Papers by Keyword: Carbon Dioxide

Abstract: Lubrication plays a crucial role in cold forging, influencing key factors such as material flow, surface quality and tool wear. The current state of the art presents conventional mineral-oil-based lubricants as one of a range of effective solutions; however, they generate residues, require cleaning and pose environmental concerns. This work explores CO₂ snow as a potential residue-free, sustainable alternative for cold forming of mild steels. Miniature spike tests were conducted to characterise friction behaviour under varying lubrication and surface conditions. The study demonstrates that CO₂ snow can effectively reduce friction, promote favourable material flow and achieve surface finishes comparable to conventional oils, while eliminating residue and post-processing requirements. These findings suggest that CO₂ snow represents a promising eco-friendly lubrication strategy, offering both technical performance and environmental benefits for sustainable cold forging operations.

Abstract: Emissions are substances that enter the air, whether or not they have the potential as pollutants. Emission gases can have adverse effects on the health of living beings, especially humans, and can contribute to an increase in the Earth's temperature. Therefore, separation efforts are needed to minimize the negative impacts caused by them. Adsorption method was categorized as absorption, cryogenic distillation, and membrane. Although there were shortcomings in adsorbing emission gases through the method, it remained a promising approach. Adsorption was recognized for its economic viability, technological effectiveness, thermally stability, corrosion resistance, high load capacity, and tunable surface properties. However, adsorption materials were categorized as porous carbon, zeolites, metal-organic frameworks (MOFs), porous polymers, and porous silica. A significant limitation of the method was its susceptibility to decreased capacity in the presence of water vapor. The analysis results showed that porous silica became a superior adsorption material due to its high porosity, which facilitated rapid gas diffusion. To enhance selectivity and adjust pore size, material modifications, particularly silica, became necessary. This showed that surface modification for silicasupported the improvements in selectivity and pore size.

Abstract: Inclusion compound based on crystalline water is increasingly recognized as a promising solution for carbon dioxide (CO₂) capture, either for carbon sequestration from greenhouse gas emissions or for gas mixture separation. Molecular dynamics simulations revealed that water crystallizes into a novel porous structure in a carbon nanobrush environment even at room temperature, thus termed ”hot” ice whose structure code is dtc. This study employs a hybrid Grand Canonical/isothermal-isobaric Monte Carlo (GCMC) simulations to investigate CO₂ confinement inside the cylindrical channels of ice dtc structure. The results show that CO₂ occupancy, here expressed as CO₂-to-water mole ratio, is approximately 2:5 at maximum. The simulations also demonstrate the mechanical stability of ice dtc structure under positive pressures when its voids are filled with CO₂. Furthermore, molecular dynamics simulations are performed to provide molecular insights into the structures and dynamics of CO₂ inside the porous channels framework. The results show that CO₂ molecules form a bilayer structure inside the cylindrical channels, where certain molecule orientation angles are favored. Dynamics analysis shows that CO₂ molecules are relatively immobile in all directions at maximum occupancy.

Abstract: Global warming is a concern nowadays due to excessive release of harmful gasses to the environment, leading to greenhouse effect phenomena worldwide. Based on the data provided by global pollution agencies, the release of greenhouse gasses to the atmosphere is the main cause of pollution and the increase in atmospheric temperature due to warming. Greenhouse gasses (GHGs) contents released to the environment is worrying, with carbon dioxide (CO₂) is reported at the highest concentration compared to other gasses. There are many studies conducted to develop and evaluate the performance of harmful gas sensors incorporating inorganic and organic semiconductive materials. Organic semiconductors (OSCs) are environmentally friendly materials, relatively cheaper technology, and comprised of a wide range of materials with good carrier mobility. Therefore, in this work, Organic Thin Film Transistor (OTFT) is developed for gas sensor application. As global warming is becoming more serious, this solution is instead a sustainable solution to the environment, as organic molecules which are held together via Van der Waals bond are easily processed via low-temperature deposition and solution processing as compared to more complicated processes involved in conventional inorganic counterpart. In addition, the developed sensor is generally robust due to the ability to withstand high humidity conditions and can be fabricated on flexible substrates. In this work, suitable materials are identified in basic OTFT construction, which are the electrodes, dielectric and substrate. The scope is mainly focusing on the development of bottom gate OTFT construction, incorporating p-type active material which are Trisisopropylsilylethynyl Pentacene (TIPS Pentacene), Aluminium (Al) as drain and source electrodes, PEDOT: PSS as gate electrode and Polyvinyl alcohol (PVA) as gate dielectric. The materials in bottom gate bottom contact (BGBC) configuration, fabricated via screen printing technique is experimentally tested towards CO₂ detection. CO₂ is initially detected at 1618 ppm with contact resistance of 15 kΩ, and at 10 ml/minute flow rate, the developed configuration is demonstrated able to achieve sensitivity of 2.069 Ω/ppm. In conclusion, the studied BGBC OTFT has demonstrated suitability and applicability in CO₂ gas sensing for sustainable environmental condition monitoring, that could lead to safer environment for the living things on earth. With the proposed dimensions, in the future it is possible to proceed with this work to be fabricated by using more advanced techniques such as photolithography and many others.

