Acid Value Reduction of Calophyllum inophyllum Oil by Oilseeds In situ Esterification Using Sulfuric Acid Catalyzed Methanol and Isopropyl Alcohol Mixture

Non-edible oilseed can be used in biodiesel preparation as a low-cost feedstock. However, it contains a high free fatty acid or a high acid value, which causes a problematic biodiesel reaction. The investigation of acid value reduction of Calophyllum inophyllum oilseed by in situ esterification using sulfuric acid-catalyzed methanol and isopropyl alcohol has been conducted. Calophyllum inophyllum oil was extracted by n-hexane in the Soxhlet apparatus to determine the oil content. In situ esterification using methanol-isopropyl alcohol and the sulfuric acid as a catalyst was carried out in a reflux three-neck rounded bottom flask batch process to decrease free fatty acid or acid value. Four independent reaction variables, including the ratio of mixture volume to seed weight, the ratio of methanol to mixture volume, catalyst percentage, and reaction time, were varied. The experiments utilized by the response surface methodology with central composite design configuration to obtain the optimum conditions. The oil content of Calophyllum inophyllum oilseed extraction was 57.94% and an acid value was 90.38 mg KOH/g. The maximum esterified oil yield of 91.00% and 3.81 mg KOH/g minimum acid value were achieved in the optimum reaction conditions.

Assessment of the contribution of the air-vapor mixture volume exceeding over the volumes injected to oil and petroleum product losses from evaporation

В настоящее время при экспериментальном определении потерь нефтепродуктов от «больших дыханий» резервуаров используют формулу Черникина - Валявского. При этом «однако» не учитывается, что объем вытесняемой в атмосферу паровоздушной смеси, как правило, превышает объем закачиваемой нефти (нефтепродукта). Соответствующий параметр - коэффициент превышения, - по экспериментальным данным, может принимать значения более 8. До недавнего времени не до конца были ясны даже причины этого явления, соответственно, эмпирические зависимости для расчета коэффициента превышения не учитывали всех влияющих факторов. Авторами статьи на основе уравнения Менделеева - Клапейрона в дифференциальной форме получено аналитическое выражение для вычисления среднего коэффициента превышения. Установлено, что данная величина зависит от молярной массы и температуры паровоздушной смеси в начале и конце закачки, а также от соотношения объемов газового пространства резервуара и закачиваемого продукта. Для анализа полученной зависимости был спланирован и проведен вычислительный эксперимент, предусматривающий изменение определяющих параметров в широком диапазоне. Расчеты выполнялись для нефти и бензина. По результатам 25 вычислительных «опытов» определено, что при операциях с бензином средний коэффициент превышения (за одну операцию заполнения резервуара) в исследованном диапазоне температур принимает значения от 1,029 до 1,678, а при операциях с нефтью - от 1,016 до 1,338, то есть, как правило, превышает погрешность инструментальных замеров потерь нефти (нефтепродуктов) от испарения. Математическое ожидание рассматриваемой величины при операциях с бензином составляет 1,26, с нефтью - 1,16. Таким образом, учет среднего коэффициента превышения при обработке результатов инструментальных измерений потерь углеводородов от испарений вследствие «больших дыханий» резервуаров является обязательным. Currently, the Chernikin - Valyavsky formula is used in the experimental determination of petroleum product losses from “large breaths” of reservoirs. However, it does not take into account that the volume of air-vapor mixture displaced into the atmosphere usually exceeds the volume of pumped oil/petroleum product. The corresponding parameter, the excess ratio, according to the experimental data can have values of more than 8. Until recently, even the causes of this phenomenon were not completely clear, and thus, the empirical dependencies for calculating the excess ratio did not take into account all the influencing factors. Based on the Mendeleev-Clapeyron equation in differential form, the analytic expression to calculate the average excess ratio was obtained. It was found that this value depends on the molar mass and temperature of the air-vapor mixture at the beginning and the end of the injection, as well as on the ratio of the tank gas space volume and the injected product volume. To analyze the resulting dependency, a computational experiment involving changes in the defining parameters over a wide range was planned and conducted. The calculations were performed for oil and gasoline. According to the results of 25 computational experiments, it was determined that during operations with gasoline the average excess ratio (per one tank filling operation) in the investigated temperature range has values from 1.029 to 1.678, and during operations with oil - from 1.016 to 1.338; that generally exceeds the instrument error of oil/petroleum product losses from vaporization measurement. The mathematical expectation of the value in question during operations with gasoline is 1.26, it is 1.16 with oil. It is therefore mandatory to take into account the average excess ratio when processing the results of instrumental measurements of hydrocarbon losses from evaporation due to “large breaths” of reservoirs.

