Jia-Hong Kuo

The prospect and development of incinerators for municipal solid waste treatment and characteristics of their pollutants in Taiwan

Abstract Taiwan is a small, densely populated island with unique experiences in the construction and operation of incinerators. In such a small area, Taiwan has built 22 incinerators over a short span of time, combusting large amount of municipal solid waste as much as 23,250tons per day. This study focuses on the history of construction and development of incinerators in Taiwan as well as the characteristics of pollutants, such as heavy metals (Pb, Cd, and Hg), acid gases (NO x , SO x , CO, and HCl), and dioxins emitted from the incinerators. Furthermore, the study also covers the generation and composition of municipal solid waste (MSW), and the production of energy in Taiwan. According to Taiwan’s data on pollutant emissions, the emission level of pollutants is under control and meets the stringent regulations of Taiwan Environmental Protection Administration (TEPA). Researches have shown that using air pollution control devices (APCDs) in the operation of incinerators provides effective measures for air pollutant control in Taiwan. The main advantage of using incinerators is the generation of electricity (waste-to-energy) during the incineration of municipal solid waste, producing energy that can be consumed by the general public and the industry. Taiwan’s extensive experience in incinerator construction and operation may serve as an example for developing countries in devising waste treatment technology, energy recovery, and the control of contagious viral diseases.

Catalytic upgrading of syngas from fluidized bed air gasification of sawdust.

This study was conducted to investigate the effects of various gasification temperatures in a fluidized bed gasifier on biomass-derived products and to evaluate the efficiency of syngas upgraded by a secondary catalytic reactor. The results indicated that biomass vaporization was clearly affected by gasification temperature, resulting in the obtained products having different composition ratios. Additionally, the hydrogen promotion ratios were found to be strongly dependent on the condensable products, indicating that the products were upgraded via the use of a catalyst in the secondary reactor. If biomass vaporized at suitable gasification temperatures can produce a large amount of condensable products, the products could be effectively upgraded for hydrogen production by the secondary catalytic reactor under very mild conditions (250°C). Overall, the process not only upgraded hydrogen production, but also degraded contaminants; therefore, its implementation should reduce the cost of operation and pollution control in the biomass-to-energy industry.

Effect of co-contaminated soil mixtures as fixed/fluidized bed media on pollutants emission under thermal treatment

Abstract Thermal treatment of soil polluted by lube oil and heavy metals (cadmium, chromium, copper, and lead) was carried out by using a laboratory-scale incinerator. The effect of co-contaminated soil mixtures as fixed/fluidized bed media was studied with different ratios of sand bed amount to soil feeding. Additionally, the effect of soil moisture content on incineration system was further investigated. The reduction in air input altered the mode of fluidized bed to fixed bed which resulted in an increase in organic pollutants such as benzene, toluene, ethylbenzene, xylene, and polycyclic aromatic hydrocarbons. The combustion efficiency of fixed bed mode was observed to be relatively high at a lower ratio of sand bed amount to soil feeding, whereas high combustion efficiency was found in fluidized bed mode at a higher ratio of sand bed amount to soil feeding. Much higher concentration of organic pollutants in both gas phase and bottom ash is found under a higher soil moisture content. In addition, the increase in moisture content has resulted in an increase in lead, cadmium, and chromium in fly ash while copper was decreased. An important consideration is that the partitioning of heavy metals was randomly distributed in particle sizes of bottom ash. The highest concentration of heavy metals was deposited on fine-sized particle. The distribution of heavy metals in medium-sized and coarse-sized particles to form eutectic species might be produced by the soil–sand aggregation.

Effect of operating conditions on emission concentration of PAHs during fluidized bed air gasification of biomass

With the concern of future energy use, hydrogen is taken as an important role in energy alternatives. In addition, biomass air gasification by using fluidized bed is an efficient and advanced method for hydrogen production. Despite of energy product generation, some pollutants such as PAHs easily formed in gasification process because of tar decomposition. Accordingly, this study provides a fundamental work of emission behavior of PAHs generated under different operating conditions such as temperature, air factor, and addition of catalysts. The experimental result shows the emission concentration of PAHs decreases with the operating temperature increases, but PAHs increases with increasing of air factor. Besides, addition of CaO resulting a reduce influence on PAHs emission, but Al2O3 added in fluidized bed cause bimodal particle size segregate and reduce fluidized bed quality that leads PAHs formation during biomass air gasification.

Evaluating the Relationships between Pb Species and Leaching Properties in Simulated MSWI Fly Ash with Thermal Treatment by ESCA

AbstractThe aim of this study was to develop a fundamental understanding of the association between lead (Pb) species and leachability behavior in the simulated municipal solid waste incinerator (MSWI) fly ash during the thermal treatment process. Two main factors that influence this process, temperature and the carbon content in the simulated ash, were also studied. In the sequential extraction results, the main distribution pattern of Pb in treated simulated ash was carbonate fraction with different temperatures when the carbon content was 3.5%. The chief fraction of the raw simulated ash (carbon content=0%) was carbonate and that of raw simulated ash when carbon content was increased was Fe-Mn oxide Electron spectroscopy for chemical analysis (ESCA) results showed that Pb (element) in treated simulated ash could increase the toxicity characteristic leaching procedure (TCLP) concentration of Pb when temperatures reached 700°C. With a temperature of 900°C, PbSiO3 was present in the treated simulated ash ...

Filtration of nanoparticles by a fluidized-bed adsorption reactor during toluene adsorption

This study investigates the effects of toluene adsorption on the filtration efficiency of nanoparticles by a fluidized-bed adsorption reactor. Simulated flue gas is modified by different types of nanoparticle (SiO2 and Al2O3) with various particle sizes (10 and 80 nm) are also carried out in experiment. Therefore, the experimental results show that the removal efficiencies of the nanoparticles and toluene are in the range of 97% to 87% and 99.8% to 99.4%, respectively. Particularly, BET results show that the particles of 10 nm SiO2 increase obstruction of the adsorbent volume with increasing toluene content. This finding shows that filtration efficiency increases with the addition of toluene.