Spent Petroleum Catalyst Research Articles

Spent Catalyst‐Derived Mo‐MOF: Triboelectric Nanogenerators and Energy Harvesting

The spent catalysts discarded during chemical manufacturing can be a source of pollution and are classified as hazardous waste. Looking at the bright sides of the mission of waste management, such as recycling and reducing, reuse such types of the spent catalyst can be chemically treated to extract valuable salts and metals. Such a process not only reduces waste disposal issues but also promotes a circular economy ecosystem. This present study aims to extract MoO3 from the spent petroleum catalyst, Mo–Ni/Al2O3, and further processing of Mo‐metal organic framework (MOF) particles using extracted MoO3 and imidazole acting as an organic binder. The structural, morphology, and thermal properties of Mo‐MOF are evaluated. The surface roughness and positive surface potential of the Mo‐MOF are achieved. The Mo‐MOF/Kapton‐based triboelectric nanogenerators (TENG) generate a 148 V voltage, 470 nA current, and 17 nC charge. Further, TENG is utilized to charge the capacitors, and powering of the electronic devices is demonstrated. The repetition of the boxing punches and exercises can be monitored using TENGs and paves the way toward intelligent sports or healthcare.

Recovery of nickel and preparation of ferronickel alloy from spent petroleum catalyst via cooperative smelting–vitrification process with coal fly ash

ABSTRACT Spent petroleum catalyst (SPC) is a highly toxic material since it contains heavy metals and hazardous substances. A novel recycling technology based on the cooperative smelting–vitrification process by using coal fly ash (CFA) as a fluxing material was proposed. The benefits of employing CFA in this cooperative smelting–vitrification process of SPC have been demonstrated via the results of lab-scale and scale-up experiments. The experimental results indicated that with a collector iron (Fe) addition of 26 wt%, a C/O molar ration of 1.4, and an H3BO3 addition of 14 wt%, the maximum nickel (Ni) recovery was ∼98% by controlling the CFA addition of 40–50 wt%, basicity of 0.4–0.5, smelting temperature of 1550°C, and smelting time of 60 min, respectively. In this process, a ferronickel (Ni–Fe) alloy with a high Ni grade of 10 wt% was successfully obtained, which could be directly further produced stainless steel. Meanwhile, a glass slag with a low Ni content (below 0.12 wt%) was also obtained, and its leaching characteristics further confirmed it is a non-hazardous slag because heavy metals were successfully encapsulated in glass slag, and thereby, this proposed method achieved the transformation from hazardous solid waste to general solid waste. The results of the 10 kg scale-up experiment indicated the possibility of industrialization of this new technology. Therefore, the process proposed in this study is a practical and promising process for Ni recovery from SPC and reutilization of CFA.

Sequential-Anaerobic and Sequential-Aerobic Bioleaching of Metals (Ni, Mo, Al and V) from Spent Petroleum Catalyst in Stirred Tank Batch Reactor: A Comparative Study.

The online version contains supplementary material available at 10.1007/s12088-021-00978-8.

