(Abstract)
Professional Engineer is a national qualification established by the Professional Engineer Act. It is a qualification that proves that a person has competence as an engineer and high-level engineering ethics. The Professional Engineer System that is the qualification system for this was established for the purpose of contributing to reconstruction and world peace after World War II. The Professional Engineer System has been reconsidered when appropriate, such as in accordance with changes in the social conditions and revisions of the Professional Engineer Act. It is worthwhile to gain an understanding of the details of the system, not only for those who have already obtained Professional Engineer status, but also for those who are aiming to become Professional Engineers from now on. Therefore, this paper introduces the outline of the Professional Engineer System and briefly introduces the trends in the reform of the system.
(Abstract)
Substituting biomass for fossil fuel as a supplementary fuel is an effective way to reduce the amount of greenhouse gas emitted by sludge incineration. However, as biomass contains a large amount of potassium, there is a concern about clinker formation due to the production of low melting point and low boiling point compounds in the co-firing of sludge and biomass. This study considered the characteristics and behavior of the ash from co-fired sewage sludge and biomass and investigated the risk of clinker formation in the co-firing process by analyzing simulated ash samples with elemental analysis, thermal analysis, and high temperature microscopic observation. In the results, some substances in the simulated ash started volatilization from around 600℃, and the amount of volatilization tended to increase with increasing temperature. In addition, the high temperature microscopic observation suggested that the shrinking and melting temperature of the ash depended on the combustion conditions, e. g. the shrinking and melting temperature decreased about 100℃ in the co-firing with grass clippings and pruning branches compared with the single combustion of sludge. Therefore, the possible temperature range of clinker formation may fall around 100℃ in co-firing compared with the single combustion of sludge.
(Abstract)
To achieve carbon neutral in 2050, it will be essential to capture and recover the carbon dioxide from sources of carbon dioxide emission such as combustion exhaust gas and then to store and fix it. With carbon dioxide capture and recovery by the chemical absorption method, the method is suitable for the capture and recovery of a large amount of carbon dioxide, but there is the issue that a large amount of heat energy (currently about 2.5 GJ/t-CO2) is consumed in the absorption liquid regeneration process, which is where the carbon dioxide absorption liquid is heated to dissipate the carbon dioxide. Our company has made it possible to aim for a reduction of the thermal energy required to less than 1.5 GJ/t-CO2, through the adoption of a new non-aqueous absorption liquid and also the construction of a total process that includes the use of the waste heat from the facility emitting the carbon dioxide. This paper reports the development related to the energy-saving carbon dioxide capture and recovery using a new nonaqueous absorption liquid
(Abstract)
As was reported in the Takuma Technical Review Volume 28 No. 1 in 2020, to upgrade the autonomous operation function of a garbage crane with the aim of achieving greater garbage uniformity in the garbage pit than with the conventional automatic stirring control, we developed a system to quantify the visual sense of the operator (regarding variations in color). This system identifies pixels of a specific color tone from the color components of the ITV image of the garbage pit and calculates the area ratio and dispersion of the extracted pixels in each address of the garbage pit so that it is possible to quantify how well the garbage has been mixed (the garbage mixing degree). This is a report of the results of an evaluation of the impact on combustion stability improvement and garbage crane power consumption reduction at an actual plant when autonomous operation equipment for a garbage crane equipped with the Garbage Mixing Degree Quantification System was delivered and automatic operation was conducted.
(Abstract)
Unshaped refractories used for the water tube wall of waste incinerator boilers can easily be damaged due to the usage environmental conditions. However, it is not easy to repair or replace them, so there are demands for durability and ease of maintenance so that the facilities can be operated for a long period of time. Refractory tiles were developed to address these challenges, and recent improvements in materials and structure have made them highly durable and easily replaceable. This report introduces the materials and structures of the refractory tiles used in the boilers supplied by our company and introduces examples of their application to boilers other than waste incinerator boilers.
(Abstract)
In January 2023, the Yufutsu Biomass Power Plant was delivered to Yufutsu Energy Center LLC, which was established by Nippon Paper Industries Co., Ltd. and Sojitz Corporation. This plant was the first 75 MW class biomass power plant from our company and is one of the largest biomass power plants in Japan. This paper gives an outline of the Yufutsu Biomass Power Plant facility and reports the results of its operation.
(Abstract)
The Sumiyoshi Plant (later renamed the Suminoe Plant) was constructed in 1963 as the first continuous type incinerator in Japan. The current Suminoe Plant was relocated and rebuilt from 1985 to 1988 as the successor to that plant. After operating for 28 years, the plant operation was temporarily suspended in 2016 due to the aging of its equipment. Ever since the beginning of the reconstruction in 1985, the Suminoe Plant had planned to use the building for a long period of time. In this latest construction work, the existing building was utilized whilst also securing earthquake resistance and functions as a designated emergency evacuation site. The entire set of the plant equipment was then renewed and the construction work was completed in March 2023. The newly updated facility has performed the setting of voluntary control values to meet the stringent exhaust emission regulations and has realized high-efficiency waste power generation. The operation business has also been commissioned by the Osaka Waste Management Authority. This paper reports the features of this facility, the results of the performance testing at its delivery, and the situation of its various operations.
(Abstract)
The Kahoku County City Clean Center energy recovery type waste treatment facility was completed in March 2023 based on an order our company received from the Kahoku County City Wide Area Affairs Association, which consists of the city and two towns of Kahoku City, Tsubata Town, and Uchinada Town. This facility performs the mixed combustion of waste and sewage sludge and also recovers the heat energy from that incineration and generates electric power with a steam turbine generator. The electric power generated is used as the power supply to drive the various equipment in the facility and for the equipment in adjacent facilities within the same grounds, and any surplus electric power is sold. In addition, the recovered thermal energy is also utilized for the pretreatment (drying) of sewage sludge and for road heating, a hot water supply and air conditioning. This paper reports the features and operation status of this facility.
