Journal of Engineering Research

Evaluating the Potential of Refractance WindowTM Drying Technology in Food Preservation: A Review of Current Research and Future Directions

Journal engineering — 2025-03-12

One significant issue facing developing nations is the preservation of agricultural products, especially during harvesting. Dehydration remains critical in food preservation as dried products are cost-effective, lightweight, and have an extended storage duration. However, traditional drying techniques are either time-consuming, energy-intensive, or degrading the product. In the quest for efficient and sustainable technologies to preserve and enhance the quality of agricultural produce, Refractance Window Drying (RWD) has emerged as a promising technique with vast potential that remains largely unexplored. This review introduces this novel technique, including its principles, unique advantages, efficacy compared to traditional drying methods, and potential application in dehydrating agro-products. By discussing the current challenges and future research directions of this innovative drying technique, this review contributes to the growing knowledge of advanced dehydration technologies and empowers the audience with practical insights for their adoption in the food industry.

Characterization of Carrot (Daucus Carota) Slices During Oven Drying

Journal engineering — 2025-03-13

This research investigated the drying properties of yellow carrots (Daucus Carota) using an oven dryer, with the potential to significantly improve the design of oven dryers. The study utilized the DS Memmert Universal oven UF55 dryer, drying 1.5, 3.0, and 4.5-mm thick carrot slices at 60, 70, and 80℃ temperatures. The variation in moisture content with time was recorded during dehydration to monitor the drying progress. The drying, drying rate, and Krischer curve plots were constructed using the recorded variation in moisture content over time. The study estimated the effective moisture diffusivities and dehydration activation energies of the carrots, as well as their thermodynamic properties, such as changes in Enthalpy (∆H), Entropy (∆S), and Gibbs free energy (∆G). Observations indicated that carrot slices achieved a moisture ratio (dry basis) below 0.1 after approximately 25 and 70 minutes of drying. The statistical analysis of the moisture ratio data revealed that all models fitted to the thin-layer drying model had a coefficient of determination ( ) value better than 0.99. The effective moisture diffusivity of the 1.5, 3.0, and 4.5-mm thick carrot slices, dehydrated at 60, 70 and 80℃, varied between 8.30E-09 to 6.78E-10 m²s^-1. The study observed that the activation energy of dehydration varied between 3.2753E+04 and 2.3449E+04 J/mol for different slice sizes based on the moisture-content history data. The thermodynamic properties, such as changes in ∆H, ∆S, and ∆G, were subsequently estimated to range between 20,514.37 and 29,984.58 J.mol^-1, -123.77 and -109.38 J.mol^-1.K^-1, and 66,407.83 and 64,204.92 J.mol^-1, respectively. The data obtained from the study will prove beneficial in the specification, design, modelling, and operation of oven dryers.

Physics-Informed Neural Networks for the Prediction of Critical Sand Transport Velocity in Oil and Gas Pipelines

Journal engineering — 2025-03-18

Poorly consolidated reservoir formations make the generation of sand alongside hydrocarbons unavoidable. The condition of petroleum pipelines can be seriously compromised by the rapid generation of sand or by sand deposition at low velocities, leading to degradation and reduced capacity. Consequently, it is essential to investigate the minimum transport velocity needed to prevent pipeline sand accumulation. This study employed two predictive modelling tools, a physics-informed neural network (PINN) and a multilayer perceptron (MLP) regressor, to estimate the minimum transport conditions in a solid-liquid-gas pipeline. The models were developed using 182 experimental data sets, which included variables such as superficial velocity, pipe diameter, particle diameter, sand density, sand concentration, liquid density, viscosity, pipe angle of inclination, and critical velocity parameters. The results indicated that the physics-informed neural network outperformed the MLP regressor, achieving an R² coefficient of 0.9999 and a root mean square error (RMSE) of 0.00465. In comparison, the MLP regressor attained an R² coefficient of 0.9992 and an RMSE of 0.0295. Both models were evaluated alongside existing empirical and data-driven models and demonstrated superior performance in predicting minimum transport velocity, with the PINN yielding the best results. A sensitivity analysis revealed that the superficial velocity is the most influential parameter for predicting minimum transport velocity, followed by pipe diameter, sand concentration, and pipe angle. This research highlights the potential of effectively integrating physical laws into the machine learning training process to estimate minimum transport velocity in multiphase pipelines better