Current technologies for recovery of metals from industrial wastes: An overview

Fast industrialization has increased the demand for heavy metals, on the other hand, high-grade ore natural reserves are belittling. Therefore, alternative sources of heavy metals need to be investigated. Massive amounts of industrial wastes are being generated annually. The majority is sent to landfills or to incinerators, which eventually poses environmental challenges such as ecological contamination and health hazards to living beings. Such industrial wastes contain hazardous elements of various metals (Au, Ag, Ni, Mo, Co, Cu, Zn, and Cr), whose improper disposal leads to adverse effects to human being and the environment. As a result, methods for industrial waste management such as reuse, remanufacturing, and recycling have received much attention due to the fact that they improve cost effectiveness over time and enable the metal recovery businesses to thrive profitably. The present study provides a state of art review on the current technologies existing for the recovery of precious metals from industrial wastes streams to analyse the sustainability. Among the wastes, spent petroleum catalysts, medical waste, electronic scraps, battery wastes, metal finishing industry waste, and fly ash are some of the largest industrially-generated wastes. Various metal recovery processes involve physical, chemical, and thermal characteristics of waste streams and target metals for separation and extraction. The current challenges of pyrometallurgy, modification on the hydrometallurgy, physical and chemical methods and other advanced technologies are presented in this review. The hydrometallurgical method, which involves dissolving and leaching, is a proven and successful process for recovering metals from various raw materials. Several other recovery methods have been proposed and are currently being implemented; the problem is that most of them are only successful in retrieving certain metals based on specific properties of industrial waste. The recovered metal solutions are further concentrated and purified using adsorption, cementation, chemical precipitation, ion exchange, membrane filtration and ion flotation techniques, which can also be applied to other liquid waste streams. The recovery method only makes sense if the recovery cost is much less than the value of the precious metal. The limitations placed on waste disposal and stringent environmental legislation require environmental-friendly metal recovery technologies. This review paper provides critical information that enables researchers to identify a proper method for metal recovery from different industrial wastes, and also it benefits researchers and stakeholders in determining research directions and making waste management-related decisions. • Methods for metal recovery from solid/liquid waste streams are critically reviewed. • Pyrometallurgical methods effectively recover less reactive oxides in solid waste. • Hydrometallurgical methods rely on chemical reactions in various leaching mediums. • Metal recovery from wastewaters is based on either chemical or physical techniques. • Physical metal recovery method is superior by low chemical use and sludge produced.

Generation behavior of extracellular polymeric substances and its correlation with extraction efficiency of valuable metals and change of process parameters during bioleaching of spent petroleum catalyst

The vital functions of extracellular polymeric substances (EPS) have been well recognized in bioleaching of sulfide ores. However, no report is available about the role of EPS in bioleaching of spent catalyst. To completely and deeply understand the functions of EPS in bioleaching of spent catalyst, the generation behavior of EPS at various pulp densities during bioleaching was characterized by three-dimensional excitation-emission matrix (3DEEM), and its relevance with bioleaching performance and process parameters were analyzed using mathematical means. The results showed that the EPS contain humus-like substances as main component (>70%) and protein-like substances as minor component (<30%). Both total EPS and humus-like substances mainly keep growing over the whole duration of bioleaching at low pulp density of 5.0% or lower; whereas total EPS and humus-like fraction keep declining at high pulp density of 7.5% or higher. Among the total EPS and its components, humus-like substances only have a positive significant correlation with bioleaching efficiencies of both Co and Mo and affect bioleaching process more greatly due to greater correlation coefficient. Biofilm appears at the spent catalyst surface under 2.5% of pulp density mediated by EPS while no biofilm occurs at 10% of pulp density due to shortage of EPS, accounting for the great difference in bioleaching efficiencies between high and low pulp densities which are 48.3% for Mo and 50.0% for Co at 10% of pulp density as well as 75.9% for Mo and 78.8% for Co at 2.5% of pulp density, respectively.

Recovery of pure molybdenum and vanadium compounds from spent petroleum catalysts by treatment with ionic liquid solution in the presence of oxidizing agent

Nonaqueous solutions were employed to investigate the selective recovery of vanadium and molybdenum from the spent petroleum catalysts. In this work, commercial extractants such as D2EHPA, Alamine336 and Aliquat336, and an ionic liquid synthesized from Aliquat336 and D2EHPA, ALi-D2, were employed as a lixiviant and extractant for the target metal ions in the presence of oxidizing agent, H2O2. Among the 4 nonaqueous systems, ALi-D2 showed the best performance for the selective and effective leaching of vanadium and molybdenum over alumina, nickel and iron. The effect of several parameters on the leaching efficiency was also studied. Under the optimum conditions, the leaching percentage of vanadium and molybdenum was 74.6 and 89.6% in the first stage and 26.0 and 66.9% in the second stage by ALi-D2 system. Vanadium and molybdenum from the ALi-D2 loaded phase can be sequentially precipitated by NH4Cl and BaCl2 solutions in alkaline media. Precipitation percentage of vanadium were 94.2% and its purity was 99.5%, whereas that of molybdenum was 99.4% with 84.1% purity. A process was proposed for recovery of vanadium and molybdenum from the spent petroleum catalysts. Pure vanadium and molybdenum compounds can be recovered by this process with less burden to the environment.

