Chemical Industry & Chemical Engineering Quarterly

EFFECTS OF EXHAUST GAS RECIRCULATION ON DIESEL ENGINE USING HYBRID BIODIESEL

Fri, 12 Apr 2024 00:00:00 +0200

The primary aim of this study is to alternate between conventional fossil fuels and reduce the emissions of greenhouse gases and sulfur dioxide from diesel engines. In the current study, to mitigate NOx emissions, the exhaust gas recirculation (EGR) technique was implemented utilizing hybrid alternate biodiesel at three varying proportions of 5%, 10%, and 15% at an optimum compression ratio of 20:1. The findings demonstrate that for hybrid alternative biodiesel at a compression ratio of 20:1 and fully loaded, the brake thermal efficiency (BTHE) is 31.8% with 10% EGR. With 15% EGR, the peak pressure for the hybrid biodiesel is lower than it would be without EGR by around 2.28%. When EGR is increased, the ignition delay and NOx emissions are reduced slightly. With only an increase in EGR rates of up to 10%, brake-specific fuel consumption (BSFC) values were reduced efficiently. The hybrid biodiesel with 10% EGR reduces exhaust gas temperature to 341 °C.

THE INFLUENCE OF MOISTURE CONTENT ON DRILLED CUTTINGS’ PROPERTIES OF BED PACKING AND FLOWABILITY

Fri, 12 Apr 2024 00:00:00 +0200

To design and operate various equipment of the solids control system in offshore drilling platforms, it is important to establish how the moisture content influences the characteristics of drilled cuttings to form packed beds and flow over solid surfaces. The current study comprehensively analyzes how moisture content, primarily composed of water and representing water-based muds (WBMs), influences the bed packing properties and drilled cuttings' flowability. The particle aggregation/disaggregation dynamics, loose and tapped bulk densities and porosities, compaction dynamics of packed beds, Hausner ratio, and angle of repose of drilled cuttings with ten distinct moisture contents (1.4—44.0 wt%) were analyzed. It was noticed that the increment of moisture content up to 15.2% promoted the formation of looser interparticle structures. However, these structures were steadier, showing greater difficulty flowing and releasing air/liquid. The continuous increment of moisture content beyond 15.2% promoted a complete change in the material behavior. The interparticle structures became denser. The material could flow and release air/liquid more easily. In addition, it was possible to establish a classification of the different behaviors of drilled cuttings according to the moisture content. Predictive models were proposed to describe the influence of the moisture content on the bed packing and flowability properties of drilled cuttings.

COMBUSTION, EMISSION, AND PERFORMANCE CHARACTERISTICS OF HYBRID BIOFUEL AT DIFFERENT COMPRESSION RATIOS

Fri, 12 Apr 2024 00:00:00 +0200

The primary aim of this study is to alternate between conventional fossil fuels and reduce the emissions of greenhouse gases and smoke from diesel engines. The current study aimed to improve the performance and emission characteristics of a variable compression ratio (VCR) diesel engine operated with hybrid biodiesel. Experiments were done with the best hybrid biodiesel, which was made by mixing 20% rubber seed oil (RSO) with 80% waste plastic oil (WPO). The tests were done at four compression ratios (CRs): 16:1, 17:1, 18:1, and 20:1. Under a CR of 20:1 and at full load, the engine’s brake thermal efficiency went up by 30.5%, its brake-specific fuel consumption went down by 0.347 kg/kWh, and notably diminished emissions of carbon monoxide (0.43% volume), hydrocarbons (79 ppm), and smoke (22%). However, with increasing CRs, NOx emissions rose unfavourably (1092 ppm) compared to diesel (820 ppm). Also, diesel and clean (WPO) were compared to see how the CR values affected combustion, performance, and emissions. Compared to diesel, under maximum load and the CR of 20:1, hybrid biodiesel demonstrated approximately 3.7% higher brake thermal efficiency. The findings suggest potential applications for this hybrid biodiesel in the automobile sector, the power generation industry, and marine applications.

IMPACT OF CHEMICAL REACTION, VISCOUS DISSIPATION, AND THERMAL RADIATION ON MHD FLOW PAST AN OSCILLATING PLATE

Rengasamy Rajaraman, Rajamanickam Muthucumaraswamy — Fri, 12 Apr 2024 00:00:00 +0200

This study analyzes the consequences of first-order chemical reactions, radiation, and viscous dissipation on the unsteady magnetohydrodynamic natural convective flow of a viscous incompressible fluid over a vertically positioned semi-boundless oscillating plate with uniform mass diffusion and temperature. An implicit finite-difference technique is employed to solve a set of dimensionless, coupled, nonlinear partial differential equations. The numerical results for fluid velocity, concentration, and temperature at the plate under different dimensionless parameters are graphically displayed. Due to first-order homogeneous chemical reactions, it has been discovered that the velocity rises at the time of a generative reaction and drops during a destructive reaction. A decline in velocity is observed with an increase in the phase angle, radiation parameter, and chemical reaction parameter. Further, it has been revealed that plate oscillation, radiation, chemical reactions, and the magnetic field significantly influence the flow behavior.

