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[JDC]

Anybody can help me about this definition?

[luuquocdai]

Dear JDC

LHSV means LIQUID HOURLY SPACE VELOCITY
For example, in Catalytic Reforming Process:
Space velocity is defined as the amount of naphtha processed over a given amount of catalyst over a given length of time. The space velocity is an indication of the residence time of contact between reactants and catalyst. When the hourly volume charge rate of naphtha is divided by the volume of catalyst in the reactors, the resulting quotient, expressed in units of 1/h, is the liquid hourly space velocity (LHSV). Alternatively, if the weight charge rate of naphtha is divided by the weight of catalyst, the resulting quotient, also expressed in units of 1/h, is the weighted hourly space velocity (WHSV). Although both terms are expressed in the same units, the calculations yield different values. Whether LHSV or
WHSV is used depends on the customary way that feed rates are expressed in a given location.
Where charge rates are normally expressed in barrels per stream day, LHSV is typically used. Where the rates are expressed in terms of metric tons per day, WHSV is preferred.
Space velocity together with reactor temperature determines the octane of the product. The greater the space velocity, the higher the temperature required to produce a given product octane. If a refiner wishes to increase the severity of a reformer operation, she or he can either increase the reactor temperature or lower the space velocity. A change in space velocity has a small impact on product yields when the WAIT is adjusted to maintain constant severity. Higher space velocities may lead to slightly higher yields as a result of less time available in the reactors for dealkylation reactions to take place. This advantage is partially offset by the higher rate of hydrocracking reactions at higher temperatures.

If you have any question about LHSV, please reply.
Good luck.
LuuQuocDai
luuquocdai@gmail.com