Formalin is among the most important commodity chemicals, used mainly as a precursor to a wide range of value-added products. Currently, formalin is widely produced from methanol derived from natural ...gas, however a transition from fossil-based production to sustainable feedstocks and pathways is crucial. This study evaluates the environmental impacts of selected promising formalin production technologies to shape a pathway towards more sustainable production of key chemicals. Among the investigated production routes are through methane steam reforming of other fossil and renewable sources, hydrogenation of CO2, and direct conversion of methane, syngas or CO2. to formalin. A comparative Life Cycle Assessment (LCA) is performed for seven different formalin synthesis routes with higher readiness levels. Technologies utilizing waste CO2 and biogas from manure as feedstocks show the most promising results, reducing greenhouse gas footprint by roughly 60% compared to the conventional pathway. Results show that a key contribution to the environmental impact mitigation was the unburdening effect due to the use of waste and product's substitution. With this study, a more comprehensive outlook focusing on the environmental sustainability of formalin production is provided. Environmental performance and readiness levels of formalin production technologies utilizing renewable or waste feedstocks indicate that such pathways could be applied to industrial scale in the future.
•Formalin production routes with higher Technology Readiness Levels are studied.•Environmental impacts for selected formalin production technologies are evaluated.•Technologies utilizing waste CO2 and biogas from manure show promising results.•Greenhouse gas footprint is reduced by up to 60% compared to conventional pathway.•A key mitigation is unburdening effect due to waste use and product substitution.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
High-yield ZnO spheroidal nanoparticles with an average diameter around 23 nm (≈ 25% frequency) and 30 nm (≈ 28% frequency) were obtained by controlled semicontinuous precipitation at low ...temperatures. This synthesis was obtained from hydrozincite (Zn5(CO3)2(OH)6) as primary nanoparticles. The Zn5(CO3)2(OH)6 nanoparticles were synthesized by hydrolysis of Zn(NO3)2 in aqueous solution of (NH4)2CO3 and later, the precipitation becomes. Two temperatures of 60 and 70 °C in combination with three times of reaction were tested; followed by calcination of the precipitate at 400 °C. This range of sizes of nanoparticles is comparable with those obtained by other methods reported in the literature, such as microemulsions, however, here the advantage was not using solvents or surfactants. The ZnO nanoparticles were characterized by energy dispersive X-ray spectroscopy coupled to a scanning electron microscopy (SEM-EDS), transmission electronic microscopy (TEM), and X-ray diffraction. The antibacterial activity of the films against Gram-positive (S. aureus) and Gram-negative (E. coli.) bacteria was investigated using the disc diffusion method. The best results were found in the inhibition zone for Gram-positive bacteria, when the concentration of ZnO NPs incorporated was 3 mg disc-1.
With the rapid advances in biotechnological tools and strategies, microbial cell factory-constructing strategies have been established for the production of value-added compounds. However, optimizing ...the tradeoff between the biomass, yield, and titer remains a challenge in microbial production. Gene regulation is necessary to optimize and control metabolic fluxes in microorganisms for high-production performance. Various high-throughput genetic engineering tools have been developed for achieving rational gene regulation and genetic perturbation, diversifying the cellular phenotype and enhancing bioproduction performance. In this paper, we review the current high-throughput genetic engineering tools for gene regulation. In particular, technological approaches used in a diverse range of genetic tools for constructing microbial cell factories are introduced, and representative applications of these tools are presented. Finally, the prospects for high-throughput genetic engineering tools for gene regulation are discussed.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
As the main factors affecting stable and high production and the production regularity of lacustrine shale oil are unclear, the theoretical understandings, key exploration and development ...technologies, development effect and production regularity of lacustrine shale oil have been analyzed and summarized based on 700 m cores taken systematically from Paleogene Kong 2 Member of 4 wells in Cangdong sag, over 100 000 analysis data and formation testing data. Three theoretical understandings on shale oil enrichment and high production have been reached: (1) High-quality shale with “three highs and one low” is the material base for shale oil enrichment. (2) Medium—slightly high thermal evolution degree is the favorable condition for shale oil enrichment. (3) Laminar felsic shale is the optimal shale layer for oil enrichment in semi-deep lake facies. Key exploration and development technologies such as shale oil enrichment layer and area evaluation and prediction, horizontal well pattern layout, shale oil reservoir fracturing, optimization of shale oil production regime have been established to support high and stable shale oil production. Under the guidance of these theoretical understandings and technologies, shale oil in Cangdong sag has achieved high and stable production, and 4 of them had the highest production of over 100 tons a day during formation testing. In particular, Well GY5-1-1L had a daily oil production of 208 m3. By April, 2022, the 28 wells combined have a stable oil production of 300–350 tons a day, and have produced 17.8×104 t of oil cumulatively. It is found that the shale oil production of horizontal well declines exponentially in natural flow stage, and declines in step pattern and then tends stable in the artificial lift stage. Proportion of light hydrocarbons in produced shale oil is in positive correlation with daily oil production and decreases regularly during production test.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Whether a coalbed methane (CBM) well achieves high yield is controlled by various factors. Structural and hydrological control models of CBM productivity in vertical wells were built using a combined ...investigation of basic tectonic settings and hydrological conditions, as well as drainage parameters of the coal reservoir in the Fanzhuang Block, Southern Qinshui Basin. This study indicates that gas/water production differs significantly among wells with different structural settings or hydrogeological conditions. Low and unstable gas production rates in individual wells are the primary problem for the CBM development in the Fanzhuang Block. The impacts of some geologic and engineering factors on gas production were analyzed and estimated based on comparative analysis, quantitative analysis, and gray system theory. The results indicate that the critical reservoir ratio (CRR), liquid column height (LCH), and gas content are the most important factors in determining well productivity, followed by the equivalent drainage radius (EDR), the volume of frac sand, and the decline rate of working fluid levels during initial production. High-yield wells in the Fanzhuang Block always have the following conditions: gas content >20m3/t; burial depth of 500–700m; CRR>0.7; LCH>400m; volume of frac sand >40m3; EDR of 30–60m; and a decline rate of working fluid level lower than 2m/day during the initial production stage.
