A new type leakage isolation sheet with self- repairing mechanism is developed, in which there is no water leakage when the sheet is broken. The sheet consists of two rubber sheets with lattices inside, polymer particles are in the lattices, and sandwiched between the rubber sheets. The polymer particles expand in contact with water, and they become gel. In addition, the large pressure is generated in the lattice of the sheet. Hence, the sheets isolate water leakage. When the rubber is broken, polymer particles fall down with water. In order to keep the particles in the lattice of the sheet, a textile lies on the back surface of the rubber sheet. Experimental tests have carried out for a model of the sheet, and it is clarified that the proposed sheet isolates leakage perfectly under 2KPa pressure when the sheet is broken by a 20mm diameter punch.

抄録全体を表示

A support method of operation in municipal solid waste incineration plants using TOX (Total Organic Halogen) that was developed as a useful flue gas index for dioxins was investigated and evaluated. The evaluation was conducted based on parallel measurements of dioxins and TOX in flue gas. The data sets of dioxins and TOX were within a correlation formerly developed. TOX could be determined in the sampling time of 1 or 2 hours compared to 4 hours for dioxins. The behavior of TOX for inlet volumes of activated carbon and for temperatures was easy to explain, hence the usefulness of TOX as an operational parameter was clearly shown.

抄録全体を表示

To reduce DXNs (PCDDs/DFs and Co-PCBs) in the flue gas of incinerators, a catalytic oxidation process has come into wide use because of its high effectiveness and easy operability. In this study, catalytic decomposition characteristics of various aromatic compounds, for example PolyChlorinated Naphthalenes (PCNs) and Polycyclic Aromatic Hydrocarbons (PAHs) as well as Chlorophenols (CPs) and Chloro-benzenes (CBzs), have been investigated comparing with DXNs, using V-W/Ti catalyst reactor in the flue gas from the municipal solid waste incinerator plant. It is found that 1) PCNs and CPs can be decomposed with high efficiency such as DXNs, 2) decomposition rate of PAHs is a little lower than DXNs, 3) CBzs is rather hard to be decomposed and 4) the activity of the catalyst has been kept after 18000hrs of exposure time in stearm of the flue gas.

抄録全体を表示

In order to reduce the dioxins contained in the exhaust gas from ash-melting furnaces, we used bag filters packed with dioxin-destroying catalyst. We measured the concentrations of dioxins and their precursors in the exhaust gas and in the fly ash. Sampling was done at the outlet of the baghouse with the gas temperature of 170℃, and the results were 0.015ng-TEQ/m^3 of dioxins from the exhaust gas, and 0.023ng-TEQ/g from the fly ash. Compared with the activated-carbon injection system, these dioxin concentrations represent one-third for the exhaust gas, and one-sixth for the fly ash. This proves that the catalytic filter is an effective means to treat exhaust gas from melting furnaces.

抄録全体を表示

A system is developed to produce activated charcoal from sewage sludge. It is composed of a pneumatic conveying dryer, and a carbonization and activation furnace. The activated charcoal produced performed well to remove dioxins from the exhaust gas and scrubber waste of an incinerator. The dioxins removal ability of the charcoal is found to be identical to that of a commercially used activated carbon.

抄録全体を表示

Slaked lime is usually used in Japan as the dry gas cleaning reactant for MSW incineration exhaust gas. We tested sodium reactant for the dry gas cleaning system instead of slaked lime. The removal rate of acid gas is appropriately 98% for HCl and 90% for SOx at an exhaust gas temperature of 170℃ to 210℃. Leaching test result of the collected ash shows that any heavy metal is not exceeded to the regulated value. This system is proved the stable operation and high removal rate of acid gas through one month continuous operation.

抄録全体を表示

This paper describes a new treatment of HCl in exhaust gas to use wet scrubbers in some municipal solid waste incinerators. We designed a closed system by which HCl in the exhaust gas is first dissolved into water, and the resulting dilute HCl water goes through proton permselective membrane that recovers by-product HCl by electrodialysis. We have studied the HCl Concentration from HCl in exhaust gas to bench-scale test Equipment. As a results, we have obtained 13.3 wt% HCl Concentration. In this case, Current Density is 10A/dm^2, Current Efficiency is 57%.

