Developing Clean Technologies: The Design, Construction and Automation of a Pressure Swing Adsorption (PSA) Pilot-Plant for CO2 Adsorption
Sustainable process-product development & green chemistry
Sustainable & Clean Technologies-I: Extraction & Remediation (T1-4P)
Keywords: adsorption, PSA, automation.
Environmental restrictions on pollution have stimulated research on technologies for both controlling and reducing CO2 emissions. Furthermore, CO2 has been used for oil recovery in mature fields, provided that CO2 capture, separation, drying, compression and transportation are economically feasible. This CO2 will not only enhance oil recovery but also contribute to the control of environmental pollution, by remaining fixed in the oil reservoir.
PSA adsorption is a process that has shown good potential for CO2 separation and purification from gaseous streams. However, if this CO2 is later to be used in industrial applications PSA presents an additional difficulty, since, contrary to its usual applications, the desired product (CO2) is the adsorbed substance. Since CO2 may be present in high concentrations in these gaseous streams, the adsorbent bed will rapidly saturate, due to the great amount of the adsorbed substance. This means that desorption must be fast, in order to allow the continuous operation of the PSA unit, requiring a complex sequence of cyclical manoeuvres, only possible through automatic control.
This research work is aimed at the development, design, construction and automation of a PSA pilot-plant for CO2 adsorption from flue gas streams. The pilot-plant consists of two columns, operating at alternating cycles of adsorption and regeneration (desorption) and is fully automated, which allows an adequate control of these cycles by on-line opening and closing pressure and flow control valves.
The automatic PSA pilot-plant is now being used in evaluations of commercially available zeolites for CO2 adsorption. This also involves further developing PSA technology for this kind of application, in order to determine parameters such as optimum cycle times (adsorption and desorption) and operating conditions (pressure and temperature and gas flow rate) as well as adsorbent bed pressure drop.
Results already obtained show a very good performance of the PSA pilot-plant, designed and constructed in this research work, for CO2 adsorption. However, this requires specific operating conditions for each cycle (adsorption and desorption) so as to maximize CO2 output.
Presented Monday 17, 13:30 to 15:00, in session Sustainable & Clean technologies - I: Extraction-Remediation (T1-4P).
