Hub-Only Pipeline Topology Architecture Standard (HOPT-ASv1.31) Version v1.31

The large-scale deployment of Carbon Capture, Utilization, and Storage (CCUS) is constrained by the complexity, cost, and permitting challenges of conventional emitter-connected CO₂ pipeline networks. This paper introduces the "Hub-Only Pipeline Topology Architecture Standard (HOPT-AS v1.31)", a system architecture and assurance framework for designing, governing, and preserving hub-centric CCUS infrastructure. HOPT-AS replaces direct emitter-to-pipeline connections with a hub-centric topology in which CO₂ is captured in solid-bound form, transported through conventional logistics, and regenerated and introduced into gaseous CO₂ pipeline networks only at centralized hubs. This decoupling reduces infrastructure complexity and participation barriers while supporting scalability and interoperability across industrial clusters. HOPT-AS further introduces "Dynamic Compliance, Architectural Drift, Dynamically Preserved Architectures," and "Real-Time Stewardship", establishing a continuous assurance model that maintains architectural integrity as infrastructure evolves. The standard defines system boundaries, stakeholder responsibilities, permitted topology classes, governance mechanisms, and compliance requirements. By treating architecture as a distinct dimension of infrastructure governance, HOPT-AS complements engineering, financial, regulatory, and environmental considerations. It provides policymakers, developers, operators, financiers, regulators, and standards practitioners with a structured and auditable framework for coordinated, scalable, and long-term CCUS deployment.