Production and flow behaviors of CO2+TBAB hydrate slurry for cold storage and transport application

The CO2+TBAB (tetrabutylammonium bromide) hydrate slurry emerges as a promising phase change slurry for cold storage and transport applications due to its large latent heat, favorable fluidity and adjustable phase change temperature for secondary refrigeration. To investigate the cold storage and transport characteristics of CO2+TBAB hydrate slurry, the production and flow properties are experimentally studied. Furthermore, the system energy efficiency is analyzed based on the determined cold storage capacity and rheological characteristics. The cold storage capacity of CO2+TBAB hydrate slurry is influenced by the quantity of generated TBAB semi-clathrate hydrate and the quantity of encaged CO2. Increasing pressure effectively enhances CO2 absorption quantity due to larger driving force for CO2 diffusion, resulting in greater cage occupancy and larger latent heat. The CO2+TBAB hydrate slurry exhibits shear-thinning behavior for solid mass fractions ranging from 7.1 wt% to 49.2 wt%. The apparent viscosity is modeled using the power-law equation to predict the pressure drop. The energy analysis underscores that the pumping power consumption decreases by 77.9 % at a cooling capacity of 100 kW when the solid mass fraction is increased from 17.1 wt% to 34.1 wt%, and this energy-saving feature is further enhanced with the increase of cooling capacity.