process design and feasibility study of synthetic crude production by the combination of methane decomposition, reverse water gas shift reaction, and fischer-tropsch synthesis
abstract
in this dissertation, the conversion of co2 to gas-to liquid (gtl) products was investigated for the
production of 30000 bbl per day syncrude. the gtl plant consisted of four main units: hydrogen
production by catalytic thermal decomposition of methane in a cu-bi molten media, syngas
production by the reverse water gas shift (rwgs) reaction using a nickel-based catalyst, syncrude
production by the low temperature fischer-tropsch (ltft) synthesis over a cobalt-based catalyst,
and an energy recovery unit for electricity generation. the plant was simulated by the coupling of
hysys and matlab to simulate the rwgs and ft reactors and converge their recycle streams.
150 alkanes and 149 alkenes were included in the simulation to accurately estimate the product
distribution of the ft reactor. the fixed capital investment of the plant and the manufacturing cost
of syncrude were $1.6 billion and $137 bbl-1
, respectively. it was found that hydrogen production
by methane decomposition reduced the manufacturing cost of syncrude by 32% when compared
to gtl plants that sourced their hydrogen from water electrolysis. the profitability analysis
showed the plant could not be economically viable without selling the produced solid carbon. the
breakeven price of the produced solid carbon was estimated to be $633 tonne-1
for a syncrude
selling price of $59.31 bbl-1
. the economic performance of the plant was highly favourable at
syncrude selling prices higher than $80 bbl-1
. it was determined that the plant was a net emitter of
co2 at a rate of 19.92 g co2 per 1 mj of syncrude, which was lower than the reported values for
different types of natural-gas based gtl plants, but higher than water electrolysis-ft plants.