Mercury removal from crude oil using natural minerals
M.-A. Gatou, D.S. Tsoukleris, E.A. Pavlatou
35th International Conference on Environmental Geochemistry and Health (2019), 1-5 July, Manchester Metropolitan University, UK (oral)
Mercury has been reported to be naturally occurring trace contaminant in the oil reservoirs. The chemical nature of mercury in oil reservoirs is of interest for a variety of reasons, but especially because it is important to understand the fate of the various species, as they partition to fuels and waste streams in processing. Practical considerations also exist as mercury affects equipment integrity, catalyst performance, product quality, as well as the health and safety of workers. This study, evaluates the suitability of natural minerals (zeolite and attapulgite) as sorbents of mercury in artificial aqueous solution and crude oil. The tested materials were natural zeolite (clinoptilolite), thermally treated zeolite, silver-loaded zeolite and attapulgite. Mercury sorption experiments were carried out under stable conditions using anartificial aqueous solution, characterized by an Hg concentration of the order of 50 mg dm-3 , simulating the concentration of mercury in crude oil. In the case of attapulgite and silver-activated zeolite, the sorption efficiency was achieved at a level of above 90%. Under the same experimental conditions testing of commercially available resins took place, in order to be used for further enhancing the absorption capacity of the natural materials, and therefore to present overall higher selectivity in mercury. Additionally, the removal of mercury from real crude oil was investigated. The results for the tested samples indicate a significant increase of the sorption efficiency. Based on these results, a novel, effective and low-cost mercury-selective adsorbent is proposed and therefore, it can be used as a filter during oil production processes.