Dirk Willem van Krevelen (8 November 1914, Rotterdam – 27 October 2001, Arnhem) was a prominent Dutch chemical engineer, coal and polymer scientist. He successfully combined an industrial career, managing a research division at DSM, and an academic career, as a Professor of Delft Technical College. His contributions span a wide range of research fields, and his name is linked to the van Krevelen–Hoftyzer diagram for chemical gas absorption, the Mars–van Krevelen mechanism for catalytic oxidation reactions, the van Krevelen–Chermin method to estimate the free energy of organic compounds, the van Krevelen diagram that is used in coal and coal processes, the van Krevelen method to calculate additive properties of polymers, and the van Krevelen–Hoftyzer relationship on the viscosity of polymer