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 , India

Fuel Processing

Fuel Processor

C + O 2 CO 2 C + H 2 O CO + H 2 C + CO 2 2CO CO + H 2 OCO 2 + H 2 CO + 3H 2 CH 4 +H 2 O Moving bed Fluidized bed Entrained bed BGL Shell Texaco KRW HT Winkler and many more Second generation Generic Types Gasification of solid fuels

Steam Reforming C x H y + x H 2 O x CO + (x + y)/2 H 2 C x H y O + (2x-1) H 2 O n CO 2 + (2n-1+(m/2)) H 2 Catalytic system: CuO/ZnO, CuO/SiO 2, CuO/ZnO/SiO 2 For Methanol: C Ethanol : >300 0 C Advantages : Maximum Hydrogen generation Disadvantages: Indirect Heat transfer

Partial Oxidation C x H y + x/2 O 2 x CO + y/2 H 2 Advantages:  Any type of hydrocarbon  Direct Heat transfer Disadvantages:  Low H 2 production  Dilution of gas with N 2  Soot formation

Auto thermal Reforming CH 4 +H 2 O  CO+3H 2  H= kJ/mol CH 4 +1/2O 2  CO+2H 2  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 CH 3 OH 2 H 2 + CO Mostly suitable for Alcohols Soot formation and carbon deposition for Hydrocarbons

Desulphurisation  Gas phase Desulphurisation ZnO + H 2 S ZnS (s) + H 2 O (g) 2 to 3 kg ZnO sufficient for one year Automobile operation  Liquid Fuel Desulphurisation Gasoline ppm 1-2ppm Sulphur For high sulphur Fuels hydro treatment followed by gas phase Desulphurisation Adsorption Chemical reaction

High temperature & Low temperature Shift reaction CO + H 2 O CO 2 + H 2 HT Shift: Iron and Chromium Oxide Catalyst. Temperature C LT Shift: Copper and Zinc Oxide Catalyst. Temperature C

Carbon Monoxide Clean-up  Chemical Preferential oxidation CO + ½ O2 CO2 H2 + ½ O2 H2O Pt, Pd, Rh, Ru are catalysts (~ C) Methanation CO + 3 H2 CH4 + H2O Ru, Rh are catalysts. Temperature C  Physical Pressure Swing Adsorption (PSA) Membranes-Metal or polymeric Solvent Absorption

Primary Reformer CO + H 2 O = CO 2 + H H 2 Fuel Air H 2 O H 2,CO,N 2 H 2, CO 2, N 2 To Fuel Cell Fuel Processor using Membrane Reactor

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 ( psig)  Plasma Reformers HT plasma ( C) 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