Separation of Al(III), Mo(VI), Ni(II), and V(V) from model hydrochloric acid leach solutions of spent petroleum catalyst by solvent extraction

AbstractBACKGROUNDA large number of spent catalysts are regularly discharged by petrochemical industries. The spent catalysts contain some valuable metals, such as molybdenum, nickel, and vanadium. Therefore, it is necessary to recover these high purity metals from the spent petroleum catalysts with environmentally friendly processes.RESULTSIn order to recover valuable metals such as molybdenum, vanadium, nickel, and aluminum from spent petroleum catalysts, a hydrometallurgical process consisting of leaching followed by solvent extraction was developed in the present work. First, molybdenum was separated from the leaching solution by extraction with D2EHPA and the loaded organic phase was stripped by a mixture of NH4OH and (NH4)2CO3. Second, the molybdenum free raffinate was contacted with Aliquat 336‐decanol to separate the vanadium, and then a hydrochloric acid solution was employed to strip vanadium from the corresponding loaded extractant. Since the acidity of the leach solution was high, TEHA (tris‐2‐ethylhexylamine) was chosen for the extraction of hydrochloric acid in order to increase the pH of solution. The loaded TEHA phase was then stripped by distilled water, which enabled the recovery of HCl. The nickel and aluminum in the molybdenum and vanadium free raffinate were separated by the extraction of nickel with saponified Cyanex 301 at a solution pH of 2.5. It was possible to strip nickel from the loaded organic phase by a strong hydrochloric acid solution.CONCLUSIONSA flow sheet of the proposed process for the separation of Al(III), Mo(VI), Ni(II), and V(V) was presented. The current process can be applied to aqueous solutions containing these four metals from diverse material resources. © 2020 Society of Chemical Industry

Separation of Mo(VI), V(V), Ni(II), Al(III) from synthetic hydrochloric acidic leaching solution of spent catalysts by solvent extraction with ionic liquid

The recovery of metals from spent petroleum catalysts has been attracting much attention owing to an increase in the metal demand. In this work, bi-functional ionic liquid, ALi-D2, in kerosene synthesized by Aliquat336 and D2EHPA was employed for the separation of Mo(VI), V(V), Ni(II) and Al(III) from the synthetic HCl leaching solution of spent petroleum catalyst. The metal ions were efficiently separated by adjusting the concentration of ALi-D2 and acidity of the leaching solution. First, Mo(VI) was selectively extracted into ALi-D2 together with a small amount of V(V). The co-extracted V(V) was removed from the loaded ALi-D2 by selective stripping with H2SO4 solution. Then the Mo(VI) was stripped from the stripped ALi-D2 with NH4OH solution. Second, the V(V) in the raffinate was selectively extracted by ALi-D2 over Al(III) and Ni(II). Al(III) was selectively extracted over Ni(II) from the raffinate by extraction with ALi-D2 after adjusting the pH at 2. The solvent extraction reaction of metal ions by ALi-D2 was identified by applying slope analysis method. The interaction between extractant and metal complexes was analyzed by FT-IR spectra. A process was proposed to separate the four metal ions in the leaching solution based on the results.

Selective dissolution of vanadium(V) from spent petroleum catalysts by oxalic acid solution

The spent petroleum catalyst contains a significant amount of vanadium and its recovery is essential. Oxalic acid has good metal selectivity due to its complex properties. Leaching experiments with oxalic acid were done to investigate the dissolution behavior of vanadium from spent petroleum catalyst by varying leaching conditions, such as temperature, concentration, pulp density, stirring speed and time. Vanadium and molybdenum were selectively dissolved by oxalic acid from the spent catalysts, while the leaching percentage of other metals was very low. However, the leaching percentage of vanadium by oxalic acid was lower than 45% in most of the leaching conditions. Our results provide some basic information on the dissolution of valuable metals from the spent catalyst by using organic acid.