抄録全体を表示

A high-performance sewage sludge incinerator has been developed using a circulating fluidized bed. Demonstration testing verified that (1) water evaporation rate in the bed is about 4 times that for the conventional incinerator, (2) emissions of pollutants at the incinerator outlet were dramatically reduced, (3) the size of the flue gas treatment system is reduced due to the low air ratio, (4) flue gas treatment is simplified by de-SOx with CaCO_3 in the incinerator, and (5) screenings added to sewage sludge are incinerated cleanly and RDF is also used as auxiliary fuel.

抄録全体を表示

We have newly developed an industrial wastes pyrolysis process using kiln system and constructed the first plant with a capacity of 85kg/h (in case of sludge feed). From the test pyrolysis operation of sewage sludge, which is emitted from our office, a safety and stable operation of the process has been demonstrated. The pyrolysis coke is now under field test as a volume increaser for a fertilizer. And the property of that pyrolysis coke shows a possibility of an application for an adsorbent. We have also conducted pyrolysis test of RDF and car shredder dust. Those pyrolysis coke have a sufficient heat value for use of solid fuel. We will continue to study to expand an application of the pyrolysis coke.

抄録全体を表示

The char which removed 70%〜95% of the chlorine by the thermal cracking of municipal waste at 400〜450℃ is burned in a fluidized bed having a superheater made from ordinary low cost tubing and electrical power can be generated with a 30% efficiency by recovering superheated steam (80ata, 500℃). At the same time, the cracked gas is burned with air in an ash melter of the vertical swirling type, in which ash can be melted continuously at 1300〜1500℃. The slag from the melted ash in a number of ways. We carried out demonstrationtest at these processes by not only municipal waste but RDF. The result of demonstrationtest shows that these processes have adaptability of a wide of LHV of waste.

抄録全体を表示

From the viewpoint of earth-environment protection, the tendency of development of the new waste-treatment approach replaced with the conventional incineration system is increasing. One of such a next generation system is a pyrolysis, gas-cracking, and gasification waste treatment system. A 10 t/d demonstration plant was constructed, and the demonstration test was conducted over 100 days by municipal solid waste. As a result of the test, high recycling performance and superior harmless ability of the plant was verified and the system is proved to be an excellent waste treatment method. Major test results are as follows ; (1) The stable waste treatment is possible for the wide range quality of a waste (LHV of 3230 to 14300 kJ/kg). (2) Clean gas is produced from the waste and the energy recovery ratio by clean gas is approximately 40%. (3) 99.3% of dry waste weight is recovered as valued materials. (4)Dioxins total emission to the outside of the plant is very small amount of 0.0051-0.018 μg-TEQ per 1 ton waste treatment.

抄録全体を表示

In a pyrolysis, cracking , and gasification waste treatment system which we have developed, it is necessary for melting furnace to achieve both functions of gasification and mineralization. We developed a melting furnace for a 10t/d demonstration plant, which conducts gasified pyrolysis char combustion utilizing oxygen, and the demonstration test was conducted over 100 days including 35 day consecutive operarion by municipal solid waste. As a result of the test, excellent performance is verified in both of gasification and mineralization, that is, 100% of gas conversion ratio and slag conversion ratio are achieved. Also slag leachate test result meets governmental regulation.

抄録全体を表示

Our company have developed the ash melting furnace which utilizes carbon combustion heat. We constructed 12T/D test plant last year and tested ash melting. As a result, this type melting furnace have the merits of lower size and running cost, clean exhaust gas, high quality slag, etc. This paper describes the outline of test plant operation data and test results.

