Technical analysis of a simple cycle gas turbine with carbon capture storage.

Abstract

Since the ratification of the Paris agreement in December 2015 large part of the world has committed to taking drastic steps towards decarbonization. The introduction of variable renewable sources causes the increase for flexible energy supply. A conventional carbon emitting flexible energy supplier is the simple cycle gas turbine. Carbon capture technology which is appointed by the International Energy Agency as one of the key contributors towards decarbonization, has potential to decarbonize the simple cycle gas turbines. With the aim of finding cost-effective solutions this research performs a technical feasibility analysis of the carbon capture process on a simple cycle gas turbine. Post combustion carbon capture technology is selected for the framework. The post combustion carbon capture does not require major adjustments in the infrastructure opposed to oxy-fed or pre-combustion technologies. Within the post combustion technologies, as a first step, the multiple options are screened in literature and adsorption process is selected as most suitable for the simple cycle gas turbine. As a second step the sorbents of the adsorption process are screened in literature and hydrotalcite like compounds is selected as best suited sorbent. It shows relative low regeneration energy and high cyclic stability. The third step is finding a mathematical explanation for the sorbents sorption behaviour. Isotherm models mathematical explain the sorption behaviour of the sorbents. Multiple isotherm models are analysed and their ability to model the sorption behaviour of the sorbent is tested. The Langmuir isotherm model displayed the best fit to the sorbent and is adapted for temperature dependency. The carbon capture set-up coupled on to the simple cycle gas turbine is temperature swing adsorption process with fixed beds. The temperature in the column is low when CO2 enters the column and the CO2 is adsorbed on the sorbent. The temperature is increased so that the CO2 desorbs from the sorbent and can be separated from the flue gas. The fixed bed entails beds fixed in the column filled with the sorbent. The fourth step is analysing the size of the set-up using the isotherm model. The adsorption and desorption processes are analysed, and the size of the column is determined. The set-up is modelled in an optimistic way, due to simplification. Flue gas is considered as a single component, where it is multi component. Also, adsorption kinetics are excluded in the modelling, moreover only one sorbent is used due to limited data availability. Concluding the results show that the set-up is not feasible. The size of the column in the framework varies between 251 meters and 40 meters diameter with a 15 meters height. Improvement of the sorption capacity of the sorbent is suggested as best possibility for improving the feasibility of the set-up.