• Megasonic cleaning performance of Si wafer & polysilicon line pattern is evaluated. • Role of SDS surfactant in the presence of DIW and H₂-DIW megasonic cleaning studied. • SDS concentration is found to be a playing key role in obtaining optimized performance. • Bubble dynamics in the megasonic standing wave field are observed using HSC. • Clustering and population density of bubbles is a key factor to enhances the PRE.

The separated and sorted combustibles from automobile shredder residue (ASR) can be pyrolyzed and used as a heat source or liquefied to produce materials with added value. In this study, the thermal decomposition properties of ASR were determined and thermal kinetic studies were performed. Four types of raw materials were separated from ASR and mixed at a constant ratio: 38.5 wt.% of plastic; 31.6 wt.% of fiber; 17.3 wt.% of sponge; and 12.3 wt.% of rubber. Pyrolysis kinetics analysis was carried out using the Thermogravimetric analysis-derivative thermogravimetry (TGA-DTG) technique and activation energy were calculated by differential and integral isoconversional model methods, Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Friedman. Thermogravimetric analysis was performed under nitrogen with four temperature rate conditions from room temperature to 800 °C. In the thermal degradation profile, peaks representing mass loss rates were observed for each sample at different temperature ranges. It was observed that the final mass reduction temperature in the mixed samples was lower than in the individual samples. The activation energies of plastics and rubbers were 105.39 kJ/mol and 115.20 kJ/mol respectively. The sponge foams and fibers were 172.59 kJ/mol and 160.30 kJ/mol respectively. The mixed sample had an activation energy value of 159.56 kJ/mol. The basic physicochemical and pyrolysis characteristics of ASR were examined to be used as basic data for the recycling of ASR for future pyrolysis.

논문, 전자책, 학술정보 통합서비스 Biomass is considered one of the most promising renewable energy sources, which are being actively researched due to the depletion of fossil fuels and the global warming issue. Biocrude-oil can be pro

Coffee ground has been recently considered as a new biomass resource in relation to the increasing coffee consumption worldwide. The bio-crude oil can be produced by fast pyrolysis of coffee ground, and it has advantages of larger heating values in comparison with those from other biomass. But the bio-crude oil from coffee ground has a significantly high viscosity which can hinder the application to conventional burners. In this study, a pilot-scale burner system with a 35 kW capacity with an air-blast atomizing nozzle was developed for the combustion of bio-crude oil from coffee ground with a high viscosity. A downward fuel injection system was adopted to enhance the ignition of fuel spray and the flame stabilization, and a movable block swirl generator was installed for the combustion air. The bio-crude oil was blended with ethanol at the volumetric ratio of 9:1 to enhance the combustion characteristics. The effect of various atomizing air pressures, swirl intensities, and overall equivalence ratios on the flame stability and gaseous emission were investigated to find out the optimum operating conditions for a bio-crude oil burner.

The fast pyrolysis of coffee ground for bio-crude oil production was simulated in a tilted-slide reactor. The biochemical composition was derived by an extended biomass characterization method based on the elemental analysis. The simulation was performed in a steady-state and a Lagrangian multiphase model was adopted to describe the transport of sand and biomass particles together with a multistep kinetic mechanism for fast pyrolysis. When the secondary tar cracking reactions were not considered the volatile yield increased monotonically with temperature. The inclusion of secondary reactions could improve the prediction of volatile yield which turn to decrease at higher temperature. It was found that not only the maximum volatile yield but also the corresponding reactor temperature agreed well with the experimental results. At the temperature higher than 550 °C the trend of volatile yield is similar to that of experiment while it is larger at lower reactor temperature. The individual species yields were compared at various reactor temperatures and the pyrolysis processes were analyzed by tracking the reference components when they were decomposed along the distance. It was found that the reactor temperature should be above 500 °C for effective pyrolysis of all reference components of coffee ground.