Applied Mechanics and Materials Vols. 799-800

Abstract: The cellulose-based hydrogel was successfully prepared from rayon fiber residue obtained from the fiber manufacturing industry. By chemical means, the hydrogel was simply prepared at an ambient temperature by mixing rayon with carboxymethyl cellulose (CMC) in NaOH/urea solution with epichlorohydrin (ECH) as a crosslinking agent. Rayon cellulose was used for stabilizing of hydrogel structure, providing a dimensional stability to the hydrogel whereas CMC acted as a porogen, widening the pore size within the hydrogel structure while swelling in water. With increasing CMC content, the percent water uptake of the hydrogel was increased but the structural stability was impaired. The prepared rayon cellulose/CMC hydrogel could take up more than 200% water within 60 minutes with an appropriate rayon cellulose-to-CMC ratio of 1:1 providing an ultimate balance between percent water uptake and the structural stability of the hydrogel. Its percent water uptake was as high as 285% to its initial dry weight.

Abstract: Among different natural oils, recycling of waste vegetable oils from palm oil is widely explored for polyol synthesis to prevent pollution of waterways and clogging private and municipal drain systems, restaurants and other food preparation. The polyol is solidifying using cross linker and known as Sustainable Polymer (SP). SP is compounded with High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE) by melt-mixing using an injection molding machine. The effect of polymer compounding ratio on the mechanical properties was studied by tensile test. The result indicated that increasing the SP content in LDPE or HDPE was responsible to the reduction of tensile strength and elongation at break of the samples, if compared to pure thermoplastic LDPE and HDPE. This can be verified by increased in SP amount which gave a significant increase in density of the polymer compounds. Morphological of tensile specimens’ surface fracture is revealed the homogenous characteristic with high compatibility properties of sustainable polymer with its compounded polymers.

Abstract: When waxy crude oil becomes a gel, predicting a restart pressure in pipelines has been a challenge. The formation of gas voids within the gel following sufficient cooling has an impact on the restarting pressure. This study is aimed at analyzing the effects of cooling rates on voids in waxy crude oil gel using Magnetic Resonace Imaging (MRI) technique. The flow loop rig simulating offshore oil production was designed. Waxy crude oil underwent cooling through the same temperature range to observe the effects of cooling rates on voids formed. Cooling rates were found to have different influence on the formation of voids. A maximum total voids volume of 6.96% was formed at cooling rate of 1.00°C/min. Cooling rate of 0.55°C/min produced a minimum voids volume of 5.74% near pipe wall. Higher cooling rates generally produced higher voids volume near pipe wall and in entire pipe. However, there was no definite trend observed for the voids around pipe core at which slower cooling rates were also observed forming higher voids volume.

Abstract: This research is started by mixing in-house produced sustainable polymers (SP) from waste cooking oil with the standard low density polyethylene (LDPE) via melt-mixing at low ratios. These mixtures are then compounded via injection molding to produce tensile samples according to ISO 527 (5A). The parameters used in injection molding were initially set to follow the parameters of neat LDPE. Fortunately, by using the quality of individual compounds injected, the parameters obtained for all ratios were the same with neat LDPE. The corresponding mechanical behaviors of each ratio were also examined and the results showed that both tensile strength and strain of the LDPE/SP were better than neat LDPE. Therefore, not only does the presence of SP provide biodegradable properties, but it also improves the mechanical properties. It was concluded that the processing temperature and composition of SP will both influence the quality and mechanical behavior of the product made. This study may aid any intention on processing these in-house produced polymers by injection molding.

Abstract: This project researched a mechanism of the decomposition of zinc ferrite (ZnFe₂O₄) to be zinc oxide (ZnO) and calcium ferrite (Ca₂Fe₂O₅) by using calcium oxide (CaO) from lime as a reducing agent. Zinc ferrite was mostly found in electric arc furnace dust (EAFD), which is a by product from a steel making industry. The experiment was simple as following. The EAFD was mixed with lime in mole ratio of zinc ferrite and calcium oxide at 1:2, 1:3 and 1:4 and then compressed into pellets. Effects of mole ratio, temperatures and times on the decomposition were studied. The conditions used in these experiments were 800, 900, 1,000 and 1,100 oC for 2, 4 and 6 hours. The results showed that the suitable conditions for the decomposition of zinc ferrite by calcium oxide could be as low as 800 oC for only 2 hours with mole ratio of zinc ferrite from EAFD and calcium oxide from lime as 1:2. A solubility test was provided to processed samples at the conditions as 0.1 M hydrochloric acid (HCl) at 50 oC for 20 minutes. It was found that EAFD from pyrometallurgical treatment could be decomposed to be zinc oxide and the following by hydrometallurgical treatment could recovery high zinc yield from the remaining residue. However, EAFD treated by only hydrometallurgical process obtained lower zinc recovery due to the high stability of zinc ferrite in HCl and most of the solutions.