Leaching of Rare Metals from Spent Petroleum Catalysts by Organic Acid Solution

Leaching of Rare Metals from Spent Petroleum Catalysts by Organic Acid Solution

The effect of spent petroleum catalyst powders on the multiple properties in blended cement

A growing number of spent petroleum refining catalysts, SPC, were mainly disposed in landfills, which has brought about serious occupation of land resources and environmental security risks. In this paper, the effects of SPC powders on the workability, development of mechanical property, microstructure and the environmental safety with the incorporation of SPC (≤5 wt%) in the blended cement were systematically researched. The results indicated that the SPC powders should be regarded as heavy metals-polluted materials due to the plenty of heavy metals in SPC powders: 5804.81 ppm Ni, 2559.72 ppm V, 2429.83 ppm Sb. And the incorporation of the SPC powders resulted in the increase of the water requirements of standard consistency due to the relatively high Blaine fineness and porous micromorphology of SPC powders, but the addition of polycarboxylic acid water reducer improved effectively the reduced workability of the blended cement. It was also demonstrated that only the incorporation of 0.5% SPC powder leads to the accelerated setting time and early strength. The incorporation of SPC powders up to 5.0% all exhibited increasing enhancement influence on the long-term mechanical strength. These findings are well consistent with the subsequent analyses of non-evaporable water content and XRD. Meanwhile, the convincing evidences were presented by the SEM coupled with EDS to illustrate the effects of filling, nucleation, pozzolana and particle-reinforcement of SPC powders on the blended cement. The leaching toxicity tests also suggested that the disposal of SPC powders as cement admixture was quite unhazardous to the environment safety during the age of 28 days. However, the specific application environments, the long-term durability and the aggressive environment safety of utilizing SPC powders in cement need to further study.

Dissolution behavior of sulfur and some metals from spent petroleum catalysts by alkaline solutions

Dissolution behavior of sulfur and some metals from spent petroleum catalysts by alkaline solutions

Integrated bio-pyro-hydro-metallurgical approach to recover metal values from petroleum refinery spent catalyst

Abstract The present study reports an integrated three-step bio-pyro- hydrometallurgical process to recover nickel (Ni) and molybdenum (Mo) from spent petroleum catalyst. High leaching yields of nickel (94%) and molybdenum (92%) along with other critical metals like rhenium, selenium, niobium, chromium, and zirconium were obtained. A toxic element like Pb was leached entirely from the spent catalyst while precious metal like palladium was concentrated during the treatment. The waste petroleum catalyst and all the residues were characterized to understand the morphology, chemical composition, and mineralogy by Scanning Electron Microscopy-Electron Dispersive X-Ray spectroscopy (SEM-EDAX), X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) respectively, while the Ni and Fe concentration in the bioleach liquor was analyzed by Atomic Absorption Spectroscopy (AAS). In the first stage, bioleaching of spent catalyst leached up to 94% Ni and 71% Mo. The rate-limiting step in Ni bioleaching kinetics was calculated to be both chemically as well as diffusion controlled. The Ni bioleaching followed 1st order reaction kinetics. Integrating roasting (1 h) and alkaline leaching (6 h) with the bioleaching process remarkably increased the recovery of Mo by 21%. Roasting of the spent catalyst after bioleaching lessened not only harmful SO2 emission by 64.95% but also liberated residual Mo by 23% from the aluminium silicate matrix. Therefore, employing a sequential bio-pyro-hydrometallurgical technique is a more eco-friendly and cost-effective strategy to recover metal values from spent petroleum catalyst.

