Chemical Industry & Chemical Engineering Quarterly

CHEMICAL CHARACTERIZATION OF DIFFERENT WOOD FRAGMENTS AND THEIR VOLATILE COMPOSITION IN MODEL SPIRIT SOLUTIONS

2024-04-25T12:07:55+02:00

This study characterizes oak (sessile and pedunculate oak) and alternative wood (black locust, Myrobalan plum, wild cherry, and mulberry) species as important sources of volatile compounds of aged spirits. Nowadays, their fragments are used to hasten the brandies’ aging process. The ATR-FTIR spectra of analyzed wood samples are similar, only the mulberry FTIR spectrum contains unique peaks primarily due to its highest lignin content (40.93%). Using the untargeted GC-MS approach, a total of forty-one volatile compounds were identified in the wood extracts in a model spirit solution. The volatile profiles of alternative wood extracts in a model spirit solution were significantly different, both quantitatively and qualitatively, compared to those of oak. Coniferyl (23.14 µg/g—26.6 µg/g) and sinapyl (23.56 µg/g—25.82 µg/g) alcohols were the most abundant volatile compounds in investigated oak extracts. Resorcinol and coniferyl alcohol were the most abundant volatile compounds in black locust, sakuranin in wild cherry, while resorcinol and β-resorcinaldehyde in mulberry wood. To the best of our knowledge, sakuranin has not been detected in wild cherry wood until now. Besides wood chemical characteristics, the technology used during the aging process strongly influences on volatile profiles of aged brandies, thus, these compounds are potential chemical markers for discrimination between wood species as well as aging technologies.

INFLUENCE OF MAIN PRODUCTION VARIABLES ON NUTRITIONAL CHARACTERISTICS OF WINERY EFFLUENT KOMBUCHA

2024-01-18T21:13:45+01:00

Determination of sugar, nitrogen, and phosphorus consumption by kombucha culture is necessary to gain additional insight into the kombucha metabolic pathways and nutritional value of the produced beverages and to set a basis for optimizing the conditions for large-scale production. Kombucha beverage was made using effluent obtained from grape must clarification phase of white wine production. The fermentation medium was prepared by diluting the sterilized initial medium with approximately 16% of total reducing sugars to 3, 5, and 7% of total reducing sugars. The duration of the fermentation was nine days at 20, 25, and 30 °C. Sugars, nitrogen, and phosphorus content were measured using DNS, Kjeldahl, and molybdenum blue methods, respectively. The highest sugar content was in the initial medium (16.34%) and the lowest was after nine days of fermentation at 30 °C with 3% initial sugar content (0.17%). Residual levels of sugars, nitrogen, and phosphorus after three days were modeled using response surface methodology. The proposed mathematical models for sugars and nitrogen content showed an exceptional correlation with the experimentally obtained values. With this study insight into kombucha’s consumption of basic nutrients, nutritional value of the obtained products, and optimization of product composition was provided.

EFFECT OF SALT BATH NITRIDING ON TRIBOLOGICAL PROPERTIES OF AISI52100 STEEL COATINGS USING RESPONSE SURFACE METHODOLOGY

2024-02-14T19:42:25+01:00

This investigation employs the salt bath nitriding to extend the service life and improve the surface characteristics of AISI 52100, commonly employed in bearing applications. A wear test was conducted using a pin-on-disc device according to the ASTM G-99 standard, and the findings show a 30% reduction in wear loss. Sliding wear experiments were conducted at 1.5 m/s with a 5 N force at room temperature on uncoated and nitrided pins which was obtained as optimum value from RSM. The three variables and five levels of central composite design (CCD) were utilized to reduce the number of trials and the model relations were examined through ANOVA. Surface hardness, friction coefficient, wear coefficient, and loss in wear are measured over pins without coating and nitride pins. Investigations were done into how 5W30 oil affected passive and drip lubrication. Nitride substrates had a hardness of 590 HV. Also, nitriding has a favorable effect on the friction coefficient, lowering it by up to 23%. The 5W30 lubricant will further decrease the friction coefficient. The lowest friction coefficient was seen with the addition of 14% drip oil lubrication. Significantly less wear loss in the pin was caused by a combination of high hardness and low friction coefficient.

CONCEPTUALIZATION AND PROCESS SIMULATION OF A CO2-BASED METHANOL PRODUCTION PLANT

2024-02-19T12:15:47+01:00

The present study conceptualizes and simulates a methanol production process through the direct hydrogenation of captured CO₂. CuO/ZnO/ZrO₂ was employed as the catalyst and Aspen HYSYS was used for the process simulation. Configurational optimization of the process flowsheet was carried out using a step-by-step hierarchical approach. Many alternate flowsheets have resulted, and their capital investment, product cost, and profitability measures were calculated. The discrimination among the competing flowsheets was carried out based on net profit and percent return on investment. The retained flowsheet was further analyzed for optimizing the recycle ratio and evaluating the effect of the price of captured CO₂, green H₂, natural gas (fuel), and catalyst on the economic performance of the plant. The optimum value of the recycle ratio was computed to be 4.23. Additionally, it was found that the price of H₂ is the most important parameter in defining the feasibility and profitability of the process. Mathematical correlations were also developed that relate the profitability and price of the above-mentioned feed materials.

