Advanced Materials Research Vol. 1184

Abstract: Intumescent systems are passive fire-retardant systems which employ the insulative property of a condensed char. The texture, strength and appearance of the intumescent char are affected by the individual fire-retardant components. In the present work, the char behaviors of chemically reactive and physically reactive intumescent systems were compared. Bauxite residue (BR) was used as reinforcing filler in pentaerythritol (PER)/ammonium phosphate (APP), a chemically reactive system, and expandable graphite (EG)/ammonium phosphate (APP), a physically reactive intumescent system. BR was found to have antagonistic effect on the char properties of the traditional PER-APP system due to chemical interference with the intumescent reaction. Secondly, the resulting highly viscous char impeded the expansion of available intumescent gases. Consequently, a hard, crusty, char was produced with the degree of expansion reducing from 18.5 to 1.2. On the other hand, the graphite flakes expanded independent of the intumescent reaction, their forceful expansion complimented the BR-reinforced viscous char resulting in a stronger, compact, expanded char. Therefore, EG-intumescent systems may be said to be less selective in its synergism compared to PER-intumescent systems. BR offers a promising potential as a cohesive, reinforcing filler for EG-based intumescent systems.

Abstract: The detection of ethanol (C₂H₆O), a toxic and hazardous gas, is important for environmental monitoring and industrial safety. This study synthesised a SnO₂-doped NiO (SnO₂-NiO) heterojunction via a hydrothermal method for high-performance ethanol gas sensing applications. The thick films of synthesized materials were developed by using the screen printing technique. In this work, SnO₂ is used as a dopant while NiO is base material. The concentration of SnO₂ is varied from 0.1 N, 0.3 N, 0.5 N, to 0.7 N in the NiO during synthesis. The nanostructure leverages the superior gas-sensing properties of the n-type semiconducting behavior of SnO₂ and the p-type semiconducting behavior of NiO, forming an efficient p-n heterojunction interface. The synthesized material was characterized using X-ray diffraction (XRD), TEM (Transmission Electron Microscopy), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS) to confirm the formation of the heterojunction and analyze its morphology and elemental composition. Gas sensing examinations demonstrated that the SnO₂-doped NiO heterojunction exhibited excellent selectivity (86.74%) and sensitivity towards ethanol at 150°C operating temperatures, with rapid response and recovery times. The enhanced gas-sensing performance is attributed to the synergistic effects between SnO₂ and NiO, which promote electron transfer and improve the interaction with ethanol gas molecules. This work highlights the potential of SnO₂-doped NiO heterojunction in developing highly sensitive and selective ethanol gas sensors for environmental and industrial applications.

Abstract: This paper reviews the advancement in assessing caprock failure for Carbon Capture and Storage (CCS). Caprock plays a pivotal role in structural trapping as it acts as a seal to prevent carbon dioxide (CO₂) leakage. However, when a substantial volume of CO₂ is injected into the geological formation, the risk of shear failure associated with certain fractures and faults increases, potentially leading to CO₂ escaping into the atmosphere. Such an outcome directly contradicts the fundamental purpose of CCS, which aims to securely contain CO₂ and prevent its release into the atmosphere, thereby mitigating its impact on climate change. The review highlights Mohr-Coulomb criterion as rock failure prediction methodology to facilitate predict caprock behavior under pressure. This review has identified a gap in understanding the mechanism of structural trapping, particularly on caprock integrity for an effective CCS implementation.

