Klebseilla Oxytoca; An Efficient Pyrene-Degrading Bacterial Strain Isolated from Petroleum Contaminated Soil

Polycyclic aromatic hydrocarbons (PAHs) are the hazardous xenobiotic agents of oil production. One of the methods to eliminate hazardous compounds is bioremediation, which is the most efficient and cost-effective method to eliminate the harmful byproducts of crude petroleum processing. In this study, five pure bacterial isolates were isolated from petroleum-contaminated soil, four of which showed a robust growth on pyrene as a sole carbon source. Various methods viz mass spectroscopy, biochemical assays, and 16s RNA sequencing employed to identify the isolates ascertained the consistent identification of Klebsiella oxytoca by all three methods. Scanning electron microscopy and Gram staining further demonstrated the characterization of the K. oxytoca. High-performance liquid chromatography of the culture supernatant of K. oxytoca grown in pyrene containing media showed that the cells started utilizing pyrene from the 6th day onwards and by the 14th day of growth 3/4th of the pyrene was completely degraded. Genome search for the genes predicted to be involved in pyrene degradation using Kyoto Encyclopedia of Genes and Genomes (KEGG) confirmed their presence in the genome of K. oxytoca. These results suggest that K. oxtoca would be a suitable candidate for removing soil aromatic hydrocarbons.

Catalysts for the Conversion of CO2 to Low Molecular Weight Olefins—A Review

There is a large worldwide demand for light olefins (C2=–C4=), which are needed for the production of high value-added chemicals and plastics. Light olefins can be produced by petroleum processing, direct/indirect conversion of synthesis gas (CO + H2) and hydrogenation of CO2. Among these methods, catalytic hydrogenation of CO2 is the most recently studied because it could contribute to alleviating CO2 emissions into the atmosphere. However, due to thermodynamic reasons, the design of catalysts for the selective production of light olefins from CO2 presents different challenges. In this regard, the recent progress in the synthesis of nanomaterials with well-controlled morphologies and active phase dispersion has opened new perspectives for the production of light olefins. In this review, recent advances in catalyst design are presented, with emphasis on catalysts operating through the modified Fischer–Tropsch pathway. The advantages and disadvantages of olefin production from CO2 via CO or methanol-mediated reaction routes were analyzed, as well as the prospects for the design of a single catalyst for direct olefin production. Conclusions were drawn on the prospect of a new catalyst design for the production of light olefins from CO2.

Anthracene and Pyrene Biodegradation Performance of Marine Sponge Symbiont Bacteria Consortium

Every petroleum-processing plant produces sewage sludge containing several types of polycyclic aromatic hydrocarbons (PAHs). The degradation of PAHs via physical, biological, and chemical methods is not yet efficient. Among biological methods, the use of marine sponge symbiont bacteria is considered an alternative and promising approach in the degradation of and reduction in PAHs. This study aimed to explore the potential performance of a consortium of sponge symbiont bacteria in degrading anthracene and pyrene. Three bacterial species (Bacillus pumilus strain GLB197, Pseudomonas stutzeri strain SLG510A3-8, and Acinetobacter calcoaceticus strain SLCDA 976) were mixed to form the consortium. The interaction between the bacterial consortium suspension and PAH components was measured at 5 day intervals for 25 days. The biodegradation performance of bacteria on PAH samples was determined on the basis of five biodegradation parameters. The analysis results showed a decrease in the concentration of anthracene (21.89%) and pyrene (7.71%), equivalent to a ratio of 3:1, followed by a decrease in the abundance of anthracene (60.30%) and pyrene (27.52%), equivalent to a ratio of 2:1. The level of pyrene degradation was lower than that of the anthracene due to fact that pyrene is more toxic and has a more stable molecular structure, which hinders its metabolism by bacterial cells. The products from the biodegradation of the two PAHs are alcohols, aldehydes, carboxylic acids, and a small proportion of aromatic hydrocarbon components.

Comparison of Biodegradation Performance of Marine Sponge Symbiont Bacteria Consortium Against Anthracene and Pyrene

Every petroleum processing industry produces sewage sludge containing several types of poly-cyclic aromatic hydrocarbon (PAHs) components. The degradation of PAH components by physical, biological and chemical methods is not efficient. The use of marine sponge symbiont bacteria is considered an alternative method in the degradation and reduction of PAHs com-pared to the previous method. This study aims to explore the potential and performance of a consortium of sponge symbiont bacteria in degrading anthracene and pyrene. There are three types of bacteria (Bacillus pumilus strain GLB197, Pseudomonas stutzeri strain SLG510A3-8, Acineto-bacter calcoaceticus strain SLCDA 976) were mixed to form a consortium. The interaction between the bacterial consortium suspension and PAH components was measured at 5-day intervals for 25 days. The biodegradation performance of bacteria on PAHs samples was determined based on five biodegradation parameters. The analysis results showed a decrease in the concentration of anthracene (21.89%) and pyrene (7.71%), equivalent to a ratio of 3: 1. The data was followed by a decrease in the abundance of anthracene (60.30%) and pyrene (27.52%), an equivalent ratio of 2: 1. The level of degradation of the pyrene component is lower than that of the anthracene compo-nent, presumably due to the higher toxicity of pyrene and the more stable molecular structure, making it difficult for bacterial cells to destroy it. The biodegradation products are organic compounds of alcohol, aldehyde, carboxylic acids and a small proportion of aromatic hydrocarbon components. Keywords: performance; biodegradation; bacterial consortium; marine sponge; PAHs

