Catalytic conversion of synthesis gas: Methods and applications Ulla Lassi HighBio projektiseminaari 18.11.2008
Introduction Synthesis gas is traditionally produced from fossil fuels (GTL) HighBio project aims at producing and utilisation of biomass-derived synthesis gas (wood gas) Catalytic conversion of biomass (BTL) enables the utilisation of wood gas (syngas), i.e. in the production of (new) chemicals, fuels and fuel derivatives
Catalyst and catalysis A catalyst is a substance that increases the rate at which chemical reaction approaches equilibrium without itself becoming permanently involved in the reaction. Catalysis is the art of manipulating chemical molecules in order to facilitate their transformation along the desired reaction pathway (selectivity).
How does a catalyst work?
Catalysis More than 90% of all industrial chemical reactions are catalysed (homogeneous catalysts, heterogeneous catalysts) Catalysis can be applied in e.g.: Production of (new) chemicals and chemical products Pollution prevention cf. Holmgren, A. 1998
Catalyst The catalysts consists of three main components: Substrate (support), Washcoat and Active phase (nanometals) cf. Lassi 2003
Catalytic conversion of synthesis gas Ref. www.inano.dk Hayes & Kolaczkowski, 1997
Catalytic materials Promising materials (catalytic combustion); Substrate Metal FeCrAl; excellent thermal shock, low ΔP, <1100 C Mullite-Zr; good thermal shock Cordierite; good thermal shock, T < 1200 C Hexaaluminates; incorporate catalytic activity, retain specific surface area, too high thermal expansion Washcoats Stabilised alumina (with Ba/La/Zr) Active materials Pd, Pt, Rh, Mn, Fe (Cr, Co, Ni, Cu)
Catalyst development - How to do it? Present technology Models and ideas SYNTHESIS Catalyst design CHARACTERI- ZATION CHARACTERI- ZATION TESTING Product o It never worked o Will it work today?
Materials demands for catalysts High selectivity i.e. minimization the formation of by-products High catalytic activity High stability and physical integrity High resistance to sintering Low volatility High surface area Resistance to rapid variations in temperature Long-term durability in stationary (operation hours) and transient (kilometres) applications A GOOD CATALYST IS ACTIVE, SELECTIVE AND STABLE MATERIALS DEVELOPMENT IS ONE OF THE KEY ISSUES!
Catalyst characterization X-ray Diffraction Solid state NMR SEM, TEM XPS Temperatureprogrammed methods (TPD, TGA) Physisorption Chemisorption cf. Lassi, 2005 Chemical analyses
Testing (activity and selectivity)
Catalyst deactivation In the case of thermal shocks (high temperature peaks), the catalyst may be deactivated (thermal deactivation, sintering) In the presence of carbon species ( e.g. HC oxidation), catalyst may be deactivated (coke formation) If sulfur or halogenated compounds or high particulate loadings (e.g. heavy metals) are in the emission gas streams, the catalyst may be poisoned/deactivated (chemical deactivation) Irreversible deactivation -> catalyst has to be replaced Reversible deactivation -> catalytic activity can be partly restored cf. Suhonen 2002
Reactions from syngas to chemicals
Demands for the syngas Demands; *low amount of impurities in the syngas *gas composition, in particular H 2 : CO ratio (between 0,6-2) *reaction conditions (temperature, pressure, inert gases (below 2 %), catalyst)
Reaction steps in the catalytic reaction Fischer-Tropsch synthesis (Co and Fe catalyst): Methanol synthesis (Cu catalyst): Methane synthesis (Ni catalyst):
Reaction steps in the catalytic reaction
Current status of the project (Kokkola) Ulf-Peter Granö, project coordinator Anne Rönnskog, M.Sc. (researcher, catalytic experiments) Henrik Romar, M.Sc. (researcher, development of analytics) Pekka Tynjälä, D.Sc. (advisor) Anu Rantamäki, project secretary Ulla Lassi, D.Sc. (advisor)
B.Sc. Theses Juha Tiitto, Biomassojen kaasutus ja kaasun tervapitoisuuden määritys (draft) Reetta Alahäivälä, Biosynteesikaasun hyödyntäminen uusiksi kemikaaleiksi (draft) Anna-Riitta Mäenpää, Biomassan kaasutus ja tuotekaasun hyödyntäminen
Future plans