Singh A., Stephenne K. Shell Cansolv CO2 capture technology: Achievement from First Commercial Plant

Energy Procedia. — 2014. — 63. — p. 1678 – 1685.The Shell Cansolv proprietary DC-103 solvent is a regenerable amine based solvent, developed to capture carbon di-oxide (CO2) from any low pressure stationary source and produces a treated gas stream, lean in CO2. Cansolv DC-103 is a binary mixture comprised of 50 wt% of amine and 50% of water. One of the client’s chemical plant requires high concentrated CO2 as a raw material and steam as a energy for their manufacturing process. However, a projected maintenance shutdown at the company’s carbon dioxide supplier meant that the plant might have to suspend operations, or at least reduce capacity significantly, until the supplier came back on stream, a consequence that would have a serious impact on its revenues. The chemical plant was also dependent on an industrial neighbour for steam supply but had suffered costly supply interruptions owing to
unplanned boiler shutdowns. In order to avoid disruption to its plant operations, client developed a concept to become independent on steam and carbon dioxide supply to the chemical plant. It was proposed to build a natural gas fired boiler to generate 21 bar steam and capture CO2 from resulting flue gas. The Shell Cansolv CO2 capture technology was selected to capture CO2 from the flue gas, due to its low energy demand, low emission, no restriction on use of technology and a proposal to form a long-term partnership for improving the technology. The client entered into a licensing agreement for the use of the technology and a material supply agreement for the supply of the Cansolv absorbent DC-103. This marked the first commercial license agreement in the chemical industry for the Cansolv CO2 Capture System. Shell Cansolv CO2 capture technology helped client to become independent on CO2 and enable client to “individually steer” its chemical production. Cansolv DC-103 amine based CO2 capture technology was deployed to the chemical plant to capture up to 170 tonnes of CO2 per day, from a flue gas containing about 9-11% CO2 on a wet basis, coming out from a natural gasfired boiler. However, due to the limitation on boiler capacity, the plant runs at 120 tonnes of CO2 capture per day. The plant was started successfully in Q3, 2013 and since then, the Shell Cansolv CO2 capture plant has been running smoothly. The plant has provided a unique opportunity for Shell Cansolv to monitor the plant performance over a period of time, validate the design envelop, capture learnings and & optimize the design envelop further. The present article covers the following sections. Section 2 will discuss the process plant line-up, which includes pre-scrubber, absorber, water wash, regenerator lean flash, condensate flash and mechanical vapour compression (MVR). Section 3 will discuss the plant performance which includes CO2 capture rate, steam consumption, amine emission, CO2 purity, and performance of the Thermal Reclaimer Unit. Section 4 will summarize the learnings attained from the capture plant. Section 5 will cover the conclusion.