(734d) A Pilot Plant Study of a VSA Process for CO2 Capture From Power Plant Flue Gas

Science and Engineering Research Council (SERC) of Singapore in 2009 launched a research programme on Carbon Capture and Utilization (CCU). One project under the programme is entitled, Development and Demonstration of an Adsorption-based System for Post-combustion Carbon Capture, which will be the basis of this presentation. It is a collaborative project among the adsorption and process systems research groups at National University of Singapore (NUS), Nanyang Technological University (NTU) and Institute of Chemical and Engineering Sciences (ICES).

A detailed non-isothermal and non-isobaric simulation model has been developed to simulate the performance of a Vacuum Swing Adsorption (VSA) Process to capture and concentrate CO₂ from power plant flue gas. As a start, dry flue gas containing 15% CO₂ in N₂ has been chosen as the feed. A detailed parametric study of a simple 4-step cycle has been conducted using unary isotherms of these gases on Zeochem 13X measured gravimetrically, fitted to dual site Langmuir isotherm and macropore molecular diffusion controlled transport mechanism verified with breakthrough experiments. A pilot plant has been designed based on these preliminary results from the simulation study. The plant uses 1 m long columns with 0.3 m internal diameter and is rated to capture ~ 3 tonnes CO₂ per cubic meter of adsorbent per day.

Construction of the pilot plant is complete and it is currently being commissioned. Operated from a PLC, the pilot plant is designed to track all the process variables as a function of time. Special attention has been given for tracking power consumption by the vacuum pumps so that a reliable estimate of energy penalty may be obtained. Over the next few months, we expect to validate the simulation model with pilot plant data. The verified simulation model will then be used to optimize the process economics. The pilot plant results and process economics will be presented at the meeting.