A novel approach for preliminary sizing and cost screening of CO2 pipeline transport: The ECOB method

Efficient CO 2 transport design is essential for early-stage carbon capture and storage (CCS) studies, yet detailed pipeline optimization is difficult to repeatedly embed in CCS chain assessments with varying CO 2 quality and economic assumptions. Conventional process optimization is based on comprehensive analysis through diameter-by-diameter hydraulic simulations and cost evaluations. In contrast, simple sizing rules do not usually capture the trade-off between pipeline investment and operating costs. This study develops an Economic Operating Band (ECOB)-based framework for rapid CO 2 pipeline sizing and transport cost screening. Full-process optimization shows that cost-optimal diameters cluster within a narrow band in erosional velocity ratio (EVR) space. The ECOB center is correlated with mass flow rate, electricity price, and steel cost, enabling single-step estimation of the optimal inner diameter. Validation against 166 internal out-of-sample full-process cases yielded median and P90 absolute diameter errors of 1.6% and 3.9%, respectively. Corresponding levelized-cost errors were 0.0% (median) and 4.9% (P90), with a maximum deviation of 22.6% in a stress-type case following discrete NPS selection. Literature-model comparisons showed transport cost deviations of 0.8–5.5%, while comparison with six existing CCS projects confirmed broadly consistent pipe-size estimates. Computational benchmarking further showed an approximately four-order-of-magnitude runtime reduction relative to exhaustive diameter-by-diameter evaluation. ECOB therefore provides a rapid and interpretable approach for preliminary pipeline sizing and cost screening, facilitating integration of CO 2 transport into broader CCS chain assessments.