Papers by Keyword: Additive

Abstract: Biodiesel is an environmentally friendly and renewable alternative fuel; however, it continues to face technical challenges related to oxidative stability, combustion efficiency, and exhaust emissions. One widely studied solution involves the use of fuel additives, particularly calcium oxide (CaO). CaO possesses strong basicity, high thermal stability, and notable catalytic activity, making it applicable in both the production and application stages of biodiesel. As a heterogeneous catalyst, CaO accelerates the transesterification process, enhancing biodiesel conversion efficiency. It also acts as an adsorbent, removing water, free fatty acids, and other impurities, thereby improving fuel purity and storage stability. Moreover, CaO contributes to more efficient combustion and has been shown to reduce emissions of carbon monoxide and particulate matter. Despite these benefits, challenges remain, including the risk of residue formation and engine deposits. Recent studies highlight the superior performance of CaO, particularly in nanoparticle form, compared to other inorganic additives. Future research should focus on surface modification strategies, dosage optimization, and long-term engine performance assessments. With proper engineering approaches, CaO holds significant potential to support the development of more efficient, stable, and sustainable biodiesel formulations for cleaner energy applications.

Abstract: In fuel manufacturing, a catalyst is an additive added from the base material to the intermediate product, which functions to accelerate the process of forming the intermediate product. Meanwhile, an additive is a material added to the intermediate product to improve the properties of the fuel before it undergoes combustion. Keywords: additive, nanoparticle, biodiesel.

Abstract: This research demonstrates the production of membranes utilizing polyethersulfone (PES). Cellulose Acetate (CA) at 5% and Polyethylene Glycol (PEG) at 5% are incorporated into the PES membrane as additives, while ethanol serves as a variable non-solvent in the coagulation bath. The incorporation of CA and PEG additives serves to enhance the performance and characteristics of PES membranes. Fabrication of PES membranes utilizing the non-solvent induced phase separation (NIPS) technique. The impact of additive incorporation was assessed through various characterization tests, including Swelling degree, Tensile strength, contact angle, Scanning Electron Microscopy (SEM), and Fourier transform infrared (FTIR). The results indicated that the swelling degree value increased from 13.66% (PES) to 39.40% with the addition of PEG and CA. Nevertheless, the membrane's mechanical strength was diminished as a result of the inclusion of PEG. PES/CA exhibits the highest tensile strength value at 1.8 MPa, while PES/PEG has a peak of 1.4 MPa. The optimal contact angle measurement was achieved on the PES/CA/PEG membrane at 50°. The SEM characterization results indicated an increase in membrane pore size, with the modified membrane exhibiting a pore size range of 0.331-0.664 μm. The incorporation of 60% ethanol as a non-solvent resulted in the maximum swelling degree value of 41.05%. In conclusion, the characteristics of the membrane are influenced by the combination of additive Cellulose Acetate (CA) and Polyethylene Glycol (PEG) through blending.

Abstract: Biogas has been effectively produced from solid as well as liquid biomass waste through anaerobic digestion (AD). It has been proved that AD is the most efficient technology and less environmental effect in converting biomass to biogas. However, it is challenging that the rate of biogas production might slow down by many factors. It requires continues research in order to overcome the problem, such as by adding an additive. The use of several additives for AD has received great attention due to the positive influence in improving the production performance of biogas in terms of process stability and efficiency, and production capacity. Among all types of additives, carbon material in the form of bio-char has been considered as the most profitable due to low cost and easy to produce from various carbon source materials. This study aimed to determine the characteristics of coffee pulp bio-char which will be used as an additive in biogas production from coffee mucilage by the AD method. Coffee pulp biomass and coffee mucilage were obtained from Aceh Tengah, Indonesia. Preparation of bio-char was carried out by washing and soaking of the coffee pulp with tap water for 24 hours, then drying under the sun for three days. Carbonization of dried coffee pulp was then performed using a pilot plant-scale pyrolysis reactor at temperature of 400 °C for 60 minutes. Resulting biochar was then ground and sieved to 60 mesh size. Based on to proximate analysis result, it was found that the moisture, ash, volatile matter, and fixed carbon contents were respectively 1.98%, 11.93%, 42.36%, and 43.72%. N₂-physisorption analysis of coffee-pulp bio-char suggested pore volume of 0.21 cm³/g. From BET calculation method it was found that the surface area was 224.1 m²/g. This high surface area is beneficial for providing sheltered spaces for microbes to attach and hindering them against metabolic inhibitors. The effect of adding biochar additives from coffee skin waste in the anaerobic digestion process of coffee mucilage waste provides significant results on the yield of biogas products. The yield of biogas products increased by 225% with the addition of 15 gr/L of biochar coffee pulp.

