Experimental and Modeling Study on Precipitated Asphaltene Biodegradation Process Using Isolated Indigenous Bacteria

Abstract

Removing the precipitated asphaltenes from the facilities of oil industry is of vital importance. In this study, the possibility of the precipitated asphaltene biodegradation from a crude oil sample using indigenous bacterial species isolated from different oil-contaminated samples of a Middle East oilfield has been investigated. On the basis of the achieved designed experiments results using response surface methodology, identified bacteria were cultured in the flasks on pure and consortium. Three levels of temperatures, salinity, pH, and initial asphaltene concentration were considered as growth medium parameters, and the flasks were incubated for 60 days. The CHNS and FT-IR analysis have been performed to evaluate the asphaltene elemental and structural alteration after the biodegradation process. The validity of some kinetic models to predict the behavior of the microbial systems was studied. The maximum asphaltene biodegradation was 41.95% and carbon, hydrogen, and nitrogen content of treated samples decreased significantly during the bacterial activity.

Whatsoever things are true: Hypothesis, artefact, and bias in chemical engineering research

“…For example, a recent study on asphaltene biodegradation by oilfield organisms included no control experiments of any kind. [14] Even worse, the authors erroneously referred to the unreacted asphaltene as a "control sample." Unlike the study by Kirkwood, [12] sterile and killed-cell treatments were not used as negative controls, and the need for positive control experiments was not even considered.…”

“…For example, a recent study on asphaltene biodegradation by oilfield organisms included no control experiments of any kind. [ 14 ] Even worse, the authors erroneously referred to the unreacted asphaltene as a “control sample.” Unlike the study by Kirkwood, [ 12 ] sterile and killed‐cell treatments were not used as negative controls, and the need for positive control experiments was not even considered. Such studies often appear in engineering journals that rarely publish biochemical engineering work, and which lack a pool of reviewers who are aware of the requirement for positive and negative control experiments.…”

Study on a Strain of Lysinibacillus sp. with the Potential to Improve the Quality of Oil Sands

“… 2 With the help of an auxiliary carbon source, a fungus of Pestalotiopsis degraded 92% of the samples in the medium within 30 days (the initial concentration of crude oil was 1000 mg/L). 3 At present, researchers mainly focus on the environmental pollution caused by the petroleum industry. Zhang et al found a strain of Pseudomonas aeruginosa DQ-8 that can effectively degrade n -alkanes and polycyclic aromatic hydrocarbons in petroleum pollutants.…”

Asphaltene biotransformation for heavy oil upgradation

“…This precipitated asphalt forms a solid mass which deposits in the pipelines and clogs them (Tavakkoli et al 2015 ). Several physical (wireline cutting and hydro blasting), thermal (oil or water vapor injection, heating bottom well) and chemical (solvent or soluble amphiphile injection) methods have been used to remove the precipitated asphaltene (Shahebrahimi et al 2018 ). These methods require extreme conditions and are cost and energy intensive.…”

“…Biological methods of asphaltene biodegradation or biotransformation offer certain advantages over the ones mentioned above by being specific, less severe, environmentally friendly and cost effective. There are several reports on microbial degradation of asphaltenes (Lavania et al 2012 ; Pineda-Flores et al 2004 ; Pourfakhraei et al 2018 ; Shahebrahimi et al 2018 ; Uribe‐Alvarez et al 2011 ). During asphaltene biodegradation, microorganisms utilize asphaltene as a primary carbon source for their growth.…”