Wei Yan is an associate professor in the Department of Chemistry at the Technical University of Denmark (DTU). He leads the energy resources engineering group at the department. He received his PhD degree in chemical engineering from the China University of Petroleum in 1999, and joined DTU in 2001. His research area is applied thermodynamics and high-pressure phase behavior. He applies thermodynamics to industrial processes at elevated pressures, such as oil and gas production and CO₂ sequestration, where the interplay between phase equilibrium and fluid flow plays a crucial role. He works on experimental measurement, thermodynamic modeling, and equilibrium calculation algorithm in an integrated manner. His experimental study is focused on phase equilibrium and thermophysical properties for high-pressure high-temperature underground processes. He applies advanced thermodynamic models to complex equilibrium systems involving associating compounds, capillary pressure, and adsorption. He has strong expertise in phase equilibrium calculation, and develops robust and efficient algorithms for multiple phase and chemical equilibrium, which lie at the heart of modern compositional simulation. He currently serves as the executive editor for Journal of Natural Gas Science and Engineering and the associate editor for Journal of Petroleum Science and Engineering. He is active in organizing international conferences related to petroleum fluid PVT, such as SPE workshop on Complex Reservoir Fluids, IEA EOR workshop and symposium, and PetroPhase.