Microbubble-Enhanced Bitumen Separation from Tailing Slurries with High Solid Contents

Abstract

Bitumen residues in oil sand tailings ponds create greenhouse gas emissions and threaten the ecosystem. However, it is technically challenging to recover bitumen residues from tailing slurries with high solid contents. This study investigates a novel concept of microbubble-enhanced bitumen recovery during hydrotransport in a laboratory-scale pipeline loop. Our results revealed that bubbles had a positive impact on bitumen recovery. Furthermore, bitumen recovery efficiency increases significantly when the temperature increases up to 52 °C. The recovery efficiency was even higher from the addition of CO 2 bubbles compared to air bubbles. The generation of microbubbles enabled the recovery of 61% bitumen from an extremely low initial fraction of 0.2 wt % at a solid content of 50 wt %. Our work demonstrated an effective combination of bubbles and operational conditions for separating bitumen effectively from highly concentrated tailings. The approach may be also valuable for reducing the environmental impact of other industrial waste slurries.

Effects of Gas Type, Oil, Salts and Detergent on Formation and Stability of Air and Carbon Dioxide Bubbles Produced by Using a Nanobubble Generator

“…For a large gas flow rate, the efficiency of mechanical shearing in decreasing the mean bubble diameter is weakened owing to the energy dissipation to a larger gas volume [50,51]. In addition, at the higher gas flow rate, bubbles coalesce more at a higher gas fraction [9]. However, the high pressure gradient in the chamber can force the deformation of bubbles and in turn contributes to the breakup of large bubbles [52].…”

“…Recent studies demonstrate that these bubbles have promising potential as separation agents in various industries, such as oil recovery and mineral processing [7,8]. For example, microbubbles greatly improve heavy oil recovery from concentrated slurries [9] and enhance the extraction of organic waste and valuable minerals [10,11]. Moreover, microbubbles have been found to be effective in defouling contaminated surfaces [12,13].…”

“…Several techniques requiring high energy input have been developed to produce a large number of micro/nanobubbles, such as electrolysis [31], hydrodynamic cavitation [9,32] and ultrasound [33,34]. The swirling-flow nanobubble generator is an efficient hydrodynamic cavitation method that can continuously produce enormous quantities of bulk nanobubbles.…”

Numerical Insights from a Population Balance Model into the Distribution of Bitumen Residues in Industrial Horizontal Pipes During the Hydrotransport of Oil Sands Tailings

“…Interestingly, microbubble injection is found to be effective in enhancing bitumen recovery. Bubbles with small sizes (such as nanobubbles) can lead to the attachment of large bubbles onto solid particle surfaces and possibly improve the separation efficiency. , Experimental studies have demonstrated that microbubbles in the slurry flow improve the recovery efficiency of bitumen in a lab-scale pipeline. − …”

Introducing the I&ECR Virtual Collection of Industrial and Industrially Relevant Research (2022–2023)

“…Articles included in the present collection include three cover articles: an electrochemical H 2 pump membrane technology (July 2023), 36 a study on the permeability of hydrofluorocarbons (HFCs) in polymer membranes (March 2023), 37 and the recovery of He from natural gas streams using membranes (January 2023). 38 Additional separation-focused articles include the removal of perfluorinated and polyfluorinated substances (PFAS) from H 2 O, 39 a process analytical methodology and development of thermodynamic phase diagram of ternary mixtures of agrochemicals in solvent, 40 a description of membrane test equipment, 41 microbubble-enhanced bitumen separation, 42 and the conversion of CO 2 to dimethyl ether (DME), using a membrane reactor. 43 Thermodynamics, Transport, and Fluid Mechanics is the topic area in I&ECR with the highest rate of participation of industrial authors as a percentage of the articles published.…”