Technical informationTECHNOLOGY

VOL.29 NO.1 (published in Jun-2021)

VOL.29 NO.1 (published in Jun-2021)
Approaches through Sewage Works Business for a Decarbonized Society
(*Sewerage Engineering Dept.)


Large scale flooding damage occurs almost every year as a result of recent mega typhoons and increases in local rainfall due to global warming.
 As part of the efforts to prevent global warming, Japan also declared its intention to achieve carbon neutrality which keeps the discharge of greenhouse gases at substantially zero by 2050. This paper introduces our approaches through the sewage works business for protecting urban areas from inland flooding damage due to climate change and sewage treatment technology contributing to greenhouse gas reduction for suppressing climate change.

Solution Lab
Satoshi NISHIO*,Takashi HASHIMOTO*,Junichi TANAKA**
(*Operation & Maintenance Technology Dept., **Electrical & Instrumentation Dept.)


We opened the “Operation Support Center” in 2004 and launched the remote monitoring support service. Business forms such as the DBO system and O&M system in which local governments entrust operation and management duties to private enterprises comprehensively in the long term are recent trends in general waste treatment facilities. The support center was renamed the “Solution Lab” in 2018 and its roles and the functions of the support system, the “Plant Optimization Comprehensive Support System (POCSYS®),” have been continuously expanded and updated to address problems and meet needs inside and outside the company in such circumstances.
 This paper reports on the role and activities by the “Solution Lab” which was expanded and transferred in October, 2020 as a base for remote monitoring and operation support.

Development and Operation Report of the Pressure Wave Dust Removal System
Hiroshi TAI*
(*Mechanical Design & Engineering Dept.)


We developed an original pressure wave boiler dust removal system as an alternative to the conventional steam type soot blower. This paper describes the features of the pressure wave boiler dust removal system and reports on the results of the demonstration test applied to a group of superheated tubes in an actual facility.

Operation Report of the Biomass Power Generation Facility for General Wood and Unused Wood for FIT
Takashi KAWANO*
(*Energy Engineering Dept. 1)


Many biomass power generation plants have been completed in Japan in the last nine years since the feed-in tariff system (FIT system) was introduced for the effective use of renewable energy in 2012. Among them, the spread of woody biomass power generation plants using woody biomass such as unused wood and general wood as fuel is remarkable, and we have delivered many plants. This paper introduces the overview of a biomass power generation facility which adopts the bubbling fluidized bed system by mixing unused wood with general wood as the main fuel and reports on the operation results.

Evaluation of a Sewage Sludge Incineration Power Generation System using a Step Grate Stoker Furnace for Digested Sludge
Yukiya ATSUMI*,Daisuke IWASAKI*,Takaaki MIZUNO*,Naoki KABUTAN*
(*Sewerage Engineering Dept.)


For the purpose of evaluating the effectiveness of a sewage sludge incineration power generation system using a step grate stoker furnace for sewage treatment plants performing sludge digestion (methane fermentation), we examined the reduction effect of the digestion gas of a drying incineration system used as an auxiliary fuel when combined with a steam-indirect heating sludge dryer as a pretreatment for incineration. Through the examination, it was confirmed that the use of digestion gas can be greatly reduced compared with direct incineration without drying. In addition, it was confirmed that the sale of surplus digestion gas, which is not used as auxiliary fuel for incinerators, to digestion gas power producers would enable municipalities to secure further profits and contribute to the reduction of greenhouse gas emissions by increasing the amount of power generated from biomass.

Clean Oshima primary equipment improvement work for the Oshima District Cooperative of Municipal Solid Waste Management
Toshihide MATSUMOTO*
(*Environmental Design Dept.3)


The Clean Oshima primary equipment improvement work project, ordered by the Oshima District Cooperative of Municipal Solid Waste Management, was completed in March, 2021. This project was the first primary equipment improvement work for a pyrolysis gasification melting furnace, which is one of the few projects we worked on. This is a report of the overview and operation status after the improvement work.