•High-yield wells are controlled both by structural and hydrological conditions.•Gas rate varies significantly under various geological and engineering settings.•Critical reservoir ratio has the largest impact on CBM well productivity.•Coal reservoir damage should be avoided during the CBM development process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A multi-residue method based on gas chromatography-mass spectrometry combined with pressurised liquid extraction was developed to determine seven organophosphate esters (OPEs), six phthalate esters ...(PAEs), four benzotriazoles (BTRs), five benzothiazoles (BTHs) and four benzenesulfonamides (BSAs) in particulate matter samples from outdoor air. All of these compounds are among the named high-production volume chemicals (HPVCs) and some of them have shown to be harmful to human, therefore they have been subject for legal regulation in order to control their production and usage. Under optimised conditions, high recovery values (>80%) and low detection limits (pg m−3) were obtained for most of the compounds with accuracy values between 83% and 118%.
Some samples from two locations surrounded by different industry activities showed the widespread occurrence of all the PAEs, followed by some OPEs. Diethylhexyl phthalate (DEHP) was the most abundant compound with concentrations ranging from 1.9 to 97.7 ng m−3. With the concentrations found, estimated daily intakes through outdoor inhalation were calculated for each contaminant and for different population groups classified by age (infants, children and adults) in two possible exposure scenarios (low and high). Then, hazard quotients and carcinogenic risks were estimated for several compounds, those that had toxicological parameters available. This preliminary result showed no significant risks via ambient inhalation for the exposed population, however more research is needed to confirm the present results.
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-PLE achieves high recovery values (>80%) for most of the compounds.-PLE/GC-MS is a reliable technique to determine HPVCs at low levels (pg m−3).-Phthalate esters are ubiquitous in the atmospheric particles of both sampling sites.-The highest human exposure was to DEHP and DiBP, being the greatest for children.-No significant risk via ambient inhalation was assessed in this study.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Our aim was to simultaneously investigate the gut bacteria typical characteristic and conduct rumen metabolites profiling of high production dairy cows when compared to low‐production dairy cows. The ...bacterial differences in rumen fluid and feces were identified by 16S rDNA gene sequencing. The metabolite differences were identified by metabolomics profiling with liquid chromatography mass spectrometry (LC‐MS). The results indicated that the high‐production dairy cows presented a lower rumen bacterial richness and species evenness when compared to low‐production dairy cows. At the phylum level, the high‐production cows increased the abundance of Proteobacteria and decreased the abundance of Bacteroidetes, SR1, Verrucomicrobia, Euryarchaeota, Planctomycetes, Synergistetes, and Chloroflexi significantly (p < 0.05). At the genus level, the rumen fluid of the high‐production group was significantly enriched for Butyrivibrio, Lachnospira, and Dialister (p < 0.05). Meanwhile, rumen fluid of high‐production group was depleted for Prevotella, Succiniclasticum, Ruminococcu, Coprococcus,YRC22, CF231, 02d06, Anaeroplasma, Selenomonas, and Ruminobacter significantly (p < 0.05). A total of 92 discriminant metabolites were identified between high‐production cows and low‐production cows. Compared to rumen fluid of low‐production dairy cows, 10 differential metabolites were found up‐regulated in rumen fluid of high‐production dairy cows, including 6alpha‐Fluoropregn‐4‐ene‐3,20‐dione, 3‐Octaprenyl‐4‐hydroxybenzoate, disopyramide, compound III(S), 1,2‐Dimyristyl‐sn‐glycerol, 7,10,13,16‐Docosatetraenoic acid, ferrous lactate, 6‐Deoxyerythronolide B, vitamin D2, L‐Olivosyl‐oleandolide. The remaining differential metabolites were found down‐regulated obviously in high‐production cows. Metabolic pathway analyses indicated that most increased abundances of rumen fluid metabolites of high‐yield cows were related to metabolic pathways involving biosynthesis of unsaturated fatty acids, steroid biosynthesis, ubiquinone and other terpenoid‐quinone biosynthesis. Most down‐regulated metabolic pathways were relevant to nucleotide metabolism, energy metabolism, lipid metabolism and biosynthesis of some antibiotics.
