 저분자의 탄화수소 생성

olefin 중합에 따른 고비점 화합물 생성

② catalytic reforming (1950 UOP) most widely used refinery reaction

(1/4 of crude oil in USA)(1/4 of crude oil in USA)

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Reactions

① isomerization of paraffin to branched chain molecules (iso paraffin)

CHn-C7H16 H3CCH2CH2CCH3

CH3

CH3

② dehydrocyclization of paraffin to cycloparaffin

3

CH CH

n-C7H16

CH3

+-3H2

CH3

H2

n-C7H16

CH2CH3

+ H2

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n-C7H16 + H2



③ hydrocracking of paraffin to paraffin

④ hydroisomerization of olefin to iso-paraffin

+ H2n-C9H20 n-C5H12 n-C4H10+

+ H2Heptene-1 H3CCH2CH2CH2CHCH3

CH3

⑤ dehydrogenation of naphthenes to aromatics

CH3 CH3

3H2+ (very rapid)

CH33H2+ (rapid)

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⑥ hydrodealkylation of cyclic hydrocarbons

C2H5

+

CH3

H2

CH3

+ C2H6

CH3

+CH3

2

⑦ hydrodesulfurization of S-compounds

CH3

S CH3

+ 4H2 C5H12 + H2S

⑧ hydrodenitrogenation of N-compounds

3H2+ + H2 C5H11NH2+ H2 C5H12 + NH3

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N NH

3



Representative Heterocyclic Nitrogen CompoundsName Formula Structure

P l C H NPyrrole C4H5N

Indole C H N

NH

Indole C8H7N

Carbazole C12H9N

NH

12 9

Pyridine C5H5N

NH

Quinoline C9H7N

N

N

Isoquinoline C9H7N N

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N



Variation of Sulfur Content of Kuwait Crude Oil

Fraction: boiling point range,℃(℉) Sulfur content, wt%

Naphtha: C4-150 (300) 0.02

Kerosene: 150 230 (300 450) 0 175Kerosene: 150-230 (300-450) 0.175

Furnace oil: 230-345 (450-650) 1.23

Heavy furnace oil: 345-370 (650-700) 2.37

Heavy gas oil: 350-550 (660-1020) 2.91

Residue: >370 (700) 4.22

Residue: >550 (1020) 5 12

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Residue: >550 (1020) 5.12



Summary of Catalytic Reformingy y g

IsoparaffinsDehydrocyclization Alkylcyclopentanes

( M th l l t )

Cracked

Isoparaffins

Isomer ization

(e.g., Methylcyclopentane)Hydrogenolysis Isomer

IsomeCracked

products

Dehydrocyclization

Isomer ization

DehydrogenationHydrogenolysis

ization

erization

n-Paraffins(e.g., n-Hexane)

DehydrocyclizationCyclohexanes

DehydrogenationAromatics

(e.g., Benzene)

Hydrogenolysis

dual catalyst

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Catalytic Reformate Production Ratio versusCatalytic Reformate Production Ratio versus US Chemicals Demand

Chemical Reformate Production Ratio (%)

Chemicals Demand (%)Ratio (%) Demand (%)

Benzene 11 56

Toluene 55 10

Xylene 34 34

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Composition (wt%) of C8 Fractions from C t l ti R f i d P l i G liCatalytic Reforming and Pyrolysis Gasoline

Catalytic Pyrolysis End UseComponent Catalytic Reforming (%)

PyrolysisGasoline (%)

End-Use Requirement (%)

E h lb 17 22 43 57Ethylbenzene 17 - 22 43 - 57

p-xylene 16 - 20 10 - 12 56

m-xylenes 40 - 45 23 - 26 4

o-xylene 17 - 22 16 - 19 16

Mixed xylenes(f l t ) 24

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(for solvents) 24



다. Other important conversion reactions in refining• cracking to olefin and paraffin

R-CH2-CH2–CH2-R´ R-CH=CH2 + CH3-R´

• dehydrogenation of paraffin to olefinR CH CH R´ R CH CH R´R-CH2-CH2–R´ R-CH=CH-R´

• isomerization of paraffin to iso-paraffinR-CH2-CH2–CH3 R-CH–CH3

CH3

CHCH3

Hor

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• alkylation by combining olefin with paraffin

C C

C

- + C C= C C

C

- -C C-C

C C

C

C C

• polymerization by combining low MW olefin

C C C C

= C C

C

C

= C C

C

C

+ C C

C

C- -C C= -C

C

C C C

H2

CC C

C

C C

C

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CC C

C- -C- -C



• hydrotreating

① to remove impurities② to reduce viscosity of heavy residue oil

(add H to heavy oil)(add H2 to heavy oil)

• coking (cokes 생성)

① heavy fraction volatile + cokes② reverse of hydrotreating

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Variation in S ContentVariation in S Content

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Petroleum Fractions

Petroleum feedstock Approximate boiling range (℃)boiling range (℃)

Light:

Light gasoline < 80Light gasoline < 80

Naphtha (reformer feed) 80-160

Kerosene (jet fuel) 150-230

Gas oil (diesel and heating oil) 170-370

Heavy:

Residual oil (fuel oil) > 350

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Chapter 2 Petroleum Refining

2. 석유정제 및 전환Chapter 2. Petroleum Refining

2) Reactions

고가의 H2사용, 효율적 (불순물처리, 폐기물처리 불필요)

CnH2n + 2H2 CnH2n+2

RS + 3/2H HR + H S RS + 3/2H2 HR + H2S

RN + 2H2 HR + NH3

ROH H HR H O ROH + H2 HR + H2O

(Ex: methyl thiophene and pyridine)

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1) distillation 2) conversion (전환 전화home.sogang.ac.kr/sites/sgpml/testmenu2/lists/b13... ·...

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