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Hydrogen fermentation by using pretreated wood were investigated and the results showed that hydrogen production had been kept for two month. After the time, hydrogen production and oxidation reduction potential (ORP) were decreased rapidly and little hydrogen had been produced for 100 hour in spite of ORP recovering. Response surface methodology was adapted to analyze the results and maximum hydrogen production rate was estimated at pH 5.8 and ORP -68mV.

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We carried out a questionnaire survey on organizations producing BDF(Bio Diesel Fuel) from waste cooking oil to know the running authority, the capacity, the producing body of waste cooking oil, the method of BDF production , the usage of BDF and etc. Then, we analyzed BDF system and revealed Energy Balance, Cost, CO2 emission of the whole system. From this study, we concluded that expanding of the plant, promoting of the domestic waste cooking oil recycle, effective usage of residue, and promoting of waste water treatment is an issue in the future

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The purpose of this research is to produce 20L/h pilot scale plant for converting the glycerin to the lactic acid.Condition of reaction are reaction temperature 310degree, reaction pressure 11Mpa, glycerin concentration 400kg/m3, sodium hydroxide concentration 174kg/m3.As a result of the operation, it was confirmed that the operation control could be stabilized.At observed material balance, the lactic acid yield was 54wt%, the hydrogen gas yield was 1.2wt%, and survival glycerin yield was 10wt%.The by-product yield except for the lactic acid was 35wt%.Also the corrosion test was carried out in order to select the metal quality of the reactor.As the result, the corrosion resistance might be verified on SUS316L and 600 alloys.

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Synthesis of substituted diesel gas oil from wasted fatty acid has been remarkable. It is pointed out that considerable amount of glycerin is formed in the process treating fatty acid with methanol. Unfortunately, it is difficult to utilize the glycerin at the present time. Authors tried to generate hydrogen by steam reforming of glycerin using catalyst and as a result hydrogen was continuously obtaied during the steam reforming.

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For purpose of bioethanol production from citrus peel waste, simultaneous saccharification and fermentation (SSF) by the immobilized cells of Saccharomyces cerevisiae was studied. Limonene content had affected the ethanol production of S. cerevisiae free cells, but not that of immobilized cells. In the SSF of Citrus unshiu peel, ethanol production is not recognized in free cells. On the other hand, ethanol production is observed in immobilized cells. It was found that SSF by immobilized cells was useful for the bioethanol production from citrus peel waste.

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For high efficiency of production of bioethanol, crush technique of a sawdust was examined. Furthermore,examination about burning characteristic of saccharification residue after saccharification was performed.

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To realize resource recycling society, it is required to shift conventional "one-way" type waste treatment system (landfill disposal) to resource recycling-based type. Our melting treatment technology aims to minimize landfill disposal and to act an important part of resource recycling by detoxifying waste through high-temperature processing, effectively utilizing molten slag and recovering metals from fly ash. Kubota has made the melting treatment technology the key to resource recycling society from the start of development. This report explains the superiority of our melting treatment technology over conventional system by use of actual two treatment cases. Case A is an application of waste melting process for various waste from wide area in Mie prefecture and the other case B is an environmental restoration project of an illegal dumping site in Kagawa prefecture.

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In order to increase the value of solid fuel, it is necessary to control heat release rate during combustion, decrease amount of soot and char residue, and improve storing stability. To achieve this goal, thermal degradeation and combustion properties and storing stability were investigated by using simulated biomass fuel made from waste wood and polyethylene and controlled combution heat.

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Ash melting technology has been introduced into municipal solid waste(MSW) treatment systems to satisfy the new regulations on Dioxins and the growing shortage of landfill site since 1990's in Japan. Authors have developed MSW gasification and melting furnace technology by combination of fluidized-bed MSW incinerator and swirling-flow ash melting furnace. In the melting furnace, minimum burner flame had been kept to ensure ignition and combustion of pyrolysis gas, even if the heating value and temperature of the gas varies with change of waste quality. Authors have developed a new on-line measuring system to monitor whether the pyrolysis gas can be ignited and combusted in the melting furnace. This system is installed in Aki Clean Center, and keeping burner flame is not necessary with this system. As the result, fuel consumption is reduced by 80% from that of conventional operation.

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With utilization of valuable energy in MSW, high-temperature combustion is performed in gasification and melting process, so this process has less environmental load and a superior resource recovery ratio and has grown up to a standard type after construction of over eighty plants in Japan. (as of June, 2008) Our company has completed eight plants including Chubu-kamikita plant in October 2000. All of our completed plants have been successful in stable operation. Especially, Okuetsu plant has achieved continuous operation of 228 days.

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This paper describes product distribution from hydrogenation of model materials as heavy liquid elements by pyrolysis of wood wastes mixture containing adhesive, plastics, and so on. The mixing effects of materials on reaction were also discussed. As a result, product distribution was differed by hydrogen pressure. It was shown C6H6 and C2H6 influenced as middle products which could be converted to CH4. Whole reaction was enhanced by pressure increase. The effects of mixing on increasing in product yield were observed even it was small. It is possible to say exothermic reaction promotes endothermic reaction in a short time.