Abstract: Cellular concrete (known as foamed concrete) is a lightweight building material with low densities ranging from 900 kg/m³ to 1900 kg/m³, which can have potential applications in civil engineering practices. However, it is very weak in withstanding tensile loads which leads to cracks during shrinkage in the drying stage. Therefore, six different groups of cellular concrete are prepared for a possible application in grouting underneath the foundations to achieve a minimum compressive strength of 2000 psi (13.79 MPa) as per ASTM C476, and for soil nail grout with a minimum compressive strength of 3000 psi (20.86 MPa) as per ASTM C109 at 28 days. Furthermore, these mixtures are undergoing laboratory testing for pushout (using steel cylinders with varied diamters and thickneses) and pullout tests as the subsequent part of this project. All groups contain 0.34 water-to-cement ratio, same size and amounts of sands and superplasticizer (SP). The first group included four control mixes without bentonite and polypropylene fiber (PPF) additives with varied foam content (C1-F1,F2,F3,F4). The remaining groups consist of 17 different mixes blended with either one or both additives. The content effect of foam agent, bentonite clay, and PPF as additives on the density and compressive and flexural strengths of cellular concrete are investigated in this study. The results revealed that the introduction of bentonite and/or PPF in cellular concrete mixtures increased the density and strength. The results revealed that low dry densities (less than 1900 kg/m³) of blended cellular concrete mixtures can reach high compressive strength of 24.37 MPa with 4.74 MPa flexural strength that make them feasible for geotechnical and structural engineering applications.

Abstract: The effect of treating the wood filler of freshly cut wood species with the additive of silica sol obtained by the polycondensation method on the arbolite properties is studied. It was found by X-ray fluorescence spectroscopy that silica sol particles with the sizes of 20 to 80 nm are adsorbed on the surface of the wood filler, obstructing open pores and spaces between the wood vasculars. The most effective is the additive of silica sol with its content from 10 to 20%. It is shown by the a multilayer map of energy-dispersive X-ray spectroscopy of a wood particle treated with silica sol that calcium cations accumulate on the wood filler in the arbolite mix, thus affecting the hydration of the cementing material and the arbolite strength. After 3 and 28 days of hardening, the strength of the arbolite with the birch chips increases by 2.5-2.7 and 2.7-3.1 times, respectively; with the aspen chips its strength becomes 3.1-4.2 times higher; and the arbolite strength rises 3.1-4.2 times with birch and pine chips (1:1). The method for treating the wood filler with silica sol patented by the authors makes it possible to simplify the technology of its preparation, to reduce the exposure time of wood filler before mixing with a cementing material and to produce arbolite from freshly cut birch wood with the strength after 3 and 28 days of hardening being 2.5-2.7 and 2.7-3.1 times higher than that of the control composition.

Abstract: The quality of gel - based silicon, which forms an insulating content to prevent water and sand in oil and gas wells, have been improved. Based on the reaction between the liquid glass and hydrochloric acid, the optimal concentration of the initial reagents for the formation of the gel process was determined. The rheology, initial and final setting time of the silicon based gel, and the temperature dependencies of the gel forming process were also studied by adding 0.1-1.0% (mass ratio) of urea as cross-linking to the Na2SiO3/HCl solution. At the same time, the impact of the obtained gel of the permeability of the rock pores was determined and the filtration characteristics were studied. It has been determined that with 0.1-0.8% mass concentration of the urea added to the Na2SiO3/HCl solution, the setting time of the gel could be regulated according to the well-layer regime. The resulting silicone-based gel can be used as an injection solution that can set in 3-22 hours in oil and gas wells between the temperature of 20-80 °C.

Abstract: The main objective of the study was to obtain an effective component composition of a dry building mixture with the use of a complex additive. In this work the specific surface area of the anhydrite binder was determined. It is optimal for providing the mixtures with the required characteristics. The manufacture of experimental compositions was made, according to pre-selected recipes. From them through the performed tests, the most effective was identified. The composition of the modified anhydrite binder was established. It had to match the reference requirements for filling mixtures. The conclusion was formulated about the ability of additives to influence the technological and physical-mechanical properties of the filling mixtures.

Abstract: In the present paper, there were considered the issues of developing optimal compositions and the study of the impact of sulfur addition on strength properties of sulfur containing binders for building materials. The purpose of the research is the development of scientific principles of physical and chemical mechanics for detoxification of wastes produced by oil-processing and metallurgical industries while obtaining sulfur containing binders with enhanced adhesive and strength properties altered by the directed mechanochemical effects. While carrying out the scientific research, there have been used standard measurement methods and the methods of analysis of physical and mechanical properties of sulfur containing binding compositions obtained by the contemporary methods of analysis and testing equipment. As the result of the research, new binding substances with improved adhesive properties have been obtained and sulfur containing structural materials with the complex of enhanced physical and mechanical properties have been developed on their basis.

Abstract: The article deals with the influence of crystallization additives on the life of self-compacting concrete (so-called SCC concrete), which are exposed to chemically aggressive environments. The focus is not only on the effect of the crystallization additive on the characteristics of the capillary-pore structure of SCC concrete, but especially long life durability of self-compacting concrete (two years expozition). The effect of individual types of aggressive environment is assessed on the basis of a set of physico-mechanical and physico-chemical analyzes.