scholarly journals Treatment of Flue Gas from an Infectious Waste Incinerator using the Ozone System

2021 ◽  
Vol 19 (5) ◽  
pp. 348-357
Author(s):  
Wenich Vattanapuripakorn ◽  
◽  
Khomson Khannam ◽  
Sathapon Sonsupap ◽  
Umakorn Tongsantia ◽  
...  

Recently, levels of air pollution caused by exhaust gases from infectious waste combustion have been rising at a startling rate. Pollutant gases such as carbon monoxide (CO) and nitrogen dioxide (NO2) have numerous health implications when unsafe amounts are released into the atmosphere. Thus, Pollution Control Systems (PCS) and Gas Cleaner Systems (GCS) play an important role in industries and the monitoring of incinerators. This research evaluated the GCS of rotary kilns in medical facilities located in the Northeast of Thailand. Data was collected from various sites, analyzed, and examined. Furthermore, Ozone (O3) technology was applied to the rotary kiln allowing for the collection of new information on the pollution treatment systems. O3 technology was installed along with the Wet Scrubber System (WSS) catalyzing the oxidation of O3 and pollutant gases. In addition, a chiller was added to control and stabilize the temperature of the water. After the water temperature was controlled, the concentration of O3 increased resulting in an efficient pollution treatment system. Levels of pollutant gas emission were found to be beneath control standards of both Thailand and those of the U.S. EPA. TSP content was reduced significantly from 22.0 mg/m³ to 3.4 mg/m³ (97%), CO content from 13.6 mg/m³ to 1.7 mg/m³ (96%), and NO₂ content fell from 16.3 (mg/m³) to 2.0 mg/m³ (99%). It is clear that the rotary kiln and Ozone technology should be used together in order to create a new and far more effective method of pollution treatment in small and mid-sized cities of Thailand.

Author(s):  
Wlodzimierz Blasiak ◽  
Weihong Yang

This work presents the main features, advantages and evaluation of applications of the novel “Ecotube” combustion improvement and emission reduction system by Ecomb AB of Sweden and Synterprise, LLC of Chattanooga, Tennessee. In the Ecotube system, the nozzles used for mixing are put on the suitable position inside the combustion chamber to control uniformity of temperature, mixing and reactants distribution in boilers and incinerators since the formation and reduction of pollutants (NO, CO and VOC) and in-furnace reduction processes (Air/Fuel staging, SNCR, flue gas recirculation and SOx reduction by dry sorbent injection) are related directly to mixing in a combustion chamber. The novel Ecotube combustion improvement system allows better control of mixing of the gases for example from a primary combustion zone with secondary combustion air or a recirculated flue gas. By means of the novel system it is possible to better control the residence time and to some degree gas phase temperature distribution as well as the heat release distribution in the furnace of the waste incinerators or boilers. This new combustion improvement system can be applied to supply different gas or liquid media — for example air, fuel, urea or even solid powder. Using the system a more efficient and environmentally clean combustion or incineration process can be performed. The Ecotube System may be used to meet increasingly stringent environmental emissions regulations, such as NOx SIP Call, while it delivers added benefits of reduced and stabilized CO and reduced fly ash and improved boiler efficiency. The study tool used in this work to present influence of the Ecotube system design on temperature as well as uniformity of reactants and flow field is numerical modeling. Using this tool, the influence of the position of the Ecotube system and the injection angle of the nozzles are studied. The studied boilers included the biomass waste incinerator, municipal solid waste incinerator and coal fired boiler. The concept of the Heat Release Distribution Ratio is proposed to classify the heat release inside the upper furnace of the boilers or incinerators. The results show that Ecotube spreads reaction zone over a larger furnace volume. The furnace flame occupation coefficient can be as high as 45% with the Ecotube system and it is around 40% higher comparing with the conventional multinozzle mixing system. Ecotube system allows keeping far more uniform heat release distribution, more uniform temperature distribution, and thus longer life of the heat transfer surfaces inside the furnace. Position of the Ecotube system and the injection angle of the nozzles are of primary importance and can be used as a technical parameter to control the boiler operation at different loads and varying operating conditions.


