Which industries sulfur dioxide flue gas standard and working conditions without conversion

In the environmental protection acceptance (three simultaneous) monitoring, some industry air pollutants such as soot, sulfur dioxide, nitrogen oxides concentration value can not be reported in accordance with the measured value, but should be for different industries, according to different industries acceptance of the implementation of the standard in the provisions of the oxygen content or air excess coefficient of the conversion is derived. Today, Bodhi for you to introduce thermal power plants, industrial kilns, boilers, cement plants, household waste incineration, hazardous waste incineration of these industries in the acceptance of the monitoring process for the calculation of smoke and other pollutants in the emission concentration, and the actual monitoring data as an example, to provide reference for environmental protection.

1?Calculation of emission concentration in thermal power plants

After the release of the new standard for thermal power plants, according to the new standard of "Emission Standards for Air Pollutants from Thermal Power Plants" (GB13?223-2011), since January 1, 2012, the new thermal power boilers and gas turbine units to implement the new standard in the new provisions. Since July 1, 2014 before the existing thermal power generation boilers and gas turbine units to implement the provisions of the old standard, since July 1, 2014, the existing thermal power generation boilers and gas turbine units to implement the provisions of the new standard.

1.1?According to the "Emission Standards for Air Pollutants from Thermal Power Plants" (GB13223-2003), the measured concentration of air pollutants emitted from thermal power plants is converted into the emission concentration according to the following formula (1).

c=c'×? (α'/α)? (1)

Formula: c - discounted emission concentration of soot, sulfur dioxide and nitrogen oxides, mg/m3;

c'-measured soot, sulfur dioxide and nitrogen oxides emission concentration, mg/m3;

α'-measured excess air coefficient;

α-the prescribed excess air coefficient.

Coal-fired boilers are discounted by the excess air coefficient α=1.4; oil-fired boilers are discounted by the excess air coefficient α=1.2; and gas turbine units are discounted by the excess air coefficient α=3.5.

For example, coal-fired power plants usually exhaust gas treatment process is "electrostatic precipitator + limestone - gypsum wet flue gas desulphurization process + OFA low nitrogen combustion". A coal-fired power plant in 2007 acceptance monitoring, dust removal and desulfurization facilities outlet measured soot concentration of 7mg / L, oxygen content monitoring data for the O2 '= 6.4%, measured excess air coefficient α '= 21 / (21-O2') = 21 / (21-6.4) = 1.44, soot emission concentration of 1.44, the measured excess air coefficient α '= 21/(21-O2') = 21/(21-6.4) = 1.44, soot emission concentration of 1.4%. 1.44, soot emission concentration c=c'×(α'/α)=7×(1.44/1.4)=7mg/L.

1.2?Emission Standards for Air Pollutants in Thermal Power Plants (GB13223-2011), measured soot, sulfur dioxide, nitrogen oxides, and gong and their compounds emission concentrations are converted to benchmark oxygen content emission concentrations according to the following formula (2). The baseline oxygen content of various types of thermal energy conversion facilities in accordance with the provisions of Table 1.

Table 1?Benchmark Oxygen Content

c=c'×[(21-O2)/(21-O2')]

In the formula: c--Benchmark Oxygen Content Emission Concentration of Air Pollutants, mg/m3;

c'-measured air pollutant emission concentration, mg/m3;

O2'-measured oxygen content, percent;

O2 -baseline oxygen content, %.

2?Calculation of emission concentration of industrial furnaces and kilns

Industrial furnaces and kilns refer to the thermal equipment for smelting, roasting, sintering, melting and heating of materials or workpieces with the heat generated by combustion of fuel or conversion of electric energy in industrial production. The emission of waste gas from industrial furnaces and kilns is in accordance with the "Emission Standards for Air Pollutants from Industrial Furnaces and Kilns" (GB9078-1996). According to the "Industrial Furnace Air Pollutant Emission Standards" (GB9078-1996), the measured concentration of smoke (dust) and harmful pollutant emissions from industrial furnaces should be converted to the value of the specified excess air coefficients: the excess air coefficients of industrial furnaces are specified to be α=1.7. For example, a steel wire company produces composite metal wire project, and in the acceptance monitoring in 2008, the heat-treatment process uses coal-fired heating furnace. Process using coal-fired heating furnace, heating furnace air pollutant emissions in the exhaust gas measured soot concentration of c'=19.0mg/m3, measured oxygen content of O2'=17.8%, then the measured excess air coefficient α'? =21/(21-O2')=21/(21-17.8)=6.56, the soot emission concentration is c=c'×(α'/α)=19.0?×(6.56/1.7)=73.3mg/m3.

