This exploratory study is concerned with the ethane and propane side-streams of two new companies in the Port of Rotterdam involved in storage and transport of LNG and biodiesel. These side-streams could potentially be used as a feedstock in existing steam-cracking installations in this south-west region of the Netherlands. The project examines the technical feasibility of such a move, presents a first-pass business case and calculates the impact on supply-chain carbon emissions. The streams in question prove to be substantial, with that from the LNG terminal potentially amounting to 900 kt/y. This means the concept could be economically viable. It also means there are substantial supply-chain carbon savings to be achieved, possibly over 100 kt/y. The project was carried out for NL Agency in collaboration with VNCI, the Netherlands Association of Chemical Industries, and the cited companies.