(Abstract)

Industrial boilers come in a variety of shapes depending on the application and scale, and after start-up, they deform as the temperature and pressure rise. In addition, water circulation starts after start-up, and if the water circulation is not good, various phenomena occur. Furthermore, various phenomena occur depending on the gas flow. This paper describes the basic structural design precautions to prevent damage to the boiler due to various phenomena that occur after start-up and during operation.

(Abstract)

Initiatives for decarbonization are accelerating worldwide with the aim of becoming carbon neutral by 2050. It would be very difficult to achieve this goal with an extension of the current technology, so substantial technological innovation such as CCUS (carbon dioxide capture, utilization and storage) is required. Our company is also focusing on the development of technologies to reduce CO2 emissions, such as the capture and effective utilization of the CO2 emitted from waste incineration and biomass power generation, which are our core businesses.
 This paper introduces the trends in Japan in the development of decarbonization technologies, and also some examples of the initiatives in our own business.

(Abstract)

We developed our original pressure wave boiler dust removal system as an alternative to the conventional steam type soot blower. In the previous report, we reported the result of a demonstration test which applied this system to a municipal waste incinerator with a waste treatment capacity of 110 ton/day per furnace. With the aim of application to even larger facilities, in this paper, we report the results of a demonstration test which applied the system to a municipal waste incinerator with a waste treatment capacity of 250 ton/day per furnace.

(Abstract)

Our company developed technology for the on-site production of slaked lime (Ca(OH)2) from quicklime (CaO), for the purpose of reducing the expense for the chemicals required to remove the acid gas (HCl, SOx) contained in exhaust gas from municipal waste incinerators. In the previous reports, we described how acid gas removal performance equivalent to that of commercially available high reactive slaked lime was obtained by adding organic chemical to the water for slaking to produce slaked lime. In this report, we report the results of investigating the factors that improve the acid gas removal performance of slaked lime. By the addition of organic chemical to the water for slaking, the slaked lime became fine particles. Furthermore, when the amount of water for slaking was increased, the fine particles agglutinated. The gaps between the fine particles have a pore shape, and also the pore volume composed of fine pores was increased. It was indicated that this may be contributing to the improvement of the acid gas removal performance. Depending on the scale of the facility and the region, the results of estimations indicated that a large cost benefit can be obtained from the on-site production and use of high reactive slaked lime from inexpensive quicklime.

(Abstract)

Urea decomposing system produce ammonia gas as denitration agent from safe and inexpensive urea by using urea decomposition catalyst.
 In this report, we introduced urea decomposing system at the latest municipal waste incinerator that achieved energy reduction for exhaust gas treatment and high-efficiency power generation by combining exhaust gas recirculation technology and SNCR technology. As a result, we confirmed long-term stable operation of urea decomposing system for over six months at the incinerator.
 We confirmed that this system can reduce the amount of urea water and increase the power generation efficiency compared to the conventional urea spray method.

(Abstract)

The Eco-Clean Center Nanetsu was completed in March 2021. The facility was newly developed in response to the aging of the former No. 1 Cleaning Center, which used to treat the combustible waste from Echizen City, Minami Echizen Town and Ikeda Town in Fukui Prefecture. In addition to the continuation of that waste treatment function, the facility was also developed to contribute to the construction of a recycling-oriented society and the prevention of global warming.
 The “Establishment of operation standard values for compliance with required levels” and “High-efficiency waste power generation that exceeds the requirements for subsidies for the construction of high-efficiency waste power generation facilities” have been conducted at the facility and it is continuing its operation business. This paper reports the results of the delivery performance testing and the status of the operation of the high-efficiency waste power generation, which is a feature of the facility.

(Abstract)

As a measure against global warming, Prime Minister Suga announced in April 2021 that Japan would aim to reduce greenhouse gas emissions by 46% from the level in FY2013 by FY2030, and Japan is now accelerating initiatives for a decarbonization in all sectors of energy. In the waste management industry, and particularly in the incineration of industrial wastes, the original purpose of the waste treatment is for “volume reduction” and “hygienic treatment”. In the present day, “heat recovery” has been added to this, and “waste power generation” in particular is regarded as an effective means for a decarbonization. Under such circumstances, our company delivered the 2nd Industrial Waste Incineration Treatment and Power Generation Facility to Aoki Environmental Enterprise Co., Ltd. In Niigata Prefecture. A waste heat boiler, which was not installed on the first furnace, was installed on the second furnace to accelerate heat recovery. This waste heat power generation system supply almost all electricity used in the entire plant. This paper reports the outline of that plant and the results of its operation.

(Abstract)

We have delivered an energy saving and energy creation type sludge incineration system to the Tamagawa Joryu Water Reclamation Center of the Bureau of Sewerage Tokyo Metropolitan Government. The system combines a step grate stoker furnace that conforms to the “high-temperature energy-saving incinerator” standard of the Bureau of Sewerage Tokyo Metropolitan Government, and steam power generating equipment that uses the waste heat from sludge incineration. By combining a sludge dryer, step grate stoker furnace, waste heat boiler, and steam power generator, etc., this system does not require the use of auxiliary fuel and can significantly reduce the power used through low power consumption and steam power generation. In addition, high-temperature incineration at 900 ℃ or higher is possible, so the system can significantly reduce the emission of dinitrogen oxide (N2O) which is a greenhouse gas. As a result, the system can achieve energy saving, energy creation, running cost reduction, and greenhouse gas reduction. The delivery of this facility was completed in December 2020, and the facility has been operating smoothly with satisfactory performance.

(Abstract)

In March 2021, “The Clean Plaza” of the Regional Cleaning Union of Ota City and Three Towns was completed. This facility was constructed for the wide-area treatment of combustible waste from Ota City, Chiyoda Town, Oizumi Town and Ora Town in the eastern part of Gunma Prefecture.
 This facility was constructed and is operated based on our business proposal of the “Realization of high-efficiency waste power generation (power generation efficiency 26.2%)” and “Stable operation combining our companyʼs extensive past results and the latest technologies”. This paper mainly reports the results of delivery performance tests regarding the high-efficiency waste power generation, and the introduction of the latest technologies.