Implementation of Dry Hydrated Potassium Carbonate Carbon Capture
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Sustainable energy systems (MPSES), MSc
Publicerad
2024
Författare
Jacobson, Kajsa
Törnqvist, Frida
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
In near future, Waste-to-Energy (WtE) plants are required to reduce their CO2
emissions drastically in order to achieve carbon neutrality. Since energy recovery
from waste likely will persist, a necessary mitigation strategy is to implement a
Carbon Capture and Storage (CCS) technology on site. In contrast to conventional
methods, Dry Hydrated Potassium Carbonate (DHPC) carbon capture can provide
low energy penalty, easy regeneration and opportunities to integrate the excess heat
in the District Heating (DH) system. The DHPC process is based on solid absorp tion and performed by circulating a sorbent, potassium carbonate, K2CO3, between
two fluidized bed reactors. This thesis performs a case study which implements the
DHPC process at Renova’s WtE plant in Sävenäs.
The application of the DHPC carbon capture is investigated by modeling the WtE
and the DHPC process, using the simulation tools Ebsilon and Aspen Plus, re spectively. When modeling the capture process according to the design proposed
in research, an alternative design of the regeneration reactor is discovered able to
reduce its steam demand, the fluidized bed heat exchanger (FBHE). The FBHE
configuration as well as the original design of the DHPC process, lay the foundation
for the construction of multiple system cases to analyse throughout the project. The
potential for heat integration, in the different cases, is evaluated by performing a
pinch analysis which creates the basis for retrofitting the WtE plant. In addition,
the energy performance, reactor sizes and capture cost are investigated.
The thesis reveals that the DHPC process is a promising CCS method for Renova,
especially the case using a FBHE. In particular, integrating this capture process
increases the delivery of DH by 2.27-3.29% while reducing the electricity production
by 2.09-8.51%, depending on the pressure level of the utilized steam. As a result,
the total energy efficiency of the WtE plant is expected to increase by 1.47-1.57%,
after applying the FBHE DHPC processes. In addition, the economic evaluation
indicates on low capture costs including operational costs which are relatively in sensitive in terms of future energy prices.
In conclusion, it is recommended for Renova to investigate the DHPC process fur ther, since by choosing this method, the WtE plant can almost maintain its normal
production of electricity and DH. However, in order to enable a future implementa tion of the process, it is of importance to verify the function of the FBHE reactor
and evaluate the physical footprint of the system in the light of the found reactor
sizes as well as the practical feasibility of the proposed retrofits.
Beskrivning
Ämne/nyckelord
CCS , WtE , DHPC , Process Modeling , Heat Integration , Pinch analysis , FBHE