Development of an Environmental-Friendly Wax Inhibitor for Crude Oil Transport in Oil and Gas Pipelines

Journal engineering — 2025-03-18

Wax deposition has caused significant operational problems and economic losses for many oil and gas companies. Typically, crude oil is transported at conditions below Wax Appearance Temperature (WAT) causing wax to precipitate and build up leading to flow restriction and sometimes eventual pipe blockage. Wax inhibitors (WI) have been known to be a formidable solution to this problem. However, conventional wax inhibitors are known to have caused environmental and health concerns due to their toxicity. They could also be quite expensive therefore, the need to develop economically attractive and environmentally friendly WI. In this study, a wax inhibitor Methanol-Cellulose (WI-MC) was formulated from coconut husk bio raw material. The coconut husk was treated and prepared in the laboratory and applied at different dosages of 0.2ml, 0.6ml and 1.0ml to two different crude oil samples. The effect on WAT examined from viscosity readings obtained at varying temperature was compared with Toluene. Without inhibitor the WAT for samples A and B was 55°C. Comparative analysis however reveals WI-MC is comparable with Toluene. At 0.2ml dosage, WI-MC had no effect on WAT whereas at 0.6 and 1.0ml, the temperature-viscosity plot showed WAT lowered to 50°C, Similar result was also obtained for Toluene. This indicates WI-MC inhibitor can be considered a feasible and potentially cost-effective alternative for synthetic and imported WIs. The reduced dependence on such chemicals is an environmental advantage brought about by renewable and locally available materials.

Copper (II) ion removal from synthetic wastewater using chitosan-impregnated coconut shell adsorbent: optimization, kinetic, and thermodynamic studies

Journal engineering — 2025-03-18

A chitosan-impregnated coconut shell adsorbent composite was prepared for copper (II) ions adsorption from synthetic wastewater. Optimization and characterization of the prepared composite adsorbent was conducted along with the kinetics and thermodynamics experiments. Optimization investigation was achieved using Box-Behnken-based response surface methodology. The highest adsorption factors was obtained, yielding a copper removal efficiency of 76.82% at pH of 6, shaking speed of 150 rpm and initial concentration of 150 mg/g. Maximum Cu²⁺ ion adsorption capacity of 53.49 mg/L was obtained. The experimental data for chitosan-impregnated coconut shell adsorbent composite was analyzed using the kinetic and equilibrium adsorption isotherm models. The Langmuir adsorption isotherm model fit the experimental data, which suggests a highly energetic heterogeneous surface, with an R² of 0.9993. Pseudo-second order explicitly represents the kinetic data with R² range of 0.9989 to 0.9998, indicating a strong correlation between the actual and calculated values. In conclusion, the thermodynamic parameters change in Gibbs’s free energy (∆G), change in enthalpy (∆H), and change in entropy (∆S) indicates copper ion adsorption onto chitosan-impregnated coconut shell adsorbent composite was endothermic and spontaneous. These results suggest that chitosan-impregnated coconut shell adsorbent composite is an excellent adsorbent for removing copper ions from wastewater.

Mathematical Models for predicting CO2 Density and Viscosity for Enhanced Gas Recovery and Carbon Sequestration

Journal engineering — 2025-03-18

There is limited work on mathematical correlations in place for predicting density and viscosity of supercritical carbon-dioxide (CO₂), necessary for Enhanced Gas Recovery - Carbon Sequestration (EGR-CS) operations. In this work, three categories of mathematical correlations were developed by Split Regression Analytical method and validated using Equation of State (EOS) models for predicting density and viscosity of carbon-dioxide under supercritical conditions as expected in EGR-CS operation. The models range for application is for reservoir depths of 1000-1500m, 1600-5000m and beyond 5000m for both CO₂ density and viscosity, which are ideal for carbon sequestration and covers depths of most gas reservoirs in Niger-Delta. The new “UDA-Model” matched with Peng Robinson and Soave-Redlich-Kwong (EOS) models at the tested reservoir conditions, with low Absolute Average Deviation. Application of these mathematical correlations on four depleted gas reservoirs in Niger Delta formations shows Relative Density Difference (RDD) and Relative Viscosity Difference (RVD) on CO₂ and natural gas. CO₂ densities at those depths range from 0.5-0.6g/cm³, 0.6-0.7g/cm³, and 0.7-0.8g/cm³ respectively while the viscosities range from 0.05-0.06cP, 0.06-0.07cP, and 0.07-0.08cP respectively. The results promise smoother displacement of natural gas by CO₂ during EGR-CS operations.

