Pretreatment of biomass plays an important role in IGCC processes. Optimized operating conditions improve overall process eciency, product diversity and producergas composition. This project focuses on the pretreatment of spruce woodbiomass using high pressure superheated steam in a packed bed reactor with heated walls. The objective is to optimize the operation for ecient energy consumption and uniform thermal treatment of wood particles along the reactor. For this purpose,two models have been developed: Single-phase superheated steam in porous media where local thermal nonequilibrium condition prevails, Multi-phase ow in porous media.The rst model investigates the essential parameters to be taken into accountto ensure a uniform thermal treatment as the pyrolytic agent i.e. steam exchanges heat with solid particles. It is found that solid matrix and steam reach thermalequilibrium at early stages of the process however, sharp decrease in uid temperatureis observed. This trend is believed to be aected mostly by uid inlet velocity and solid initial temperature. The model suggests that the initial solid temperaturedoes not play an important role compared to the uid inlet velocity.The focus of the second model is optimization of reactor heat source to avoidthe complications attributed by a two-phase ow. The model can predict the phasesaturation of uid in the porous media along with the pressure and velocity prolesfor a given inlet ow condition and reactor heating power. A reactor with heatsource localized at the inlet is recommended to satisfy the thermal requirements ofthe system.Steam treatment of biomass at elevated pressures is a novel technology whichis believed to bring about many advantages for IGCC process. However, detailed optimization is necessary to benet from these advantages.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kth-238585 |
| Date | January 2018 |
| Creators | Kamalian, Amirali |
| Publisher | KTH, Skolan för kemi, bioteknologi och hälsa (CBH) |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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