Purification of hydrogen gas by diffusion through a palladium sheet.
Show that the number of kilograms of hydrogen that pass per hour through a 5-mm-thick sheet of palladium having an area of 0.20 m2 at 500°C is 2.6x10-3 kg/h.
Assume a diffusion coefficient of 1.0 ´ 10-8 m2/s, that the respective concentrations at the high- and low-pressure sides of the plate are 2.4 and 0.6 kg of hydrogen per cubic meter of palladium, and that steady-state conditions have been attained.
This problem calls for the mass of hydrogen, per hour, that
diffuses through a Palladium sheet :-
M = JAt = - DAtC/
x
= - (1.0 * 10-8 m2/s) (0.20 m2)
(3600 s/h) [(0.6 - 2.4 kg /m3) / 5 * 10-3 m)]
= 2.6 × 10-3 kg/h
Where, J = the diffusive flux, kg/(m^2 * s)
D = the diffusion coefficient, m^2/s
C/
x =
the concentration gradient, kg/m^4
Purification of hydrogen gas by diffusion through a palladium sheet. Show that the number of kilograms...
7.6 The purification of hydrogen gas by diffusion through a palladium sheet was discussed in Section 7.3. Compute the number of kilograms of hydrogen that pass per hour through a 5-mm- thick sheet of palladium having an area of 0.25 m at 500°C, Assume a diffusion coefficient of 1.0 × 10-3 m2/s, that the concentrations at the high- and low-pressure sides of the plate are 2.4 and 0.6 kg of hydrogen per cubic meter of palladium, and that steady-state conditions...
The purification of hydrogen gas is possible by diffusion through a thin palladium sheet. Calculate the number of kilograms of hydrogen that pass per hour through a 1.6-mm-thick sheet of palladium having an area of 0.45 m2 at 500°C. Assume a diffusion coefficient of 1.9 × 10-8 m2/s, that the concentrations at the high- and low-pressure sides of the plates are 4.3 and 0.60 kg/m3 of hydrogen per cubic meter of palladium, and that steady-state conditions have been attained.
7. Compute the number of kilograms of hydrogen (M), which pass per hour through a 3-mmuthick sheet of palladium having an area of 0.30 m at 450 2.5 x 10 mils. The concentrations at the high and low pressure sides of the plate are 2.5 and 0.5 kg of hydrogen per cubic meter of palladium. Consider that steady-state conditions have been C. Assume a siffusion costficisnt (D) of AM attained. (20 pts) At XA-XB
1. Problem 5.8 Purification of hydrogen gas by diffusion through a Pd sheet is discussed in part 5.3. Compute the number of kg of hydrogen that can pass per hour through a 6- mm sheet of PD having surface area 0.25 m2 at 600 C. Diffusion coeff=1.7 x 10-8 m2/sec. (rest is in the book)
CompuHHU number 엽 Kilograms (06 hydrogen (M) which Pass ρer hour through a 3 mm thick Palladium hayınơ an area Sheet Assume di oukficnt CD) ffusionc 2.5 x 10-1 mils. Thc conc entrations t the higb and low pressure sidus o hyclrogen per cubic metev pallacdium Censider hat steady- state cenditions have been aHained Са-Св
Problem 5.10
A sheet of BCC iron 4.9-mm thick was exposed to a carburizing
atmosphere on one side and a decarburizing atmosphere on the other
side at 725°C. After having reached steady state, the iron was
quickly cooled to room temperature. The carbon concentrations at
the two surfaces were determined to be 0.011 and 0.0074 wt%.
Calculate the diffusion coefficient if the diffusion flux is 2.6 ×
10-8 kg/m2-s, given that the densities of
carbon and iron are 2.25 and...
Problem: When alpha-iron is subjected to an atmosphere of hydrogen gas, the concentration of hydrogen in the iron, CH (in weight percent), is a function of hydrogen pressure, PH2 (in Mpa), and asbsolute temperature (T) according to Ch= 1.34 x 10-2 sqrt(PH) exp(- (27.2KJ/mol) /RT) Consider a thin iron membrane with the thickness and temperature listed below. Calculate the flux in (kg/(m²-s)) through this membrane if the hydrogen pressure on one side of the membrane is 0.17 MPa, and on...
Problem: When alpha-iron is subjected to an atmosphere of hydrogen gas, the concentration of hydrogen in the iron, CH (in weight percent), is a function of hydrogen pressure, PH2 (in Mpa), and asbsolute temperature (T) according to CH= 1.34 X 10-2 sqrt(PH2) exp(- (27.2KJ/mol) / RT) Consider a thin iron membrane with the thickness and temperature listed below. Calculate the flux in (kg/(m2-s)) through this membrane if the hydrogen pressure on one side of the membrane is 0.17 MPa, and...