This study investigates the sociotechnical transition of the Rotterdam Harbour Industrial Cluster (RHIC), focusing on the emergence and interaction of three dominant sustainable technologies: hydrogen, carbon capture and storage (CCS), and bio-circularity. To reveal systemic innovation patterns and structural lock-in risks, it applies an integrated framework, combining the Multi-Level Perspective (MLP) and Technological Innovation Systems (TIS) theory. This research analysis uncovers how each innovation follows a distinct transition pathway shaped by institutional, infrastructural, and market dynamics. Hydrogen innovation is primarily top-down, driven by strong knowledge development and political support creating high legitimacy and potential for regime destabilization. CCS, by contrast, operates as a regime-reinforcing technology with high political legitimacy but limited actor diversity and market incentives, posing risks of techno-institutional lock-in. Bio-circularity innovation, involving circular economy practices and bio-fuel adoption, is the sole emerging bottom-up, catalysed by entrepreneurial activity and industrial symbiosis principles, but remains underdeveloped due to fragmented value chains, weak guidance, and insufficient institutional support. Through the MLP lens, landscape pressures such as Clean Industrial and Green Deal, European carbon taxonomy (e.g., EU-ETS, CBAM), and geopolitical energy shifts have opened windows of opportunity, yet the response of the regime remains uneven. Hydrogen aligns with a transformation pathway, CCS with reconfiguration, and bio-circularity with a tentative substitution trajectory. Furthermore, the study emphasizes on critical policy and investment gaps potentially hampering the endogenous innovation capacity of clustered industrial systems. The findings underline the need for tailored, function-specific strategies and stronger regime-niche coordination to overcome systemic failures and support a just and accelerated energy transition.