PRODUCTION OF HYDROGEN AND ELECTRICITY FROM COAL WITH CO 2 CAPTURE T.G. Kreutz 1 , R.H. Williams 1 , R.H. Socolow 1 , P. Chiesa 2 , G. Lozza 2 1 Princeton Environmental Institute, Guyot Hall, Princeton University, Princeton, NJ 08544-5263, USA 2 Dipartimento di Energetica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy ABSTRACT This paper summarizes a series of studies examining the prospective performance and cost of facilities that convert coal to H 2 , co-product electricity and a stream of concentrated CO 2 (for sequestration). Synthe- sis gas is produced via oxygen-blown, entrained flow coal gasification, quench cooled and shifted to (pri- marily) H 2 and CO 2 via sulfur-tolerant water-gas shift (WGS) reactors. Our focus is on separating H 2 from the syngas and processing the carbon-bearing raffinate/purge gas to produce electricity and CO 2 . We explore the use of novel inorganic membrane reactors for H 2 separation and compare their performance and cost with conventional gas separation technologies: CO 2 capture via solvent absorption followed by H 2 purification using pressure swing adsorption (PSA). This work highlights potential economic benefits of high system pressure, low H 2 purity, and co-sequestering CO 2 with sulfur-bearing waste gases, H 2 S and SO 2 . I. INTRODUCTION Carbon-free energy carriers, H 2 and electricity, are likely to play a critical role in a world with severe constraints on greenhouse gas emissions. Most fossil fuel decarbonization studies to date have focused on CO 2 capture in central-station electric power generation, which accounts for only ~30% of global CO 2 emis- sions. Much less is known about the prospects for producing CO 2 –free H 2 from fossil fuels. This paper pro- vides a very brief introduction to our research on the performance and cost of technologies for producing H 2 and/or electricity from coal with CO 2 capture; four detailed papers will be available [1,2,3]. Coal is a feed- stock of particular interest because of its relative abundance, high carbon intensity, and low cost. Coal-to-H 2 plants based on gasification have been studied by Doctor et al. [4] and the Parsons Power Group [5]. The former investigated “conventional” gas separation technologies - CO 2 capture via glycol absorption and pressure swing adsorption (PSA) for H 2 purification - while the latter considered an inorganic (ceramic mi- croporous) H 2 separation membrane reactor (HSMR) to produce H 2 and CO 2 . Our work compares these two approaches in a consistent thermodynamic and economic framework and explores the design space for HSMR-based plants, seeking to understand the conditions that might lead to lower cost for H 2 from coal. The study focuses on one particular inorganic membrane technology, a 60/40% Pd/Cu dense metal film (for which experimental permeance data are available [6]) and explores how the efficiency and H 2 costs for such plants are affected by design parameters such as: H 2 recovery (i.e. percentage of H 2 extracted by the mem- brane), H 2 purity, raffinate turbine blade cooling, and system pressure. For the base case calculations, the plant products are: H 2 suitable for use in a PEM fuel cell (99.999% purity, 60 bar), co-product electric power, and dry (20 ppmv H 2 O) supercritical CO 2 (at 150 bar) for pipeline transport and sequestration. II. SYSTEM DESCRIPTION The membrane-based plant is shown schematically in Fig. 1. In the conventional technology variant (not shown, but for base case parameters, see Table 1), the components downstream of the high-temperature WGS reactor are replaced by, in order: syngas cooler, low-temperature WGS reactor, H 2 S and CO 2 physical absorption units, pressure swing adsorption (PSA) module, purge gas compressor, and gas turbine combined cycle (GTCC) for co-product electricity generation. The systems studied use an abundant, low cost feed- stock and have essentially zero emissions. We seek simplified designs that minimize the cost of H 2 rather than maximize the system efficiency (e.g., by using syngas cooling via quench rather than more efficient and expensive high-temperature radiant/convective syngas coolers). System performance was modeled using Aspen Plus [7], GS [8], and Fortran (for membrane modeling). Production of Shifted Syngas. Common to both conventional and membrane-based systems are system components designed to produce partially shifted syngas. High volatility Colorado bituminous coal (73.4% C, 5.1% H, 6.5% O, 1.3% N, 0.6% S, 1.4% moisture, 11.7% ash; HHV=29.58 MJ/kg) is gasified in an O 2 - Prepared for the Sixth Greenhouse Gas Control Technologies Conference, Kyoto, Japan, September 30 - October 4, 2002.