Abstract: In the paper catalytic hydrogenation of natural bitumen (NB) of Kazakhstan oil sands were investigated. The process provided under 350 bar of H₂ pressure and a temperature of 430 °C. At the experiment activated carbon supported catalyst was used. It has 699.807 m²/g of surface area and 0.0635 nm of medium pore size. In the processes the yield of hydrogenated natural bitumen was 91%, including 1st fraction is 13.12 wt.%; yield of 2nd fraction increased, that the temperature range from 216 to 316 °С formed in amount of 45.68 wt.%; vacuum residue of the distillation takes the 41.20 wt.% in natural bitumen.

Abstract: During the development of M gas reservoir which is a typical fracture-pore carbonate reservoir with bottom water, excessive water production is frequently encountered during the lifetime of gas-producing wells, which generally results in a rapid productivity decline and a remarkable increase in operating costs caused by the handing and treating of large amount of water. Nevertheless, there exists no comprehensive analysis method to accurately obtain it. In combination with previous studies about water inrush source in gas reservoirs and the static and dynamic developing data of M gas reservoir, there are four methods brought up firstly, which are means of water sample salinity analysis, water-gas ratio (WGR) analysis, comprehensive logging interpretation analysis and production performance analysis. Subsequently on the basis of formation parameters and fluid data of M gas reservoir, the mechanism model of fracture-pore reservoir with bottom water have been set up by utilizing the Eclipse software to research the water-invasion principles. According to the dynamic change characteristics of water invasion, the numerical simulation analysis method has been brought up. Finally the identification process is illustrated accurately by taking two representative wells in M gas reservoir for example. A timely and precise identification of water inrush source plays a significant role in understanding the principles of gas-water motion in the reservoir, making corresponding and reasonable development measures and improving the development efficiency.

Abstract: Numerical analysis of plasma gasification process was carried out base on the combination of magnetohydrodynamics (MHD) and computational fluid dynamics (CFD). A two stage gasification system which consists of a heater and a plasma rector was used to enhance syngas production in the present work. Nitrogen thermal plasma jet generated by a low power plasma torch was analyzed by a self-developed MHD code, and complex thermal flow field in the plasma reactor was simulated with a commercial CFD code. The accuracy of numerical simulation was confirmed from the comparison between numerical results and experimentally measured data of arc voltage and reactor temperature. From the numerical analysis, a high temperature for the thermal cracking of methane was expected in the upper region of the plasma reactor.

Abstract: Nowadays, Municipal Solid Waste (MSW) becomes a crucial problem worldwide where it is created the impact to environment, social as well as health. The non-sanitary landfill is widespread used for waste disposal in the rural area because of its low investment and operation cost. However, it has negative effect on human health and environment. Thermal treatment of MSW by incineration is considered as an option for effective treatment technique due to the fast reduction in mass and volume of MSW. However, with high moisture content in MSW, it is necessary to use auxiliary fuel in order to maintain the high temperature of combustion process and led to the high operating cost, especially for the small scale incinerator without energy recovery. A novel hybrid incineration-gasification can be used in order to overcome this drawback by using a downdraft gasifier with Refuse Derived Fuel (RDF) as feedstock to generate the syngas which can be substituted the auxiliary fuel. Hence, this study emphasizes on the development of a novel hybrid incineration-gasification as a cleaner technology to get rid of MSW generated with a destruction capacity of 30 ton per day (TPD). The novel system comprises of a controlled-air incinerator with two combustion chambers, automatic feeding machine and wet scrubber. A 100 kg/hr downdraft gasifier has aim to use RDF from dry fraction of MSW as feedstock to produce syngas to substitute the auxiliary fuel used in the secondary burner of the incinerator in order to maintain the desire its temperature. This cleaner and novel hybrid technology can implement to get rid of MSW properly for energy saving and sustainable development.

Abstract: As Thailand is importantly an agricultural country driving the bio-ethanol production from agricultural feedstock via fermentation process and a solid oxide fuel cell (SOFC) has been known as an attractive energy conversion device due to its high efficiency and fuel flexibility, SOFC fueled by ethanol for electrical power generation has been performed. Hydrogen-rich gas from ethanol steam reforming is used as fuel carrier converting to generate electrical energy in SOFC. This paper presents an energy analysis of integrated steam reformer and SOFC system to determine the suitable ethanol concentration giving the optimum SOFC electrical efficiency. In this study, the ethanol concentrations between 20 and 56 %wt corresponding to water-to-ethanol ratios from 10 to 2 were varied at a fixed feed flow rate of 1 g/s of ethanol solution for hydrogen production. The SOFC power efficiency increased although the amount of hydrogen and SOFC electrical power decreased with decreasing the ethanol concentration. However, for the first law analysis, the heat load of each unit was calculated and it can be concluded that the overall system efficiency increased with increasing the ethanol concentration.