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At Sashima Clean Center Teraku (103t/day,2line), which is the facility of the fluidized bed gasification/swirl-flow melting system, has adopted the dry-type flue gas treatment system using sodium-based dechlorinating agent. Investigation is carried out on the removal efficiency of the acid gases(HCl and SOx) in flue gas from the furnace. By injecting the sodium-based dechlorinating agent into secondary bag filter, both HCl and SOx concentrations in the flue gas at the stack is less than 10ppm and the highly efficient removal of HCl and SOx is maintained. The pressure drop and the transport of the exhaust ash of the secondary bag filter is evaluated to be the same as those of slaked lime injection. The equivalent ratio of the soldium-based dechlorinating agent is lower, and both the HCl and SOx removal efficiency is higher, in comparison with slaked lime usage respectively.

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Polybrominated diphenyl ethers (PBDEs) are a group of additive brominated flame retardants (BFRs) that are widely used in electronic equipment, insulation material, and furniture. The major commercial mixtures of PBDEs are composed of deca-BDE in Japan. The rapid increase in the use of BFRs has also raised the level of environmental concern about polybrominated chemicals such as polybrominated biphenyls (PBBs) and polybrominated dibenzo-p-dioxins/furans (PBDDs/DFs), which are present as low-level impurities in some commercial mixtures of BFRs and are produced upon their combustion. PBDDs/DFs are also formed, for example, when plastics that contain BFRs are heated during the welding of mats or the melting of polymers. The thermal formation of PBDDs/DFs from BFRs is considered to be a serious issue. In the present study, we determined the concentrations of PBDDs/DFs, PBBs, PBDEs, and polybrominated benzenes (PBBzs) in flue gas and fly ash from combustion of plastics containing deca-BDE. In addition, the concentrations of extractable organic bromine (EOBr) in flue gas and fly ash were determined using combustion ion chromatography (CIC) and applied in a study to evaluate contributions of known brominated chemicals such as PBDEs and PBBs to extractable organic bromine.

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An automatic measurement device of flue gas by using helium plasma emission spectrometry was experimentally made. The change in low volatile organic chorine (LVOCl) of concentration in flue gas was investigated with the device during start up at MSWI, and a correlation between LVOCl and dioxins was discussed. The change in LVOCl concentration at bag filter (BF) outlet showed that a concentration of dioxins decreased to the regular level with term of a few days. The change is caused by the memory effect, and witch is important for the emission of dioxins at start up of MSWI. The change was hard to be detected by CO measurement, but was able to be done by LVOCl measurement. Therefore, monitoring of LVOCl at start up is effective in control of dioxins emission.

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To inhibit the dioxins formation from municipal solid waste incinerator, especially its formation mechanism in fly ash should be clarified because high concentration of dioxins are caused from the fly ash containing unburned carbon, chloride, and metal compounds. Recently a stable control system of combustion requires reliable on-line and real-time monitoring. VUV-SPI-IT-TOFMS for on-line, real-time monitoring of chlorobenzenes known as the precursors of the dioxins in waste incineration flue gas has been newly developed. Chlorobenzenes in flue gas during fly ash and model fly ash heated at the temperature, mostly organic chlorides as dioxins formed, were monitored in real time by VUV-SPI-IT-TOFMS. Comparing the chlororbenzenes' real-time pattern of the fly ash and the model fly ash mixed with a metal compounds which caused dioxins formation, it was suggested that copper compounds and iron chlorides were the key factors for the formation mechanisms of the organic chlorides as chlorobenzenes and dioxins. Carbon matrix in fly ash was thought to be chlorinated directly by the copper and iron chlorides and catalyzed indirectly by the copper oxides and hydroxides. On the other hand, chlorobenznenes almost never formed by lead and zinc compounds.

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Mercury has attracted great attention as persistent bioaccumulative and toxic substance. Mercury atmospheric emission inventories are indispensable basic data for international management and control of mercury emission. In this study, mercury atmospheric emission in Japan ant its temporal trend were reported. Evaluating the reliability or confidence intervals of emission factors and removal efficiencies for exhaust gas treatment equipments, mercury emission in 2002 was estimated to be 21 to 28 Mg/yr. For 16 years since 1990, mercury emission showed decreasing trend followed by increasing trend. Dry-cell battery manufacturing without mercury contributed to decreasing trend. Rising consumption of coal and increased amount of incinerated sewage sludge contributed to increasing trend of mercury emission. Because of the promotion of sewage sludge incineration treatment and other emerging mercury emission sources, mercury emission would be increased potentially. Exhaust gas treatment equipments that had higher removal efficiency should be applied for effective reduction of mercury emission.

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