抄録全体を表示

This paper describes a municipal waste gasification process, by using a pyrolyzer, a reformer and a slag-melting furnace, for small and/or middle scale power-generation technology. Pyrolysis and gasification of wastes supposed to be in a gasifier were analyzed by thermogravimetry under the constant heating rate 2℃/min. Gasification of char with CO_2 and/or H_20 proceeds in the temperature range of 700-1,250℃. It was shown that the TG curves of degradation process of municipal waste and char gasification processes were well simulated by a modified volume reaction model equation. The reaction rate constants, the related activated energies and preexponential factors were determined from the model equations. We also studied a one-dimensional steady state mathematical model to simulate each furnace. The model showed to approximately predict municipal waste gasification processes.

抄録全体を表示

Refuse incineration plants (RIPs) are required to reduce concentrations of dioxins in the exaust gas and recover thermal energy from waste gas efficiency. However, it is difficult to grasp the characteristic of RIPs, because fuel property is unstable. The purpose of this work is to develop a combustion control method for stoker-type incinerators to make the combustion stable. In this paper, we propose to apply fuzzy based on estimation of residence quantity of refuse in the furnace. Furthermore, we report the results of experiments in an actual plant.

抄録全体を表示

This paper reports on the results obtained by treating automobile shredded residue in a kiln-type pyrolysis and melting plant. The results are as follows. (1) The amount of recycled aluminum and ferrous metals was about nine times as much as obtained with conventional municipal solid waste (MSW) treatment. (2) Slag leaching performance was excellent and the release of six heavy metals such as Pb,Cr^<6+> satisfied soil environment regulations. No dioxin in slag was detected. Furthermore, metal-Fe content of slag was very low, which is advantageous for slag utilization in the civil engineering field. (3) Due to the high temperature combustion of the pyrolysis gas and recycled carbon at around 1300℃ and a 1.2 air excess ratio, the formation of dioxin was suppressed. Furthermore, as the result of feeding activated carbon to both fabric filters, dioxin emissions were below 0.01ng-TEQ/m^3N at the stack. (4) Although the amount of dechlorinating agent was increased to the fabric filter for high HCl content in the flue gas, bulk reduction of the waste to less than 1/38 was achieved, as compared with 1/200 for MSW treatment.

抄録全体を表示

Gasification of glucose in high temperature and pressure steam was investigated. Steam condition was in super-critical or sub-critical state. A small pressure vessel made of Inconel with 81cm^3 inside volume was used as a reactor. Reaction temperature was changed between 873 to 973 K, and reaction pressure was 2 to 30MPa. Glucose was supplied into the reactor as an aqueous solution of 0.5 mol/l to 2 mol/l concentration. More than 90% of glucose supplied was converted into the gaseous substances. High efficiency gasification was achieved because total organic carbon in water was less than 300 ppm. Main substances were H_2, CH_4, CO, and CO_2. Reaction temperature was primary factor on the yield of produced gaseous substances other than reaction temperature. For example, hydrogen production at 978 K was 10 times larger than that at 873 K. Yield of H_2, CH_4, and CO_2 was increased with residence time up to 20 sec, and carbon conversion was achieved almost unity. However, CO production was independent of residence time. This result suggests that required residence time for complete gasification was 20 sec.

抄録全体を表示

A micro-gasification system for solid wastes is proposed which is known as STAR-MEET system. Using rubber chips as a fuel, it was demonstrated that injecting of high temperature air into the pyrolyzer significantly increases the heating value of the pyrolysis gas. It has also been demonstrated that injecting of high temperature steam/air mixture into the pyrolysis gas effectively decomposes tar and soot components in the pyrolysis gas with keeping the heating value of the reformed gas.

