VOL.25 NO.1 (published in Jun-2017)

Photo in Cover :Clean Park Hokutan

VOL.25 NO.1 (published in Jun-2017)

Effective Utilization of Incinerated Sewage Sludge Ash

Satoshi HAGITA*, Takaaki MIZUNO*, Naoki KABUTAN*, Kenichi SHISHIDA*
(*Sewerage Engineering Dept)

(Abstract)

Currently, about 70% of sewage sludge is incinerated in Japan, and the effective utilization of the incinerated ash has become an issue. More municipalities are seeking ways to use the incinerated ash effectively, and companies and research facilities are exploring such methods. Methods to use the incinerated ash are roughly categorized into the use as construction materials and as fertilizer. With regard to use as construction materials, attempts have been made to shift from used as the material of cement, the mainstream use of the ash at this point, to diversifying its uses. In regards to the use as fertilizer, many research and development are being actively conducted to use phosphorus contained in the incinerated ash due to rising phosphorite prices. Meanwhile, in using the incinerated sewage sludge ash as the source of phosphorus, it has become issues to keep heavy metal content standards as designated in the Fertilizer Regulation Act and to convert phosphorus into an absorbable form for plants. On the other hand, because of its costs and the availability of users, the number of practical technologies is limited currently. Diversified approaches are required to propose methods to effectively use incinerated ash with higher values.

Clean Park Hokutan Operation Report

Akihiro MATSUMOTO*
(*Environmental Engineering Dept. III)

(Abstract)

Clean Park Hokutan was constructed in August 2016. Waste treatment plants of the city of Toyooka, town of Kami, and town of Shinonsen in the Hokutan area of Hyogo were integrated in this facility. This facility thus treats wastes and sewage collected from wide areas. This facility continues its operations by setting “autonomous management values which are higher than required standards” and “proposing operations at a higher level than the required level for highefficiency power generation from wastes (14% power generation efficiency)”. This report describes results of these activities and the operating condition of high-efficiency waste power generation, the feature of this facility.

Report of the Operation of Woody Biomass Power Generation Plant for FIT

Satoshi YOSHIMOTO*, Teruyuki KITA*
(*Energy Engineering Dept. 1)

(Abstract)

The system for purchasing renewable energies at fixed price (feed-in-tariff, FIT) started in July 2012. Since then, we have delivered 18 biomass power generation facilities by January 2017 for FIT. We select suitable type of combustion systems depending on fuel types and facility power generation amount. We selected bubbling fluidized bed combustion systems which was suitable for woody biomass fuel with high moisture content. This report discusses the overview of the woody biomass power generation facility with bubbling fluidized bed combustion systems for FIT and its operating condition. The facility was delivered to Tsugaru Biomass Power Generation Co., Ltd. as the first power generation unit at TAKEEI Corporation Group Companies and started its commercial operation on December 1, 2015.

Example of the Installation and use of Distributed PLC Instrumentation System

Junichi TANAKA*
(*Electrical & Instrumentation Dept.)

(Abstract)

The PLC instrumentation system, “TS-PAT1000” delivered to Suwa Koshu Clean Center is the type of system which has been delivered to many waste incineration plants and sludge incineration plants as monitoring and control system and automatic combustion control system. The maximum scale of TS-PAT1000 as a system is enough for the system equipment configuration, the quantity of monitors, the quantity of instruments, and the performance of monitoring and control system for waste incineration plants with power generation feature. The scale is at the same level as commonly used DCS (distributed control system). It is also a type of system which can be expanded and apply as Operation & Maintenance Administration Support System (POCSYS®) and remote operation system. Remote operation support testing was conducted in March 2017.

Development of On-site Production Technology of Slaked Lime

Takuya OKUMURA*, Takayuki KUDOU*,
(*Energy & Environmental Development Dept.)

(Abstract)

We developed a technology of producing slaked lime (Ca(OH)2) from quicklime (CaO) on site, where municipal waste incineration facilities and boiler plants. This technology brings cost reduction for removing acid gas (HCl and SOx) contained in exhaust gas. We have produced experimental equipment which is capable of producing 30 kg/h of slaked lime, and evaluated physical property and acid gas removal performance of produced slaked lime. As a result, we confirmed that produced slaked lime had similar or greater physical property and acid gas removal performance than a JIS special-grade slaked lime commercially available. In addition, we have also confirmed that slaked lime produced with the addition of chemicals had similar acid gas removal performance to a high reactive slaked lime commercially available.

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