Measurement and advanced thermodynamic modelling for accurate predictions in liquefied natural gas distillation columns

An improved apparatus for reliable VLE measurements at conditions representative of LNG scrub columns was used to measure new data for four principal methane binary mixtures and two multi-component mixtures. These new data have demonstrated which of the literature data contain significant errors or uncertainties and which are reliable. They also allow the primary deficiencies of the equations used to describe the VLE of these systems in process simulations to be qualified. Improved predictions were achieved using a cubic crossover equation of state; however the required interaction parameters were not sufficiently general to be broadly applicable.