抄録全体を表示

The municipal solid waste (MSW) gasification and melting system has been developed using a 20t/d demonstration plant built in SHI Niihama Works. This system is comprised of a gasifier of circulated fluidized bed type and a melting furnace of kiln type. In the gasifier, MSW is converted to combustible gas and char at a gasification temperature of 750-900℃. In the melting furnace, a part of combustible gas and char is burned at a temperature of over 1200℃. Then the ash in char is melted. Surplus gas is used as fuel at a MSW dryer and a boiler. The demonstration test has been conducted for a period of 1.5 years (including continuous 30days) since November 1999. During this operation, this plant has processed 2,224tons of MSW. Operation results indicate that dioxins emission in flue gas (stack inlet) is below 0.05ng/m3N and safely and useful slag is produced in this plant

抄録全体を表示

It is necessary to construct the information network system which constituted by consumer, producer and administration, etc. in order to plan the optimum recycling system. This study constructed the algorithm which deduced optimum recycling. system based on dispersive product information from the viewpoint of energy and resources. This model was constructed by applying multiagent system. By the agent with the criterion respectively affecting the product-waste database, it becomes possible that the optimum recycling map is calculated.

抄録全体を表示

In recent years, air pollution and depletion of oil resources become major issues all over the world. So environmental products and environmentally sensitive technologies are required. And fingers are pointing at importance of long-term using products for the construction of cycloid type society about resources is requested. Therefore this study proposes the concept of the product up-grading by exchanging main components. Applying this manufacturing concept, long-term use and the early intake of the new technology will be possible. In this study, we improved the electric vehicle converted from internal-combustion engine vehicle and tested its performance. Then we estimated its possibility of the product up-grading and validity for environment.

抄録全体を表示

In recent years, air pollution and depletion of oil resources become major issues all over the world. So environmental products and environmentally sensitive technologies are required. And fingers are pointing at importance of long-term using products for the construction of cycloid type society about resources is requested. In this study, from the view of long-term using products' parts, we think it is important to use reuse parts. So, we think to promote to use reuse parts in the case of treatment of End-of-Life Vehicle (ELV). Then we indicate validity for problems about environment and waste.

抄録全体を表示

In these years, increase of wastes and exhaust of resource become major issues according to the progress of mass productive, mass consumptive and mass waste economic system. As the correspondence, the construction of the resource-recycling society is strongly required. For constructing such society, the consideration to 3R (Reduce, Reuse, Recycle) at the design stage of industrial products become very important. Especially, as concerns Reuse and Recycle, the improvement of disassembling property of the products is one of the most important things to be considered. In this study, we attempted to investigate Disassembly-Oriented Design (DOD) for several industrial products by disassembling them. The products that we disassembled were desk-top PC, PC monitor, ink-jet and laser printer and sewing machine. By disassembling them, we understood the problems of the structure and compared the disassembling property of these products by applying the method of estimating products' disassembling property. Then we got the guide about DOD for these products.

抄録全体を表示

In these years, increase of wastes and exhaust of resource become major issues according to the progress of mass productive, mass consumptive and mass waste economic system. As the correspondence, the construction of the resource-recycling society is strongly required. For constructing such society, the consideration to 3R (Reduce, Reuse, Recycle) at the design stage of industrial products become very important. Especially, as concerns Reuse and Recycle, the improvement of disassembling property of the products is one of the most important things to be considered. In this study, we attempted to investigate Disassembly-Oriented Design (DOD) for sewing machine by disassembling them. Then, we understood the problems of the structure and compared the disassembling property of these products by applying the method of estimating products disassembling property and we got the guide about DOD for sewing machine.

抄録全体を表示

We aimed to realize the effective utilization of incinerated ash by installing additionally to the existing incineration equipment. The stable operation status of Incineration Ash Melted and Crystallized Sludge Manufacture Validating Equipment installed and operated at Yamazaki Water Quality Purification Center between August 1998 and April 1999 will be reported. In addition, the obtained crystallized slug was applied to replace the crushed stone for asphalt mixture upper layer roadbed material. The test application to road in site was made (May, 1999), and after approximately two years of application (April, 2001) no deterioration has been found comparing with normal road.

抄録全体を表示

The mixture was prepared by mixing an adequate amount of clay with the ash contaminated by heavy metals from a municipal solid waste incinerator, then was sintered at the temperature range of 1000〜1250℃ to remove or stabilize heavy metals on ashes. It was examined whether the mixture sintered was worth using as an aggregate. The patent on the recycling technique of ashes has already been applied. In this study, we try to manufacture a plant equipment.

