Desulfurization of heavy oil

Abstract

Strategies for heavy oil desulfurization were evaluated by reviewing desulfurization literature and critically assessing the viability of the various methods for heavy oil. The desulfurization methods including variations thereon that are discussed include hydrodesulfurization, extractive desulfurization, oxidative desulfurization, biodesulfurization and desulfurization through alkylation, chlorinolysis, and by using supercritical water. Few of these methods are viable and/or efficient for the desulfurization of heavy oil. This is mainly due to the properties of the heavy oil, such as high sulfur content, high viscosity, high boiling point, and refractory nature of the sulfur compounds. The approach with the best chance of leading to a breakthrough in desulfurization of heavy oil is autoxidation followed by thermal decomposition of the oxidized heavy oil. There is also scope for synergistically employing autoxidation in combination with biodesulfurization and hydrodesulfurization.

A Review on Desulfurization Techniques of Liquid Fuels

“…In HDS process aliphatic sulfur is more reactive and removed completely from liquid fuel according to following mechanisms [4]: [8] In general the reaction mechanism of DBT through HDS process was suggested via two main routes Fig 1: one is direct desulfurization route, where sulfur removal occurs without affecting the aromatic rings and another is Even though HDS process is still the main technology applied in the petroleum refining industry some advantages appear as it described below [9] a) Severe reactor conditions such as high temperature and pressure required to process more refractory sulfur compounds. b) Use of expensive catalyst; due to the high organometallic content of heavy hydrocarbon the catalyst life shortens as the metal (Nickel, Vanadium) sulfides causes deposit formation on the catalysts.…”

“…[17]. The biodesulfurization process carried out in two phase system, whether whole cell used as biocatalyst in the aqueous phase interacts with oil phase [4,33]. Long ago only gram positive bacteria utilized for biodesulfurization of sulfur compounds.…”

“…The refractory sulfur compound becomes more refractory with increasing of boiling point, the dominant sulfur compounds such as thiols, thiophene, and sulfides in naphtha to substituted benzothiophenic compounds in distillate. Recent studies on desulfurization show that sulfur content in the environment is increasing and could gesture series health consequences like the respiratory disease such as emphysema [4].…”

Comparison of Mo/MgO and Mo/γ-Al2O3 catalysts: impact of support on the structure and dibenzothiophene hydrodesulfurization reaction pathways

“…Desulfurization methods, including various approaches such as adsorptive desulfurization (Saleh and Danmaliki 2015;Ahmed and Jhung 2016), oxidative desulfurization (Fox et al 2015), biodesulfurization, chlorinolysis, and use of supercritical water (Javadli and Klerk 2012), have been introduced to meet the challenges of producing ultra-clean fuels at affordable prices. Although these methods are very promising for removing the refractory sulfur or nitrogen compounds at ambient temperature and pressure, hydrodesulfurization (HDS) is the most common method used in the petroleum industry to reduce the sulfur content of fuel products.…”

Simultaneous recovery and desulfurization of bitumen from oil sand using ultrasound irradiation

“…[24][25][26][27][28][29] Oxidation of sulfur leads to the production of sulfone (S=O=S), which is more polarized than the original sulfur and is selectively removed by extraction via alkali treatment. 25) Sulfide compounds are also removed via alkali treatment. 30) In our previous study, ODS was combined with ultrasonic irradiation to produce low-sulfur bitumen; we obtained 52% sulfur removal using H 2 O 2 (30 wt %) and saturated NaOH under ultrasonic irradiation.…”