CO2 Reduction Measures in Steam Cracker Plants: Process integration opportunities of electrified steam methane reforming for fuel gas valorization
Typ
Examensarbete för masterexamen
Program
Sustainable energy systems (MPSES), MSc
Publicerad
2022
Författare
Lehle, Tobias
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Steam cracking is the main production route for the light olefins ethylene and propylene,
which are considered a cornerstone of the chemical industry. The endothermic
cracking reactions are conventionally supplied with heat by combusting fossil fuel
and therefore entail large carbon dioxide emissions. Typically the fuel grade byproducts
methane and hydrogen are used as fuel gas. Possible options to decarbonize the
process include either the substitution of fossil feedstock, by e.g. biomass or recycled
waste, or the heat supply to the reactions. While the industry strives for electrification
of the cracker to decarbonize the heat supply, using hydrogen as fuel gas is
a readily available decarbonization measure. To obtain hydrogen, the co-produced
methane can be reformed. This work modelled the integration of an electrified steam
methane reformer with an ethane steam cracker. The emission reduction potential
and impact on the energy balance of an ethane cracker of two emission reduction
scenarios was analysed. One scenario is categorized as pre-combustion carbon capture,
while the other uses oxy-fuel combustion to reduce emissions. It was shown
that both scenarios allow significant emission reduction of approximately 95 %,
where the residual emissions steam from electricity consumption assuming Sweden’s
carbon grid intensity. The modeled scenarios showed that usage of reformed hydrogen
for combustion entails a lower increase (1.1 MJ/kgEthylene) in specific energy
consumption than oxy-fuel combustion (1.7-2.4 MJ/kgEthylene).
Beskrivning
Ämne/nyckelord
Steam Cracking , CO2 Reduction , Steam Reformation , e-SMR , Methane Valorization , Fuel Switching , Pre-combustion , Oxy-fuel Combustion