  Multi-product pipelines are a highly efficient means of transporting liquids.
Traditionally used to transport petroleum, its products and derivatives, they
are now being repurposed to transport liquified natural gas admixed with
hydrogen of various colors. We propose a novel mixed-integer linear programming
(MILP) formulation, which optimizes efficiency while satisfying a wide range of
real-world constraints developed to meet the needs of the Czech national
pipeline operator CEPRO. We provide tests on well-known synthetic (path-graph)
networks and demonstrate the formulation's scaling properties using open-source
and commercial MILP solvers.
