Crude Oil Vacuum Distillation
Crude oil is generally processed to produce gasoline and other Hydrocarbon fuels via either atmospheric or vacuum distillation in refineries.
This application involves applying a vacuum to a crude oil distillation column. The combination of heat and vacuum separates the crude oil into different components based on their boiling temperature. Its purpose is to enhance the recovery of the lighter components, such as gasoline. Vacuum distillation is more energy efficient than the atmospheric distillation tower.
Vent Gas Compression
Non-condensable light Hydrocarbon gases from the crude distillation tower and other refinery vents are collected in a common header and piped to either flare or vent gas compressors. These compressors compress vent gases that have some fuel value (BTU'S) up to the desired discharge pressure and burn to recover the energy. Often the payback period is very short and recovery of vent gas very desirable environmentally.
Vapor Recovery/Gas Boosting
This application differs from vent gas recovery in that the vapors recovered are of a relatively fixed composition rather than a variable mixture. A typical application is capturing gases vented from storage tanks. The depth of vacuum is closely controlled in order to protect the storage tanks. Usually the discharge pressure is relatively low. Often these gases are returned to the process, or are liquefied and returned to the storage tanks.
In this application, chlorine gas is recovered and compressed. The seal liquid is concentrated (> 96%) sulfuric acid. Materials used must be compatible with this highly dangerous gas and seal liquid.
This application involves the recovery of hydrogen gas. The low molecular weight of hydrogen and its explosive nature create challenges.
In this application, the moisture from the filtrate receiver of a rotary vacuum filter is collected and fed back into the system. If a plant upset occurs, such as the failure of the filtrate pump, slugs of liquid can carry over into the vacuum system. Soft solids from the filter can also enter the vacuum system. In both cases, the liquid and soft solids will not damage the liquid ring vacuum pump, improving the overall reliability of the vacuum filtration system. A variety of seal liquids compatible with the process vapors may be selected in order to minimize contamination of gases extracted during the filtration process.
The vacuum system is used in a batch process to recover solvents through evaporation at a maximum sustainable rate. During later portions of the cycle, a compatible seal liquid can be used to extract residual solvents.
Vinyl Chloride Monomer
In the monomer recovery system, unreacted vinyl chloride is transferred into a holding tank. The vacuum system scavenges gas out of the PVC and delivers it to the compressor at or near atmospheric pressure. A single stage compressor system then compresses the gas for condensation and storage as a pressurized liquid.