Transcript Fuel Processing - Ministry of Power

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