||Analysis of a gasification plant fed by woodchips integrated with SOFC and Steam cycle
||Rokni, Masoud (Thermal Energy Systems, Department of Mechanical Engineering, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
||Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
||Conventional biomass plants for electric power generation are not effective in terms of system performance. A gasification plant integrated with SOFC and steam cycle has been studied; calculations have proved a significant increase of plant efficiency.
Simulations have been run by means of DNA (Dynamic Network Analysis) a component-based simulation tool for energy systems analysis developed at the Thermal Energy Systems department (DTU).
Two different plant configurations have been studied. In the first no hybrid recuperation is considered; efficiency is 47.74%. Second configuration (hybrid recuperation) shows a significant increase in terms of performance (53.09%). Optimized system is also analyzed; efficiency is up to 57%.
Alternatively steam cycle is replaced by a Kalina cycle; ammonia-water mixture has been added as a new fluid inside DNA library. Plant efficiency for optimized system is 52.53%. It has been concluded that better solution is to integrate woodchips gasification and SOFC with a steam cycle (higher efficiency).
This solution has also been investigated by means of thermoeconomic analysis; simulations have been run with EES (Engineering Equations Solver).
Equations allow also to calculate plant exergy losses; major sources of inefficiency are: gasifier, cathode preheater and burner. An exergetic efficiency of 50% is calculated.
With a woodchips price of 165 [€/ton], a price of electricity of 0.40 [€/kWh] is obtained. Future price of SOFC is supposed to decrease by lowering SOFC operating temperature: with a purchase cost of 300 [€/kW] price of electricity is around 0.19 [€/kWh].
The analyzed plant is proved to be theoretically feasible by an energetic and thermoeconomic point of view.
||Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
||SOFC, gasification, steam cycle, hybrid cycles, Kalina cycle
Creation date: 2010-09-15
Update date: 2011-06-27