Industrial Organic Chemicals Introduction 1) Process Engineering & Economy (1) Bench Scale Pilot Scale Scale-Up - Reactor Deign: Temp Control : Heating Mantle Steam 사용 가열 (150℃) Rxtor Size : 1L 1 루베(1000L), 8 루베 for 500Kg product, <70-80% charge Material : RB Flask Carbon steel - GL for acidic condition Stainless steel for basic condition Cooling vs. Reactor Vol : Vol.증가 vs cooling efficiency (surface증가)
- Process Design : 안전성 문제: LAH, NaBH4 H2 환경 문제: Friedel Craft 촉매 (FeCl3) 인건비 : Continuous vs. Batch
문제 1: 수소를 값싸게 얻는 방법 문제 2: 99.9%의 Abs. 에탄올을 얻는 방법 문제 1: 수소를 값싸게 얻는 방법 (물 + e, 물 + C, HC reforming ,..) 문제 2: 99.9%의 Abs. 에탄올을 얻는 방법 문제 3. 페놀의 공업적 제법: 메커니즘? ? 1. Cummen Process 의 Mechanism??
(2) Yield 와 Conversion (3) 다음의 경우 일반적으로 high cost - Labor cost 는 multi stage reaction 비례 - 고온, 고압 반응 (Energy cost) - Highly acidic reaction - Extensive separation steps - Pollution control
(4) Terminology Filtration, Heat Transfer, Distillation,... -Unit Operation (단위조작) : "Physical Change" Filtration, Heat Transfer, Distillation,... Heating is simple, But how about in scaling up? Filtration is simple. But how about in scaling up? (예): Ethambutol pilot 생산 -Unit Process (단위공정): “Chemical Change" Nitration, Chlorination, Hydrogenation, Amination,.. Oxidation, Alkylation, -Chemical Conversion : used in Petroleum Industry Unit Process 와 병행 사용
- Batch Process (회분식) Lab process 와 유사 Reaction mixture in one reactor More labor cost Fine Chemical 합성 시: 고가의 의약, Explosive 등 -Continuous Process (연속식) Flow processing Automation-computer control Energy saving process, Short Reaction Time control: (예) acetylene 합성, rxn time, 0.002 sec at 1600 C Gas Phase Reaction
(6) Process Economics High Cost Factors - Labor : multi-step reactions - High Temp, High Press (high energy) - Acidic reaction: corrosion need special equipment - Complicate separation steps eg) Filtration step : crystal form is important - Pollution control Low Cost : Scale Up Plant Design : Technology and Economy (예) Phenol Plant Filtration step : Crystal structure (alpha from, beta from, etc)가 매우 중요
2) Carbon Source: Where organic chemicals come from? (1) Coals : acetylene, water gas, BTX 등 aromatics - WWII 이전 Chemical Industry (2) Natural Gas & Petroleum : major source (~95%) since 1975 7 major chemical building blocks - Ethylene : C2-Chemicals : Naphtha (Jpn, EU), Natural Gas(USA) - Propylene : C3-Chemicals - Butylene : C4-Chemicals - Benzene, Toluene, Xylene : BTX - Methane : C1-Chemicals
(3) Fats, Oils & Carbohydrates - Fatty acids (Palm oil, 우지(牛脂), Lad, ..) - Sugars - Cellulose - Fermentation Product: 에탄올, 식초 (4) 기타 Sterols (대두 폐기물), Alkaloids, Phosphatides (egg york,.. ), Gums 등 - 값비싼 고급 정밀화학제품 제조 원료 - highly specialized field
Petroleum Refining (석유정제) A. Introduction 어원 : Petro… (Latin: Peter,바위), Crude oil: 배사구조에서만 발견 2) 성분 : C : 84-87%, H : 11-14%, N : 0-1%, S : 0-5%, O : 0-1% Complex mixture HC 》S, O, N, (tr.metal) (파라핀계) Alkanes : straight HC, branched HC, > CH4 (나프텐계) Cycloalkanes : 5, or 6 (방향족계) Aromatics : > C6H6 (올레핀계) Olefines
3) Classifications of Petroleum (1) 성분 분포에 따라 Paraffin base crude oil - open chain HC major Naphtha base crude oil - cyclic HC major Intermediate base crude oil (2) M.W. 분포에 따라 ~ 가격 Light Crude : light M.W. major Heavy Crude : high M.W. major (3) 생산지에 따라 : 두바이산, 텍사스 중질류, 북해산 등
B. Petroleum Refining Process Fractional Distillation: first op in refining process by b.p. differences 50 Cracking : A. C5-C12 from large size molecule B. Ethylene (or propylene) from sat’d HC (1) Thermal cracking (for B) : so called steam cracking (2) Catalytic cracking (for A) : - also produces branched HC, aromatic (3) Hydrocracking : " catalytic cracking + H2 " - prevents coking of catalyst - S, N, O 제거 → H2S, NH3, H2O (예; S- oil)
3. Polymerization - low M.W. HC → gasoline-range molecule (via H+ catalyst) - not widely used today 4. Alkylation - olefine + paraffin → branched HC - HF, or H2SO4 catalyst 사용 - very important process for premium gasoline high O.N. 5. Catalytic Reforming - dehydrogenation of straight-chain, cyclic aliphatic HC aromatic HC (BTX) - very important for high O. N - most widely used refinery reaction
