desulphurisation hemant pandit, ranjan agrawal. dtu chemical engineering technical university of...
TRANSCRIPT
Desulphurisation
Hemant Pandit, Ranjan agrawal
DTU Chemical Engineering Technical University of Denmark
The wet FGD processCaCO3(s) + SO2(g) + 2H2O + ½O2 → CaSO42H2O(s) + CO2
Major reactions (Kiil, 1998)
● Absorption of SO2
● Oxidation of HSO3- to SO4
2-
● Limestone dissolution
● Gypsum crystallisation
Important parameters
● Desulphurisation degree
● Gypsum moisture content
● Gypsum impurity content (limestone etc.)
CHEC Annual Day, 2009 01.10.2009
Courtesy of DONG Energy
Wet Flue Gas Desulphurisation
1
DTU Chemical Engineering Technical University of Denmark
Oxy-fuel combustion
● Substitution of fuel air with oxygen
● Flue gas recycle in order to control
temperature/convective heat transfer
● Gas phase enriched in CO2 & H2O
● Capture and compression of CO2
Flue gas desulphurization
● Ensuring a clean product
– i.e. transport and geological storage considerations
● Wet FGD before compression (traditional)
● As part of the compression (research stage)
Courtesy of Vattenfall
The oxy-fuel concept
2 CHEC Annual Day, 2009
01.10.2009
DTU Chemical Engineering Technical University of Denmark
Fuel Processing
DTU Chemical Engineering Technical University of Denmark
Fuel Processor
DTU Chemical Engineering Technical University of Denmark
C + O2 CO2 C + H2O CO + H2
C + CO2 2COCO + H2O CO2 + H2
CO + 3H2 CH4 +H2O
Moving bed Fluidized bed Entrained bed
BGL Shell Texaco KRW HT Winkler and many more
Second generation
Generic Types
Gasification of solid fuels
DTU Chemical Engineering Technical University of Denmark
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
DTU Chemical Engineering Technical University of Denmark
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 1-2ppm Sulphur
For high sulphur Fuels hydro treatment followed by gas phase
Desulphurisation
Adsorption Chemical reaction
DTU Chemical Engineering Technical University of Denmark
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
DTU Chemical Engineering Technical University of Denmark
Desulphurization plant in Germany
DTU Chemical Engineering Technical University of Denmark
NEW MEXICO
DTU Chemical Engineering Technical University of Denmark
UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
DTU Chemical Engineering Technical University of Denmark
UNITED STATES OF AMERICA, Louisiana
DTU Chemical Engineering Technical University of Denmark