Effect of Monoethylene Glycol Injection in Hydrate Management

Journal engineering — 2025-03-25

The presence of hydrates in deep water oil-gas-field operations is a fairly frequent issue. It is very important to have a hydrate management strategy for normal operation. This work evaluates the optimum mass concentration of monoethylene glycol (MEG) in hydrate management for a deep-water operation condition. A simulation-based approach was adopted and OLGA Dynamic Multiphase flow simulator and Multiflash fluid model modelling package were used. A base model was initially developed and subsequently adjusted for different mass concentrations of 10, 20, 30, 40, 44, and 45 MEG. The results for the actual production with no inhibition, shows that at 2268.53ft along the pipeline that 6.74853 х10-5 volume fraction of hydrate was formed at a pressure and temperature of 318.196psia and 3.41765°F in the pipeline. It also reveals that hydrates were formed at the inlet section of the pipeline. For 10 mass percent of Monoethylene glycol added to the fluid system, 573.651ft and 1.21864х10-7 volume fraction of hydrate was formed in the pipeline. Hydrate was thermodynamically unstable up to 573.651ft along the pipeline. After the unstable section, 1.21864х10-7 volume fraction of hydrate was formed in the pipeline. Result shows that increase in the mass percent of the MEG increases the length of instability of the hydrate formation along the pipeline and increase in the mass concentration of the MEG decreases the volume fraction of hydrate formed in the pipeline. Results further reveal that 45 percent mass concentration of MEG inhibited hydrate formation in the gas mixture.

Numerical Investigation of the Thermal Performance of Different Shapes of Fiber-Glass/Talc-Epoxy Insulated Cryotanks

Journal engineering — 2025-03-25

This study focuses on the thermal performance of different shapes of fibre-glass/talc-epoxy insulated cryotank with the aim of minimizing heat leakage into the stored cryogenic fluid. Numerical simulations were performed using a computational fluid dynamics software on rectangular-, cylindrical-, and spherical-shaped cryotank geometries while maintaining a constant inner shell volume. The outer shell was subjected to a temperature boundary condition of 28°C, while the inner shell volume was initially set to a temperature of -196°C, which is equivalent to the temperature of liquid nitrogen. The heat transfer from the environment to the cryogenic fluid stored within the cryotank was analysed, and the optimal insulation thickness that minimises the heat flux into the different cryotank shapes was determined. The results obtained revealed that the spherical-shaped cryotank had the best performance in minimising heat leakage with the lowest temperature of -156.1°C and optimum insulation thickness of 279 mm after 3 hours of storage within the tank. Optimising the insulation thickness was required to determine the minimum thickness required to maintain liquid nitrogen at approximately -196°C after one hour of storage. This was determined to be 240 mm, 180 mm and 160 mm for the rectangular-, cylindrical- and spherical-shaped cryotanks respectively. The findings in this study validates the importance of optimisation studies in the design of small and compact cryotanks to ensure material cost savings and optimal thermal performance.

Investigating the Effect of Energy Density on Corrosion Susceptibility of Additively Manufactured Thin-walled Cobalt Chrome Alloy

Journal engineering — 2025-03-25

Metal additive manufacturing is an innovative technology based on fabricating near-net shaped metallic components from a digital model in a layer-by-layer manner. Although, it has many advantages over conventional subtractive methods, understanding the correlation between process parameters and properties of additively manufactured alloys is key to producing components with optimal performance. Hence, in this study corrosion susceptibility of laser powder bed fusion additively manufactured cobalt chromium alloy (CoCr) alloy produced with three different energy densities (0.58 J/m, 0.87 J/m, 2.26 J/m) was investigated. Some of the CoCr alloys produced were subjected to post-build heat treatment by hot isostatic pressing (HIP). Corrosion resistance of both as-built and HIP CoCr alloys in 0.5 M H₂SO₄ solution at room temperature was investigated using gravimetric method. The results indicated that additively manufactured (AM) CoCr alloy produced with energy density of 0.58 J/m and 2.26 J/m respectively were less susceptible to corrosion compared to that produced with energy density of 0.87 J/m which is the standard energy density recommended by the Original Equipment Manufacturer (OEM). This result was consistent with the trend observed in previously reported mechanical properties of the AM CoCr alloys.