Flexible operation of coal fired power plant integrated with post combustion CO2 capture using model predictive control

The growing demand for CO2 capture from coal-fired power plant (CFPP) has increased the need to improve the dynamic operability of the integrated power generation-CO2 capture plant. Nevertheless, high-level operation of the entire system is difficult to achieve due to the strong interactions between the CFPP and post combustion CO2 capture (PCC) unit. In addition, the control tasks of power generation and CO2 removal are in conflict, since the operation of both processes requires consuming large amount of steam. For these reasons, this paper develops a model for the integrated CFPP-PCC process and analyzes the dynamic relationships for the key variables within the integrated system. Based on the investigation, a centralized model predictive controller is developed to unify the power generation and PCC processes together, involving the key variables of the two systems and the interactions between them. Three operating modes are then studied for the predictive control system with different focuses on the overall system operation; power generation demand tracking and satisfying the CO2 capture requirement. The predictive controller can achieve a flexible operation of the integrated CFPP- PCC system and fully exert its functions in power generation and CO2 reduction

Renewable hydrogen utilisation for the production of methanol.

Electrolytic hydrogen production is an efficient way of storing renewable energy generated electricity and securing the contribution of renewables in the future electricity supply. The use of this hydrogen for the production of methanol results in a liquid fuel that can be utilised directly with minor changes in the existing infrastructure. To utilise the renewable generated hydrogen for production of renewable methanol, a sustainable carbon source is needed. This carbon can be provided by biomass or CO2 in the flue gases of fossil fuel-fired power stations, cement factories, fermentation processes and water purification plants. Methanol production pathways via biomass gasification and CO2 recovery from the flue gasses of a fossil fuel-fired power station have been reviewed in this study. The cost of methanol production from biomass was found to lie in the range of 300–400 €/tonne of methanol, and the production cost of CO2 based methanol was between 500 and 600 €/tonne. Despite the higher production costs compared with methanol produced by conventional natural gas reforming (i.e. 100–200 €/tonne, aided by the low current price of natural gas), these new processes incorporate environmentally beneficial aspects that have to be taken in

Design and evaluation of a high-density energy storage route with CO2 re-use, water electrolysis and methanol synthesis

In the context of the Energy Transition, electricity storage ranging from seconds to seasons is needed to increase the integration of variable renewables sources. The power-tofuel process uses a liquid energy vector with high energy density for long-term energy storage. In the present work, we simulate the power-to-methanol process in Aspen Plus. Then, we use heat integration to increase the conversion efficiency from 40.1 to 53.0 %, evidencing large improvement potential thanks to process integration. Further work includes experimental design and development of control strategies