抄録全体を表示

Environmental pollution caused by waste in illegal or unqualified dumping sites is getting attention in various places in Japan. To solve this problem, the measure against the waste dumped in the past is required as well as that against the waste to be dumped from now on. The melting treatment is now known as the technology to provide harmless, less voluminous and recyclable waste. In January 2000, the operation of Plant for Melting Treatment of Waste in Dumping Site was started in Isahaya city, Nagasaki prefecture. The performance of this system is daily 24 MT melting treatment of mixed waste, namely 17 MT of waste from the landfill of a dumping site and 7 MT of residue from a nearby incinerator. The following is our report to explain the outline of this system and the actual performance.

抄録全体を表示

Since the bottom ash or fly ash from the municipal solid waste incinerator contains heavy metals or dioxins, it is necessary to be detoxified after the incineration. One of the popular processes is the vitrification of the ash to produce slag. NKK developed the ash melting system using slag electric resistance furnace and commercialized it. The computational analysis of electro-magnetic field and thermal fluid dynamics of the slag in the slag electric resistance furnace clarified the temperature distribution and the fluid flow in the slag bath. The results are coincident with the observation of the small scale slag electric resistance furnace. The slag is heated by the Joule heat at the each electrode and the heated slag rises along the electrode due to the reduction of its density and diverse at the top of the slag bath from the electrode. The buoyancy is found to be the major driving force of the fluid flow in the bath.

抄録全体を表示

One of the accepted methods of utilizing ash from a RDF incinerator is melting and solidification, but this is known to be a costly method. As a lower cost method, Kawasaki Heavy Industries, Ltd. has been developed an utilizing technology of RDF incineration ash by hydration. We conducted solidification tests of RDF incineration ash by hydration for road base material.

抄録全体を表示

This paper describes a new cooling method suitable for molten slag from the ash vitrification process using an electric-resistance furnace. The system consists of twin drum type copper rolls cooled indirectly by coolant flowing inside. Slag is poured between the turning twin rolls and solidified. Experience from the test plant showed melting slag forming into harmless, hard flakes. The cooling process is examined by calculation and the amount of heat recovery from the heat of the slag is estimated. The result shows that this method solves the conventional problems of space and water treatment and saves melting energy.

抄録全体を表示

Advanced Oxidation Processes (AOPs) for the treatment of waste waters containing non-biodegradable organic compounds rely mainly on the production of a potent oxidizing agent, the hydroxyl radical. This paper reports the test results of AOPs with photocatalyst for waste water including non-biodegradable compounds. The mechanism of AOP applied in this work ; 1) UV irradiation against photocatalyst 2) Reduction of Fe^<3+>ion by electron generated from photocatalyst 3) Enhancement of Fenton reaction. Compared to the degradation efficiency for 2,4-dichlorophenol(2,4-DCP) of several AOPs, UV/FeCl_3/H_2O_2 process (Photo-Fenton reaction) and UV/TiO_2/FeCl_3/H_2O_2 process have higher degradation efficiency. Both systems are effective processes for waste water from dyeing industry. These treatments do not require a large amount of Fe salt usually necessary for the Fenton Reaction(Fe^<2+>/H_2O_2). As a result amount of sludge (as Fe(OH)_3) is decreased.

抄録全体を表示

We experimentally investigated the decomposition of dioxins and endocrine disrupting organic compounds in the landfill leachates by the ozone/ultraviolet irracliation (O_3/UV), one of the advanced oxidation process. As the result of this study, the dioxins were decomposed to over 90% by O_3/UV. The concentration of dioxins was less than the environmental criterion. The decomposition rate of bisphenol A and benzophenone were over 90%, and the concentration of those were below 0.1 μg/L. Therefore the dioxins and endocrine disrupting organic compounds were treatable simultaneously. However, the decomposition rate of DEHP was 57.5%, it was low compared to the others.

