Sustainable and renewable ways to produce fuel are urgently needed to reduce greenhouse gas emissions, avoid abrupt change in oil prices, and solve the problem of finite fossil-fuel resources. Of the several means of renewable fuel production, biofuels production is one of the most promising technologies for replacing fossil fuel in the near future and can provide a significant contribution to the renewable-energy supply. Biodiesel is a non-toxic, biodegradable, and sustainable fuel that can be used with existing technology such as diesel cars and industrial applications. However, biofuel-production processes have yet to become economically competitive with petroleum due to its complex production process and significantly higher operating cost. In the present work, we thus propose a way make biodiesel production economically feasible through rigorous process modelling and optimization. The global sensitivity of the process model reveals the key variables in the process from which we produce techno-economic guidelines for biodiesel production of biodiesel as a replacement for fossil fuels.
Schematic representation of biofuel production process using biphasic reaction. The stream lines are colour coded according to the unit process. (1) Grey lines: xylose dehydration and furfural refinery, (2) green lines: furfural hydrogenation, (3) blue lines: 2-MF condensation, (4) yellow lines: water stream out from process, and (5) red lines: input and output stream except for water stream.
Global sensitivity analysis results and contour results. (a) NPV distribution and sensitivity index depending on the external variables, (b) CAPEX and OPEX distribution, (c) contour results depending on water and CPME flowrates when xylose conversion and CPME price equal 0.9 and $0.05/kg, (d) 0.7 and $0.05/kg, (e) 0.5 and $0.05/kg, (f) 0.9 and $0.5/kg, (g) 0.9 and $5/kg, and (h) triangular diagram for water-CPME-furfural system phase equilibria. , and indicate mass flowrates of water, CPME and xylose. The contours are plotted according to the dimensionless number representing the ratio of water and CPME flowrates to xylose flowrates. The red shaded area shows the current diesel price range.