Municipal Refuse Incinerators Research Articles

都市ごみ焼却炉の燃焼制御 : ダイオキシン類発生抑制への取組み (環境問題における解析・計画・制御特集号)

都市ごみ焼却炉の燃焼制御 : ダイオキシン類発生抑制への取組み (環境問題における解析・計画・制御特集号)

Effect of Furnace Temperature on Emission of Nitrous Oxide from Municipal Refuse Incinerators

Effect of Furnace Temperature on Emission of Nitrous Oxide from Municipal Refuse Incinerators

Oxidation Characteristics of NO and SO2 in Exhaust Gas from Municipal Refuse Incinerator by Pulse Corona Discharge

Oxidation Characteristics of NO and SO2 in Exhaust Gas from Municipal Refuse Incinerator by Pulse Corona Discharge

A PID ratio control for removal of [formula omitted] in flue gas from refuse municipal incinerators

This paper presents a PID-based ratio control scheme for flue gas cleaning systems (FGCSs) to remove acid emissions ( SO X and HCl) from municipal refuse incinerators. The FGCS uses a semi-dry scrubber that injects diluted hydrated lime ( Ca ( OH ) 2 ) droplets to scrub high temperature, polluted flue gas from incinerators. The development of the control scheme was initiated by treating the scrubbing process as a grey system perceived as conceptual chemical dynamics. The scheme was implemented on a redundant programmable logic controller (PLC) and the control parameters were tuned based on responses from commissioning operations. The scheme, never re-tuned, has accomplished promising performance and consumable savings since its commission in the year 2000.

Life Cycle Management for Selecting the Way of Disposing Domestic Kitchen Garbage

In this paper, a Life Cycle Management (LCM) for a resident to select the way of disposing domestic kitchen garbage is proposed. The alternatives to dispose the kitchen garbage are the following three methods: (i) discharging the garbage as the municipal waste and incinerating the waste in the municipal refuse incineration plant, (ii) crushing the garbage with disposer and discharging into public sewerage after sewage treatment, (iii) composting the garbage with domestic composting facility and using it for the plants in one‘s garden. The amounts of emissions of the green house gases (GHGs) for each alternative are estimated using Life Cycle Assessment (LCA) analysis. Then the preference of housewives to each alternative is evaluated, where the items for evaluation are related to the emissions of GHGs, cost, and conveniences of life. To evaluate the preference of housewives, we use the model of descriptive extension of Analytic Hierarchy Process.

都市ごみ焼却炉の高温腐食対策 : 溶射方法の利用(FR3 バイオマス・自然エネルギー・廃棄物利用2)

都市ごみ焼却炉の高温腐食対策 : 溶射方法の利用(FR3 バイオマス・自然エネルギー・廃棄物利用2)

Dioxins and Related Compounds Decreasing Measures in Municipal Refuse Incineration Process (Oxygen Enriched Air and Flue Gas Recirculation Effects).

There are two kinds of main pollutants (NOx and Dioxins) which can be controlled by municipal refuse combustion procedure improvements. The reduction phenomena of both of them are completely different, so that appropriate combustion condition must be considered separately. The basic theory to decrease NOx is to make self de-NOx combustion area and to maintain longer residence time in this area by decreasing primary combustion air supply. Also it is required for low dioxins combustion to maintain high furnace temperature and longer residence time in this area by decreasing combustion gas volume and well mixing of unburned combustion gas and air. We present in this paper the experimental results to determine the lower limit volume of primary combustion air, using over fire air and/or recirculated combustion gas injection into furnace and oxygen enriched primary combustion air supply. The best result would be presented by actual scale municipal refuse incineration test. The combination of oxygen enriched primary combustion air, recirculated combustion gas injection into lower furnace and overfire air injection into upper furnace can decrease NOx and dioxins simultaneously.

Dioxins and Related Compounds Formation Mechanism in Municipal Refuse Incineration Process. Source Materials and Basic Reactions.