抄録全体を表示

We have developed a purification separator that combines high gradient magnetic separation, which is newly developed continuous rotary magnetic filter, and a superconducting magnet. In a purification experiment, we used the purification separator to remove ferromagnetic floc, which we generated by adding ferromagnetic powder and coagulant to influent water. The experiment showed that the continuous rotary magnetic filter can be practically used in the developed purification separator and that when the separator operates at high speed (i.e. about 10 times faster than normal speed), it achieves good (90% improved) performance

抄録全体を表示

This study is aimed at elucidating the mechanism of air scrubbing in membrane separation activated sludge processes. It is closely related to how the flow with random fluctuations induced by bubbly flow exerts shear stress on a vertically-set flat plate. Shear stress is directly measured for water and the fluid of high viscosity changing air flow rate and bubble diameter. Effects of air flow rate and bubble diameter on shear stress is investigated and factors which influence the maintenance of the membrane bioreactor is presented. It is shown that shear stress is smaller in larger bubble diameter conditions when air flow rate is kept constant.

抄録全体を表示

This study was carried out to verify the applicability of membrane separation bioreactor (MSB) system to municipal wastewater treatment plant in Japan. Five series of pilot plants with two types of flat sheet membrane, two types of hollow fiber membrane, and a ceramic membrane were operated. Each plant consisted of an aerobic tank, an anoxic tank, and membrane units immersed in the aerobic tank. The capacity of the plants was 40 - 70 m^3/day. Raw wastewater was supplied to the plants as the influent. The objective of this study is to investigate ; treatment performance throughout a year and behavior of micropollutant in MSB. The results are summarized as followed ; continuous operation for about two years, temperature ranging from 15 to 33℃ and the concentrations of five kinds of exogenous endocrine disrupting chemicals were measured for the influent, the effluent, and mixed liquor in MSB.

抄録全体を表示

This paper describes a new sludge-recycling center built in IKOMA city and its operational results of methane fermentation process. This facilities not only treats organic wastes, but also regenerates it effectively as a resource. This center is equipped with the biological denitrifying treatment system, the methane fermentation unit and the composting unit. This is the first facilities in Japan perfectly fit the idea of the "sludge-recycling center," a new facility which adds functions for the circulation of resources and coexistence with the natural environment to conventional night soil treatment facilities for the betterment of public health and preservation of the social environment. It started to receive garbage on Aug. 2000, and it stated its full operation on Dec. 2000. Operational results of water treatment unit, methane fermentation unit and composting unit are going well.

抄録全体を表示

The decomposition process of nitric compounds in water by using various nitrous acid bacteria was experimentally investigated for successive mass breeding of Genji firefly. Controlling the balance of various nitrifying bacteria is important when breeding the firefly successively, because they play important roles in decomposing NH_4^+ and NO_2^- in a water of the aquatic environment. We have newly proposed an effective method for controlling the aquatic environment. It was revealed throughout a series of experimental investigation that the amount of soluble nitric compounds in the water for successive firefly breeding, NO_2^-, NO_3^- and NH_4^+, are 0.00 - 0.02, 0.00 - 50.00 and 0.00 (mg/l), respectively. The method is useful in controlling the quality of water appropriately.

抄録全体を表示

The water purification apparatus using charcoal for the microorganism support was developed. This apparatus have a cartridge which filled up with charcoal support,and the cartridge is soaked directly in the pond or river. Using the air-lift pump, the water is flowed into the cartridge, and purified by biological water treatment. This apparatus have been installed in a water receiver for agricultural use. A result which indicates the restriction effect on the occurrence of the water-bloom have shown in this practical examination. Moreover, it was confirmed that it is possible to keep up the ability of purification by the backwash for clogged cartridge.

