Biomass-integrated gasification fuel cell systems – Part 1: Definition of systems and technical analysis Florian P. Nagel, Tilman J. Schildhauer*, Serge M.A. Biollaz Paul Scherrer Institut, Laboratory for Energy and Materials Cycles, Department General Energy, CH-5232 Villigen PSI, Switzerland article info Article history: Received 27 December 2008 Received in revised form 15 May 2009 Accepted 29 May 2009 Available online 17 July 2009 Keywords: SOFC Model Biomass Gasification System analysis B-IGFC Sulfur abstract The combination of biomass gasification with fuel cells is commonly referred to as Biomass-Integrated gasification fuel cell systems (B-IGFC). In this two-part system analysis, we investigate seven B-IGFC systems and four solid oxide fuel cell (SOFC) designs with a system power output of around 1 MW el . In this part, we define the B-IGFC systems and asses their technical feasibility using a finite volume based SOFC model and ASPEN PLUSÔ models for the simulation of the gas processing. It is found that the low operational temperature of the ZnO employed for the H 2 S removal in all systems requires an additional humidification of the producer gases (PG) to avoid carbon deposition. Diluted PGs require highly active anode catalysts to yield low activation losses and satisfying mean current densities. The air-to-fuel ratio required to maintain the operational temperature of the different cell designs generally increases with decreasing internal reforming potential of the producer gases. In this respect, counter-current cells are less sensitive than co-current cells. The maximum solid temperatures and temperature gradients resulting from the operation of SOFCs with producer gases are lower than with pre-reformed natural gas. ª 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved. 1. Introduction With an expected growth of the worldwide installed capacity of biomass power plants of approx. 70 GW by 2030, biomass will increasingly play an important role for heat and power generation, [1]. Despite efficiencies up to 25%, the state-of-the- art large scale technology based on grate fired boilers and steam cycles will hardly allow for the exploitation of the potential of biomass as power generation feedstock due to the lack of customers for the byproduct heat and due to logistic issues that render economic operation difficult. Small scale steam cycle based biomass plants can be used in residential heating but suffer from high specific investment costs and low electric efficiencies, again making economic operation difficult. Combined heat and power (CHP) biomass plants based on gasification technology are widely considered as promising approach regarding a soon market penetration. This is because the gasification technology enables the appli- cation of gas engines, gas turbines or fuel cells as power generation devices with high efficiencies at small to large scale. First generation gasification based CHP plants employ- ing gas engines are operating commercially, [2,3], and the application of gas turbines has also been demonstrated on full plant scale, [4]. Especially for CHP plants in the range of 1 MW el , fuel cells have drawn a lot of interest in the past years due to their higher efficiency than gas engines and gas turbines. The combination of biomass gasification with fuel cells is commonly referred to as biomass-integrated * Corresponding author. Tel.: þ41 56 310 27 06; fax: þ41 56 310 21 99. E-mail address: tilman.schildhauer@psi.ch (T.J. Schildhauer). Available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/he 0360-3199/$ – see front matter ª 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.ijhydene.2009.05.125 international journal of hydrogen energy 34 (2009) 6809–6825