Basic considerations to identify dioxins and related compounds formation through Municipal Refuse Incineration process are classified into two different fields. One is concerned with combustion process another with after-combustion process. For the after-combustion field, dioxins formation theory is well established with apparent hack data. This paper describes the first attempt to verify the dioxins formation pathways, which are predicted as the combination of HCl, Cl2, Aromatic Chloride Compounds, and Dioxins (by-products) formation in combustion zone, through basic chemical reactions and small scale combustion experiments.

都市ごみ焼却炉ボイラー過熱器管内面におけるアルカリ腐食の事例と対策

都市ごみ焼却炉ボイラー過熱器管内面におけるアルカリ腐食の事例と対策

239 高効率廃棄物発電スーパヒータ用開発材の実炉腐食試験

239 高効率廃棄物発電スーパヒータ用開発材の実炉腐食試験

213 都市ごみ焼却施設における灰シュート部の閉塞物生成機構

213 都市ごみ焼却施設における灰シュート部の閉塞物生成機構

ごみ焼却におけるＨＣｌ除去とダイオキシン排出量の抑制

ごみ焼却におけるＨＣｌ除去とダイオキシン排出量の抑制

Fuzzy Combustion Control for Reducing Both CO and NOx from Flue Gas of Refuse Incineration Furnace.

NKK developed a new combustion controller that reduces both NOx and CO concentrations in the exhaust gas of municipal refuse incineration furnaces. We found that the manipulation of the cooling air flow rate is important because it affects the furnace temperature and the O2, NOx and CO concentrations in the exhaust gas. The new controller manipulates the cooling air flow rate. The controller monitors the furnace temperature and the O2, NOx and CO concentrations as process variables and then operates the cooling air flow rate as a manipulated variable. This multi-input / single-output controller was designed using a fuzzy control algorithm and tested on site at a municipal refuse furnace. The result of the on-site test was quite successful.

Fuzzy Combustion Control for Reducing both CO and NOx from Flue Gas of Refuse Incineration Furnace.

NKK has developed a new combustion controller that reduces both NOx and CO concentrations in the exhaust gas discharged from municipal refuse incineration furnaces. We have found that the manipulation of the cooling air flow rate is important because it affects the furnace temperature and O2, NOx and CO concentrations in exhaust gas. This controller manipulates the flow rate of the cooling air. It monitors the furnace temperature and O2, NOx and CO concentrations as process variables, and outputs the cooling air flow rate control signal as a manipulated variable. This multi-input/single-output controller was designed using by a fuzzy control algorithm and tested on site at a municipal refuse furnace. The result of the on-site test was quite successful.

Full-scale plant study on fly ash treatment by the acid extraction process

Fly ash discharged from a municipal refuse incineration plant is regulated, by 1992 legislation, to be treated to prevent leaching of heavy metals before final disposal. We have developed a stable and simple fly ash treatment method “Acid Extraction-Sulfide Stabilization Process (AES Process)”, in which the fly ash is acid-extracted and stabilized by NaHS to change the residual heavy metal into insoluble heavy metal sulfide. The results of many fundamental experiments and pilot tests indicate that it is important to consider the characteristics of fly ash (fine, scattering, moisture-absorbing, etc.) in designing the AES Process. Since 1977, seven municipal incineration plants with AES Process have been constructed. At one of these plants, the fly ash and waste water is treated together by the AES Process and evaporation/crystallization process. The fly ash is discharged as stabilized cake for final landfill disposal; solid salt is recycled to soda production plants and condensed water is recycled in the plant as cooling water. This plant discharges no waste water. Operating results of the AES Process is that the stabilized cake conforms to the standard for landfill disposal in T-Hg, Cd and Pb, and the recovered solid salt contains approximately 99% NaCl. The operation cost per ton of the fly ash is ¥3,840 per ton.

