Technoeconomic analysis of co-hydrothermal carbonization of coal waste and food waste.

The aim of this research was to evaluate the technoeconomic prospect of hydrochar production through co-hydrothermal carbonization of coal waste (CW) and food waste (FW). A process flow diagram was developed that considered seven reactors, six pumps, and other necessary equipment for producing 49,192 kg/h hydrochar. Three different cases were considered for the economic analysis. Case II considered both CW and FW transportation cost while cases I and III considered only FW and only CW transportation, respectively. The economic analysis revealed the break-even costs to be $62.24 per ton for case I, $69.90 per ton for case II, and $60.26 per ton for case III. The fixed capital investment (FCI) was $11.4M for all the cases while total capital investment (TCI), working capital (WC), and manufacturing costs were higher for case II compared to cases I and III. A sensitivity analysis examined the effect of nine different variables on the break-even cost. The raw materials' cost as well as their transportation costs significantly affected the corresponding break-even cost. Additionally, increasing the hydrochar production capacity has drastically decreased the break-even cost. However, the analysis also revealed that excessive increase of production capacity can have negative impact on the process economics. [ABSTRACT FROM AUTHOR]