scholarly journals Badania hydrorafinatów z procesu współuwodornienia w zakresie oznaczania zawartości mono- i diacylogliceroli

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (6) ◽  
pp. 389-399
Author(s):  
Zygmunt Burnus ◽  
◽  
Agnieszka Wieczorek ◽  

In this work, the possibilities of using the GC-FID gas chromatography technique for determination of mono- and diacylglycerols content in the stream from the co-hydrogenation of rapeseed oil and middle distillates were investigated. Products from this process are planned to be increasingly used in the future as a new biocomponent of fuel for diesel engines. Before introducing new types of fuel components, it is necessary to test them in detail, especially in terms of residues of the fat raw material. The Regulation of the Minister of Climate of June 24, 2020 on the content of biocomponents formed as a result of co-hydrogenation indicates that the level of biomass conversion is determined on the basis of the content of triacylglycerols in the hydro-raffinate. Hence, on the basis of this determination, it is possible to assess the correctness of the co-hydrogenation process. However, other fatty components may be present in the product of this process in the form of unreacted residues. Therefore, it seems justified to carry out studies on other trace components of fatty origin in the hydro-treating material, due to the introduction of various plant materials together with petroleum hydrocarbons into the co-hydrogenation process. Due to the lack of available standardized methodologies for testing this type of products, a review of the literature was made regarding the possibility of using analytical techniques including gas and liquid chromatography to determine content of the so-called mono- and dicylglycerols, being residues of the fatty raw material, in various types of matrices, including vegetable oils and fatty acid methyl esters. In the case of examining the content of mono- and diacylglycerols in the product from the co-hydrogenation process, it was necessary to use the technique of liquid chromatography for the first-step concentration of the substances of interest. This technique made it possible to separate the sample matrix and concentrate the components to be determined prior to gas chromatographic analysis. Due to the complicated matrix of samples and the low required level of quantification, it was necessary to select appropriate conditions for removing the matrix using the classical liquid chromatography technique. A proprietary methodology for testing the content of mono- and diacylglycerols in the hydro-raffinate was developed, which was used to test selected samples of real hydro-raffinates from the co-HVO and HVO co-hydrogenation process. The ability to detect these trace fat components at a low level was indicated – as low as 2 mg/kg. The obtained sensitivity of the method allowed for additional qualitative assessment of this type of co-hydrogenation products, which are gradually gaining importance on the European market of liquid fuels.

Author(s):  
Roger A. Sheldon

This paper is based on a lecture presented to the Royal Society in London on 24 June 2019. Two of the grand societal and technological challenges of the twenty-first century are the ‘greening' of chemicals manufacture and the ongoing transition to a sustainable, carbon neutral economy based on renewable biomass as the raw material, a so-called bio-based economy. These challenges are motivated by the need to eliminate environmental degradation and mitigate climate change. In a bio-based economy, ideally waste biomass, particularly agricultural and forestry residues and food supply chain waste, are converted to liquid fuels, commodity chemicals and biopolymers using clean, catalytic processes. Biocatalysis has the right credentials to achieve this goal. Enzymes are biocompatible, biodegradable and essentially non-hazardous. Additionally, they are derived from inexpensive renewable resources which are readily available and not subject to the large price fluctuations which undermine the long-term commercial viability of scarce precious metal catalysts. Thanks to spectacular advances in molecular biology the landscape of biocatalysis has dramatically changed in the last two decades. Developments in (meta)genomics in combination with ‘big data’ analysis have revolutionized new enzyme discovery and developments in protein engineering by directed evolution have enabled dramatic improvements in their performance. These developments have their confluence in the bio-based circular economy. This article is part of a discussion meeting issue ‘Science to enable the circular economy'.


1965 ◽  
Vol 43 (8) ◽  
pp. 1281-1287 ◽  
Author(s):  
David T. Canvin

Reoplex 400 coated Chromosorb W (10% w/w on Chromosorb W, 60–80 mesh) columns (15 inches × [Formula: see text] inch) were used with an Aerograph A-90-P2 gas chromatograph. Complete separations and symmetrical peaks of the methyl esters of lactic, glycollic, oxalic, malonk, succinic, malic, aconitic, tartaric, citric, isocitric, and fumaric acids and isocitric acid lactone were obtained by programming the temperature at 4 °C/minute from 55 °C to 175 °C. Single acids could easily be assayed at an isothermal temperature. A linear relationship was obtained between the areas recorded and the quantities of acid injected. There was no consistent relationship between molecular species and response, so that the instrument was calibrated for each individual acid. The analyses of some plant materials for organic acids are presented.


