Production of bio-jet fuel from corncob by hydrothermal decomposition and catalytic hydrogenation: Lab analysis of process and techno-economics of a pilot-scale facility

The mass and energy analysis from Aspen plus model shows that the bio-jet fuel yield was 0.125 tonne/tonne dried corncob. 31.0% of carbon atoms and 47.6% of potential energy from carbohydrate compounds of corncob leave as bio-jet fuel. The estimated consumption of water, steam and electricity is relatively high of 12.3 kg, 63.7 kg and 1.22 KW h respectively due to small simulation scale and lack of process optimization. The total capital cost was ca. $3.96 MM for the 1.3 ML/a facility, of which 28% of equipment investment is spent for oxygenated precursor production. The total operation expense (OPEX) is $1.18/L bio-jet fuel, including variable and fixed costs. Expenses on corncob, catalytic catalyst and H2 contribute 23%, 19% and 16% respectively. Single point sensitivity analysis of the major breakdown of OPEX shows that catalyst lifetime is the priority factor. Economy of scale of minimum selling price of bio-jet fuel (MSPB) for different capacity facilities (1.3 ML/a, 6.5 ML/a and 13 ML/a) was investigated using different discount and tax rates, of which the lowest MSPB was $0.74/L with a subsidy of $0.31/L at 10% discount rate.