Petroleum refining

A heat exchanger removes vapor from the upper parts of the fractionator, cools it to a liquid, and pumps it into an accumulator (reflux drum). Reflux pumps then draw liquid from the bottom of the accumulator and pump part of it back...

The vast piping systems within today’s refineries transport hydrocarbon gas/vapor streams, light liquid gas/liquid streams, heavier liquid streams, water, and steam throughout the refinery. Certified, reliable and accurate flow...

Upon arrival at the refinery terminal, crude oil is pumped into above-ground storage tanks with capacities of thousands to millions of gallons. Raw crude is stored in floating-or fixed-roof tanks field-built to API standards. Tank level...

The Fluid Catalytic Cracking Unit (FCCU) cracks heavy, low-value feedstocks into high-value, lighter molecular weight hydrocarbons which are blended to finished products. A cracker can produce a wide variety of yield patterns by operating...

Following desalination, crude oil enters the distillation column where fractional distillation separates hydrocarbons into separate streams, cuts or fractions. For optimum operation of the distillation column, level controls must contend...

All unrefined crude oil stored in tanks has a percentage of water entrained within it, and while stored in tanks, separation naturally occurs with water collecting at the bottom of the tank beneath the oil. The two fluids are very distinct...

Salt in the crude stream presents serious corrosion and scaling problems and must be removed. Salt is dissolved within the remnant brine of the crude oil. Desalting removes both salt and the residual free water. Though the refinery is the...

Inorganic chlorides, suspended solids, and trace metals found in untreated crude must be removed by chemical or electrostatic desalting. This reduces the risk of acid corrosion, plugging, fouling and catalyst poisoning in downstream units....

The catalytic method of converting compounds into other compounds uses a chemical catalyst to increase the rate of a reaction. The catalyst is chemically unchanged after the reaction has occurred and can be recovered from the reaction...

The heavy fraction remaining following the distillation of crudes is called petroleum resids. A variety of solvent-extraction processes yield deasphalted oil (DAO) from these resids. These oils serve as downstream feedstocks for catalytic...

Variations in cat cracking include Selective Component Cracking (SCC) for polypropylene production, a two-vessel and external-reactor design for processing heavy residue feeds, and a UOP process for converting gas oils and resid...

Heavier feedstock difficult to process by cat cracking or reforming can be converted by hydrocracking. By combining catalytic cracking and hydrogenation to crack feedstock in the presence of hydrogen, hydrocracking produces gasoline and...

Catalytic Hydrotreating treats hydrocarbon liquids in the presence of hydrogen. This process removes 90% of the sulfur, nitrogen, oxygen, and metals from feedstocks. Hydrotreating can also provide hydrodearomatization (HDAr), heavy diesel...

Isomerization in a variety of process configurations alters the arrangement of atoms to convert normal butane into isobutane, and normal pentane and hexane into highoctane gasoline components. Isomerization is similar to catalytic...

Coking is the final means of converting the heaviest products of atmospheric and vacuum distillation. Feed is heated and cracked into light gases, gasoline blendstocks, distillates, and gas oil. Level applications for delayed and...

Mixing finished gasoline requires level monitoring of blending stocks, in-line blending, additive storage, dilution systems and injection systems. Blend stocks are straight-run gasoline, alkylate, reformate, benzene, toluene and xylene....

Reboilers, or vaporizers, are heat exchangers that provide heat to the bottom of a distillation tower. They boil the bottom liquid to generate vapors which are returned to the tower to drive the distillation separation process. The...

A heat exchanger positioned near the bottom of the distillation column re-heats and vaporizes liquid and reintroduces the vapor several trays higher. This improves separation by introducing more heat into the column. For effective...

Catalytic reforming upgrades low-octane naphthas into high-octane gasoline blending components called reformates. Using heat and pressure with platinum catalysts to rearrange hydrocarbon molecules, this process converts low-octane gasoline...

Storage and wash vessels in the alkylation unit include those for fresh and depleted acid and water, an acid analyzer settling pot, and a number of wash tanks. Caustic washes neutralize free acid carried over from the reaction zone and...

Diesel-powered engine-generator sets provide emergency power to operate critical nuclear plant systems in the event of a loss of station service power. The main diesel fuel storage tank provides a fuel capacity for one to seven days of...

Alkylation is a combining process that creates alkylate, a premium, high-octane blending stock. A large acid settler tank within the unit allows for separation of the acid/hydrocarbon emulsion created in the reactor. Sight glasses have...

Selecting a separation technology from among 20 leading varieties depends upon a chemical’s nature, the number of phases, and the capacity, speed and efficiency required. Distillation - separating substances based on differences in...