Efficient Amine-based Carbon Capture in a Power-to-Jet process under varying Renewable Electricity supply

To comply with the outcomes of the Climate Change Conference in Paris (COP 21), the ever-growing greenhouse gas (GHG) emissions has to be drastically reduced. With the soaring growth rates of GHG emissions in the aviation sector, the need for a near zero-net greenhouse emission alternative is essential. The novel concept of the Power-to-Jet pathway directly utilizes renewable electricity, carbon dioxide and water to synthesize a sustainable kerosene fuel that chemically resembles the one produced from fossil sources, having ‘Drop-in’ capability allowing the use and distribution within existing architectures. In the Power-to-Jet process, hydrogen is produced via water electrolysis. Captured CO₂ (from rich point sources) then reacts with hydrogen to produce the intermediate methanol, before being upgraded to the final synthetic jet fuel along with by-products (Schmidt et al., 2012). With fluctuating electricity inputs due to the variability in photovoltaic and wind power generation, the process units within the Power-to-Jet process have to be adjusted at each time-instant to satisfy the production constraints. To find the best operating strategy for these fluctuating conditions, dynamic models are needed. In this work, we will propose a model that describes the dynamic behaviour of the carbon capture section in the Power-to-Jet process. Several dynamic scenarios can be introduced for the carbon capture rate by altering the lean solvent concentration, flue gas flow rates and re-boiler duty. The dynamic information obtained from the simulations (such as: Open loop gain, time constants and dead time) can be used to device an appropriate control scheme under varying electricity inputs, while satisfying all operational constraints.