3?Boiler emission concentration of the Calculation

Boiler refers to coal-fired, oil-fired and gas-fired boilers of various capacities and uses except pulverized coal power generation boilers and power generation boilers with a single output greater than 45.5MW (65t/h). According to the "Boiler Air Pollutant Emission Standards" (GB13271-2001), the measured boiler soot, sulfur dioxide, nitrogen oxides emission concentration should be discounted according to the air excess coefficient α specified in Table 2. For example, a chemical enterprise builds a 4t/h coal-fired boiler, which is treated by an industrial dust collector and discharged by a 30-meter-high exhaust pipe. The measured soot concentration at the outlet of the dust collector is c'=27.8mg/m3, and the measured oxygen content is O2'=15.2%, then the measured excess air coefficient α'=21/(21-O2')=21?/(21-15.2) = 3.62, soot emission concentration is c=c'×(α'/α)=27.8×(3.62/1.8)=55.9?mg/m3.

4?Calculation of emission concentration in cement plant

According to the "Cement Industry Emission Standards for Air Pollutants" (GB?4915-), the emission concentration at the end of the kiln can be calculated as follows 2004), the end of the kiln particulate matter, sulfur dioxide, nitrogen oxides, fluoride refers to the flue gas O2 content of 10% state of the emission concentration and emissions per unit of product. The main sources of air pollution in the cement plant are kiln head and kiln tail exhaust from the firing system and dust emitted from the coal mill, warehouse and transfer station conveying system. Kiln head and kiln tail exhaust are generally treated with electrostatic precipitators, and the rest are generally treated with bag filters. For example, a cement plant in the 2011 environmental protection completion acceptance monitoring, kiln tail ESP outlet of the measured dust emission concentration c′ = 25.9mg/m3, the measured oxygen content of O2′ = 7.2%, c = c′ × [(21-O2)/(21?-O2′)] = 25.9 × [(21-10)/(21-7.2)] = 20.6mg/m3.

5?Calculation of emission concentration of domestic waste incineration power generation

According to the provisions of the "Pollution Control Standards for Incineration of Domestic Waste" (GB18485-2001), the emission limits of air pollutants in incinerators are converted to the reference value of dry flue gas containing 11% O2 in the standard state. Furnace flue gas produced by a set of "semi-dry spinning lime slurry deacidification + activated carbon adsorption + bag dust removal" equipment management, respectively, by an 80-meter-high chimney emissions For example, a domestic waste incineration power generation enterprises in 2010 environmental protection acceptance of the monitoring of the completion of the measured flue gas emission concentration after the exhaust gas treatment facilities c′ = 24.4mg / L, the measured flue gas emission concentration of 24.4mg/L, measured oxygen content of O2′=4.1%, c?=c′×[(21-O2)/(21-O2′)]=24.4×[(21-11)/(21-4.1)]=14.4mg/m3.

6?Calculation of hazardous waste incineration emission concentration

According to the "Pollution Control Standards for Incineration of Hazardous Waste" ( GB18484-2001), 11% O2 (dry gas) is used as the conversion basis in the test calculation process. Conversion formula for c = 10?/(21-OS) × cS

Where: c - the standard state of the pollutant being measured by the conversion of the concentration (mg/m3);

OS - the concentration of oxygen in the exhaust gas (%);

cS - the concentration of the measured pollutant in the standard state (mg/m3).

The exhaust gas of the incinerator is discharged by one 35-meter-high exhaust pipe after being treated by the process of acute cooling and humidification, slaked lime spraying in, activated carbon spraying device and cloth bag dust removal. For example, a hazardous waste incineration enterprises in 2011 environmental protection completion acceptance monitoring by the "acute cooling humidification + slaked lime injection + activated carbon injection device + dust bag" after the measured concentration of soot emissions cS = 26.0mg / L, the measured oxygen content of OS = 9.7%, c = cS × [10 / (21 - OS) ]=26.0×[10/(21-9.7)]=23.0mg/m3.

7?Summary

In the acceptance monitoring, the project leader should firstly be familiar with the specific production process of each industry, know the project's exhaust gas management measures and the layout of monitoring points. Secondly, against the environmental impact assessment report and relevant standards need to clarify the baseline oxygen content or excess air coefficient values. Closer to home, according to the conversion formula, the measured value is accurately converted into emission concentration.