Governance of marine biofuels as a transitional fuel for Thailand's shipping decarbonization: Ensuring Well-to-Wake integrity through a Triple-Layer assurance framework

Abstract

Drop-in marine biofuels are frequently presented as a near-term bridge for shipping because they may leverage existing engines and bunkering infrastructure. Yet climate benefit is not inherent to the biofuel label: well-to-wake (WtW) outcomes vary substantially across feedstocks, conversion routes, process-energy sources, logistics, and methodological assumptions. This paper develops a governance-oriented approach for Thailand to deploy marine biofuels as a transitional fuel while safeguarding WtW integrity and avoiding lock-in. We conducted an evidence-informed policy analysis using a targeted scoping review of English-language scholarly literature and official policy documents published between 2010 and 2026. The initial corpus comprised 42 sources identified through targeted searches and source tracing. Following reviewer feedback requesting a Thailand-specific case application, three additional official/context sources were added during revision. The final corpus therefore comprised 33 sources retained from 45 sources screened against eligibility criteria: 21 topical peer-reviewed studies, nine official/regulatory/context documents, and three methodological references. Sources were included when they addressed marine biofuel pathways or directly relevant maritime fuel governance and provided evidence on WtW/LCA, techno-economics, market dynamics, operability, or policy instruments. The synthesis shows that volumetric blending targets are a weak proxy for credible mitigation when traceability and verification are not institutionalized. The central contribution is a triple-layer assurance framework integrating operability/fuel-quality assurance, traceability/chain-of-custody assurance, and WtW climate-integrity assurance. Applied to Laem Chabang Port, the fraework identifies a practical regulatory sandbox sequence for pilot-to-scale deployment through fuel-quality control, batch-level traceability, and WtW- based monitoring, reporting, and verification (MRV).