I would like to carry out a NO reduction reaction involving carbon fibers and NO with out using oxygen and reducing gases such as H2, CO, NH3, urea and hydrocarbons. The feed contains NO diluted with He to achieve the desired concentration levels. A fixed bed of carbon fibers will be used to carry out the reduction. How could one calculate the GHSV in that case. Kindly suggest me how to calculate that. Thanks in advance.
GHSV is gas hourly space velocity. To calculate this parameter, you should have the flow rate of feed gas (involved inert and main components). Then, GHSV is the ratio of gas flow rate in standard condition to the volume of the bed (only active phase i.e. catalyst).
The GHSV of either total gas flow including the inerts or just the reacting gas species, can be calculated by taking the ratio of the respective volumetric gas flow at STP conditions (taken at 298 K, 1 atm) to the volume of the bed of the carbon fibres (taking i.d. of reactor & the bed height including the height occupied by the packing materials on which the C fibres might be dispersed for a tubular flow reactor). ;)
Hi
Gas Hour Space Velocity= volumetric flow rate (or feed flow rate)/ Volume of the catalyst
To calculate, for example
1- Calculate the volume of cylindrical reactor =
Where r=3mm, h=0.5 cm
V= (0.5) = 0.1413 cm3
By substituting in this low
Gas Hour Space Velocity= volumetric flow rate (or feed flow rate)/ Volume of the catalyst
Space Velocity= *60 =35,372 h-1
Have a very good day and best of luck
Hey Ahmed it should be
Gas Hour Space Velocity= Volumetric flow rate (or feed flow rate)/ volume of the catalyst
Gas hourly space velocity (GHSV) = Volumetric flow rate of reactant or exhaust gas/External volume of catalyst monolith.
For a cylindrical section, volume of catalyst monolith = pie.r2.h
Dear David.
I am sorry I dont know the case of GHSV for monoliths. But the active surface of a monolith is the internal surface of the tubes. WHSV is a practical measure of the inverse of the contact time, the internal void volume of the monolith should appear somehow.
If you look at monoliths reactors in Chemical Reactor Design (Peter Harriott, M. Dekker, 2003), you find the following definition:
Space Velocity in s-1= gas flowrate/volume = uA/LA = u/L ( u= Superficial velocity of gas, m/s; L = monolith tube length, m; A= total frontal area), where u = Q/A, with Q at STP conditions. Then Harriott gives, for catalytic combustion, GHSV = 10,000- 200,000 h-1.
I would take that definition. Thas is similar to what you say, except that flowrate of gas is taken.
GHSV = STP Gas superficial velocity (m/h)/Length of tubes (m). At least this definition is taken from a serious reference (Harriott)
FR
I wonder how could I calculated the total gas flow if only the flow rate of inert gas is given. it is hard to know the Volumetric flow rate of reactant or exhaust gas
- Badges
- Science topic
- Similar topics
- Engineering
- Chemical Engineering