Chemical Treatment to Recover Molybdenum and Vanadium from Spent Heavy Gasoil Hydrodesulfurization Catalyst

Abstract

Large quantities of spent hydrodesulfurization (HDS) catalysts are available from petrochemical industry. Disposal of spent catalyst is a problem as it falls under the category of hazardous industrial waste due to its vanadium concentration. Most of these catalysts are usually supported on alumina containing a variable percentage of elements such as nickel or molybdenum. Hence these catalysts contain environmentally critical, and economically valuable metals such as molybdenum, vanadium, and, nickel. In this paper, a spent HDS catalyst was treated with caustic soda solution. Parameters such as temperature, time, and NaOH solution concentration have been studied thoroughly, in order to settle the appropriate conditions for the maximum recovery of molybdenum and vanadium. Under the best leaching conditions (20% w NaOH, room temperature, 2 h) about 95% recovery of Mo and V was achieved, and the recovery of nickel obtained was of 99% in the form of NiAlO 4 .

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

“…Therefore, the material was calcined at 800 o C in 4 h to oxidize vanadium sulfide before leaching experiments. This step is a fundamental process which has been reported in several publications [9,23,24]. As is shown in Table 1, the chemical compositions of metals were changed after heat treatment.…”

“…Both hydro-and pyrometallurgical treatments are generally employed for the extraction of vanadium from the ores or secondary resources. In hydrometallurgy, vanadium is dissolved by leaching with either alkaline (NaOH, KOH, Na 2 CO 3 , NH 3 ) or acidic (H 2 SO 4 , HNO 3 , HCl, HF, H 2 C 2 O 4 ) solutions, while pyrometallurgy uses the heat treatment at high temperature like roasting or smelting to extract vanadium [3][4][5][8][9][10][11][12]. In hydrometallurgical processes, vanadium is separated from the leaching solutions by several unit operations such as solvent extraction, precipitation, and ion exchange.…”

“…In order to improve the leaching efficiency of vanadium, the addition of additive agents has been employed. When vanadium exists as a sulfide form, the prior treatment of spent catalysts before leaching would enhance the leaching efficiency of vanadium [9]. Although the acidity of oxalic acid is very weak [15], the oxalate has good chelating properties and thus has a strong tendency to J. Min.…”

A review of the valorization and management of industrial spent catalyst waste in the context of sustainable practice: The case of the State of Kuwait in parallel to European industry

“…A different technique to recover V, Mo and Ni from waste catalyst produced from heavy gasoil hydrodesulphurization is by using caustic soda solution (Rojas-Rodríguez et al, 2012). Spent catalyst with a particle size between 1.5 and 7.3 mm is calcinated at temperatures up to 450°C.…”

Synthesis and Industrial Application of Protective Layer Catalysts Based on Kaolin for Hydroclean Installations

“…At present there is a tendency to extract oil with high sulfur content, resinous asphaltenic substances and organometallic compounds along with a reduced yield of light distillates [1,2] due to the continuous increase of demand for environmentally clean fuel and oil fractions. Processing of problematic raw materials makes it important to develop protective layers taking into account its specificity [3], features of the adopted technology, economic feasibility of regeneration for reuse [4][5][6] and recovery of used catalysts with extraction of valuable metals [7][8].…”