Biodesulfurization of the mixture of dibenzothiophene and its alkylated derivatives by Sphingomonas subarctica T7b

Abstract

Organosulfur compounds classified as dibenzothiophenes (DBTs) and their derivatives are contained in petroleum. When used as fuel, these substances release SOx emissions, thus contributing to air pollution, acid rain, and climate change. Therefore, it is necessary to reduce the content of these organic sulfur compounds in fuels and one way to achieve this is through bacterial desulfurization. This study reports the biodesulfurization process of a mixture of DBT, 4-hexyl DBT, 4,6-dibutyl DBT, and various organosulfur compounds in light gas oil (LGO). The experiment was conducted by treating 1 mL of aromatic organosulfur compounds with 100 mg/L in \textit{n}-tetradecane or 1 mL LGO with 5 mL mineral salts in sulfur-free medium, incubated at 27 °C for 5 days with shaking at 273 rpm. Gas chromatography analyses revealed that the growing Sphingomonas subarctica T7b cells desulfurized and converted 88.29% of DBT to 2-hydroxybiphenyl as a metabolite while a mixture of DBT and 4,6-dibutyl DBT was desulfurized at 86.40\% and 7.00%, respectively. Furthermore, the mixture of DBT, 4-hexyl DBT, and 4,6-dibutyl DBT had a desulfurization percentage of 84.40%, 41.00%, and 6.66%, respectively, after five days of incubation. The compounds were observed to desulfurize slightly better as single compounds compared to when mixed with other aromatic sulfur compounds.

Optimization of Biodesulfurization of sour heavy crude oil

“…Whereas Rhodococcus erythropolis IGTS8 has a tendency of specificity towards DBT more than alkylated forms and BT respectively, Also, each microorganism has special selectivity for which sources of sulfur [ 22 , 32 , 33 ]. Also, the various availability of sources of sulfur compounds generate a competitive in desulfurization, therefore the efficiency with multiple substrates is less than single substrate [ 10 , 26 , 34 ]. Therefore, the microorganisms desulfurize crude oil and its derivative with different efficiencies according to the presence of these HCS in fractions [ 32 ].…”

Biochemical Analytical Methods of Fossil Fuels Biodesulfurization Treatment

“… GC-FID: GC-FID for quantitative estimation of DBT removal [19] and estimation of sulfur compounds by GC-FID-CP-Sil5CB [20].  GC-FPD: such as GC-14A connected with a column Zebron ZB-1 and an FPD for analysis of the content of DBT and its compounds in the culture [21].  GC-AED: (GC-AED, G2350A; Agilent, Hewlett-Packard, USA) for analyzing the variation of HCSs in diesel and the oil (Yu 2006).…”

“…The decrease in content of sulfur was estimated from the decrease in the sum of each sulfur peak area determined by GC-FPD, as described by Helnández-Moldonado and Yang [25]. GC-FID connected with a DB-17 column for determination of contents of DBT and derivatives, and metabolite (2-HBP) [26]. GC-MS-QP5000; Shimadzu was applied for identification of 2-HBP metabolite ).…”

Biodesulfurization of Fossil Fuels: Analysis and Prospective

“…However, the pure rate of BDS is generally low. To increase the bioreaction rate, electrokinetic or sonochemical fields can be used ( Awadh et al ., 2020 ; Chauhan et al ., 2015 ; Gunam et al ., 2021b ; Ismail et al ., 2016 ; Shahaby and Essam-El-din, 2017 ; Boshagh et al ., 2014 ).…”

“…Rhodococcus strains, such as R. erythropolis , have been isolated from contaminated soil using basal salts or sulfur-free medium (Jarullah, 2012). Other isolates, such as Gordonia sp., Noocaria sp., Pantoea agglomerans , Pseudomonas delafieldii , Pseudomonas aeruginosa , SRB, and Sphingomonas subarctica , have also been prepared and studied ( Chen et al ., 2019a , 2019b ; Gunam et al ., 2021a , 2021b ; Saeed et al ., 2022 ).…”