Bioleaching of nickel from equilibrium fluid catalytic cracking catalysts

Abstract

SummaryThis study investigates the possibility of reusing metal-contaminated equilibrium fluid catalytic cracking (FCC) catalyst after bioleaching. Leaching with Aspergillus niger culture was found to be more effective in the mobilization of nickel from the catalyst particles compared to chemical leaching with citric acid. Bioleaching achieved 32% nickel removal whereas chemical leaching achieved only 21% nickel removal from catalyst particles. The enhanced nickel removal from the catalysts in the presence of A. niger culture was attributed to the biosorption ability of the fungal mycelium and to the higher local concentration of citric acid on the catalyst surface. It was found that 9% of solubilized nickel in the liquid medium was biosorbed to fungal biomass. After nickel leaching with A. niger culture, the hydrogen-to-methane molar ratio and coke yield, which are the measures of dehydrogenation reactions catalysed by nickel during cracking reactions, decreased significantly.

Geopolymers based on spent catalyst residue from a fluid catalytic cracking (FCC) process

“…The zeolitic structures in spent FCC catalyst have the ability to promote the formation of an Al-substituted C-S-H type gel (via the pozzolanic reaction) and/or hydrated aluminate phases [16]. The presence of some contaminants, such as Ni, can reduce the pozzolanic reactivity of the spent catalyst, and so the potential use of spent FCC catalysts in the production of Portland cement-based building materials must be very carefully assessed [14,17]. It has been reported that mechanical [18], thermal [19], and chemical treatments [20] can enhance the effectiveness of spent FCC catalyst as an SCM in ordinary Portland cement systems.…”

Bioleaching of spent hydro-processing catalyst using acidophilic bacteria and its kinetics aspect

“…To avoid pollution in land disposal as well as minimise landfill space, the spent catalysts are subjected to metal extraction by var-V, Sb are reported to be mobilized by Aspergillus niger from the metal-contaminated fluid cracking catalysts. The production of primary metabolites such as citric, gluconic and oxalic acids do play the major role to leach out metals from such wastes [15][16][17]. Vanadium has also been recovered from spent vanadium-phosphorus catalysts using Acidithiobacillus thiooxidans [18].…”

Seismic Upgradation of RC Beams Strengthened with Externally Bonded Spent Catalyst Based Ferrocement Laminates

“…To address this issue and conserve natural resources and energy, much research has been carried out on the reuse of used catalysts. Without causing any negative effects, the catalytic cracking catalyst may be used to replace 10% of the sand or 15% to 20% of the cement content [18,19]. To strengthen the strength of structural elements, ferrocement was adhered to their surfaces [ 20,21].…”