Techno-economic assessment of hydrogen and power production from supercritical water reforming of glycerol

• The supercritical water reforming (SCWR) of glycerol was assessed techno-economically.
• Electrical power by an expander and hydrogen were the products.
• An autothermal (ASCWR) version of the process was also assessed.
• The break-even price of hydrogen was 5.36 $/kg H2 for SCWR and 5.75 $/kg H2 for ASCWR.
• The competitiveness of the technology seems to be promising versus other renewable processes.

Hydrogen and power production from supercritical water reforming of glycerol was techno-economically assessed, considering future states of technology because there is no demonstration plant using this technology. Two different configurations were proposed: supercritical water reforming (SCWR) and autothermal supercritical water reforming (ASCWR). A plant size of 1000 kg/h of glycerol was considered on a process flow-sheet simulated by Aspen Plus with the criterion of being energy self-sufficient. The results reveal that, although ASCWR presents better performance than SCWR in terms of energy efficiency, the investment capital and operational difficulties of ASCWR process leads to higher hydrogen production costs. The levelized production cost of hydrogen was evaluated using a discounted cash flow analysis with a discount rate of 10% and 100% equity financing. Thus, the minimum hydrogen selling price (achieved when net present value is zero) is 5.36 $/kg for SCWR and 5.75 $/kg for ASCWR. These values are somewhat higher than in a few conventional technologies, such as steam methane reforming, although lower than other renewable processes, such as wood gasification. In a future scenario, possible improvements in SCW reforming performance may lead to a decrease in the estimation of renewable hydrogen price.