ONE—STEP CONVERSION OF ETHANE TO ETHYLENE OXIDE IN AC PARALLEL PLATE DIELECTRIC BARRIER DISCHARGE

Fri, 12 Apr 2024 00:00:00 +0200

This work studied the one-step conversion of ethane (C₂H₆) to ethylene oxide (EO) in an AC parallel plate dielectric barrier discharge (DBD) system with two frosted glass plates under ambient temperature and atmospheric pressure. EO is directly produced from C₂H₆ in a single step without the requirement to separate and recycle ethylene. The effects of the applied voltage, input frequency, and O₂/C₂H₆ feed molar ratio on the EO synthesis performance were examined. The results showed that a higher applied voltage and lower input frequency generated more highly energetic electrons, resulting in a higher current. More electrons collided with reactant gas molecules to initiate plasma reactions, increasing C₂H₆ and O₂ conversions. The increased O₂/C₂H₆ feed molar ratio enhanced C₂H₆ and O₂ conversions. The optimum conditions were found to be an applied voltage of 7 kV, input frequency of 550 Hz, and O₂/C₂H₆ feed molar ratio of 1:1, which demonstrated the highest EO selectivity (42.6%), EO yield (19.4%), and lowest power consumption per EO molecule produced (6.7 x 10^-18 Ws/molecule).

FUNCTIONALIZED CARBON NANOSTRUCTURES AS TEMOZOLOMIDE CARRIERS: PHYSICOCHEMICAL AND BIOPHARMACEUTICAL CHARACTERIZATION

Fri, 12 Apr 2024 00:00:00 +0200

In this study, temozolomide (TMZ), a drug used in the treatment of anaplastic astrocytoma and glioblastoma multiforme, was incorporated in multiwalled carbon nanotubes (MWCNTs) and hybrid carbon nanotubes with graphene (MWCNTs-G) functionalized by polyethylene glycol (PEG). The aim was to evaluate the potential of these nanocarriers for targeted delivery and sustained release of TMZ in brain tumor cells. Oxidized MWCNTs and MWCNTs-G were noncovalently functionalized with PEGs of different molecular weights and subsequently loaded with TMZ following standard procedures. Thorough physicochemical and biopharmaceutical characterization of the TMZ-loaded carbon nanocarriers pointed to high encapsulation efficacy (up to 67%) and drug loading (up to 18% out of 25% theoretical value) and homogeneous particle size distribution, with z-average (160 to 300 nm) and zeta potential (–31 to –21 mV) of the particles adequate for crossing the blood-brain-tumor-barrier (BBTB) and entering into the tumor cells. Successful functionalization and TMZ loading were confirmed by SEM and TEM images, UV-Vis absorption, infrared and Raman spectroscopy, and TGA analyses. Sustained release of TMZ from the carbon nanocarriers was observed in vitro. The presented findings form a fundamental platform for further investigation of these formulations against different types of glioma cells and in adequate animal models.

HEAT TRANSFER PERFORMANCE OF AN Al2O3-WATER-METHANOL NANOFLUID IN A PLATE HEAT EXCHANGER

Fri, 12 Apr 2024 00:00:00 +0200

A plate heat exchanger is one of the smallest and most efficient heat exchangers on the market. This experiment aims to assess the performance of methanol-water as a base fluid in a plate heat exchanger that affects the heat transfer performance. For this study, aluminum oxide (Al₂O₃) nanoparticle was used in various ratios (0.25, 0.5, and 0.75 vol. %) in a base fluid (10 vol.% methanol & 90 vol.% water) to prepare a nanofluid. At two different temperatures, such as 55 °C and 60 °C, with varying flow rates (2 to 8 L/min) and varying nanoparticle concentrations (0.25 to 0.75%), thermo physical characteristics and convective heat transfer studies were performed, and the results are presented. The overall inference was that there was a notable enhancement in the hot side, cold side, and overall heat transfer coefficient by the combination of Al₂O₃ nanoparticle and methanol-water-based fluid. It was noted that utilizing Al₂O₃/methanol-water nanofluid could significantly reduce the temperature gradient in the heat exchanger and improve its performance. Maximum hot fluid coefficient of 4300 W/m²°C, cold fluid coefficient of 4600 W/m²°C, and overall coefficient of 2200 W/m²°C were noted for 0.75 vol.% nanoparticle concentration and at a flow rate of 8 L/min.

DEVELOPMENT OF A MULTI-LAYERED, WATERPROOF, BREATHABLE FABRIC FOR FULL-WEATHER APPAREL

Fri, 12 Apr 2024 00:00:00 +0200

In this research, a laminate was produced by assembling five textile layers. These layers were a coated double-sided knitted structure, a non-woven fabric, a hydrophilic membrane that was thermally assembled to a surface veil, and an open-work knitted fabric. The laminated textile's breathability, windproofness, and waterproofness were evaluated. The multi-layered fabric was windproof, and its water vapor permeability was 347.297 g×m^-2×s^-1(CV= 8.902%). Its resistance to water penetration was equal to 117.68 Schmerber (CV = 7.81%). The assembled fabric's mechanical properties were also evaluated. Young’s modulus values were equal to 2 MPa (CV= 8.613%) and 1.6 MPa (CV= 8.349%) for both fabric directions. Its flexural rigidity was 5056.659 mg×cm and its surface total deformation was lower than 450 µm when measured under 20, 40, 60, and 80 mN loads. Based on the results obtained, it was concluded that the developed multi-layered fabric could be used to produce raincoats and jackets to protect the wearer from light rain and drizzle.