Resumo

ALONSO, Fernando; RAMIREZ, Sergio; ANCHEYTA, Jorge  e  MAVIL, Martha. Alternatives for recovering of metals from heavy hydrocarbons spent hydrotreating catalysts: a case of study. Rev. Int. Contam. Ambient [online]. 2008, vol.24, n.2, pp.55-69. ISSN 0188-4999.

The increasing production of spent hydrotreating catalysts used for processing heavy hydrocarbons and the problems related to their disposal are described in this work. These catalysts contain important amounts of heavy metals such as molybdenum (Mo), nickel (Ni), cobalt (Co) and vanadium (V), which can be recovered and hence an economical benefit may be obtained. The results of experimental tests for alkaline leaching (NaOH) to recover V and Mo, and the effect of operating conditions on metal recovery are also presented. The results show that, in general, the highest recovery of Mo is obtained at pH 8.5 and leaching time of 12 hours, while in the case of V, the highest recovery is observed at pH 9.0 and 8 hours. In both cases, the leaching solution contained 10 wt % alkaline. Based on the experimental information and data from a commercial plant, a preliminary economy study was developed, in which the expected economical benefits of metals recovery from spent catalysts used for hydrotreating heavy hydrocarbon are estimated.

Palavras-chave : spent catalyst; hydrotreatment; leaching; molybdenum; vanadium.