Development of a three-zone combustion model for stratified-charge spark-ignition engine

A thermodynamic model for calculating the operating process in the cylinder of a spark-ignition engine with internal mixture formation and stratified air-fuel charge based on the volume balance method was developed. The model takes into account the change in the working fluid volume during the piston movement in the cylinder. The equation of volume balance of internal mixture formation processes during direct fuel injection into the engine cylinder was compiled. The equation takes into account the adiabatic change in the volume of the stratified air-fuel charge, consisting of fuel-air mixture volume and air volume. From the heat balance equation, the change in the fuel-air mixture volume during gasoline evaporation in the fuel stream and from the surface of the fuel film due to external heat transfer was determined. Basic equations of combustion-expansion processes of the stratified air-fuel charge were derived, taking into account three zones corresponding to combustion products, fuel-air mixture and air volumes. The equation takes into account the change in the working fluid volume due to heat transfer and heat exchange between the zones and the walls of the above-piston volume. Dependences for determining the temperature in the three considered zones and pressure in the cylinder were obtained. Graphs of changes in the volumes of the combustion products, fuel-air mixture and air zones with the change of the above-piston volume in partial load modes (n=3,000 rpm) were plotted. With increasing load from bmep=0.144 MPa to bmep=0.322 MPa, at the moment of fuel ignition, the volume of the fuel-air mixture increases from 70 % to 92 % of the above-piston volume. At the same time, the air volume decreases from 30 % to 8 %. Analysis of theoretical and experimental indicator diagrams showed that discrepancies in the maximum combustion pressure do not exceed 5 %

Modeling of the nitrous oxide synthesis in a microchannel reactor: the effect of parameters on the temperature regimes and output

The study deals with the synthesis of nitrous oxide via selective oxidation of ammonia in a microreactor (MCR), which is a metal disk with cylindrical channels filled with the manganese-bismuth oxide catalyst. The proposed 3D mathematical model of MCR takes into account axial and radial heat and mass transfer, catalytic reactions and related changes of the reaction mixture volume, heat exchange between the disk and channels, and thermal conductivity of the disk. Parameters providing the maximum output of nitrous oxide were determined with allowance for restrictions on the temperature in MCR channels. The highest efficiency of the nitrous oxide synthesis is achieved at a temperature of the outer edge of reactor 370 °С and an inlet concentration of ammonia 20 vol.%. The output per unit catalyst volume in MCR is approximately 1.5 times higher as compared to a tubular reactor; the maximum temperature corresponds to the optimal one, which provides the best selectivity of the process with respect to nitrous oxide.

Reduction of Pesticide Use in Fresh-Cut Salad Production through Artificial Intelligence

Incorrect pesticide use in plant protection often involve a risk to the health of operators and consumers and can have negative impacts on the environment and the crops. The application of artificial intelligence techniques can help the reduction of the volume sprayed, decreasing these impacts. In Italy, the production of ready-to-eat salad in greenhouses requires usually from 8 to 12 treatments per year. Moreover, inappropriate sprayers are frequently used, being originally designed for open-field operations. To solve this problem, a small vehicle suitable for moving over rough ground (named “rover”), was designed, able to carry out treatments based on a single row pass in the greenhouse, devoted to reduce significantly the sprayed product amount. To ascertain its potential, the prototype has been tested at two growth stages of some salad cultivars, adopting different nozzles and boom settings. Parameters such as boom height, nozzle spacing and inclination, pump pressure and rover traveling speed were studied. To assess the effectiveness of the spraying coverage, for each run several water-sensitive papers were placed throughout the vegetation. Compared to the commonly distributed mixture volume (1000 L/ha), the prototype is able to reduce up to 55% of product sprayed, but still assure an excellent crop coverage.

