An innovative method on synthesis of carbon-zeolite porous composite from tailings solvent recovery units and its utilization in the CO2 adsorption process

Abstract

Millions of metric tonnes of tailings solvent recovery units (TSRU) stream are produced annually by the oil sands mining industries and stored in the tailing ponds. This study was focused on implementation of a physiochemical methodology for the conversion of TSRU into the activated carbon-zeolite composite materials (ACZ). ACZ composites were fabricated via physiochemical activation approach using CO₂ stream along with the use of NaOH and KOH in different ratios. The activation step was followed by the hydrothermal treatment for the crystallization of zeolite. All the composites have been characterized by X-ray diffraction (XRD)—X-ray fluorescence (XRF), N₂ adsorption–desorption, Barrett–Joyner–Halenda (BJH) desorption pore size distributions, and scanning electron microscopy (SEM) techniques. CO₂ isotherm is also generated for all the composites and CO₂ capture capacity is also tested for multiple cycles for all the composites using TGA at 1 atm pressure and 30°C. It was observed that the composite synthesized using a higher ratio of KOH and NaOH showed more porosity. It was also recorded that ACZ-Na-KOH-1 had more CO₂ adsorption capacity as compared to other composites. Results indicated that all the ACZ composites were stable for multiple CO₂ adsorption cycles.