This work addresses
the process and economic performance
of the
production of gasoline and diesel range fuels from urban sewage sludge.
The overall production route involves direct conversion of the sewage
sludge to an intermediate oil phase, so-called biocrude, via hydrothermal
liquefaction at near-critical water conditions and further upgrading
of the biocrude based on conventional refinery processes. The overall
mass and energy yields of combined naphtha and middle distillate from
sewage sludge on dry basis are approximately 19 and 60%, where the
naphtha fraction represents about 45% of the total, with a minimum
fuel selling price ranging between 2.4 and 0.8 €/liter assuming
full investment in both the biocrude production and upgrading plant
with sewage sludge feed capacities in the range of 3 to 30 dry-ton/day.
If existing equipment at refinery can be used for upgrading of the
biocrude, the minimum fuel selling price can be reduced by approximately
7%.