Recovery of Platinum from Spent Petroleum Catalysts: Optimization Using Response Surface Methodology

The global yield of platinum (Pt) recovery from spent catalysts is about 30%. Pt recovery from spent catalysts is one of the most significant methods to reduce its supply risk and meet future demand. The current hydro-leaching processes always involve extremely high acidity (c(H+) &gt; 6.0 mol/L), causing serious environmental issues and consuming large amounts of reagents. This paper studied the recovery of Pt from spent petroleum catalysts in a mild leaching solution (c(H+) = 1.0−2.0 mol/L). The HCl and NaCl were used as leaching agents, while H2O2 was used for oxidation of Pt. The leaching factors, including solid/liquid ratio (S/L), acidity, leaching temperature, and H2O2 usage, were studied. The leaching efficiency of Pt was 95.7% under the conditions of S/L of 1:5 g/mL, HCl of 1.0 mol/L, NaCl of 5.0 mol/L, 10% H2O2/spent catalysts of 0.6 mL/g, and temperature of 90 °C for 2 h. The leaching kinetic of platinum fits best to the Avrami equation. The apparent activation energy for leaching platinum was 114.9 kJ/mol. Furthermore, the effects of the operating variables were assessed and optimized by employing a response surface methodology based on Box-Behnken Design. The result shows that HCl concentration had the greatest impact on the leaching efficiency as compared to the H2O2 concentration and S/L ratio. Pt leaching efficiency was increased to 98.1% at the optimized conditions of HCl of 1.45 mol/L, NaCl of 4.55 mol/L, 10% H2O2/spent catalysts of 0.66 mL/g, and S/L of 1:4.85. The purity of Pt is over 90% by the reduction of iron powder.

An integrated sequential biological leaching process for enhanced recovery of metals from decoked spent petroleum refinery catalyst: A comparative study

We report on the effectiveness of a two-stage sequential integrated bioleaching process for enhanced recovery of metals from decoked spent petroleum catalyst. Fourier transform-infrared spectra confirmed that decoking led to removal of entrained hydrocarbons and carbonaceous deposits from the raw spent catalyst. Several two-stage sequential leaching strategies (two-stage bioleaching, two-stage abiotic leaching, bioleaching followed by alkali leaching, alkali leaching followed by acid leaching, and two-stage alkali leaching) were evaluated in batch reactors. The results suggested that two-stage bioleaching (240h) with Acidithiobacillus thiooxidans was the most effective strategy to recover Ni (79%) and V (90%). Whereas integrating bioleaching with alkaline leaching remarkably improved leaching yield of Mo (88%) in a shorter period of time (125h). A mineral liberation analysis of the treated residue also confirmed that most of the Mo was leach out during second stage alkali leaching.

Bioleaching of metals from spent refinery petroleum catalyst using moderately thermophilic bacteria: Effect of particle size

The present work investigated the leaching potential of moderately thermophilic bacteria in the recovery of metals from spent petroleum catalyst of varying particle sizes. The batch bioleaching experiments were conducted by employing a mixed consortium of moderate thermophilic bacteria at 45°C and by using five different particle sizes (from 45 to >2000 μm) of acetone-washed spent catalyst. The elemental mapping by FESEM confirmed the presence of Al, Ni, V and Mo along with sulfur in the spent catalyst. During bioleaching, Ni (92–97%) and V (81–91%) were leached in higher concentrations, whereas leaching yields of Al (23–38%) were found to be lowest in all particle sizes investigated. Decreasing the particle size from >2000 μm to 45–106 μm caused an increase in leaching yields of metals during initial hours. However, the final metals leaching yields were almost independent of particle sizes of catalyst. Leaching kinetics was observed to follow the diffusion-controlled model showing the linearity more close than the chemical control. The results of the present study suggested that bioleaching using moderate thermophilic bacteria was highly effective in removing the metals from spent catalyst. Moreover, bioleaching can be conducted using spent catalyst of higher particle size (>2000 μm), thus saving the grinding cost and making process attractive for larger scale application.

