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What technologies are available to reduce the VOCs from the truck loading? Our truck loading is bottom loading type.
 
Answers
02/10/2007 A: KengYong Chan, Air Products & Chemicals, Inc, chanky@apci.com
Regardless of top or bottom loading, there is always a certain amount of vapour loss or VOC venting due to vapour displacement or temperature changes (loading into a hot ambient surface truck etc). In your case, it seems like this is a non-flammable liquid loading where there is no vapour return line back to the storage tank.
Recovering the VOC and then condensing it back to the storage tank is one method to reduce losses. Or else install some type of adsorption vessel (activated carbon is probably the cheapest) to trap the VOC before venting to open atmosphere. Low pressure at source (truck) and head loss across adsorption bed may be an operational issue.
Another cheaper alternative is the cold trap / vacuum method for vapour recovery. Vapour can be condensed via cold trap (coils immersed in liquid nitrogen bath container etc) and then recovered in a closed container/vessel (the container or vessel is pulled with a vacuum first to create the siphon effect). This is more applicable for small scale operations.......
22/09/2007 A: Amarjit Bakshi, Refining Hydrocarbon Technologies LLC, abakshi@rhtgulfcoast.com
The VOCs can be just about eliminated by using a vent compressor from the tank, and condensing that and sent back to storage as liquid.
This saves all the vapors and condenses those as liquid without any loss or emissions. At present with the price of oil at 80 $/bbl, major loss of hydrocarbon vapors during loading uploading is not economical. One can design a system to recover vent vapors during loading.......