Papers by Keyword: Blending

Abstract: Demands for energy are rising as the world's population expands. To meet these demands, fossil fuels have been overused, yet this over reliance on them has led to their depletion. The usage of fossil fuels has also significantly contributed to the release of greenhouse gases, which is a serious environmental concern. Sustainable energy is therefore environmentally friendly and financially sound. Petro-diesel can be replaced by biodiesel because it is biodegradable and less hazardous. Biofuel is any fuel produced from biomass, which can be either animal fats or waste, plant or algae material as a feedstock. Biomass benefits in producing fuels which helps to lessen the demand for petroleum fuel and products. Petroleum fuel and gas increase the greenhouse gas emissions profile of the transportation sector. The Republic of South Africa (RSA) is the 14^th world's largest emitter of greenhouse gases. This is due to the emissions resulting from burning and heavy reliance on coal. Since biofuel can be produced domestically from natural sources like soybeans, rapeseed, macadamia nuts, coconuts, and even leftover cooking, it has the potential to serve as a remarkable substitute for the commonly used petroleum-derived diesel fuel. This study addresses the historical development of macadamia nuts with a focus on the South African Macadamia Nuts (SAMN) industry, its origin, and as a feedstock for biodiesel production. The generation and classification of biodiesel, physicochemical properties, biodiesel standards, and both American Society for Testing and Materials (ASTM), European Committee for Standardization (EN 14214), and South African biodiesel framework standards are discussed. Furthermore, the biodiesel blending requirements, techniques, and benefits were outlined. Finally, the biodiesel regulatory framework of SA and biodiesel framework as per the Biodiesel Task team (BTT) was examined.

Abstract: Plastic packaging that applied material value conservation paradigm will generate good quality plastic waste. It can be recycled to produce raw material for new packaging. However, repetitive recycling has impacts on lowering its mechanical properties. Recycled plastic is expected not to undergo mechanical properties degradation. This research proposed to blend recycled plastic pellets with its virgin plastic to reduce mechanical properties degradation. Mechanical properties of recycled polypropylene are compared to 100% virgin polypropylene and recycled/virgin polypropylene blends with composition 90/10, 70/30, 50/50, 30/70, and 10/90. Mechanical properties tested in this research are modulus of elasticity, tensile strength, elongation at break, and density. All were tested according to ASTM for mechanical properties testing materials. This study revealed blending 50% virgin polypropylene significantly improves mechanical properties of recycled plastics and keep improving at 70% virgin polypropylene. The optimum improvement based on four mechanical properties was found at composition 30/70 of recycled/virgin plastic. Elongation at break is the most critical property where degradation was found at 90/10. Blending 6^th recycled and virgin polypropylene gives opportunities to improve the mechanical properties of recycled plastic products with careful consideration of the compositions. By implementing material value conservation, good quality plastic waste can be recycled repetitively. This will decrease accumulation of plastic waste generation and usage of non-renewable plastic’s raw material. The positive impact is not only to economic of plastic industry but also to the quality of environment.

Abstract: Aviation industry is considered one of the contributors to atmospheric CO₂emissions. It is forced to cut off carbon dioxide emission starting 2020. Current trends in bio-jet production involve mega projects with million dollars of investments. In this study, bio-jet fuel production by blending bio-diesel with traditional jet fuel at different concentrations of bio-diesel (5, 10, 15, 20 vol. %) was investigated. This blending technique will reduce bio-jet production cost compared to other bio-jet techniques. Bio-diesel was originally produced by the transesterification of non-edible vegetable oil (renewable sources), so, its blend with jet fuel will has a reduced carbon foot print. The blend was tested to ensure that the end product will meet the ASTM D1655 international specifications for Jet A-1 and Jet A and can be used in aircrafts.Available data on biodiesel blending with jet fuel in the literature is not consistent, there are many contradictory results. Hence, more investigations are required using locally available feedstocks. The main physicochemical properties for Jet A-1 and Jet A according to ASTM D1655 were tested to check if the blend will be compatible with existing turbojet engine systems. Different tests were conducted; vacuum distillation, smoke point, kinematic viscosity, density, flash point, total acidity and freezing point. In addition, heating value of the blend was calculated. The result was then compared with calculated value using blending indices available in the literature. Blending indices were able to predict the laboratory measured specifications for the studied blends.It was found that only 5% bio-diesel- 95% jet fuel blend (B5) meets ASTM standard for Jet A. Hence, biodiesel can be safely used as a blend with fossil-based jet for a concentration of up to 5% without any change in the ASTM specifications. Freezing point is the most important constrain for this blending technique. Higher blends of biodiesel will cause the bio-jet blend to fail ASTM specifications. In general, blending technique will reduce the cost impact that may have been incurred due to change in infrastructure when using other production techniques.