Development of Films, Based on Oxidized Ipomea Batatas Starch, with Protein Encapsulation

Dialdehyde starches (DAS) have been used as biomaterials due to their biocompatibility and biodegradability; nonetheless, sweet potato (Ipomea batatas L.) starch has not been researched. Films based on sweet potato DAS, mixed with native starch (NS), poly-vinyl alcohol (PVA) and glycerin have been developed with protein encapsulation, using central composite design (CCD) and response surface methodology (RSM). Input variables were oxidation degree, NS concentration and polymeric mixture volume, while output variables were film's thickness, equilibrium swelling and BSA (Bovine serum albumin) release. DAS was obtained through hydrogen peroxide (H2O2) oxidation, and the oxidation degree is referred to as H2O2 concentration. Films presented rough surfaces, and formulations containing 10% H2O2 DAS presented micropores. Water uptake was greater with higher DAS content. Film thickness depended on the volume of the polymeric suspension and influenced swelling capacity. According to RSM, the optimal formulation was DAS with 5% H2O2 and 35% NS. These results demonstrate that oxidized sweet potato starch has potential for protein encapsulation and delivery.

Study of Mixture Formation Process During in Batching for Collapsible Pipelines

The issues of determination mixture volume during in batching for collapsible pipelines of different groups and brands fuels examined. The based on Taylor theory of longitudinal diffusion in turbulent flows a mathematical model of mixture formation process during in batching of fuels was approved. For the fuels viscosity-temperature characteristics analytical presentation proposed dependences. The fuels mixture volume during in batching for collapsible was simulating.

Theoretical analysis of hydromixture transport

This paper presents theoretical considerations and working parameters analyzes of hydrotransport during unstable flow. The variable flow of hydraulic mixture in installations causes unsteady operation and pipes spraying, pump damage, obturation in various sections of the pipeline, reduced capacity as well as higher operating costs. Using mathematical equations presented in this paper, such parameters of the hydraulic mixture, hydrotransport installation and control devices can be determined which protect system from possible clogging. Considering the fact that critical speed of hydraulic mixture depends on transported material grain size, mixture volume mass, diameter of pipeline and specific gravity of solid phase, it is possible to accurately analyze obturation in hydrotransport installations depending on those parameters. In order to prevent hydraulic impacts in hydrotransport installation pipelines, which value can be determined mathematically, it is necessary to adjust installation to hydromixture parameters and pump, or vice versa.

Standardization the effect of shape of aggregates with respect to compressive strength of concrete

It is proved that aggregate’s types have the severe effect on physicomechanical properties of concrete as aggregate covered almost 70 to 80 percent of the total volume of concrete. The effect of Flaky and Elongated aggregates on strength, durability, and workability of concrete has often been qualitatively expressed. The aim of this work is establishing the same quantitatively. M25 grade concrete for different ratios of weights of Elongated to normal aggregate, Flaky to normal aggregate and combined Flaky & Elongated aggregate to normal aggregate was tested for compressive strength at 28 days concrete. Three different types of aggregates were employed in the investigation, namely; normal aggregate, Elongated aggregate, and Flaky aggregate. Density and water absorption also kept constant to identify the effects on properties of concrete only for differences in shape. Thirty-six concrete cylinder was cast at 28 days. Varying dosages of Normal aggregate (60%, 65%, 70%, 75%,80% 85%), flaky aggregate (40%, 35%, 30%, 25%, 20%, 15%), elongated aggregate (40%, 35%, 30%, 25%, 20%, 15%), by mixture volume and length of 12inch (304.8 mm) & diameter of 6inch (152.4 mm) cylinder were used to test. Compaction was done by temping rod. Concrete cylinder was tested at the age of 28 days of curing. This study proposed of mixing three different types of aggregate in concrete. Compressive strength of concrete was measured by the effect of three different shapes of aggregates of varying dosages.