Zero-impact emission limits of enterprise-scale air pollutants—a case study of a typical petrochemical enterprise in Shanghai Chemical Industry Park

Figures & data

Table 1. Air pollutant emission standards of the petrochemical industry worldwide. (unit: mg/m³)

Pollutants	Nitrogen oxide (NOx)	Sulfur dioxide (SO2)	Particulate matter (PM)	VOCs
				(benzene)
Industrial Emissions Directive in EU (2010/75/EU)	50 ~ 100	50	10	1
Emission standard of pollutants for petroleum chemistry industry in China (GB 31571–2015)	100	50	20	4
Technical instructions for air purification in Germany (TA Luft 2002)	200	60	20 ~ 50	1
Pollution Prevention and Abatement Hand Book by World Bank	300	100	20	1
Emission standard of pollutants in Shanghai Chemical Industry Park	100	50	10	4

Table 2. Basic information of each chimney of Enterprise A

No.	Chimney height(m)	Chimney diameter(m)	Pollutant
1	50	2.48	NOx\PM\VOCs
2	50	2.48	NOx\PM\VOCs
3	50	2.48	NOx\PM\VOCs
4	50	2.5	NOx\PM\VOCs
5	50	2.56	NOx\PM\VOCs
6	50	2.5	NOx\PM\VOCs
7	50	2.48	NOx\PM\VOCs
8	50	2.48	NOx\PM\VOCs
9	50	2.48	NOx\PM\VOCs
10	50	2.58	NOx\PM\VOCs
11	50	2.58	NOx\PM\VOCs
12	15	1.25	NOx\SO2\PM\VOCs
13	15	0.75	NOx\SO2\PM\VOCs
14	24	0.3	NOx\SO2
15	65	2.8	NOx\SO2\VOCs
16	65	2.37	NOx\SO2\VOCs
17	65	2.37	NOx\SO2\VOCs
18	50	2.8	NOx\VOCs
19	50	1.5	NOx\SO2\PM\VOCs
20	80	4.8	NOx\SO2\VOCs
21	80	1.5	NOx\SO2\PM\VOCs
22	68	3.3	NOx\SO2

Figure 1. Distribution of chimneys, and meteorological and monitoring stations

Figure 2. Wind roses in January, April, July, and October in Shanghai Chemical Industry Park (SCIP) in 2019

Table 3. Zero-impact concentration limits of each pollutant and 10% concentration of conventional pollutants as short-term average time

No.	Pollutants	Average time	concentration
			($\mu \mathbf{g}/m^3$)
1	SO2	Annual	2*
		24-hour	5**
		1-hour	15**
2	NOx	Annual	5*
		24-hour	10**
		1-hour	25**
3	PM10 (Particle diameter ≤ 10 µm)	Annual	4*
		24-hour	5**
4	PM2.5 (Particle diameter ≤ 2.5 µm)	Annual	1.5*
		24-hour	3.5**
5	VOCs (benzene)	1-hour	9*

*is the zero-impact concentration limit, and * * is the 10% concentration of the Level I standard of each pollutant on the 24-hour and 1-hour average time scales.

Table 4. Performance statistics for meteorological predictions

Variable		Obs.	Sim.	MB	RMSE
WS10 (m/s)	Jan	3.16	5.39	2.1	2.61
	Apr	2.59	3.78	1.03	2.29
	Jul	2.68	4.05	2.79	2.8
	Oct	2.56	4.01	2.46	2.91
WD10 (degree)	Jan	166.73	180.1	5.83	36
	Apr	154.78	168.17	−10.46	39.03
	Jul	162.4	168.01	15.61	37.63
	Oct	192.52	163.23	−27.81	37.46

Figure 3. Time series of the measured and California Meteorological Model (CALMET) simulation results for the wind speed (m/s) and direction (°) at M1 station

Figure 4. Time series of (a) wind direction (the blue shadow represents the downwind direction of emission sources for M2 station (wind direction is about 100°~140°)), the measured and simulation results of the NOx concentrations (?g/m^3) and (b) the correlation between the simulation and measured concentrations at M2 station

Figure 5. Spatial distribution of annual average concentration of pollutants. The concentration is the average of the annual simulation results; the red contour line is the scope of the chemical industry park, and the black contour line covers the area that exceeds the zero-impact limits

Figure 6. Spatial distribution of the 1-hour average concentration of volatile organic compounds (VOCs). The concentration is the maximum 1-hour ground level concentrations of VOCs (benzene) on each grid in the annual simulation results

Figure 7. Spatial distribution of 1-hour average concentration of VOCs (benzene) during four seasons (shown in the order of winter, spring, summer, autumn; the concentration refers to the maximum 1-hour ground level concentrations of pollutants on each grid in the annual simulation results)

Figure 8. Spatial distribution of 24-hour average concentration of pollutants. The concentration refers to the maximum 24-hour average concentration of pollutants on each grid in the annual simulation results, and the black contour line covers the area that exceeds the 10% concentration

Figure 9. Spatial distribution of 24-hour average concentration of SO2 during four seasons

Figure 10. Spatial distribution of 1-hour average concentration of pollutants

Table 5. Zero-impact emission limits. (unit: mg/m³)

No.	Pollutant	Average time	Zero-impact emission limits (m$\mathbf{g}/m^3$)	The gap with current emission standards (m$\mathbf{g}/m^3$)	Tighten situation
1	SO2	Annual	50	0	balanced
2	NOx	Annual	78	−22	22% stricter
3	PM	Annual	10	0	balanced
4	VOCs (benzene)	1-hour	0.32	−3.68	92% stricter

The gap with current emission standards = zero-impact emission limits – current emission standards.

Figure 11. Comparison of the short-term pollutant concentration with the corresponding 10% of the Level I standard in Enterprise A. The blue and green lines refer to 10% of the Level I standard of 24-hour and 1-h average concentration, respectively