VOL.10 NO.1 (published in Jun-2002)

Photo in Cover : Taiwan Refuse Resource Recovery Plant

VOL.10 NO.1 (published in Jun-2002)

The Biomass-Utilizing Technology -- Current Situation and Outlook

Akihiro SAIGA
(Energy and Environmental Development Dept.)

(Abstract)

During the past half century, Takuma has built more than 500 steam boilers in Japan and aboard that use forestry and agricultual biomass such as wood chip, bagasse, palm and corn residues etc. for power generation and steam heating. This effectibe use of the biomass energy is gaining great interest now for its regenerating sources and Carbon neutral operation.

Concerning as biomass utilization, in Japan, its large-scale application is difficult because of the geographical limitations and unfavorable economics. However, Japan actively encourages biomass power generarion and fuel conversion researches at the government level. Except in sugar cane and a portion of lumber industries, only small-scale plants are operating. In Europe, CHP (Combined Heat and Power Co-generation) using biomass is becoming commonplace, and its power generation by pyrolysis has already reached a demonstrarion stage. In USA, combution and ethanol using biomass is popularity.

In the preceding article, we have reviewed the current situation of biomass utilization in Japan and abroad, and discussed the research and development of the technologies with emphasis on gasification, predicting the future of this technology.

New-Generation Stoker-type MSW Incineration Plant
(Mass-burn Renaissance)

Tomonori ASOU*, Jin AKIYAMA*,
Kohsaku OHMORI*, Ryoji Sameshima
Kiyomitsu IKAWA**, Hiroyuki FUJIKAWA***,
Takatoshi TAMURA***, Yoshihiro HAYATA***,
Daisuke NAKATSUKA*** and Akihiro MATSUMOTO****

(* Energy & Environmental Development Dept.
** E & E Project Dept.
*** Electrical & Instrumentation Dept.
**** Environmental Engineering Dept.1)

(Abstract)

We wanted to develop a New-Generation Stoker-type MSW incineration Plant with higher efficiency as well as lower load on environmental than the conventional one. Our aim was the concept of an advanced combustion technology that can handle combustion at a air ratio of 1.3, while reducing the amount of flue gas and toxic pollutant. Combustion tests were conducted with a test furnace at our Harima Factory and at a commercial furnace equipped TAKUMA EXCEL STOKER with reduced primary air. The tests had confirmed that waste combustion is possible with reduced primary air. Next, demonstration tests of advanced combustion technology were carried out for approximately six months in 2001 at an 85ton/day continuous-operation incinerator using exhaust-gas re-circulation and advanced fuzzy control. The tests assured us that complete combustion is possible with an air ratio of 1.3 (0.9 primary air and 0.4 secondary air), reducing exhaust gas by 20%, controlling CO to less than 1ppm, and dioxins to 0.5ng-TEQ/m3N at the furnace outlet.

Demonstration Test of a New High Efficiency Flue Gas Treatment System by Sodium-based Chemical Agent

Masaki KURATA*, Ryoji SAMESHIMA*,
Jiro HIROSUMI** and Takaaki SHINODA**

(* Energy and Environmental Development Dept.
** Air Pollution Control Engineering Dept.)

(Abstract)

We have experimented with a dry flue gas treating system that uses a new sodium-based chemical agent BICAR, instead of slaked lime currently used for treating acid gases int the flue gas from waste incinerators. The demonstration test was aimed at confirming the capabilities of this system for acid-gas removal and long-term stable operation. It has shown removalrates of 98% for HCI and 90% for SOx at 1.2 equivalency, proving that it is capable of lowering concentrations below 10ppm, hitherto attainable only by wet scrubbers. Furthermore, no problem was observed during the continuous in areas such as measured feeding and pneumatic transfer of the chemical agent, and the stability of pressure differentials at the bag filter. The test has demonstrated that this system can be applied to a commercial plant.

Report on Test Results of a Plastic Packaging Materials Treatment Facility -- Shiki Sanitary District Recycling Plaza--

Seiichiro INOUE
(Environmental Design Dept.2)

(Abstract)

We have been awarded a contract to build a recycling plaza (Plastic Packaging Material Treatment Facility) for Shiki Sanitary District in Saitama Prefecture. The plant was to meet the requirements of The Law Concerning Promotion of Separated Collection and Re-merchandising of Packaging Materials (Package Recycling Act) enacted nationally in April 2000. The plant construction began in June 2000. After successful operational and performance tests, it was delivered in March 2002.

The plant throughput is 26ton/5H. It has two lines of treating plastic packaging materials. It separates collected plastic wastes into three groups, film, bottle and non-packaging. Each group is baled by its own compactor.
The foregoing article describes the outline and the test results of the recycling plaza (plastic packaging material treatment facility).

Test Report on Multi-disk Screw Press Dehydrator

Masato Fujita and Hideaki Hayashi
(Water-Treatment Dept., Environmental Division.)

(Abstract)

During the past half century, Takuma has built more than 500 steam boilers in Japan and aboard that use forestry and agricultual biomass such as wood chip, bagasse, palm and corn residues etc. for power generation and steam heating. This effectibe use of the biomass energy is gaining great interest now for its regenerating sources and Carbon neutral operation.

Concerning as biomass utilization, in Japan, its large-scale application is difficult because of the geographical limitations and unfavorable economics. However, Japan actively encourages biomass power generarion and fuel conversion researches at the government level. Except in sugar cane and a portion of lumber industries, only small-scale plants are operating. In Europe, CHP (Combined Heat and Power Co-generation) using biomass is becoming commonplace, and its power generation by pyrolysis has already reached a demonstrarion stage. In USA, combution and ethanol using biomass is popularity.

In the preceding article, we have reviewed the current situation of biomass utilization in Japan and abroad, and discussed the research and development of the technologies with emphasis on gasification, predicting the future of this technology.

Development of U-turn Destruction Equipment of Dioxins from Fly Ash

Takahiro MASUDA* and Yoshitada KAKUTA**
(*Environmental Dept.1
**Assistant Professor,Technology of Recyclable Resources Assessment(Takuma Endowed)Laboratory, Graduate School of Engineering, Hokkaido University)

(Abstract)

We have developed a thermal destruction equipment that breaks down dioxins in fly ash cheaply and surely. Fly ash contains major portion of total dioxin emission. Heating to 450°C, with residence time of one hour, it requires no reducing atmosphere or quick chilling. In addition, the U-turn mechanism achieves vast energy saving by recovering sensible heat from the fly ash. The foregoing article reports on the unit No.1 we just delivered to Anan Clean Center (Anan City, Tokushima Prefecture) after its successful demonstration test.

Exhaust-Gas Driven Absorption Water Chiller-Heater

Akio MORITA, Origane TAKAFUMI
and Masatoshi KATAYAMA

(General Machinery & Engineering Department)

(Abstract)

In addition to generating electricity, it is important for a co-generating system to recover waste heat. Heat recovery from exhaust gas by hot water and steam is well known already. In this report, we have introduced the absorption chiller-heater driven by the exhaust gas of the micro-turbine at 280°C and 820m3(N)/h. It raises the efficiency of waste heat recovery by the absorption action of the single and double effect cycles, and achieves 13USRT of air-conditioning ability.

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