抄録全体を表示

We have made a prototype of an ultrasonic sterilizer which induces cavitation utilizing the squeeze-film effect. It is demonstrated by experiments that the sterilizer can inactivate cryptosporidium oosysts efficiently. When the oosysts are batched by the sterilizer for ten minutes, more than 96% of the oosysts is inactivated. In the continuous treatment at the flow rate from 33 to 1500 ml a minute, 78.7% to 96.9% of the oosysts is inactivated. Moreover, the experimental results show that the ratio of inactivation becomes high as increase of the flow rate. Running costs of the sterilizer can be much lower than that of a conventional ultrasonic sterilizer.

抄録全体を表示

We have developed a new continuous purification system for water that applied bulk high Tc superconductors to rapidly remove. The new membrane- magnetic separator system consists of (1) a preapplication treatment unit in which magnetic flocs (made up by suspended solids and seeded with ferromagnetic particles) are coagulated in a flocculation vessel, (2) the membrane separator in which water is purified by using a rotating net to gather the flocs, and (3) a magnetic separator in which the magnetic flocs on the net are recovered. The magnetic field of the magnetized bulk superconductors was 0.89T. This device was able to remove 95% of the contaminants, recovering a sludge with a concentration of 130,000 mg/l.

抄録全体を表示

Using sludge from a water treatment plant drawn from a clarifier using ferric chloride as a coagulant, a sludge thickening experiment using a rotating flat-sheet membrane module was performed followed by a dewatering experiment using filter press test. The performance of the rotating flat-sheet membrane module was evaluated and its effect on the dewatering process was studied. The optimal operating conditions of the rotating flat-sheet membrane module were clarified. It was found that pressurized dewatering after sludge thickening by a rotating flat-sheet membrane module results in a decrease of moisture content in the dewatered cake by about 7% and an increase in filtration rate by about two times compared to dewatering of sludge obtained by gravity-settling thickening.

抄録全体を表示

A corona discharge collector for diesel particulate matter (CCPM) is designed to collect diesel particulate matter (PM) electrically on central electrode. Accumulated PM (mainly soot particles) will be removed by a controlled burning (regeneration) process whenever the sparks appeared. In a corona discharge reactor for NOx removal (CRNR), the NO is oxidized to NO_2, and OH radical generated from H_2O in gas reacts with NO_2, and NOx concentration decreases as a result of formation of HNO_3. The configuration of a prototype CCPM and CRNR is proposed in our study, CCPM contains φ54mm reactor with φ0.5mm roll nichrome wire serving as a central electrode. The NOx removal reactor has a stainless wire electrode of φ1.0mm. In this paper, the discharge instability of CCPM by the PM accumulation on electrodes is investigated in a electric voltage field, and PM collection efficiency 60% is obtained under the condition of 2.5kV, 0.1mA〜1.0mA, and the gas flow rate of 14liter/min.

抄録全体を表示

A technique for removing the NOx contained in combustion exhaust gas has been developed by using radicals produced in the mixing arc plasma. By feeding the gas mixture (Ar+NH_3),(Ar+ H_2) and (Ar+ diesel oil) into arc plasma torch, ammonia, hydrogen and diesel oil radicals such as NH_2,NH,HC,N,H are produced, and these radicals are mixed in a reactor with the simulated exhaust gas (N_2+NO),(Air+NO). The NO decreases as a result of the formation of the innocuous products N_2 , H_2O and CO_2 when O_2 is not contained in the gas. Under present experimental conditions, the thermal De-NOx process and the oxidation of ammonia, hydrogen and Diesel oil are not expected. In the case of the gas (Air+NO), NOx increase with increasing input power to plasma. The effects of input power to plasma, molar ratio NH_3/NO, H_2/NO and diesel oil/NO, cathode length and gas flow rate on the NOx removal rate are investigated experimentally.

抄録全体を表示

As the oxygen concentration decreases in high temperature air combustion of kerosene, the size of combustion flame becomes larger and larger, and the local region at high temperature decreases. The existing region of chemical species, OH, CH, and C_2 radicals, observed in the combustion flame becomes larger and larger and the local region with strong emission intensity decreases. Namely, uniform temperature profile and uniform distribution of chemical species were confirmed under the condition of high temperature air combustion, which leads low NOx combustion. The effect of carbon dioxide on the homogeneous distribution is stronger than that of nitrogen, because carbon dioxide has a larger specific heat value than nitrogen.