The leachability of elements in solid wastes

Landfills and waste disposal sites are now routinely used for disposal of solid wastes and their incinerator ashes. Trace elements from these ashes are leached by rain and acid rain into nearby waterways providing a pathway for toxic elements to re-enter the food chain and the human life cycle. This paper examines the mechanism and the extent of leaching of 20 elements viz. Ag, Al, As, Ba, Br, Ca, Cd, Co, Cr, Fe, Hg, La, Sb, Sc, Ce, Sm, Ta, V, W and Zn. Instrumental neutron activation analysis (INAA) was used for the assay. The solid wastes studied are municipal refuse incinerator ash, coal fly ash, hospital incinerator ash, raw sewage sludge and its incinerator ash.

Prediction of environmental availability of cadmium from ash morphology

Morphologies of ash from six different sources were examined and characterized by secondary electron imaging using the JOEL Model JSM 6100 scanning electron microscope. Ash sources included an aluminum smelter, conventional lignite electrical generating plant, fluidized bed lignite electrical generating plant, municipal refuse incineration, sewage sludge incineration, and household wood stove. These characterized morphologies were ranked by their estimated volume to surface area ratio, and their rankings were tested nonparametrically against rankings derived from reported pozzolana‐induced reductions (prior to steady‐state and at steady‐state conditions) in the environmental availability of cadmium. The null hypothesis tested was that there was no predictability in the rankings by these three criteria. The Friedman test statistic value was 9.333 and the probability of a type I error was equal to 0.096. The null hypothesis was rejected, with the logical conclusion that the rankings vary predictably. This p...

Mutagens in urine sampled repetitively from municipal refuse incinerator workers and water treatment workers.

Municipal refuse incinerator workers may be exposed to mutagenic compounds from combustion gases and particulates during plant operation, maintenance, and ash removal procedures. The frequency of mutagens was measured by the Ames assay in 3 urine samples collected from each of 37 workers in 4 refuse incinerators and 35 (control) workers from 8 water treatment plants during June-August 1990. When comparing the first urine samples contributed by workers in each cohort, incinerator workers had a significantly (p < .05) increased risk of both direct-acting mutagens and promutagens (8/37 or 22% for each mutagen type) compared with water treatment workers (2/35 or 6% for each mutagen type). Smoking within 24 h before urine sampling was not a confounder of these results. Interestingly, there was no significant (p > .05) difference for risk of urinary mutagens or promutagens between the two cohorts when comparing, respectively, the second and third urine samples from each cohort. The repeatability of demonstrating urinary mutagens in individual incinerator workers was poor, suggesting that their exposure was highly variable and/or that these workers modified their exposure (e.g., wore masks) as a consequence of being studied. Factors that influence production of mutagenic compounds during refuse incineration and subsequent worker exposure are discussed.

Leachability of toxic elements from solid wastes

We have examined the leachability of the toxic elements cadmium, arsenic, mercury, and selenium from solid wastes. The solid wastes studied are municipal incinerator ash, coal fly ash, hospital incinerator ash, raw sewage sludge, sewage incinerator bottom ash, and sewage incinerator lagoon ash (which is a combination of bottom and fly ashes). Cadmium displayed the greatest leachability in all waste types, with 76% leached from the municipal refuse incinerator ash. Although the sources of elements in the wastes are diverse, the leachability and hence the bioavailability in the incinerator ash appears mainly determined by the volatility of the element.

Cadmium and lead concentration in foliage near a municipal refuse incinerator

Whereas landfilling still remains a necessary means of disposing of municipal solid waste, construction of refuse incineration facilities is increasing in the United States. There is currently much public opposition to building such incinerators because of health concerns about toxicants emitted as particulates and gases from the stacks. Cadmium and lead are typically present at significant levels in refuse incinerator fly ash. In this study these heavy metals were determined in tree foliage sampled at increasing distances in the vicinity of a municipal refuse incineration plant equipped with electrostatic precipitators to reduce emitted particulates. There was a high degree of correlation between diminishing foliar concentration of cadmium and lead and the logarithm of the distance north and south of the incinerator, the only directions in which foliar samples could be collected. Sources of these metals in refuse and factors which affect the magnitude of their deposition on foliage are discussed.