LHSV meaning in oil and gas

Liquid Hourly Space Velocity

Liquid hourly space velocity is a measure of how long it takes to process one reactor volume of liquid (or gases) fed to a chemical reactor. In its simplest term, it can be regarded as the reciprocal of space time. However, it must be noted that for space time, the reactor inlet conditions are almost always used while for LHSV, it is the industry standard to use the flow rate of liquid at 60 F or 75 F even though the feed entering the reactor might be a vapour at a much higher temperature. LHSV is calculated by dividing the flow rate (normalised to that of a liquid feed at 75 F or 60 F) by the voulme of the reactor. As the name suggests, the unit of time in the flow rate is hour.