The importance of energy demands that have increased exponentially over the past century has led to the sourcing of other ideal power solutions as the potential replacement alternative to the conventional fossil fuel. However, the utilisation of fossil fuel has created severe environmental issues. The identification of other renewable sources is beneficial to replace the energy utilisation globally. Biomass is a highly favourable sustainable alternative to renewable resources that can produce cleaner, cheaper, and readily available energy sources in the future. The palm oil industry is essentially ideal for the availability of abundant biomass resources, where the multifaceted residues are vital for energy production through the conversion of biomass waste into value-added products simultaneously. This article discusses the utilisation of palm oil and its residues in the energy and transportation sector. Assessment and evaluation on the feasibility of palm oil and its residues were made on the current valorisation methods such as thermochemical and biochemical techniques. Their potential as transportation fuels were concurrently reviewed. This is followed by a discussion on future challenges of palm oil industries that will take place globally, including the prospects from government and nongovernment organisations for the development of palm oil as a sustainable alternative replacement to fossil fuel. Hence, this review aims to provide further insight into the possibilities of palm oil and its residues towards sustainable development with reduced environmental-related issues.

Automotive and aircraft industries are advancing swiftly, creating a constant need for innovative and trustworthy materials. Aluminum composites (aluminum matrix composites [AMCs]) exhibit enhanced mechanical and tribological behaviors when contrasted to their conventional equivalents and as a result have superior potential to be widely accepted for automotive and aircraft engineering and other component applications. This study aims to provide a thorough and critical analysis of the most recent research initiatives concerning the processing, characteristics, and applications of AMCs. It covers the recent advancements in the aluminum-based composites reinforced with SiC, TiC, and graphene, fabrication methods, and mechanical properties of AMCs. Graphene nanoplatelets are many times stronger and yet lighter than steel and other metals, and thus a good contender for reinforcing them. However, the homogeneous distribution of graphene into the metal or aluminum is a challenging aspect for material researchers. The fabrication techniques for AMCs for achieving homogeneous distribution of graphene are critically reviewed. The mechanical properties, specifically microhardness, wear behavior, and tensile strength of aluminum-based composites, are reviewed and analyzed. Finally, a way forward for fostering further development in this area has been discussed.

The tenacious thirst for fuel-saving and desirable physical and mechanical properties of the materials have compelled researchers to focus on a new generation of aluminum hybrid composites for automotive and aircraft applications. This work investigates the microhardness behavior and microstructural characterization of aluminum alloy (Al 7075)-titanium carbide (TiC)-graphite (Gr) hybrid composites. The hybrid composites were prepared via the powder metallurgy technique with the amounts of TiC (0, 3, 5, and 7 wt.%), reinforced to Al 7075 + 1 wt.% Gr. The microstructural characteristics were investigated by optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) elemental mapping. A Box Behnken design (BBD) response surface methodology (RSM) approach was utilized for modeling and optimization of density and microhardness independent parameters and to develop an empirical model of density and microhardness in terms of process variables. Effects of independent parameters on the responses have been evaluated by analysis of variance (ANOVA). The density and microhardness of the Al 7075-TiC-Gr hybrid composites are found to be increased by increasing the weight percentage of TiC particles. The optimal conditions for obtaining the highest density and microhardness are estimated to be 6.79 wt.% TiC at temperature 626.13 °C and compaction pressure of 300 Mpa.

Erosion-corrosion is an unavoidable material degradation process in flow pipelines transporting abrasive particles with carrier fluids. In this study, the multiphase flow loop apparatus is employed to assess the erosion-corrosion behavior and mechanism relative to AISI 1018 carbon steel (CS) and AISI 304L stainless steel (SS) 90° long radius elbows with the inner diameter of 50.8 mm. Fine silica sand of 50 µm average size was used as a dispersed phase and erosion-corrosion tests were conducted for slug flow conditions. The erosion-corrosion analysis of 90° elbows was determined from its surface morphologies before and after the experiment using confocal and scanning electron microscopy (SEM). The direct mass loss was measured to quantify the erosion-corrosion rate of the elbow configurations. Additionally, multilayer paint modeling experiments were performed to relate qualitative inferences on erosion distribution and location with the erosion-corrosion mechanism. It was observed that the erosion or corrosion pitting mechanism prevailed on the 1018 CS elbow surface, and the 304L SS displayed excellent erosion-corrosion resistance properties. Moreover, the erosion-corrosion rate was found to be 4.12 times more in the 1018 CS compared to the 304L SS with the maximum particle impaction identified at the exit of the horizontal-horizontal (H-H) 90° elbow for slug flow.

Erosion–corrosion in flow changing devices as a result of sand transportation is a serious concern in the hydrocarbon and mineral processing industry. In this work, the flow accelerated erosion–corrosion mechanism of 90°, 60°, and 30° long radius horizontal–horizontal (H–H) carbon steel elbows with an inner diameter of 50.8 mm were investigated in an experimental closed-flow loop. For these geometrical configurations, erosion–corrosion was elucidated for erosive slug flow regimes and the extent of material degradation is reported in detail. Qualitative techniques such as multilayer paint modeling and microscopic surface imaging were used to scrutinize the flow accelerated erosion–corrosion mechanism. The 3D roughness characterization of the surface indicates that maximum roughness appears in downstream adjacent to the outlet of the 90° elbow. Microscopic surface imaging of eroded elbow surfaces disseminates the presence of corrosion pits on the exit regions of the 90° and 60° elbows, but erosion scars were formed on the entry regions of the 30° elbow. Surface characterization and mass loss results indicated that changing the elbow geometrical configuration from a small angle to wide angle significantly changed the mechanical wear mechanism of the tested elbows. Moreover, the maximum erosive location was identified at the top of the horizontally-oriented elbow for slug flow.

Erosion-corrosion of elbow configurations has recently been a momentous concern in hydrocarbon processing and transportation industries. The carbon steel 90° elbows are susceptible to the erosion-corrosion during the multiphase flow, peculiarly for erosive slug flows. This paper studies the erosion-corrosion performance of 90° elbows at slug flow conditions for impact with 2, 5, and 10 wt.% sand fines concentrations on AISI 1018 carbon steel exploiting quantitative and qualitative analyses. The worn surface analyses were effectuated by using laser confocal and scanning electron microscopy. The experiment was conducted under air and water slug flow containing sand fines of 50 µm average size circulated in the closed flow loop. The results manifest that with the increase of concentration level, the erosion-corrosion magnitude increases remarkably. Sand fines instigate the development of perforation sites in the form of circular, elongated, and coalescence pits at the elbow downstream and the corrosion attack is much more obvious with the increase of sand fines concentration. Another congruent finding is that cutting and pitting corrosion as the primitive causes of material degradation, the 10 wt.% sand fines concentration in carrier phase increases the erosion-corrosion rate of carbon steel up to 93% relative to the 2 wt.% sand fines concentration in slug flow.