Low production cost and preferably being environmentally sound.
Able to convert the fuel to CO2 and H2O to the highest degree possible (ideal 100%) </li></ul>
Types of oxygen carrier: Category 1:Oxide based oxygen carrier Metal oxides-NiO,Fe2O3,Mn3O4, Support-Al2O3,SiO2,TiO2, Category 2:Sulphate based oxygen carrier CaSO4 SrSO4 BaSO4 (Ni/Cu/Mn/Co)Al2O4,ZrO2, MgAl2O4
Preparation of Oxygen Carrier: <ul><li>Water-based slurry of metal oxide or composite material in chemical powder form(< 10-6m)& small amount of polyacrylic acid as dispersant are prepared by ball milling for 24 h.
Polyvinyl alcohol is added to the slurry as binder.
Spherical particles are produced by freeze granulation after spraying into liq. Nitrogen.
Frozen water in particles are removed by sublimation in freeze- drier.
Particles are sintered between 950-1600`C for 6h
Finally they are sieved to obtain well-defined size. </li></ul>
Characterization index of oxygen carriers: <ul><li>Degree of oxidation/conversion </li></ul>X=m-mred/mox-mred where m= actual mass of sample mred =mass of sample when fully reduced mox =mass of sample when fully oxidized <ul><li>Oxygen ratio-maximum mass fraction of the oxygen-carrier that can be used in the oxygen transfer </li></ul>Ro=mox-mred /mox <ul><li>Rate Index-Comparison of reaction rates between different oxygen-carrier as the normalized rate </li></ul>rate index=60*100*(dw/dt)norm <ul><li>Crushing strength
Systems: </li></ul>1.autothermal chemical looping reformer system 2 . steam reforming using chemical-looping combustion <ul><li>Major route for production of hydrogen is </li></ul>through catalytic reforming of methane with steam. Hydrogen Production