Our aim was to simultaneously investigated the gut bacteria typical characteristic and conduct rumen metabolites profiling of high‐production dairy cows when compared to low‐production dairy cows. The aim of the study was to explore the typical gut bacteria and rumen typical metabolites matter of high‐production airy cows. After that, the results can be applied in the low‐yield dairy cows to improve their milking performance.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Practical applications of microbial electrolysis cells (MECs) require high hydrogen production rates and a compact reactor. These goals can be achieved by reducing electrode spacing but high surface ...area anodes are needed. The brush anode MEC with electrode spacing of 2cm had a higher hydrogen production rate and energy efficiency than an MEC with a flat cathode and a 1-cm electrode spacing. The maximum hydrogen production rate with a 2cm electrode spacing was 17.8m3/m3d at an applied voltage of Eap=1V. Reducing electrode spacing increased hydrogen production rates at the lower applied voltages, but not at the higher (>0.6V) applied voltages. These results demonstrate that reducing electrode spacing can increase hydrogen production rate, but that the closest electrode spacing do not necessarily produce the highest possible hydrogen production rates.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Aims
Cereals contaminated with type B trichothecene nivalenol (NIV) and its acetylated derivative 4‐acetyl‐nivalenol (4‐AcNIV) are a global mycotoxicological problem threatening the health of humans ...and livestock. Toxicological studies, quantitative determinations and screening for biodegrading micro‐organisms require massive amounts of pure toxins. However, the low yield from fungal cultures and high prices of NIV and 4‐AcNIV limit research progress in these areas. This work aimed to select Fusarium asiaticum mutant strains with enhanced production of NIV and 4‐AcNIV.
Methods and Results
A total of 62 NIV‐producing F. asiaticum strains were isolated and compared regarding their ability to produce NIV. Strain RR108 had the highest yield of NIV among 62 field isolates surveyed and was then genetically modified for higher production. Targeted deletion of the FaFlbA gene, encoding a regulator of G protein signalling protein, resulted in a significant increase in NIV and 4‐AcNIV production in the FaFlbA deletion mutant ΔFaFlbA. The expression of three TRI genes involved in the trichothecene biosynthetic pathway was upregulated in ΔFaFlbA. ΔFaFlbA produced the highest amount of NIV and 4‐AcNIV when cultured in brown long‐grain rice for 21 days, and the yields were 2.07 and 2.84 g kg−1, respectively. The mutant showed reduced fitness, including reduced conidiation, loss of perithecial development and decreased virulence on wheat heads, which makes it biologically safe for large‐scale preparation and purification of NIV and 4‐AcNIV.
Conclusions
The F. asiaticum mutant strain ΔFaFlbA presented improved production of NIV and 4‐AcNIV with reduced fitness and virulence in plants.
Significance and Impact of the Study
Targeted deletion of the FaFlbA gene resulted in increased NIV and 4‐AcNIV production. Our results provide a practical approach using genetic modification for large‐scale mycotoxin production.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
China's shale gas production in 2020 exceeds 200 × 108 m³, which creates a miracle in the history of natural gas development in China. The Sichuan Basin has already been and will be the main ...battlefield of shale gas exploration and development in China. In order to further promote the large-scale efficient development of shale gas in China, under the new situation of global COVID-19 spread and domestic “carbon peak and carbon neutrality” goal, this paper analyzes the progress and challenges of shale gas exploration and development in the Sichuan Basin from four aspects, including resource exploration, gas reservoir engineering, drilling and production engineering and industry regulation, and puts forward countermeasures and suggestions for achieving large-scale efficient development of shale gas. The following research results are obtained: First, the large-scale efficient development of shale gas in the Sichuan Basin has to take the sustainable and stable production of middle–shallow shale gas and the large-scale productivity construction of deep shale gas as the base. Second, compared with the shale gas exploration and development in the North America, the Sichuan Basin has its own characteristics in terms of geographical setting, geological condition, drilling and production technology and industry regulation, which makes it difficult to copy the development pattern of large scale, high density and continuous well deployment from the North America, so it is necessary to adopt the strategy of “high production with few wells”. On the one hand, continue to apply the geology and engineering integration technology to carry out “integrated research, integrated design, integrated implementation and integrated iteration” in the whole life cycle of shale gas well; and on the other hand, carry out problem-oriented continuous researches from the aspects of geological evaluation, development policy, engineering technology and industry regulation, so as to improve geological evaluation theory and technology, innovate gas reservoir engineering theory and method, research and develop engineering technology for cost reduction and efficiency improvement, improve shale gas industry regulation, and form a new pattern of collaborative promotion of technical and non-technical elements. In conclusion, the research results provide important reference and guidance for the large-scale efficient development of shale gas in the Sichuan Basin and even the whole country.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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