Abstract: Indonesia's commitment to combat climate change through carbon capture and storage (CCS) initiatives is evidenced by the designation of the Air Benakat Formation as a potential site for global carbon emissions mitigation. This study examines the intricate dynamics of CCS within the Air Benakat Formation, focusing on CO₂ storage capacity, reservoir pressure build-up, and CO₂ plume migration, while considering the influence of Lorenz coefficients (Lk) characterizing reservoir permeability heterogeneity. The study reveals that Lk values play a crucial role in determining CO₂ storage capacity and safety. Lower Lk values indicate higher storage capacity due to formation homogeneity, while higher Lk values decrease injected CO₂ quantity, emphasizing the delicate balance between permeability, capacity, and safety. Additionally, Lk significantly impacts pressure profiles, with higher values leading to faster pressure buildup in high-permeability zones, influencing breakthrough pressure. A more uniform formation allowed for the safe storage of 0.347 million tons (Mt) of CO₂ at Lk = 0.2. In contrast, when Lk = 0.6, which is associated with more heterogeneity, the amount of CO₂ injected reduced to 0.333 MtCO₂. Variations in Lk have a major effect on the pressure profile. As Lk changed from 0.2 to 0.6, the pressure fell from 89.95% to 88.13% of the maximum pressure. In high-permeability zones, higher Lk values cause pressure to build up more quickly. Furthermore, CO₂ plume migration is influenced by Lk and reservoir permeability characteristics, with higher Lk values resulting in a more dispersed and elongated plume. Over time, CO₂ saturation increases consistently, particularly in high-permeability zones.

Abstract: Oil spills from sources such as rigs, tankers, and offshore platforms present significant environmental, economic, and social challenges. Large spills endanger human health by contaminating ecosystems. The emulsification of crude oil from the oil spill in seawater complicates remediation efforts, highlighting the need for a better understanding of factors influencing bioremediation strategies. Recently, Chlorella sp. proven to enhance the crude oil degradation by promoting the activity of indigenous microorganisms, utilizing nutrients from the oil and mitigating toxicity. This study investigates the effects of varying salinities on the growth of Chlorella sp. and its biodegradation efficiency under different crude oil concentrations. There are three experimental mixtures that were prepared: 100% seawater, 50% seawater/50% freshwater, and 100% freshwater. Each mixture received essential minerals and periodic CO₂ tablet additions to enhance growth. Optical density readings were taken every three days over a 15-day period at a controlled temperature of 30°C to assess growth rates. The results indicated that the presence of seawater significantly enhanced Chlorella sp. growth, yielding greater biomass compared to freshwater only. Additionally, Chlorella sp. effectively degraded crude oil components, with optimal degradation at lower concentrations (2%). Fourier Transform Infrared (FTIR) analysis revealed a significant reduction in hydrocarbon peaks over two weeks. However, higher crude oil concentrations (4%) negatively impacted the algae growth due to the heightened nutrient requirements necessary for Chlorella sp. to perform efficient biodegradation. This study highlights the potential of Chlorella sp.for bioremediation in oil spill scenarios.

Abstract: The amount of energy consumed is rising daily, which is swiftly depleting the availability of fossil fuels. Because fossil fuels release warming gases into the environment, they have several negative environmental consequences and contribute to global warming. To fulfill the growing demand for high-quality biodiesel, one practical solution is to employ metal: oxide nano-catalysts in transesterification of animal or vegetable oils. this review outlines into the prevalence of various metal oxide nanocatalysts, such as magnesium oxide, calcium oxide, nickel oxide, zinc oxide, and titanium dioxide, which have recently gained popularity as a means to accelerate the production of sustainable biodiesel. Converting typical metal oxide heterogeneous catalysts into nanoparticles enhances their surface configuration, porosity, crystallinity, chemical and thermal stability, and porosity. Metallic oxide nanocatalysts help make more biodiesel by lowering the reaction temperature and length and speeding up the transesterification reaction. Metal oxide nanoparticles assist in the production of biodiesel, which meets international standards and is of exceptional quality. As a result, the metal oxide nanocatalyst may be further optimized as a promising contender for the global energy business in the future.