Recovery of Platinum from Spent Petroleum Catalysts by a Hydrometallurgical Method

Platinum was recovered from the leaching solution of spent petroleum catalysts by solvent extraction. The spent catalysts were first roasted at 800 ℃ to eliminate volatile matter. Most of the platinum in the spent catalysts was dissolved at an optimum leaching condition in a mixture of HCl and H2O2. Separation of platinum from the leaching solution was accomplished by solvent extraction with Aliquat 336 after iron was removed by extraction with TBP. Platinum and iron were stripped from the loaded Aliquat 336 and TBP by using 1 M HClO4 and 0.1 M HCl, respectively. Finally, HCl in the raffinate was recovered by extraction with TEHA and then by stripping with water. The optimum conditions to dissolve platinum and to separate platinum by solvent extraction are reported together with the mass balance of the constituents of the spent catalysts in each step.

Bench-scale batch bioleaching of spent petroleum catalyst using mesophilic iron and sulfur oxidizing acidophiles

Microbial leaching of a petroleum spent catalyst was carried out using mixed mesophilic iron and sulfur oxidizing acidophiles. Bench-scale batch stirred tank reactors with a working volume of 1 L were used in this study at 35 °C. The pulp density considered for the study was 10% (w/v), while the particle size of the spent catalyst was varied by 45–106, 106–212 and >212 μm. The leaching percentage of Ni from the spent catalyst was found to be highest (97–98%) with varying particle size. However, the leaching yield for rest of the metals like Al, Fe, V and Mo was 70–74%, 66–85%, 33–43% and 22–45%, respectively. Influence of particle size was predominant on the recovery of all metals except Ni. Assessment of the generation of the bioleach residue after bioleaching showed a weight loss of 54–62% due to the dissolution of the metal values from the spent catalyst. The mineralogical study conducted by X-ray diffraction and scanning electron microscopy supports the dissolution of metals from the spent catalyst. Jarosite mineral phase was the dominant mineral phase in the bioleach residue due to the dissolution of the oxidic and sulfidic mineral phases present in the feed spent catalyst.

Recovery of Platinum from Chloride Leaching Solution of Spent Catalysts by Solvent Extraction

Platinum was recovered from the leaching liquor of spent petroleum catalyst by solvent extraction. Most of platinum in the spent catalysts was leached by using a mixture of HCl and H2O2 from the roasted spent catalyst. The effect of concentration of HCl/H2O2 in the solution, reaction temperature and pulp density was investigated. Complete extraction of Pt and Fe from the leaching liquor was obtained by Aliquat 336 at an O/A ratio of 1 in 2 stages. High purity solutions containing Fe and Pt were obtained from the loaded Aliquat 336 by scrubbing with dilute HCl solution and stripping with HClO4, respectively. Finally, HCl in the raffinate was regenerated by extraction with TEHA (Tri (2-ethylhexyl) amine) and then by stripping with water. The purity of HCl in the stripped solution was high enough to be reused in the leaching of spent catalysts. The optimum conditions in leaching, extraction and stripping together with the mass balance of the constituents of the spent catalysts in the whole process are reported. [doi:10.2320/matertrans.M2012320]

Extraction of metal values from waste spent petroleum catalyst using acidic solutions

The extraction of molybdenum and cobalt from spent petroleum catalyst (Co–Mo/Al2O3) was investigated using sulphuric and nitric acid solution. Direct leaching of spent catalyst with sulphuric acid was not effective, whereas the combination of sulphuric and nitric acid was significant for the recovery of both molybdenum and cobalt. The effect of experimental factors such as reaction time, acid concentration, temperature, solid–liquid ratio and particle size were studied to determine the best conditions for the solubilisation of metal values. The parameters, temperature and nitric acid concentration are found to be critical factors especially on leaching of molybdenum from the spent catalyst. Under optimum conditions (pulp density 10% (w/v), [H2SO4] 0.5M, [HNO3] 4.0M, particle size 51–70μm, temperature 50°C and time 5h), about 99.7% of molybdenum and 99.6% of cobalt could be extracted with 14.9% extraction of aluminium.