Energy, exergy and techno-economic analyses of hydrothermal oxidation of food waste to produce hydro-char and bio-oil

In this study, energy, exergy and techno-economic analyses of HOT (hydrothermal oxidation) of food waste to solid (hydrochar) and liquid (bio-oil) fuels were performed. The HOT process was carried with and without enzymatic pre-treatment for fuel production. A conceptual chemical mass balance model was developed. Increasing the process temperature increased the yield of bio-oil and enhanced the quality of the hydro-char. Inclusion of the enzymatic pre-treatment reduced bio-oil yield but enhanced hydro-char quality. Energy balance and exergy analyses indicated that the HOT process is feasible at different operating temperatures. However, the energy conversion efficiencies of the process decreased with increasing temperatures. TEA (Techno-economic analysis) was performed to assess economic feasibility. The minimum selling price of products was calculated and compared with the existing market prices. Finally, a sensitivity analysis was carried out, which showed that the price of bio-oil and enzymes had the highest impact on the profitability of the plant in the case of the enzymatic pre-treated process while the bio-oil yield had the highest impact for the non-enzymatic process. Monte-Carlo simulation was carried out to examine the robustness of TEA analysis. (C) 2016 Elsevier Ltd. All rights reserved.