THE OIL & GAS SUPPLY CHAIN: FROM THE GROUND TO THE PUMP ON REFINING J. Mike Brown, Ph.D. Senior Vice President Technology
BASICS OF REFINERY OPERATIONS Supply and Demand Where Does The Crude Oil Come From? Crude Oil Basics Refining Concepts Flowcharts of Petroleum Refineries Basic Refinery Operations and Optimization Conversion Refinery Overview Engineering Opportunities
SUPPLY AND DEMAND USA consumes 370 million gallons of gasoline and 226 million gallons of distillate fuel per day. Demand for transportation fuels increased nearly 50% in last 20 years. Number of refineries operating in USA has dropped from ~250 to 139 since 1982. Total refinery throughput has increased over same period. USA produces 113 billion gallons of crude per year and imports an additional 150 billion gallons. Opportunity crudes represent significant portions of refinery crude slate. Source: EIA
WHAT IS CRUDE OIL? Crude oil is a mixture of hydrocarbons formed from organic matter. Crude varies significantly in color and composition and value Composition varies - Sulfur content - Nitrogen - Density (gravity) - Contains sediment, water, salt and heavy metals - Distribution of hydrocarbons
CRUDE OIL CHARACTERISTICS Crude density is measured by API gravity API gravity provides a relative measure of crude oil density. The higher the API number, the lighter the crude. API gravity of water is 10, gasoline ~50 Sulfur content measures if a crude is sweet (low sulfur) or sour (high sulfur) Typically less than 0.5% sulfur content = sweet Typically greater than 1.5% sulfur content = sour High sulfur crudes require additional processing to meet regulatory specs for fuels ULSD, < 15 ppm
CRUDE OIL CHARACTERISTICS Crude value roughly determined by ease of refining to high value products primarily distillate fuels Salt content, especially divalent cations (Mg ++, Ca ++ ) can be highly destructive to distillation equipment Heavy metals (Vanadium, Nickel) poison catalysts and degrade residium products Opportunity crudes available at discount over benchmark crudes because of detrimental refining characteristics
CRUDE OIL CHARACTERISTICS Light crude: API >30 Medium: API 22-30 Heavy: API 10-22 Extra Heavy: API <10 Benchmark Light, Sweet Crudes West Texas Intermediate Brent Dubai Opportunity Crudes DOBA (heavy, high acid number) SJV (extra heavy Bakersfield) Venezuelan (extra heavy Orinoco)
WHAT DOES A REFINERY DO?
CRUDE TYPES VERSUS DEMAND Gasoline Gasoline Gasoline 5-15 % Naturally occuring 20-30 % hydrocarbon molecules do 40-45% Distillate not meet customer needs. 20-25% Distillate The refining processes must Distillate adjust the molecules, reshape 25-35% Heavy Fuel 30-35% Oil them and remove contaminants Heavy Fuel 60-75% to ensure they meet Oil Heavy Fuel requirements for: ~10% Oil 35-55% - end use performance - environmental performance Asphalt ~5% Other ~5-10% Light Crude Heavy Crude Example Product Product Product Composition Composition Demand
BASIC REFINING CONCEPTS CRUDE SEPARATION
BASIC REFINING CONCEPTS
BASIC FLOWCHART OF PETROLEUM REFINERY (1915)
SIMPLIFIED FLOWCHART OF A COMPLEX REFINERY
REFINERY OVERVIEW Distillation Cracking Treating Reforming (Separation) (Changing Size) (Changing Shape) Raw LPG Naptha HCU LPG Fuel gas C4 I-C4 Gasoline CRU Diesel Diesel HDS Gas Oil MHCU Gas Oil Coker Resid. Coke
BASIC REFINERY OPERATIONS Separation Distillation Conversion Changing the size or shape of molecules Re-shape molecules to improve product quality Catalytic Reforming Unit Isomerization Unit Upgrading breaking large molecules into smaller Coking Hydrocracking, Cat Cracking, Thermal Cracking Combining Molecules Alkylation Catalytic Polymerization Treatment / Blending Making on-spec products Removal of impurities desalting, desulfurization, denitrification Mixtures of components to meet specifications
CONVERSION
CONVERSION PROCESSES Alkylation React olefin with alkane to increase MW and branching Increases octane value of gasoline Cracking Breaks heavy components in lighter components Without hydrogen produces olefins Hydrocracking Converts heavier paraffins into lighter, branched components Reforming Dehydrogenation, convert low octane naphtha to high octane aromatics Aromatization of paraffins for octane improvement, premium gasoline Hydrogen byproduct used in isomerization, hydrotreating and hydrocracking
CONVERSION PROCESSES Isomerization Convert butanes, pentanes, hexanes to branched components Increases octane rating of gasoline Hydrotreating Converts unsaturates and aromatics Removes N, S to meet specs Coking Recovers gas oil from low value resids Coker gas converted to gasoline and other high value products Produces hydrogen depleted fused carbon compounds useful as fuel and steel production
REFINERY OPTIMIZATION Two areas can not be compromised Safety Reliability Economic optimization is a series of trade-offs Feedstocks Availability (crude, Intermediate products), Yields, Cost Refinery Complexity, Flexibility + Constraints Crack spread Crude rate Maximize to spread fixed costs Products Meet market demands Value added and margins Operations Maximize yields, minimize giveaway / inventories Optimize energy use
UTILITIES
ENGINEERING DISCIPLINES Chemical Mechanical Electrical Bioengineering Information Services Software Design
ENGINEERING ROLES IN REFINERIES Operations Engineer Maintenance Engineer Control Systems Engineer Design Engineer HSE Engineer Planning / Scheduling Engineer Reliability Engineer R&D Engineer Technical Sales Engineer Engineering & Construction Engineer Governmental Regulations Unit Manager Engineering Manager Operations Manager Plant Manager
CONCLUSION Trend is toward fewer refineries with high throughput Design optimization Unit operations upgrades Refineries are under economic pressure Higher crude prices reduce crack spread Soft economy has slowed demand relative to crude prices Engineering expertise in high demand Candidate pool continues to be shallow Expertise leaving workforce Exciting times ahead for all engineering disciplines
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