Fig. 1. Schematic diagram of the apparatus (Micromeritics’
AutoChem 2950HP).
The measuring system consists of the following elements:
- – an unit called by manufacturer the sample tube; the sample tube is
U-shaped and consists of two elements that are inseparably connected,
a front-end part of element with larger diameter is directly connected
with the 6-way valve, similarly to tail-end part of element of smaller
diameter; the element of larger diameter can work empty or it can be
filled by catalyst, sorbent etc. (more information can be find on the
manufacturer’s website)
- – the 6-way valve
- – the sample loop
- – steel pipes
- –thermal conductivity detector (TCD)
- – helium gas cylinder
- – nitrogen gas cylinder
- – computer.
The experiments were conducted in New Chemical Synthesis Institute,
Pulawy (Poland) at each combination of the following process parameters:
- pressure: 2.00×105, 3.00×105 , Pa
- temperature: 313.15, 333.15, 353.15, K
- volumetric rate (at STP): 3.33×10-7 ,
5.00×10-7 , m3/s
The volume of sample loop was constant and equal to
2.50×10-7 m3.
The system was flushed for 15-30 minutes with a constant flow of helium
until a stable TCD signal was received. At the same time, the volume of
sample loop was flushed also with a constant flow of nitrogen. Next, the
6-way valve was opened to allow the flow of helium with the constant
volumetric flow rate through the system and the TCD signal was recorded.
In this study, experiments were carried out with the empty sample tube
and with the packed sample tube. The sample tube was filled according to
the Temkin’s concept (Temkin and Kul’kova[15]), i.e., the sample
tube was alternately filled with zinc oxide sorbent tablet PSC, with
glass ball, again with zinc oxide sorbent tablets PSC, again with glass
ball, etc. Sorbent tablets with average diameter and height of 4.8 mm,
and glass balls with average diameter of 5.1 mm were used. As a result,
a bed of porosity ɛe equal to 0,75 is obtained.