6. Dehydrogenation : - During Cracking, Reforming process - For making Others eg) Butane → Butadiene, PhCH2CH3 → PhCH=CH2 7. Isomerization : - straight chain → branched chain eg) n-pentane → i-pentane (for alkylation) eg) ethyl benzene, xylenes p-xylenes TPA
1) Fractional Distillation 47 (1) Gases (b.p 〈 20℃) : CH4 (LNG), C2H6, C3H8 + C4H10 (LPG) - Refinery gas - similar to Natural Gas : for fuels and chemical feed stock - mostly flared because of recovery problem (2) Light Naphtha (b.p. 70-140℃): C5-C9 straight run gasoline (3) Heavy Naphtha (b.p 140-200℃) - C7-C9 aliphatic, cyclo-aliphatic + some aromatic - For fuels, chemical feed stock
(4) Kerosine (등유.석유) (b.p 175-275℃) : C9-C16 - first used as lightening, solvents - Fuel for Jet, tractor, home heating (5) Gas oil ( b.p 200-400℃) : C15-C25 - for diesel and heating fuel - raw material for cracking to oletines (6) Lub oil ( b.p〉350℃) - used for lubrication - maybe cracked to lighter fraction
(8) Asphalt : for paving, coating etc... (7) Heavy (Fuel) oil (중유) ( b.p >350℃) - Boiler fuel (bunker oil) - Ship, Industrial furnace - Visocity 에 따라 : 경질 중유, 벙커 A, 벙커 C (8) Asphalt : for paving, coating etc... * Knocking vs O.N. * Block-Flow Diagram of Typical Petroleum Refinery
2) Cracking: catalytic cracking - Thermal cracking (1912- ) - Catalytic cracking (1940- ) : Si2O3/Al2O3, of Zeolite (1) 목적 : - Increase gasoline yield : straight run gasoline (직류 가솔린) 만으로 수요부족 eg) heavy gasoline 으로부터 gasoline생산, 총 gasoline 생산량의 > 50% 차지 - Increase O.N.
(2) 반응 : See - Condition : 350-550℃(vaporize) → 수초간 catalyst 위로 통과 C7H15-C15H30-C7H15 → C7H15 + C6H12=CH2 (High O.N. gasoline) (Heavy G.O) (gasoline) + C14H28=CH2 (recycle) (Endo, + H) - Products : from middle east Oil (G.O.) Gasoline 36% Residue 23% G.O 15% *Coke 6% … 고분자의 탄화된 물질: 촉매를 inactivation 시킴 Propane 4% (촉매재생 process가 필요 → Fluidized - Bed Reactor) Etc (no ethylene) !
촉매에 deposit 되어 있는 tar 와 coke를 태워서 촉매를 재생시킴. - Orthoflow Convertor (see 675 ) 촉매에 deposit 되어 있는 tar 와 coke를 태워서 촉매를 재생시킴. (3) Mechanism : carbocation (R+ ) mechanism - Catalyst의 Acidic site에 의해 R+ 형성 C16H34 + R+ → C5H11-CH +-C10H21 + RH 28 "CH2" vs 6 "CH3" - β-Scission C5H11 CH+ -CH2-CH2C8H17 → C5H11CH=CH2 + +CH2 C8H17 (1° R+) C8H17 CH+ → C4H9CH2- CH + - CH2CH3 (C9+)
※ β-scission해서 얻는 가장 작은 단위는 “propene" RCH2-CH2 CH2+ → R CH2+ + CH2=CH2 : less possible low conc. of 1° R+ → low conc. CH2=CH2 - Further β-scission until C3+ - Hydride ion abstraction → new R+ (chain rxn) C5H11 + + C16H34 → C5H12 + C16H33+
(4) 기타 반응 - Carbon skeletal rearrangement → branched HC - Alkyl aromatics → reverse F.C. alkylation Alkyl Benzene → Benzene + Alkene ※ no change on aromatic ring itself under cracking condition (vs hydro cracking) - Double bond migration → increase O.N (terminal → internal) (5) Side Reactions - H+ transfer : propylene + t-butyl + → propane + i-butene - Polymerization of alkene :
3) Hydrocracking (1) combination of "cracking + hydrogenation" - Cond : 340-420℃, 60-130atm, over dual-function catalyst Cracking : Silica-Alumina, or zeolite Hydrogenation : Ni, W, pt, pd, - 특징: less side rxn, no coke formation no need for catalyst regeneration (2) 반응 C7H15-C15H30-C7H15 + H2 → n-C7H16 + i -C7H16 + C15H32 (recycle) Exo, - H : need cooling
(3) Application - Catal Cracking 이 안 되는 polynuclear aromatic HC 등의 cracking 에 보조수단 - For production of low S containing jet fuel, diesel fuel (3) 장단점 - High press, large H2 consumption - More expensive process than catalytic cracking - Rather low O.N → need Catal Reforming
※ Octane Number 1) 2 major quality of gasoline - 휘발성 : bp 30-190℃ < 30 ℃ 휘발로 연료 손실 > 190℃ fuel line locking - Burning property : smooth 하게 연소해야 → high O.N. (90-100℃) 2) Scale of O.N. n-heptane(0) ↔ i-octane(100) Burning property 를 i-octane 의 함량 %로 표시
(eg) n-pentane 62 2,2-dimethyl butane 92 n-hexane 25 Benzene, Tolune >100 cyclohexane 83 2-methyl butane 92 3) Structure Requirement for high O.N - Chain branching - Unsaturation - Aliphatic or Aromatic Ring