(Abstract)

Most of the combustion ash generated from woody biomass power plants is currently treated as industrial waste. Therefore, recycling the combustion ash is important not only for reducing the cost of power plants but also from the perspectives of extending the life of final disposal sites and circulating resources. This report describes the status of combustion ash generation in Japan and where the handling of the generated combustion ash fits in with the efforts for recycling it, and explains the status of studying various applications based on the characteristics of combustion ash.

(Abstract)

The boiler tubes of the combustion chambers and the super-heater tubes in waste power generation boilers are exposed not only to corrosive gases but also to severe corrosive environments. For example, combustion ash containing alkali metal chloride and heavy metal compounds adhere to the tube surfaces. This paper reports on the results of an investigation into the impact that combustion ash adhering to the boiler tubes of the combustion chambers and the super-heater tubes in waste power generation boilers has on wall thinning speed. It also introduces the details of a test to evaluate the characteristics of high temperature corrosion conducted on super-heater tubes that our company is working on.

(Abstract)

Takuma Harima Factory began operating in December 1942, and its new factory building and the Harima Office were completed in January 2023 as it marked its 80th year of business. This paper introduces the history of Takuma Harima Factory and gives an overview of the facility and functions of the new factory.

(Abstract)

In order to achieve carbon neutrality by fiscal 2050, many research and development projects are underway to produce hydrogen by making the best use of renewable energy, but there are many issues, including the reduction of hydrogen production cost and the need to build new infrastructure. On the other hand, methane is expected to be used as an energy carrier because it can use existing infrastructures. In recent years, methanation technology, which synthesizes methane by reacting carbon dioxide recovered from incinerators and other sources with hydrogen, has attracted attention, but catalytic methanation with a catalyst for chemical methane synthesis has many problems such as catalyst deactivation and energy loss. In contrast, bio-methanation, which is a biological process producing methane from carbon dioxide and hydrogen, not only can make use of existing methane fermentation reactors but also has advantages such as being capable of synthesizing methane in a mild environment. This paper reports on domestic and international efforts related to bio-methanation and the progress of our research and development on bio-methanation.

(Abstract)

In 2016, our company constructed a stoker-combustion-type demonstration testing facility with a treatment capacity of 10 tons a day in our Harima Factory Experiment Center for the purpose of swiftly responding to needs for recycling biomass fuels, reducing environmental burdens, etc. To date, the demonstration testing facility has verified the combustion characteristics of various fuels and technologies to reduce air pollutants (nitrogen oxides and acid gases), and the results have been reflected in actual plants. This paper introduces our efforts that have been made with the stoker-combustion-type demonstration testing facility.

(Abstract)

We have developed our original pressure wave boiler dust removal system (Variable Shock Pulse Soot blower, or VSPS) as an alternative to the conventional steam type soot blower for removing boiler dust. In the previous report, we reported the results of demonstration tests which applied this system to super-heater tubes and economizers of municipal waste incinerators with waste treatment capacity of 110 to 250 ton/day per furnace. In this paper, we report a demonstration test with a new material applied to the film, which is an important component of VSPS. It was confirmed that VSPS has sufficient dust removal performance with the new material film, and that the operating cost of the overall system can be reduced.

(Abstract)

Combustion control technology that can reduce combustion-derived nitrogen oxides is required in order to satisfy possible stricter regulations for municipal waste incinerator in the future. In recent years, our company has used exhaust gas recirculation technology as a combustion control technology, but we have the issue that fluctuations in generated NOx depend on the combustion conditions and the gas temperature in the combustion chamber. Denitrification equipment is designed for satisfying regulations under conditions of maximum NOx generation, but if fluctuations in generated NOx can be reduced, it is possible to make the denitrification equipment more compact or not to install the denitrification equipment itself. We have confirmed the effect of reducing fluctuations in NOx generation, through developing the combustion control technology by combining exhaust gas recirculation technology and a combustion control system using artificial intelligence.

(Abstract)

In August 2022, a biomass incineration facility was completed at Amagasaki Mill of Rengo Co., Ltd. Paper sludge and other wastes discharged from this mill were treated with a mechanical stoker type incinerator delivered by our company in 1992. But it was decided that the incinerator would stop operating due to aging, and the new facilities was installed. This incinerator completed this time has taken its place and is now operating steadily. This paper reports on an overview of the plant, ingenuity used in the construction, and operation results.