Page 37 - Impiantistica industriale

PC
S
202
PV PV-202
-
PT-06 PC PC V37 – 3-Way Stg Top
Purge MFC S
V20 V19 V18 V17 V16
S S S S S PV-201 PV-201
F
V15 V14 V13 V12 V11
S S S S S
S
S Storage Column mn CV-201
g
a

e
Co
to
u
l
r
V10 V9 V8 V7 V6
S S S S S
S V5 S V4 S V3 S V2 S V1 PT-07 PC
PV-203 - Backfill
S
PT-05 PT-04 PT-03 PT-02 PT-01
V38 –
V38 – 3-Way Stg Bottom PV-203
CV-202
TT-01
TT-02
Removable jacket TT-03 V-178
Col 5 Col 4 Col 3 Col 2 Col 1
TT-04 MFM F
TT-05
CWS
V36 – 3-Way OffGas
CWR
V25 V24 V23 V22 V21
S S S S S CV-104
Vacuum Pump
S V30 S V29 S V28 S V27 S V26
Set @ 11 barG
V35 V34 V33 V32 V31 SV-101
S S S S S MV-101 MFC He
Legend Symbol Description Symbol Description MFC Ch 4
Symbol Description MFC Co 2
PT Pressure Transmitter TT Temperature Transmitter
S Proportional Valve Lab-PSA R&D P&ID_2021AP-UNINA-PSA01
PC Pressure Controller 3-way Valve
S Design: Amnis Pura
Solenoid Valve F Flow Transmiter/Controller Vacuum Pump Frederico Relvas Figure 3 - Schematic
Relief Valve CWS Cooling Water Supply Date: 21-04-2022
PSA Vessel CWR Cooling Water Return 5-Column PSAUNINA diagram of VPSA process
Non-return Check Valve H2 UNINA
experimental apparatus
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pressure played a key role in the overall PSA per- column, open or closed depending on the specifi c
formance. Results from their study indicate that the operation to be performed during the VPSA cycle.
methane purity of 97% could be achieved if the Moreover, one of the columns is equipped with
operating conditions are optimized. a thermal jacket, connected to a circulating ther-
In order to lower energy consumption, a team of mostatic bath, and fi ve thermocouples, distribu-
researchers experimented the biogas upgrading ted along the height of the column, to control the
using carbon molecular sieve adsorbent in two temperature of the bed and allowing performing
adsorption beds with a pressure of 5 bar . They breakthrough tests at different pressure and tem-
11
optimized the methane purity and recovery using peratures. Pressure transducers are located at
different adsorption times, reaching 97.5% and the top of each column for pressure reading and
90%, respectively. monitoring. The lower side compartment contains
In general, few experimental studies are carried the helium, methane and carbon dioxide mass fl ow
out with CO /CH gas mixture, while most of the controllers (MFC), along with the vacuum pump,
4
2
results reported in the literature derives from mode- which allows the columns to be regenerated at
ling data obtained starting from single-compound pressures lower than atmospheric.
experimental data. The upper side compartment contains the Electri-
cal Control Panel of the plant and the PLC, to con-
trol the valves, the MFCs and the vacuum pump,
Oiltech Activity through a graphic Excel interface.
The outlet gas fl ow (product and off-gas) are
In the described scenario, Oiltech has planning analyzed, using an external analyzer, to evaluate
a new experimental activity aimed at defi ning the the CO and CH composition.
4
2
best performing adsorbent in terms of CO adsorp-
2
tion capacity and selectivity, and its integration in a The ongoing experimental campaign is devoted to
VPSA cycle, together with a thorough optimization the following objectives:

of the operating parameters. • A full plant characterization and a complete
The VPSA lab-scale plant dedicated to the expe- set-up with the defi nition of a typical VPSA
rimental tests was purchased from Amnis Pura cycle;
(Portugal); it consists of several components, con- • Realization of breakthrough tests in single co-
tained in a structure (100 x 80 x 74 cm). lumn aimed at characterizing different adsor-
A picture of the plant is reported in Figure on page bents in terms of both thermodynamic (i.e.
32. adsorption isotherms) and kinetic behavior;
• Desorption tests, to verify the regenerability of
In the frontal compartment, fi ve cylindrical columns the adsorbent material and the rate and opti-
of stainless steel are positioned, with a height of mal conditions of the regeneration processes;
440 mm and an internal diameter of 30 mm. • Optimization of the VPSA cycle, especially in
Seven solenoid valves are associated with each terms of purity and methane recovery, starting
Impiantistica Italiana - Maggio-Giugno 2022 35 35