Modeling and Techno-Economic Analysis of Methane Pyrolysis via Arc Plasma For Hydrogen and Carbon Black Production

Authors

Abstract

This study investigates methane pyrolysis (MP) to produce hydrogen and carbon black while eliminating process CO2 emissions via a high technology readiness level (TRL) arc plasma pyrolysis technology. The process was modeled using Aspen Plus, which revealed that the specific energy consumption is approximately 39 kWh/kg H-2 without on-site power generation and 32 kWh/kg H-2 with on-site power generation. The process was evaluated using technoeconomic analysis (TEA) via a discounted cash flow analysis, using 2023 dollars. For the annual capacity of about 52 kMT H-2 (based on Monoliths commercial plant scale), the total capital cost of the plant is estimated to be nearly $1 billion, while electricity and feedstock costs are identified as the primary contributors to the overall levelized hydrogen production cost. The revenue generated from the sale of black carbon significantly offsets the high electricity costs. The minimum selling price (MSP) of hydrogen produced via this method ranges from $1.10-1.36/kg H-2, demonstrating its economic competitiveness with incumbent steam methane reforming (SMR) technology (similar to$1/kg H-2) and water electrolysis ($4-5/kg H-2). Sensitivity analysis revealed that the carbon black price, electricity costs, and natural gas (NG) feedstock cost are the most impactful factors affecting the MSP of hydrogen. Given the recent high market value of carbon black (>$1.8/kg since 2024) and forecasted increase in market demand and price in the near future, the MP process has high potential to produce H-2,H- with very small process emissions and a competitive cost relative to incumbent technology. The life cycle greenhouse gas emission (GHG) is analyzed considering various allocation methods and are summarized in a separate manuscript.