THE MAGNETOHYDRODYNAMIC WILLIAMSON FLUID FLOW ON AN EXTENDING SHEET WITH THERMOPHORESIS AND CHEMICAL REACTION

2024-02-27T10:33:09+01:00

This research investigates the steady, two-dimensional, incompressible flow of a pseudoplastic Williamson fluid subjected to a linearly stretched sheet. The study incorporates the effects of magnetic fields, chemical reactions, and thermophoresis on fluid behavior. By applying boundary layer techniques and similarity transformations, the governing equations are simplified for numerical analysis. The MATLAB bvp4c solver is employed to solve the reduced equations. The obtained results are visually represented and thoroughly discussed to comprehend the model's physical characteristics. The investigation highlights the magnetic field's influence, chemical reaction, and impact of thermophoresis particle deposition on the flow behavior of Williamson fluid over the extended sheet. Moreover, significant roles are found for chemical reactions and thermophoresis parameters in determining the fluid concentration near the boundary layer. It is observed that an increase in the chemical reactions and thermophoresis parameters results in a reduced thickness of the fluid concentration near the boundary layer. Notably, an increase in Schmidt value also diminished the thickness of the fluid concentration close to the boundary layer. The magnetohydrodynamic parameter significantly influences the fluid's velocity and temperature near the surface. It has been noted that an increase in the magnetohydrodynamic parameter decreases the fluid’s velocity and increases the temperature near the surface. The impact of skin friction coefficient and Nusselt number and the impact of mass transfer coefficient on Williamson fluid will be discussed. The findings acquired are examined in relation to existing research and the correlation is provided as a table.

RELIABILITY-BASED DESIGN OPTIMIZATION OF SCREW SHAFT FOR CONTINUOUS HIGH-PRESSURE HYDROTHERMAL CO-LIQUEFACTION PROCESS

2024-02-27T10:42:08+01:00

Hydrothermal co-liquefaction (HTCL) is the prominent process for producing bio-products with a higher conversion rate. It is performed at high temperatures and pressure in the presence of water. Earlier, it was mostly conducted in batch reactors, but it has major limitations including operating volume, back mixing, and tedious process for high productivity. With that, the present investigation is performed on designing the screw shaft for the high-pressure HTCL process. The dimensional factors including flight length, pitch, helix angle, and depth were considered to design the optimal screw shaft. Likewise, principal stresses, shear stress, bending stress, bending moment, and total deformation were regarded as inevitable response variables to analyze the internal strength of the shaft. In this regard, the Taguchi approach provides the L₉(3⁴) orthogonal array as an experimental design. Then, the numerical results from the transient structural analysis were analyzed with the assistance of statistical methods such as Grey Relational Grade (GRG), Grey Fuzzy Reasoning Grade, Analysis of Variance (ANOVA), and Taguchi method to find the most influential dimensions for minimizing the response variable. Consequently, the results from both GRG and Taguchi optimization were compared, and selected the most optimum parameters.

BLAST FURNACE SLAG FOR SO2 CAPTURE: OPTIMIZATION AND PREDICTION USING RESPONSE SURFACE METHODOLOGY AND ARTIFICIAL NEURAL NETWORK

2024-03-07T11:16:38+01:00

The main reaction parameters examined were the amount of blast furnace slag, the hydration duration, ammonium acetate concentration, and temperature. The Response surface methodology was employed to quantify their impact on the sorbent's surface area. Using a central composite design, the surface area of the resulting sorbent corresponding to Brunauer- Emmett-Teller (BET) was investigated. The sorbents produced range in surface area from 49.89 to 155.33 m²/g. Additionally, the effectiveness and response prediction capacities of the Response Surface Methodology (RSM) and Artificial Neural Network (ANN) modeling methodologies were investigated. The models were assessed using various statistical metrics, including (MSE) mean squared error, (ARE) average relative errors, the (SSE) sum of squared errors, (HYBRID) Hybrid fractional error function, (SAE) Sum of the absolute errors, (R²)coefficient of determination, and Root means square. According to statistical evidence, the ANN approach surpassed the RSM-CCD model approach. The surface area of the sorbent was shown to be significantly influenced by interactions between variables in addition to all the individual variables examined. The sorbent was made from a material with substantial structural porosity based on SEM. The functional groups were identified using FTIR. The XRF determined the elemental composition of BFS-based sorbents.

THE EFFECT OF GLYCEROL AND SAGO STARCH ADDITION ON THE CHARACTERISTICS OF BIOPLASTICS BASED ON ORANGE PEEL PECTIN

2024-03-08T15:30:56+01:00

Sustainable food packaging materials have significant interest in addressing environmental issues by making renewable substitutes such as bioplastics based on pectin. Orange peel has a relatively high pectin content of 42.5%, which can be synthesized into bioplastics. Pectin-based bioplastics tend to have limitations in terms of mechanical and physical strength due to the hygroscopic nature of pectin. This study aims to determine the effect of adding glycerol and sago starch on the characteristics of orange peel pectin-based bioplastics. The casting method was used in the bioplastic formulation using the variation of the pectin:starch ratio (75:25, 65:35, 55:45; and 50:50%) and glycerol composition (10, 20, 30, and 40%). Based on the results, the pectin obtained was categorized as low methoxyl pectin and ester pectin. The characterizations of bioplastics achieved the maximum value of the tensile strength of bioplastics was 4.22 MPa, obtained by adding pectin:starch (50:50%) and 10% glycerol. The maximum value of the elongation properties at the break of bioplastics is 24%, obtained by adding the composition of pectin:starch (75:25%) and 40% glycerol. The more additions of the pectin:starch and glycerol composition result in a higher water vapor evaporation rate. Hence, utilizing orange peel pectin-based bioplastics offers a sustainable solution by exploring repurposing waste to create bioplastics for food packaging, thereby contributing to environmental preservation.

Contents of Vol 30

2024-06-13T20:48:34+02:00

Contents of Vol 30

Author Index Vol. 30

2024-06-13T20:55:30+02:00

Author Index Vol. 30

List of Referees July 2023 to June 2024

2024-06-13T20:59:42+02:00

List of Referees