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AN OVER VIEW OF FUEL PROCESSOR TECHNOLOGIES FOR FUEL CELL APPLICATIONS K.Venkateshwarlu, T.Krishnudu and K.B.S.Prasad Indian Institute of Chemical Technology Hyderabad- 500 007, India Fuel Processing Fuel Processor Gasification of solid fuels C + O2 C + H2O C + CO2 CO + H2O CO + 3H2 Generic Types Second generation CO2 CO + H2 2CO CO2 + H2 CH4 +H2O Moving bed Fluidized bed Entrained bed BGL Shell Texaco KRW HT Winkler and many more Steam Reforming CxHy + x H2O x CO + (x + y)/2 H2 CxHyO + (2x-1)H2O n CO2 + (2n-1+(m/2))H2 Catalytic system: CuO/ZnO, CuO/SiO2, CuO/ZnO/SiO2 For Methanol: 250-2600C Ethanol : >3000C Advantages : Maximum Hydrogen generation Disadvantages: Indirect Heat transfer Partial Oxidation CxHy + x/2 O2 x CO + y/2 H2 Advantages: Any type of hydrocarbon Direct Heat transfer Disadvantages: Low H2 production Dilution of gas with N2 Soot formation Auto thermal Reforming CH4 +H2O CO+3H2 H=+206.16 kJ/mol CH4+1/2O2 CO+2H2 H= -36 MJ/kmol Combination of Steam Reforming and partial oxidation Reactions are balanced in such a way net energy requirement is Zero (H = 0) Catalytic decomposition CH3OH 2 H2 + CO • Mostly suitable for Alcohols • Soot formation and carbon deposition for Hydrocarbons Desulphurisation Gas phase Desulphurisation ZnO + H2S ZnS (s) + H2O (g) 2 to 3 kg ZnO sufficient for one year Automobile operation Liquid Fuel Desulphurisation Gasoline 30-40 ppm Adsorption Chemical reaction 1-2ppm Sulphur For high sulphur Fuels hydro treatment followed by gas phase Desulphurisation High temperature & Low temperature Shift reaction CO + H2O HT Shift: CO2 + H2 Iron and Chromium Oxide Catalyst. Temperature 350-4500C LT Shift: Copper and Zinc Oxide Catalyst. Temperature 200-2500C Carbon Monoxide Clean-up Chemical • Preferential oxidation CO + ½ O2 CO2 H2 + ½ O2 H2O Pt, Pd, Rh, Ru are catalysts (~ 1200C) • Methanation CO + 3 H2 CH4 + H2O Ru, Rh are catalysts. Temperature 100-2200C Physical • Pressure Swing Adsorption (PSA) • Membranes-Metal or polymeric • Solvent Absorption Fuel Processor using Membrane Reactor Fuel Air H2 O Primary Reformer H2,CO,N2 CO + H2O = CO2 + H2 ----------------H2 H2, CO2, N2 To Fuel Cell Novel Reformer Technologies Solvent enhanced reforming Calcium Oxide along with steam reforming catalyst is added. Composition 90% H2, 10% CH4, 0.5% CO2 and <50ppm CO Downstream processing load is reduced. Ion transport membrane reforming Oxygen on one side of the membrane (1-5 psig) Methane & steam on the other side of the membrane (100-500 psig) Plasma Reformers HT plasma (3000-100000C) is generated by electric arc in plasmatron 10 kW Reformer at IICT • Methanol – Steam Reformer using indigenous catalyst developed • Reformer Integrated with a 500W PEM fuel Cell • Funding Agency: MNES (Rs. 60 lakhs) Present Status of Work - Project : 50 kw fuel cell power pack for technology demonstration - Outlay : Rs. 234 lakhs. - Funding agency : MNES Conclusions Presently liquid fuels like gasoline & Diesel which contain high aromatic content and sulfur are not very suitable for on board applications. Availability of Methanol & Ethanol for fuel uses are inadequate. For use of natural gas economic and environmental benefits are to studied in detail. A multi fuel Reformer needs to be developed (For fuels with small range of C/H ratio). Thrust areas for R&D • Development of reactors/separators (Membrane) • Indigenous Catalyst development