Biodegradation mechanism of naphthalene using marine sponge symbiotic bacteria

Generally, all petroleum processing industries produce oil sludge or sludge. Polycy-clic Aromatic Hydrocarbons (PAH), one of the components contained in sludge, are hazardous and toxic waste material with toxic, carcinogenic and mutagenic properties. The research objective was to understand the biodegradation mechanism of naphthalene by utilizing a marine sponge symbiotic bacterial isolate. Partial bacteria Bacillus Sp strain AB353f (BC), sponge isolate Neopetrosia sp and Acinetobacter Calcoaceticus strain PHCDB14 (AC) isolate sponge Callyspongia (Aerizusa) as biomaterial for PAH degradation. Biodegradation method integrates bacterial suspension with 10,000 ppm naphthalene for 25 days. Every 5 days, the bio-degradation indicators were observed and the products of the destruction of naphthalene components were measured using FTIR and GC-MS. The results showed that BC isolates and AC isolates from sponge symbionts could degrade naphthalene. The biodegradation performance of BC bacteria tended to be more dominant than AC against naphthalene. Based on the functional groups resulting from FTIR, three types of biodegradation products were identified, namely: alcohol, aldehyde and carboxylic acid and one transition product in the form of a cate-chol. Maximum naphthalene bio-degradation occurs at an interaction period of 20 - 25 days.

Practical Approaches towards NOx Emission Mitigation from Fluid Catalytic Cracking (FCC) Units

There appears to be consensus among the general public that curtailing harmful emissions resulting from industrial, petrochemical and transportation sectors is a common good. However, there is also a need for balancing operating expenditures for applying the required technical solutions and implementing advanced emission mitigation technologies to meet desired sustainability goals. The emission of NOx from Fluid Catalytic Cracking (FCC) units in refineries for petroleum processing is a major concern, especially for those units located in densely populated urban settings. In this work we strive to review options towards cost-efficient and pragmatic emissions mitigation using optimal amounts of precious metal while evaluating the potential benefits of typical promoter dopant packages. We demonstrate that at present catalyst development level the refinery is no longer forced to make a promoter selection based on preconceived notions regarding precious metal activity but can rather make decisions based on the best “total cost” financial impact to the operation without measurable loss of the CO/NOx emission selectivity.

Decoupling Analysis of CO2 Emissions in the Industrial Sector from Economic Growth in China

China has become the largest CO2 emission country since 2014. The industrial sector is the largest contributor to CO2 emissions in China. This paper uncovers the spatiotemporal characteristics of the decoupling status of industrial CO2 emissions from economic growth at the provincial level during 1995–2019 in China and analyzed the structural characteristics of the industrial CO2 emissions. The results suggested that 2010 is an important turning point. Since 2010, the decoupling status of industrial CO2 emissions from economic growth has kept a continuously improving trend. During 2016–2019, all provinces achieved decoupling of the industrial CO2 emissions from economic growth. More than 20% achieved absolute strong decoupling. Four subindustries, including raw chemical materials and chemical products, production and supply of electric power and heat power, petroleum processing and coking products, and smelting and pressing of non-ferrous metals, with large CO2 emissions’ contribution and a continuously increasing trend, should be paid more attention in the future CO2 reduction policies formulation.

Slug Frequency Prediction Model for Fluid Flow in Flowline Bends

The prediction of slug frequency for two-phase slug flow during multiphase transportation of oil reservoir productions is crucial in the design of slug controllers for petroleum processing installations. Mechanistic based slug prediction models have not had much successful application due to the difficulty in modelling the non-linear interface motion during slug development. The mechanism of slugging in offshore flowline-riser is complicated and requires rigorous experimental sampling and testing. This process can be time-consuming and costly. In this study, a new correlation is developed for the prediction of severe slugging frequency. The new model is developed based on the results of scaled experimental design. Dimensional analysis approach using the Buckingham pi-theorem is used in developing the two-phase correlation. The model development involves non-dimensional empirical correlations in terms of relevant dimensionless groups, which are obtained based on the design of the experiment. A broad range of experimental data from 10 varied choke opening size was used. The new correlation predicts 92.3% of the measurements within ±8% absolute error and the mean absolute deviation of the correlation is about 6.13%. The newly developed correlation can be applied for flow rates between 0.1 kg/s and 0.6 kg/s and choke openings between 10-98%.

Carbon Emissions in the Xinjiang Production and Construction Corps and Driving Factors

Xinjiang production and Construction Corps (XPCC) is an important provincial administration in China and vigorously promotes the construction of industrialization. However, there has been little research on its emissions. This study first established the 1998-2018 XPCC subsectoral carbon emission inventory based on the Intergovernmental Panel on Climate Change (IPCC) carbon emission inventory method and adopted the logarithmic mean Divisia indexmethod (LMDI) model to analyze the driving factors. The results revealed that from 1998 to 2018, the total carbon emissions in the XPCC increased from 6.11 Mt CO2 in 1998 to 115.71 Mt CO2 in 2018. For the energy structure, raw coal, coke and industrial processes were the main contributors to carbon emissions. For industrial structure, the main emission sectors were the production and supply of electric power, steam and hot water, petroleum processing and coking, raw chemical materials and chemical products, and smelting and pressing of nonferrous metals. In addition, the economic effect was the leading factor promoting the growth of the corps carbon emissions, followed by technical and population effects. The energy structure effect was the only factor yielding a low emission reduction degree. This research provides policy recommendations for the XPCC to formulate effective carbon emission reduction measures, which is conducive to the construction of a low-carbon society. Moreover, it is of guiding significance for the development of carbon emission reduction actions for the enterprises under the corps and provides a reference value for other provincial regions.