Thermal recycling of high density polyethylene and polypropylene old/new challenge during COVID-19 pandemic

Plenary Lectur

Determination of the Iodine Value – Novel Environmental Friendly Insights

The iodine value (iodine number) is characteristic for the content of unsaturated fatty acids in fats, fixed oils, emulsifiers and solubilizers. The determination of the iodine value is of significance for pharmaceutics, food chemistry and cosmetics. Standard methods for the iodine value determination approved by the Association of Official Analytical Collaboration (AOAC) International, the American Oil Chemists’ Society (AOCS), the International Organization for Standardization (ISO) and the European Pharmacopoeia (Eur. Ph.) [1-3] use hazardous solvents for fat samples such as cyclohexane/ glacial acetic acid mixture or chloroform, whereas glacial acetic acid is unique solvent for iodine monochloride or iodine monobromide that serves as iodination agent. Certain earlier proposals for more environmental friendly and faster iodine value determination considered utilization of 1,3-dibromo-5,5-dimethylhydantoin and potassium iodide instead of iodine monobromide, however also in glacial acetic acid as a solvent [4,5]. Recently, combining data from American and ISO standards, the Metrohm (2019) [6] proposed utilization of glacial acetic acid as a solvent for the fat sample and addition of magnesium acetate as catalyst to significantly reduce the reaction time, from 1 h to 5 minutes. In the current study we report certain novelties, which may contribute to development of less hazardous and environmental friendly method for the iodine value determination. Our method considers utilization of ethyl acetate as a solvent for the sample instead of cyclohexane/glacial acetic acid mixture or chloroform, whereas iodine monochloride in glacial acetic acid has been replaced by water solution of iodine monochloride (stabilized by small amount of hydrochloric acid). In the presence of ethyl acetate, starch solution does not yield the characteristic blue colour with iodine. Nevertheless, the titration end point can be recognized clearly and precisely without indicator. The method was tested on the following samples: coconut oil, olive oil, sunflower oil and linseed oil, covering a wide range of the iodine value from ~8 to ~180. Comparison of the average iodine values for studied samples obtained by the proposed and standard AOAC method indicates standard deviation less than 0.60, whereas repeatability limit for the proposed method is bellow 1.7 that is in line with statistical results for the precision of the Wijs method reported in ISO 3961 (2018) standard [2]

Utilizing metabolites from curcuma longa for the development of ph-responsive test strips

Introduction: Metabolites from Curcuma longa show pH-dependent color-changing properties. During this study, test strips were developed using Curcuma longa metabolites, which enable the rapid estima- tion of acidity/alkalinity in natural and artificial samples. Methods: Commercially available Curcuma longa powder (5.00 g) was mixed with ethanol (45 mL) and subjected to 30 minutes of ultrasonic extraction. After 60 minutes of settling, the resulting suspension was filtered and supplemented with ethanol to reach a final volume of 50 mL. Circular pieces of filter paper were immersed in 15 mL of the colored filtrate in Petri dishes for 10 minutes. The impregnated pieces of filter paper were then dried at 65°C for 10 minutes and cut into desired rectangular shapes. Results: Analysis of the prepared test strips’ behavior was conducted across a pH range from 0 to 14, en- compassing various solutions (HCl, NaOH, and buffered solutions) whose pH values were measured by a pH meter. The test strips exhibited a yellow-orange color at pH values below 8.5, while a brown color was observed at pH values of 8.5 and above. Conclusion: The experimental data obtained in this investigation demonstrate significant agreement with the literature value for the first pKa of curcumin (pKa1=8.4), a compound displaying the distinctive orange color found in dry Curcuma longa powder, and possessing pH-dependent color-changing char- acteristics. Therefore, test strips prepared from an ethanolic extract of Curcuma longa powder constitute a promising tool for the routine assessment of acidity/alkalinity across various samples in molecular bi- ology, (bio)chemistry, pharmacy, medicine, and related fields.The poster presentation of the abstract, including a 3-minute oral presentation, was conducted by the corresponding author on the first day of the conference in Belgrade, on October 6th 202

Origin of oils and source rocks characterization of the Turija-Sever oil field (SE Pannonian Basin, Serbia)

