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Crude Distillation Technologies. Company Name. Clay Buie and Matt Heckendorn Thursday April 30 th , 2009. Project Objective. Evaluate energy consumption and production rates of 5 new Crude Distillation Technologies Compare to Conventional Atmospheric Distillation
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Crude Distillation Technologies Company Name Clay Buie and Matt Heckendorn Thursday April 30th, 2009
Project Objective • Evaluate energy consumption and production rates of 5 new Crude Distillation Technologies • Compare to Conventional Atmospheric Distillation • Evaluate Economics of potential energy savings and increases in product yields
Need for Improvement • Conventional crude oil distillation is a very energy-demanding process • Depletion of crude reserves, processing costs and environmental concerns warrant energy-efficient distillation techniques • Largest processing quantity of all petroleum and chemical processing units • Minor improvements may generate significant profits
What is Crude Distillation Molecular Weight Volatility First of many major processes in transforming crude oil into usable products at an oil refinery Thermal separation of crude oil into products (naphtha, kerosene, diesel, gas oil, residue) based on different boiling point volatilities Naphtha Kerosene Diesel Gas oil Residue
Atmospheric Crude Distillation • Furnace heats crude to flash temperature of feed tray • Lighter components rise through column • Side Columns strip lighter components from liquid draws 1 2 3 3 3 2 3 1
Separating Components • Lighter component vapors separate from heavy residue liquid in the flash zone of the furnace outlet • Stripping Steam promotes separation • Side Strippers maintain product “gaps” and recover lighter components from liquid draws • Stripping Steam separates light components from residue liquid at bottom of the column
Product Composition • Products are not pure components but contain a range of molecular weights and normal boiling point temperatures • The boiling point range gives information on the composition, properties, behavior, and value of each product • The amount of product overlap is maintained to control the quality of lighter products.
Product Gaps • Products defined by their ASTM D86 5% and 95% endpoint temperatures. • Overlap defined by D86 “5%-95%” gaps of neighboring products where: 5%(Heavy)-95%(Light) = value 95% light 5% Heavy Heavy Light Flow rate Temperature Large gap values yield sharper cuts but also cost more to maintain
Separation Opportunity • Conventional distillation is limited to separation in the furnace and stripping steam sources • Unfortunately, not all light components can be separated from residue in bottom of main column • Ability to separate more volatile components from intermediates and residue can be explored Intermediates Trapped
Method of Comparison • Created Process Simulations of 5 technology configurations • Maintained operating conditions, product compositions/gaps, and feed specifications • New configurations focus on separation techniques and lowering burden of furnace • Seeking lower heating utility needed at furnace, and lower yields of residue bottoms
Invention 1 – Vapor Stripping Gas oil stripper Stripping steam is limited, so light weight vapors are used to strip intermediate components. Gas Oil Feed Compressor Compressor work and vapor flow-rate is not significant enough to negatively affect economics. Flash Drum Residue
Invention 1 – Vapor Stripping For all types of crude, increased yield of gas oil and diesel, reduced residue. No change in heating utility, although increase in cooling utility.
Carrier Effect With intermediates removed, the lighter components create a “vacuum” as they rise up the column, pulling more intermediates from the residue cut. Intermediate components removed in preflash.
Invention 2 – Feed Preflash Removes intermediates before they are fed into the column to increase carrier effect. Cooler Flash Drum 2 Diesel Flash Drum 1 Heater Main Steam Gas Oil Residue
Invention 2 – Feed Preflash Reduction in residue decreases with increase in crude weight. Reduction of furnace utility and cooling utility.
Invention 3 – Compressed VS Gas Oil Stripper Higher stripping pressure. Injected vapors include light weight vapors and lightends in addition to intermediate weight vapors. Heater Cooler Flash Drum
Invention 3 – Compressed VS Higher stripping pressure reduces effectiveness of carrier effect. Highest increases in gas oil production across all crudes. Increases diesel production in heavier crudes. Slightly increases heating utility.
Invention 4 – Combined 2&3 Feed Preflash Compressed VS Adversely affects diesel production. The two designs offset each other. Unprofitable for intermediate crude.
Invention 5 – Combined 1&2 Feed Preflash Vapor Stripping Second highest increase in diesel and gas oil production. Highest reduction in heating utility.
Interpreting Simulation Results • What constitutes a “good” design? • Hard to interpret outcome without evaluating economically • EIA and design literature help with evaluation.
Numbers for economics • Energy Information Agency product and crude prices • Peters, Timmerhaus and West utility price
Comments • Compressed vapor stripping and combined feed preflash with vapor stripping have the most promise for a profitable retrofit. • Vapor stripping is good on its own. • Applications toward future crude oil.
Invention 4 – Combined 2&3 Feed Preflash Compressed VS
Invention 5 – Combined 1&2 Feed Preflash Vapor Stripping