Abstract: This study explored the application of MOF-modified membrane for gas separation. Microporous aluminum fumarate (A520) was used to modify polyimide (PI) membrane using N-methylpyrrolidone (NMP) as solvent. The MOF-modified mixed matrix membrane (MMM) was subjected to gas permeability tests, using gas permeability apparatus (GPA). GPA results showed that adding 10wt% MOF to the membrane increased permeabilities of N₂ and CO₂ gases by up to 34%, and by 19% for O₂ gas, without compromising selectivity. Further increasing MOF loading beyond 10wt% considerably decreased selectivities despite significantly increased permeabilities. Cahn adsorption experiment confirmed and supported this GPA data. These results indicate that MOF were successfully intercalated with the polymer as revealed by scanning electron microscope (SEM) images. Other characterizations like dynamic mechanical analysis (DMA), x-ray diffraction (XRD), and positron annihilation lifetime spectroscopy (PALS) showed that the interface and mechanical properties of the MMM also improved. MOF loading beyond 10wt% revealed aggregations forming non-selective voids that probably caused lowered selectivity.

Abstract: Modification of polymers by fillers is one of the most used material alterations to improve its required properties. This article is about modification of polymer matrix by fillers with layered particles. Linear low density polyethylene (LLDPE) was used as matrix and it was mixed with different kinds of fillers. Fillers used were: CaPhP – Calcium Phenylphosphonate, double layered hydroxides (ZnAl-DDS, ZnAl-lac and ZnAl-CO3) and natural Talc. Individual fillers were mixed into the matrix by kneading machine with the use of several velocities. The article focuses on influence of the individual filler on mechanical properties measured by tensile strength test. This paper also investigates the problem of process parameters’ influence on final mechanical properties and later confirms positive impact of all fillers that were used, although the size of them differs.

Abstract: Microporous aluminum fumarate (A520) is one of the very few metal-organic frameworks (MOFs) that have been promoted to the level of commercial applications and has recently been proven to exhibit a rigid character with an accessible permanent porosity. This study explored the maximum loading amount of A520 for mixed matrix membrane (MMM) preparation by blending it with polyimide (PI) using N-methylpyrrolidone (NMP) as solvent, without compromising the membrane integrity. Scanning electron microscope (SEM) images revealed that MOFs were able to infiltrate the pores and structures of the polymer, improving the interface and mechanical properties of the polymer, as supported by different characterizations like dynamic mechanical analysis (DMA), x-ray diffraction (XRD), and positron annihilation lifetime spectroscopy (PALS). Results showed that MOF loading beyond 10wt% revealed aggregations that compromised the integrity of the membrane.

Abstract: The present energy situation has stimulated active research interest in non-petroleum and non-polluting fuels, particularly for transportation, power generation, and agricultural sectors. This paper describes feasibility of utilization of Spark ignition (SI) engine in single fuel mode and to develop the optimum operating conditions in terms of fuel injection timing and fuel injection pressure. Many modifications were made for the developed direct fuel injection system to improve the performance of the 350 cc four stroke single cylinder petrol engine. The engine is tested to conduct performance, combustion emission characteristics with the aid of carburetor. As single cylinder small engines have low compression ratio (CR), and they run with slightly rich mixture, their power are low and emission values are high. In this study, methanol was used to increase performance and decrease emissions of a single-cylinder engine. Initially, the engine whose CR was 7.5/1 was tested with gasoline and methanol at full load and various speeds. This method is used for increasing the fuel efficiency of a vehicle by adding different percentage of methanol to the petrol and to decrease the pollutants produced during combustion process.

Abstract: Waste pre-vulcanized nitrile latex (WPNL), obtained from nitrile glove dipping tank was blended at different ratios with concentrated ENR latex processed via ultrafiltration and designated as ENRLC-SP20 and ENRLC-SP50, respectively, with the number indicating, the percentage of WPNL incorporated into the blend. The blends were prepared in the latex stage and subsequently processed into dry rubber. The rubbers were then blended with virgin nitrile rubber (NBR) at various ratios and the curing characteristics and physical properties of the blends were evaluated. The results showed the maximum torque (MH) decreases while the minimum torque (ML) increases with increasing level of SP 50 rubber. Using higher concentrations of SP-50, the results showed slight reductions in the cure (t90) and scorch time (ts2), respectively. It was also found that by increasing ratio of ENRLC-SP20 and ENRLC-SP50 improves the heat ageing resistance of NBR blends at 100°C as evidenced by the higher percentages in retention of the blends, compared to the control compound.

Abstract: Melamine formaldehyde (MF) resin and its derivatives are always considered to be excellent flame retardant material, which has wide application in the flame retardant fabric, high temperature insulating filter materials, etc. However, less research on electro-spinning of melamine fiber has been reported, recently. In the study, the molar ratio, condensation polymerization temperature of formaldehyde and melamine, and the law of effect in different solid content ratio of melamine formaldehyde/polyvinyl alcohol on the electro-spinning were studied. The results showed that the best conditions for spinning were that formaldehyde and melamine molar ratio was 1:1.7, the reaction temperature was 80°C, and the MF-PVA blending solid content ratio was 1:1, meanwhile the morphology of Electron microscopy indicated the good uniformity of the fiber. The fiber presents good flame retardant property in conditions of MF-PVA blending solution viscosity 155mPa ́s, limit oxygen index 33.2%.

Abstract: With soy protein isolate (SPI) as the main raw material, and ethylene glycol (EG) and polyethylene glycol (PEG) as two additives, a number of SPI-based films were prepared through the solution casting method. Results show that the film flexibility is obviously improved after adding EG and the film tensile strength and elongation at break could reach more than 10.5 MPa and 140%, respectively. The antimicrobial results exhibit EG has higher antibacterial effect against both bacteria of E. coli and S. aureus than PEG-400.