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.

Automated summary

The aim of this research was to evaluate the technoeconomic prospect of hydrochar production through co-hydrothermal carbonization of coal waste and food waste. The economic analysis revealed that the cost and transportation cost of the raw materials significantly affected the break-even cost of hydrochar production. Increasing the production capacity decreased the break-even cost, but excessive increase in production capacity had a negative impact on the process economics.