Abstract: Fines migration in oil and gas fields leads to reduced production rates and equipment failure, resulting in substantial monetary loss. Traditional chemical sand control solutions face challenges in effectiveness and ease of placement, particularly in mitigating fines production. This research explores sand agglomeration as a novel approach to fines mitigation, focusing on the impact of clay content on sand agglomeration for enhanced sand control. Tests evaluated the performance of this approach in reducing fines migration. Findings indicate that optimizing fines mitigation through sand agglomeration significantly improves sand control. The study highlights the importance of clay mineralogy, distribution, and behavior in reservoirs for optimizing sand agglomeration and mitigating fines production effectively. Phase 1 bottle testing identified 5% NH₄Cl brine as most effective in reducing clay swelling. Phase 2 flow testing showed best agglomeration effects at 3.5%, 5.0%, and 7.0% concentrations of sand agglomeration chemicals. Lower concentrations (2.5%) were insufficient, while higher concentrations (10.0% and 12.0%) resulted in overtreated sand. The study demonstrates that clay content significantly affects sand agglomeration performance and fines mitigation, contributing to improved oil and gas production efficiency. By optimizing fines mitigation through sand agglomeration, this research seeks to provide a valuable contribution to the field of oil and gas production.

Abstract: This study investigates the feasibility of a nano-reinforced green resin derived from Almaciga tree (Agathis philippinensis) exudates as an adhesive for sand consolidation in petroleum applications. While green resins often lack mechanical strength, nanoparticle reinforcement with carbon nanotubes has shown promise in enhancing binding properties. This research seeks to investigate how curing time, temperature, dosage, and nanoparticle concentration influence the performance of Almaciga resin as a binder. By investigating these factors, the study aims to provide a foundation for advancing the understanding and application of this sustainable adhesive. The chemical composition of the resin was analyzed using Gas chromatography to confirm the presence of compounds with adhesive properties with solubility tested through insoluble solids mass-ratio method. The green resin was then formulated using multi-walled Carbon Nanotubes (CNT) as fillers dispersed within a matrix of Almaciga resin dissolved in 95% ethanol using solution processing with zeta potential measured using a Malvern Zetasizer to test whether the nanoparticle reinforced formulations can hold a stable dispersion. Sand consolidation tests were done by mixing the formulations with loose sand and placed in 1” x 2" PVC molds using different dosage, curing times, and temperatures. Results show that the resin contains adhesive compounds such as limonene, beta-pinene, pimaric acid, and palustric acid, and resin solubility in 95% ethanol was 93.5%. The zeta potential ranged from -1.66 to 3.56 mV, showing the tendency of the CNT to agglomerate and settle out of the suspension. The results demonstrate that the resin can effectively consolidate samples using a minimum of 14 mL with a curing duration of 48 hours at 30 °C or 7 hours at 90 °C. Logistic regression revealed curing time, dosage, and temperature as key predictors of consolidation success, while CNT concentration demonstrated no statistical significance within the tested range, highlighting the need for further investigation. It is recommended that future research focus on optimizing curing parameters and leveraging uniaxial compressive strength testing to refine the role of CNT concentration. With these findings, this study established a foundation for advancing Almaciga resin as a sustainable adhesive for enhanced sand consolidation outcomes.

Abstract: The aim of this study was to investigate the feasibility of manufacturing typha-based materials with a lime-based binder. For this purpose, three types of lime with different compositions were tested to produce lime-based typha concretes. The mechanical performance (compressive strength and apparent modulus of elasticity) of the materials developed was evaluated as a function of binder content and binder type. Two types of formulations were studied: one with a binder/aggregate ratio of 3, called F3, and the other with a binder/aggregate ratio of 2, called F2. Water absorption kinetics and typha particle size analysis were also studied. The dry density, compressive strength and apparent modulus of elasticity of typha concretes were determined. The results showed a reduction of mechanical performance as the binder/aggregate ratio decreased. The density of typha concretes range from 520 kg/m3to 396 kg/m3. The best mechanical performances were obtained with Thermo Tradical and Earasy binders. When the binder/aggregate ratio was reduced from 3 to 2, stress at 10% strain ranged from 0.6 MPa to 012 MPa and apparent modulus of elasticity from 31.5 MPa to 3.57 MPa. This study showed that binder composition has a significant impact on the mechanical performance of plant-based concretes.