Oils from recently drilled wells in the Turija-Sever oil field were investigated in order to understand their genetic relationships, and to define the depositional environment, thermal maturity and geologic age of the corresponding source rocks, which are still unknown. Oils from the Turija-Sever oil field are generally similar and probably belong to the same genetic type. They originate from source rocks deposited in reducing to dysoxic redox conditions, with organic matter (OM) originating from mixed marine/terrestrial sources. Slight differences among oils are reflected through certain lower contribution of algal OM to oils from the northern part of the field and/or its faster degradation under dysoxic conditions. Oils were generated from source rocks in an early stage of oil window, corresponding to vitrinite reflectance between 0.60 and 0.65 %. Source rocks are of Tertiary age. Estimated source rocks depth interval and temperature interval of oil generation correspond to 2300 m – 2500 m and 124 °C – 138 °C, respectively

Applicability of infrared aliphatic stretching region for characterisation of oils of the same genetic type

The work focuses on the applicability of infrared (IR) aliphatic stretching region for characterisation of oils of the same genetic type. Paraffinic oils (56 samples) from the Turija-Sever oil field were studied. The oils are similar originate from mixed aquatic/terrestrial sources and were generated from Tertiary source rocks in an early stage of oil window. However, slight differences among the oils were observed. They are reflected in a higher contribution of algal organic matter (OM) to the group I oils formed in more reducing environment (western part of the field), compared to the oils from eastern part (group II). The IR CH2/CH3 branching factor segregates oils into two identical groups (I and II) established based on biomarkers and aromatic hydrocarbons. The group I oils showed lower values of CH2/CH3 factor than group II oils. Enhanced CH2/CH3 ratio for group II oils indicate that in the case of uniform maturity greater average length of polymethylene fragments results from a higher content of long chain n-alkanes signifying an increased impact of terrigenous OM (land plant waxes). Correlation between the normal to isoprenoid alkanes sum ratio and the CH2/CH3 factor is useful for detecting slight differences between oils of the same genetic type

The applicability of asphaltene treatment (mild oxidation and pyrolysis) in the investigation of crude oils

The aim of this study is to check which of four performed oil asphaltene treatments shows the best similarity in distributions of biomarkers and aromatic hydrocarbons and in the values of corresponding parameters with those obtained for maltenes. The obtained results imply the lack of a unique method which can result in good fitting of all biomarker and alkylaromatic ratios in oil asphaltene treatment products and corresponding maltenes. Among the performed asphaltene treatments two methods deserve attention: oxidation by NaIO4/NaH2PO4 and pyrolysis at 400 oC

Capturing Sulfur Dioxide at Its Source: Simple and Efficient Method for Sampling and Quantification

• Introduction and scope Sulfur dioxide (SO2) is a widespread pollutant gas that releases during many industrial processes [1]. SO2 has significant environmental and health implications [2], making its accurate quantification essential. The aim of this paper was to develop a simple and efficient laboratory-scale method for the sampling and quantification of SO2 at its source. • Methodology SO2, generated in the reaction between sodium metabisulfite and orthophosphoric acid, was routed through a condenser to a recipient vessel containing an absorptive solution of sodium hydroxide. The absorption of the SO2 was performed with a consistent gas flow rate, facilitated by the use of a vacuum pump within the reaction system. Aqueous solution of potassium dichloroiodate(I) [3] was employed for volumetric determination of sulfite content in the final absorptive solution. • Results Based on the results of sulfite content determination in the final absorptive solution, which exhibited an analytical recovery of SO2 ranging from 83% to 96%, the effectiveness of the proposed method is demonstrated. • Conclusion According to the obtained results and the multifaceted challenges associated with the sampling of gaseous fluids, this study can serve as a valuable guideline for the sampling of gaseous mixtures containing SO2. Usage of a vacuum pump in the sampling system helps minimize the loss of gaseous components in the final absorptive solution, whereas the described titrimetric method enables a simple and efficient analytical procedure for determining SO2 content. Further research and refinement of this method could lead to its practical application in environmental monitoring and industrial processes

Supplementary data for the article: Kojic, I.; Bechtel, A.; Kittinger, F.; Stevanovic, N.; Obradovic, M.; Stojanovic, K. Study of Pyrolysis of High Density Polyethylene in the Open System and Estimation of Its Capability for Co-Pyrolysis with Lignite. J. Serb. Chem. Soc. 2018, 83 (7–8), 923–940. https://doi.org/10.2298/JSC171215027K

Supplementray material for: [https://doi.org/10.2298/JSC171215027K]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2201