The Phase Inversion-based Coal-CO2 Slurry (PHICCOS) feeding system: Technoeconomic assessment using coupled multiscale analysis

• PHICCOS system proposed for feeding coal into pressurized entrained flow gasifiers.
• PHICCOS uses recirculated, liquid CO2 to prepare and feed coal slurry in plants with CCS.
• System-level and component-level models coupled to study technoeconomics in IGCC.
• PHICCOS consistently economic across coal ranks and competitive with commercial systems.
• PHICCOS can feed to very high pressures and can efficiently operate on high-ash coal.

Coal-CO2 slurry feed is being examined as a way to efficiently feed coal into high-pressure reactors, such as gasifiers, in carbon capture-enabled plants. The preparation of a slurry of coal in liquid carbon dioxide is not trivial and the cost of solutions involving lock hoppers and cryogenic cooling is expected to be high. A novel method for preparing and feeding coal-CO2 slurry has recently been proposed: the Phase Inversion-based Coal-CO2 Slurry (PHICCOS) feeding system operates at ambient temperature, does not require lock hoppers, and inherently reduces the moisture and ash content in the feedstock. This work examines the technoeconomics of the PHICCOS feeding system for high and low-rank coal and compares them with those of commercial technologies. Coupled multiscale analysis, which integrates system-level modeling and component-level modeling, is used here to conduct, for the first time, an integral assessment of the PHICCOS feeding system. The analysis, which uses an Integrated Gasification Combined Cycle power plant as an example application, accounts for multiple aspects of the process that had only been considered individually in the past. Results show that the PHICCOS feeding system is competitive with coal-water slurry feed for bituminous coal gasification and is cheaper than dry feed for low-rank coal. Overall, PHICCOS is the most economic option across coal ranks and offers unique operational advantages, when compared to dry feeding systems, related to high-pressure operation and capability to process high-ash, and high-moisture coal.