2019 ◽  
Author(s):  
Chem Int

Biodiesel produced by transesterification process from vegetable oils or animal fats is viewed as a promising renewable energy source. Now a day’s diminishing of petroleum reserves in the ground and increasing environmental pollution prevention and regulations have made searching for renewable oxygenated energy sources from biomasses. Biodiesel is non-toxic, renewable, biodegradable, environmentally benign, energy efficient and diesel substituent fuel used in diesel engine which contributes minimal amount of global warming gases such as CO, CO2, SO2, NOX, unburned hydrocarbons, and particulate matters. The chemical composition of the biodiesel was examined by help of GC-MS and five fatty acid methyl esters such as methyl palmitate, methyl stearate, methyl oleate, methyl linoleate and methyl linoleneate were identified. The variables that affect the amount of biodiesel such as methanol/oil molar ratio, mass weight of catalyst and temperature were studied. In addition to this the physicochemical properties of the biodiesel such as (density, kinematic viscosity, iodine value high heating value, flash point, acidic value, saponification value, carbon residue, peroxide value and ester content) were determined and its corresponding values were 87 Kg/m3, 5.63 Mm2/s, 39.56 g I/100g oil, 42.22 MJ/Kg, 132oC, 0.12 mgKOH/g, 209.72 mgKOH/g, 0.04%wt, 12.63 meq/kg, and 92.67 wt% respectively. The results of the present study showed that all physicochemical properties lie within the ASTM and EN biodiesel standards. Therefore, mango seed oil methyl ester could be used as an alternative to diesel engine.


2019 ◽  
Vol 16 ◽  
Author(s):  
Joanna Wittckind Manoel ◽  
Camila Ferrazza Alves Giordani ◽  
Livia Maronesi Bueno ◽  
Sarah Chagas Campanharo ◽  
Elfrides Eva Sherman Schapoval ◽  
...  

Introduction: Impurity analysis is an important step in the quality control of pharmaceutical ingredients and final product. Impurities can arise from drug synthesis or excipients and even at small concentrations may affect product efficacy and safety. In this work two methods using high performance liquid chromatography (HPLC) were developed and validated for the evaluation of besifloxacin and its impurity synthesis, with isocratic elution and another with gradient elution. Method: The analysis by HPLC in isocratic elution mode was performed using a cyano column maintained at 25 °C. The mobile phase was composed by 0.5% triethylamine (pH 3.0): acetonitrile (88:12 v/v) eluted at a flow rate of 1.0 ml/min with detection at 330 nm. The gradient elution method was carried out with the same column and mobile phase components only modifying the rate between organic and aqueous phase during analysis. The procedures have been validated according to internationally accepted guidelines, observing results within acceptable limits. Results: The methods presented were found to be linear in the 140 to 260 µg/ml range for besifloxacin and 0.3 to 2.3 µg/ml for an impurity named A. The limits of detection and quantification were respectively 0.07 and 0.3 µg/ml for impurity A, with a 20 µL injection volume. The precision achieved for all analyses performed provided RSD inter-day equal to 6.47 and 6.36% for impurity A with isocratic elution and gradient, respectively. The accuracy was higher than 99% and robustness exhibited satisfactory results. In the isocratic method an analysis time of 25 min and 15 min was obtained for gradient. For impurity A, the number of theoretical plates in the isocratic mode was about 5000 while in the gradient mode it was about 45000, hence, it made the column more efficient by changing the mobile phase composition during elution. In besifloxacin raw material and in pharmaceutical product used in this study, other related impurities were present but but impurity A was searched for and not detected Conclusion: The proposed methods can be applied for quantitative determination of impurities in the analysis of the besifloxacin raw material, as well as in ophthalmic suspension of the drug, considering the quantitation limit.


Author(s):  
Ahmed I. Osman ◽  
Neha Mehta ◽  
Ahmed M. Elgarahy ◽  
Amer Al-Hinai ◽  
Ala’a H. Al-Muhtaseb ◽  
...  

AbstractThe global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compared to gasification, which operates at 800–1300 °C. We focus on 1) the drawbacks and advantages of the thermochemical and biochemical conversion routes of biomass into various fuels and the possibility of integrating these routes for better process efficiency; 2) methodological approaches and key findings from 40 LCA studies on biomass to biofuel conversion pathways published from 2019 to 2021; and 3) bibliometric trends and knowledge gaps in biomass conversion into biofuels using thermochemical and biochemical routes. The integration of hydrothermal and biochemical routes is promising for the circular economy.


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