Enabling low-emission LNG systems - Fundamentals for multilevel modelling

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This project is related to the liquefaction of natural gas (LNG) and other low-temperature processes. The objective is to develop knowledge and tools enabling the evaluation, operation and design of innovative, environmentally safe, cost-effective and ene rgy-efficient LNG systems. Such systems have a large and increasing economic and environmental significance. LNG processes have been in use for several decades, but there are still many aspects of them that need to be better understood. In particular, t his is true for the heat exchangers, which is the main focus of the project. The LNG heat exchangers are most often governed by a complex two-phase flow of multi-component mixtures, and these are not well enough understood today. Therefore, this project will study such flows on a fundamental level, from both an experimental and a mathematical modelling point of view. Models are needed to develop engineering tools, and to develop and verify models, laboratory experiments are needed. Models on two differe nt detail levels will be used. On the most fundamental level, only a few droplets or bubbles can be considered, but their speed and shape are calculated in full detail. On the intermediate-scale level, the flow and phase distribution in parts of the heat exchangers can be calculated. A further challenge is the evaluation of LNG processes using process-simulator software. This kind of simulation is necessary to analyse and improve LNG systems. To perform such simulations, we need to improve the formulatio n of associated optimization problems. The operability of LNG systems will be addressed using dynamic modelling. A case study will address selected topics, such as CO2 management, efficiency and environmental impact and operation in challenging environme nts (on a floater, in the Arctic, etc.) using the design and evaluation tools developed by the project. 3 PhDs and 2 postdocs will be educated in cooperation with internationally leading experts.