Investigation on hydrate formation from cyclopentane-loaded porous activated carbon particles

•Cyclopentane desorbs from the large pores of activated carbons to form hydrate.•Surface cyclopentane is released as droplets before being converted to hydrate.•A fraction of CP hydrates is formed inside the pores of the activated carbons.•Activated carbons with large macroporous volumes enhance hydrate formation. In this paper, the mechanisms of hydrate formation in the presence of porous activated carbon particles (PACP) loaded with cyclopentane (CP) and immersed in an excess of pure water are investigated using differential scanning calorimetry (DSC) in combination with gas porosimetry (GP) and mercury intrusion porosimetry (MIP). PACP with different pore size distributions (PSDs) are used and CP hydrates are formed at atmospheric pressure and 1 °C. CP desorption from the PACP, initially saturated or oversaturated with CP, that is induced by hydrate crystallization is studied by quantifying the amount of CP-to-hydrates obtained and/or the CP-conversion rate. It was found that the CP available for hydrate formation is predominantly contained in the large pores and on the external surface of the PACP. Therefore, to enhance the quantity of hydrates formed, PACP with pores larger than a given threshold pore size, a large macroporous volume and oversaturated with CP should be used. Moreover, the shift observed in the hydrate equilibrium temperature shows that a fraction of hydrates is formed inside the pores. The conclusions reached might offer new insights into hydrate-based processes.