Petroleum Final

what are the three largest volume transportation fuels produced in a refinery?

gasoline, diesel fuel (distillate), and jet fuel

What are the three most important characteristics of crude oil composition that determine the price?

API gravity, sulfur content, and total acid number

Why does light sweet crude sell at a higher price than heavy sour crude oil?

Light sweet crude requires less proccessing cost to produce light fuel products due to a higher yield of light fuels before conversion and less sulfur removal

Contaminants of crude oil

sand/dirt, nitrogen, water and salt, and metals

Desalter

water wash crude oil to remove salts, water, and suspended solids

Flash zone

disengage feed vapor liquid

Pumparound

remove heat and increase tower internal reflux

Sidestream stripper

remove light ends with steam injection to control flashpoint

What operating changes can be made in crude distillation to change the crude distillation cut/fraction yields?

Changing the cutpoints of the distillation cuts. These changes are made by adjusting the tower tray temperature control set points, which change sidestream products rates as needed to adjust the rower tray temperature and composition profile to match the distillation cut IBP and FBP targets.

atmospheric/heavy gas oil

330 to 430

distillate/diesel fuel oil

270 to 330

heavy naphtha

90 to 190

kerosene/ jet fuel

190 to 270

light ends

< 30

light naphtha

30 to 90

short resid

> 560

vacuum gas oil

430 to 560

what are the objectives of a catalytic naphtha reformer?

increase the octane of heavy naphtha for gasoline blending, produce hydrogen for use in hydrotreaters, and produce aromatics for chemical

What are the reaction sites of a catalytic reformed to promote different reformer reactions?

metal and acid

What causes the reaction rates to slow down and require multiple reactors with reactor reheating between reacts for a catalytic reformer?

Endothermic reactions

What is required to remove coke deposited on the catalyst by hydrocracking reactions

frequent catalyst regeneration

what does a naphtha hydrotreater remove from reformer feed to protect reformer catalyst?

sulfur, organic nitrogen, and metals

What supports good feed and catalyst mixing to promote catalytic cracking and minimize thermal cracking reactions (in the riser reactor)

fluidized catalyst

What provides the heat of reaction to drive cracking reactions

hot regenerated catalyst

What results in olefin and coke byproduct production in a catalytic cracker

lack of hydrogen in the catalytic cracker process

What does proper operation of a catalytic cracker require?

heat and pressure balance between the reaction and catalyst regenerator equipment

False

Increasing the riser reactor temperature always increases naphtha and gasoline production

What variables impact catalytic cracker conversion and yield?

feed hydrocarbon composition/molecular structure, catalyst formulation and additive selection, rise temperature, and catalyst regeneration and coke removal

Gain

the increase in product volume compared to feed volume due to the smaller molecule size and lower density of the products in a refinery process unit. It is good for a refinery, because it increases the volume of high value of product available for sale

Why do refineries with a catalytic cracking unit usually have an alkylation unit?

alkylation units upgrade byproduct light olefins produced in catalytic cracking units to alkylate, a high-quality gasoline blending component.

What are properties of alkylate that make it a good gasoline blending component?

high octane, low vapor pressure, low/no sulfur content, no benzene, and no olefins

What are hazards of sulfuric acid?

corrosive, causes severe burns to eyes/skin/respiratory tract, and reaction with water produces excessive heat

What are hazards of hydrofluoric acid?

corrosive, causes severe burns to eyes/skin/respiratory tract, toxic, and chronic exposure can cause irreversible bone damage

Why are crude oils purchased?

to match crude oil composition with refinery unit configuration and processing capability

What does proper operation of the crude oil desalter reduce?

equipment fouling, erosion, corrosion, and extends process unit catalyst life

What doe heavier hydrotreater feeds require?

higher temperatures and pressures to remove sulfur, nitrogen, and metal contaminants

carbon snowball

accumulation of coking on catalyst in a repeated cycle

Why does a hydrocracker produce higher gain than a catalytic cracker?

Excess hydrogen available in the hydrocracker reduces coke and olefin production and increases saturated light fuel production with a lower density and higher gain than a catalytic cracker

What are safety hazards associated with a delayed coker?

Frequent equipment opening allows exposure to H2S, polynuclear aromatics, coke dust, eruption of steam, tarballs, coke, and potential auto-ignition of light ends on tarballs. Valve alignment errors resulting in inadvertent opening on on-coil drums. Coking of furnace tubes causing tube failure and furnace fires. Bulging and cracking coke drums due to thermal cycling.

RVP

Reid Vapor Pressure

RVP in summer vs winter

summer is lower compared to winter

Product giveaway

better than product specification