2011 ◽  
Vol 26 (S1) ◽  
pp. s94-s94
Author(s):  
G.V. Kipor ◽  
S.F. Goncharov ◽  
L.V. Borisenko ◽  
B.V. Bobi ◽  
N.K. Pichugina

The requirements of coping with emergencies on the national level include the necessity to modify the structure of disaster medicine centers that deal with major emergencies. Sharing the responsibility for the management of emergency response and preparedness also is important. The evolution of disaster medicine service is key for disaster risk activities. The goal of this presentation is to show the center subunits and their tasks based on strict management under the leading the Ministry of Health and Social Development of Russian Federation. The main units of the disaster medicine center are proposed in view of the relationship to the regional and municipal centers and local medical facilities. The participation of corresponding-level centers in emergency response is dictated by the emergency scale, characteristics of the event, number of injured, number and capacities of local (regional) medical facilities, and other needs in emergency response management. The system of supply management during emergencies comprises a network of warehousing conserving the federal, regional, and local reserves of medical products is revised regularly. The new, information-sharing, automatic, geo-informational system manages the distribution of supplies for any event and evaluates the presence of resources and personnel around any focal point where any natural or technological emergency occurs. Such an informational system is being discussed for the revision of supplies and management on the international scale. The issues of field practice are proposed and suggestions on the modern coordinating mechanisms will be discussed.


Author(s):  
Atinder Pal Singh ◽  
P.S. Ghoshdastidar

Abstract The paper presents computer simulation of heat transfer in alumina and cement rotary kilns. The model incorporates radiation exchange among solids, wall and gas, convective heat transfer from the gas to the wall and the solids, contact heat transfer between the covered wall and the solids, and heat loss to the surroundings as well as chemical reactions. The mass and energy balances of gas and solids have been performed in each axial segment of the kilns. The energy equation for the wall is solved numerically by the finite-difference method. The dust entrainment in the gas is also accounted for. The solution marches from the solids inlet to the solids outlet. The kiln length predicted by the present model of the alumina kiln is 77.5 m as compared to 80 m of the actual kiln of Manitius et al. (1974, Manitius, A., Kurcyusz, E., and Kawecki, W., “Mathematical Model of an Aluminium Oxide Rotary Kiln,” Ind. Eng. Chem. Process Des. Dev., 13 (2), pp. 132-142). In the second part, heat transfer in a dry process cement rotary kiln is modelled. The melting of the solids and coating formation on the inner wall of the kiln are also taken into account. A detailed parametric study lent a good physical insight into axial solids and gas temperature distributions, and axial variation of chemical composition of the products in both the kilns. The effect of kiln rotational speed on the cement kiln wall temperature distribution is also reported.


Author(s):  
Bo Herrlander

High-energy recovery combined with low emissions to air and water was targeted when Jo¨nko¨ping Energi planned their new Waste to Energy plant at Torsvik in Sweden. The plant is compliant with the new EU Industry Directive and the Waste Frame Directive R-formula, which defines energy recovery levels for recycle of energy. In total about 160 000 tons of municipal (40%) and commercial waste (60%) is annually converted into usable energy. The average heat value is 11,7 MJ/kg. The energy produced is a combination of electricity (14 MWe) and heat (42–56 MWth, depending on electricity production). The heat is recovered both in a boiler and in a condenser. The flue gas condensing system is combined with a heat pump (10 MWth) to optimize the heat recovery rate. The plant is designed to fulfill the requirements set by the Swedish authorities, which are more stringent than the EU emission requirements. Some examples of the plant emissions to air guarantees: dust 5, HCl 5, SO2 20, HF1, Hg 0,03, Cd+Tl 0,05, other HM 0,5 all in mg/Nm3 and dioxin 0,05 ng/Nm3. The flue gas cleaning upstream of the condenser consists of a combination of a semi-dry system and a wet scrubber. The gas cleaning system operating range goes from 60 000 up to 127 000 Nm3/h depending on load and fuel heat value. The semi-dry system is carrying out the major part of the gas cleaning and is sufficient to comply with the air regulations. However, in order to minimize the treatment of the condensate from the condenser the wet scrubber is installed after the semi-dry system and upstream the condenser. The blow down from the scrubber is reused within the plant. Thus the polishing scrubber secures minimal treatment of the condensate to comply with the local stringent limits, particular chlorides, before release to the recipient lake Munksjo¨n. Emissions to water were 2010 nitrogen 1,7 mg/l, Cl <3,6 mg/l, As 0,66 μg/l, Cd <0,07 μg/l, Cr <6 μg/l, Cu 0,8 μg/l, Hg <0,4 μg/l, Ni <0,66 μg/l, Pb<1,2 μg/l, Tl<1,3 μg/l, Zn<7,2 μg/l and PCDD/PCDF 0,0088 ng/l. In the wet scrubber acid stage residual HCl and excess ammonia from the SNCR system are removed. The latter compound is important to capture in order to prevent eutrophication. The combination of a semidry and a wet system enables an optimization of the flue gas cleaning with regard to the different operating situations, taking into account seasonal demand variations as well as fuel alterations. The concept has demonstrated very low emissions combined with low consumption of lime. The possibility to optimize the flue gas cleaning performance is a prerequisite for minimal condensate treatment and optimal energy recovery. The paper will describe the system and the operating experiences.


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