抄録全体を表示

Thermal performance of a high temperature air combustion boiler in the experiments and three-dimensional numerical simulations is examined. The fuel can be efficiently combusted by high temperature preheated air (800℃-1000℃) are examined. The boiler has a new feature that the calorific value of the gasification gas is so low that not only air but also gasification gas is preheated to 900℃. At first, the natural gas combustion is experimented, then the high thermal performance and low NOx emission were obtained. The numerical calculation of the syngas combustion is carried out for prediction.

抄録全体を表示

The description of NO_x formation processes in turbulent flames requires the impracticable calculations of the fluctuating three-dimensional velocity, temperature and concentration fields based on detailed kinetics. We have proposed a new practicable method to predict NO_x production rate based on laminar flamelet model. In this method, we can separate the detailed kinetics calculation from the complicated flow field calclation, and recombine them to yield NO_x production rate. In the present study, we carried out the numerical simulation of the unsteady counterflow diffusion flame using GRI-mechanism in order to elucidate the unsteady combustion behavior and to verify our method.

抄録全体を表示

In this study, the combustion characteristics of jet diffusion flame with steam addition were investigated by experiment and numerical analysis. Especially, the effects of the steam addition on the flame temperature decrease and on the NOx reduction were examined. The results show that steam addition to the air-side is more effective in NOx reduction.

抄録全体を表示

We experimentally evaluate a performance and exhaust emissions of a single-cylinder, four stroke direct injection diesel engine operating on diesel fuel containing 50% volume waste food-oil (Blend 50), waste food-oil containing 50% waste polystyrene pyrolysis oil (Blend PS), diesel fuel containing 30% and 40% volume waste polystyrene pyrolysis oil (Blend3P, 4P) and soybean oil methyl ester (VDF). The combustion characteristics and emissions such as NOx,CO,HC,HCHO,O_2,CO_2 and smoke are compared with the case of JIS # 2 diesel fuel. We found that (i) the CO,HC,HCHO emissions of Blend PS are higher than Diesel fuel in the low load range, though the CO,HC,HCHO emissions of Blend PS are similar to diesel fuel in the high load range, (ii) the NOx emissions of Blend PS is higher than diesel fuel in the almost load range, and smoke emissions of Blend PS is higher than other fuels in the low load range, though smoke emissions of Blend PS is lower than other fuels in the high load range, (iii) thermal efficiency of Blend PS is lower than diesel fuel and fuel consumption of Blend PS is higher than diesel fuel in the whole engine operating range.

抄録全体を表示

To develop an emission control system for exhausted gas from automobiles, the experimental treatment system was constructed. Diesel Particulate Filter (DPF), Oxidation catalyst (OxCAT), Oxidation Catalyst impregnated DPF and Selective Catalytic Reduction (SCR) catalyst were tested to control emissions of fine particulate matter (PM), carbon monoxide (CO), total hydrocarbon (THC) and nitrogen oxides (NOx). Based on the result, a system combined with OxCAT impregnated DPF and SCR catalyst was selected to meet the requirements and installed at an existing automobile test facility for diesel and gasoline engines. A compact stationary type system was realized by the development of the OxCAT impregnated DPF.

抄録全体を表示

Under the background of increasing concerns about environment, gaseous fuel instead of liquid fuel has been highlighted recently. Consequently, demand for gas engine has been increased. Lately, the gas engine, which is ignited with small amount of diesel fuel less than 1% instead of spark plug, has been developed. The engine is furnished with many latest technologies such as common rail system for pilot injection, VG turbocharger for air/fuel ratio control, knocking detection & control system. Thanks to these elaborated devices, the engine can be always operated at the optimum condition. These enable the engine to reach high thermal efficiency of 43.8%. At the same time, extremely low NOx value of 100 ppm (O_2=0%) has been achieved due to optimization of pilot injection.

抄録全体を表示