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• Organic exclusions with hydrate growth were firstly simulated and in-situ observed. • Progressive organic exclusion caused substance migration and concentration gradient. • Higher driving formation force generated the precipitation of excluded organics. Inorganic substances and most organic compounds are typically excluded from crystalline hydrate structures. In this study, the phenomenon and mechanism of organic exclusions during hydrate formation were investigated using MD simulations and in-situ observations with an MRI experimental apparatus. The results showed that the organic macromolecules could not be trapped in the hydrate structure and formed a concentration gradient of dissolved organic substances from the growth front of the CO 2 hydrate into the aqueous solution. This study demonstrates the hydrate-based technology would be a promising method for organic wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • An improved model for hydrate particles removal from surface is proposed. • Hydrate particle diameter influencing the critical velocity than the initial liquid bridge volume. • Hydrate particles decomposition happening in the removal process. Understanding the critical velocity at which hydrate particles can be removed from a solid surface is crucial for flow assurance issues. An improved model is proposed to predict the critical velocity in hydrate particle removal process by considering a deformed liquid bridge. In situ experiments were performed for validation, and it was observed that hydrate particle decomposition occurred during the removal process. The particle diameter was determined to be a more dominant factor influencing the critical velocity than the initial liquid bridge volume. The resulting confidence level was 95% within a 30% error, showing its robust capability for engineering applications. [ABSTRACT FROM AUTHOR]