Abstract: The acetylene market is anticipated to be driven by the growing applications across numerous industries particularly chemical synthesis, oxy-acetylene welding, and metal cutting. Attributable to wide-range uses, acetylene witnesses stable growth in the global market. However, the production of acetylene results in increasing generation of carbide lime waste that is classified as a scheduled waste under Malaysian Environmental Quality Act: EQA 1974 (SW427) due to its high alkalinity. The rising amount of the waste has warranted the need for repurposing its usage to avert handling and disposal difficulties. In overcoming this crucial environmental issue, the carbide lime waste was transformed into a more marketable product so-called precipitated calcium carbonate (PCC) via feasible carbonation, promoted using natural sucrose solution. During the carbonation process, stirring rate was manipulated (i.e 300, 500, 700 and 1000 rpm) in investigating its effects on the PCC formation. Increasing the mechanical disturbance resulted in significant time reduction from 28 minutes to only 9 minutes and particle refinement. The production of PCC with purity above 98% suggested that the carbide lime waste was successfully transformed into high-grade PCC, which not only may help in preserving environmental sustainability yet can also offer profitable return to industry.

Abstract: Recent advances in the fields of artificial intelligence and machine learning have paved a way in solving the unsolved problems embarking into a new dimension, especially, when there is increase in complexity of molecules. Reports have shown the necessity to employ these techniques to address the environmental problems. Herein we report the CO₂ sequestration process by means of artificial intelligence (AI) and machine learning (ML) tools. The AI and ML approaches adopted enhance the accuracy of the results and at the same time give scope to explore new strategies in understanding the CO₂ sequestration process. Herein we considered the reported active compounds observed in traditional medicinal plants like Oscimum, Azadiracta, Psidium and Ficus leaves and Curcuma and, their interactions with CO₂. The crystal structures of the active compounds, collected from NCBI portal, are used for all the calculations. To understand the probable interactions of CO₂ with active components AI tool IBMRXN was used and the properties of molecules are evaluated. ML techniques are employed using density functional theory method. Keeping in view the complexity of the molecules, optimization of the molecules is carried out at M062X/6-31G(d) level of theory. HOMO-LUMO energy gaps and binding energies are calculated at M062X/6-311+G(d,p)//M062X/6-31G(d) level of theory.

Abstract: Abstract. in this Study, Activated Carbon was Created by Physically Activating Potato Peel Waste (PPW) with Carbon Dioxide. the Potential of this Approach, which Uses Carbon Dioxide to Produce Actuation Carbon (AC) from Precursor Potato Peel Waste, has been Investigated. Utilizing x-Ray Diffraction Analysis, Scanning Electron Microscopy, and Atomic Force Microscopy, the Microstructure of the Activated Carbon was Examined. the Average Crystallite Size was Affected by Employing Varied Periods for the Activation Process, as Seen by the Crystallite Size of the High-Intensity Peaks of the Precursor Potato Peel Waste at Various Drying Times and the Activated Products. after 60 Minutes of Drying, the Activation Stage was under Ideal Conditions, and in Comparison to the other Times, a Size of 325 Nm was Also Attained with the Rest of the Periods, as well as a High Adhesion Elevation Surface Region for the Carbon. the Activated Carbon Produced Using Physical Activation Showed a Surface Area as High as 1733 m²/g with a Pore Volume of 0.45 cm³/g, whereas the Precursor Showed a Surface Area of < 4 m²/g. this Investigation Aims to Modify the Surface of Activated Carbon without Significantly Altering its Structural Parameters for Use in Future Renewable Energy Sources and to Make the Synthesis of such Materials more Potent, more Eco-Friendly, and Less Expensive.

Abstract: In this paper, cellulose solution was obtained by dissolving cellulose in CO₂ switchable solvent, and the CNF spinning solution was prepared by mixing cellulose solution with cellulose nanofibrils (CNF) by physical blending. CNF reinforced all-cellulose composite fibers were prepared by wet-spinning. The spinning solution with good dispersion of CNF can be obtained. The rheological property test showed that the solution has spinnability. The composite fibers were subsequently prepared by wet-spinning. The structure and properties of the composite fibers were analyzed by FT-IR, XRD, SEM, TGA, and mechanical properties testing. The results showed that the chemical structure of the composite fiber was the same as that of cellulose, but the aggregate structure became amorphous, which resulted in deceased thermal stability. The composite fibers had dense and solid structure without any cavity. The mechanical strength of the composite fiber was upto 1.12cN/dtex.

Abstract: Current global environmental challenges and, above all, global warming associated with a change in the carbon balance in the atmosphere has led to the need for urgent and rapid search for ways to reduce greenhouse gas emissions into the atmosphere, which primarily include carbon dioxide as a by-product of human activity and technological progress. One of these ways is the creation of industries with a complete cycle of turnover of carbon dioxide. Aluminum is the most sought-after nonferrous metal in the world, but its production is not environmentally safe, so it constantly requires the development of knowledge-intensive technologies to improve the technological process of cleaning and disposal of production waste, primarily harmful emissions into the atmosphere. Another environmental problem related to aluminum production is the formation and accumulation in mud lagoon of huge amounts of so-called highly alkaline "red mud," which is a waste product of natural bauxite raw material processing into alumina - the feedstock for aluminum production. Commonly known resources and technological methods of neutralizing red mud and working with it as ore materials for further extraction of useful components are still not used because of their low productivity and cost-effectiveness. This article describes the negative impact of waste in the form of "red" mud and carbon dioxide of primary aluminum production on the environment. The results showed that thanks to carbonization of red mud using carbon dioxide, it is possible to achieve rapid curing and its compact formation for safer transportation and storage until further use. Strength tests of concrete samples filled with deactivated red mud were also carried out, which showed the prospects of using concrete with magnesia binder.

Abstract: The purpose of the study is to study the possibility of using secondary resources of metallurgical production, namely: steel-making slag and carbon dioxide in the production of vibropress products for construction purposes. The tests were carried out with the complete replacement of the coarse aggregate in the concrete mixture with steelmaking slag and varying the hardening processes. The optimal condition for strength gain is hardening in carbon dioxide at an increased pressure of 0,2 MPa.