Location and Characterization of VOC Emissions at a Petrochemical Plant in Taiwan

Figures & data

Figure 1 Sampling sites in this study.

Table 1 Sampling sites in this study

No.	Sampling site	Type*
1	Waste stack section	C
2	Tank farm A	B
3	Waste storage section	C
4	Electric power unit	E
5	Blending unit	A
6	Aromatic unit	A
7	Garden	D
8	Additive unit	A
9	Paraffin unit	A
10	Cooling tower	E
11	V308 Air storage tank	E
12	Hydrogenation unit	A
13	Grease unit	A
14	Filling unit	A
15	Tank farm E	B
16	Tank farm F	B
17	Northeast corner of plant	D
18	Fire department	E
19	Empty drum storage section	C
20	2nd CPI	E

Figure 2 Comparison of different types of VOCs inside the plant (a) in concentration and (b) in percentage.

Table 2 Average concentration of alkanes and aromatics at each site

	Average conc. (ppb)
Sampling site	Alkanes aromatics
Filling unit	6,357	344
Aromatic solvent unit	882	144
Blending unit	197	25
Grease unit	179	10
Cooling tower	157	8
Additive unit	101	27
Paraffin unit	100	23
V308 air storage tank	100	17
Tank farm E	75	9
Tank farm F	64	11
Tank farm A	63	13
Electric power unit	62	11
Waste storage section	56	11
Hydrogenation unit	40	14
Garden	27	8
Waste stack section	23	8
Northeast corner of plant	18	10
Fire department	16	8
2nd CPI	13	10
Empty drum storage section	11	11
CPI–Corrugated plate interceptor.

Figure 3 Contour maps for alkanes inside the plant over one year.

Figure 4 Contour maps for aromatics inside the plant over one year.

Table 3 Characterization of VOCs emitted from the primary pollution source (filling unit) and secondary pollution source (aromatic unit)

		Filling unit (ppb)				Aromatic unit (ppb)
Cn	Species	Min.	Max.	Avg.	SD	Min.	Max.	Avg.	SD
	Alkanes	—	23,714	6,655	—	—	5,028	1,129
C3	Propane	< 1	35	23	11	—	—	—	—
C4	Butane	< 1	156	40	56	—	—	—	—
C5	2–Methylbutane	34	755	239	244	< 1	451	85	163
	Cyclopentane	< 1	151	53	56	—	—	—	—
	Pentane	27	602	210	192	< 1	54	22	23
C6	2,2–Dimethylbutane	22	311	144	101	< 1	53	26	24
	2,3–Dimethylbutane	32	652	280	211	< 1	73	27	31
	2–Methylpentane	118	4,976	1019	1,619	1	215	56	82
	3–Methylpentane	115	3,291	683	1,072	1	218	47	76
	Cyclohexane	7	283	76	87	< 1	22	12	11
	Hexane	76	4,710	884	1,571	1	209	40	71
	Methylcyclopentane	< 1	3,215	706	1,144	< 1	144	30	56
C7	1,2–Dimethylcyclopentane	5	57	30	16	< 1	41	17	18
	2,2,3–Trimethylbutane	< 1	518	198	278	—	—	—	—
	2,2–Dimethylpentane	< 1	349	165	167	< 1	98	50	68
	2,3–Dimethylpentane	< 1	178	119	64	—	—	—	—
	2,4–Dimethylpentane	20	592	236	197	< 1	124	33	61
	2–Methylhexane	52	687	378	220	1	213	39	73
	3,3–Dimethylpentane	< 1	221	116	77	< 1	68	16	29
	3–Methylhexane	57	989	538	327	< 1	382	76	140
	Heptane	< 1	726	398	246	< 1	463	109	198
	Methylcyclohexane	< 1	70	38	26	< 1	240	46	95
C8	1,2,3–Trimethylcyclopentane	—	—	—	—	< 1	51	19	28
	1,2,4–Trimethylcyclopentane	—	—	—	—	< 1	55	21	29
	1,3–Dimethylcyclohexane	< 1	11	8	5	< 1	196	51	96
	1,4–Dimethylcyclohexane	< 1	16	4	6	< 1	60	16	29
	2–Methylheptane	< 1	46	22	18	< 1	332	53	123
	3-Ethyl-2-methylpentane	—	—	—	—	< 1	36	13	20
	3–Methylheptane	1	46	18	17	< 1	259	49	103
	4–Methylheptane	< 1	17	9	6	< 1	96	22	41
	Ethylcyclohexane	—	—	—	—	< 1	85	24	41
	Octane	< 1	54	21	19	< 1	752	117	280
C9	Nonane	—	—	—	—	< 1	38	13	17
	Aromatics *	—	998	330	—	—	767	196	—
C6	Benzene	3	39	12	13	1	8	4	3
C7	Toluene	6	150	91	59	5	414	66	142
C8	Ethylbenzene	1	11	4	4	< 1	55	14	23
	m,p–Xylene	< 1	33	15	12	< 1	122	25	48
	o–Xylene	< 1	14	6	6	< 1	48	14	19
	Styrene	< 1	18	10	11	—	—	—	—
C9	Ethyl–methyl–benzene isomers	5	231	66	78	< 1	53	17	20
	Trimethyl–benzene isomers	< 1	442	106	165	< 1	67	18	25
C10	Ethyl–dimethyl–benzene isomers	2	60	20	24	—	—	—	—
	Miscellaneous	—	327	169	—	—	67	18	—
C5	Pentene	< 1	88	45	61	—	—	—	—
C6	3–Hexene	< 1	20	12	8	—	—	—	—
C7	3–Methyl–2–hexene	< 1	30	20	14	—	—	—	—
C3	Acetone	< 1	146	67	59	14	26	20	8
C4	Ethyl acetate	< 1	20	12	12	—	—	—	—
C1	Methylene chloride	< 1	23	13	9	—	—	—	—
Cn-carbon number; SD-standard deviation.

Table 4 Comparison of airborne VOCs from emission sources with those from vehicle exhaust

Type	Vehicle exhaust (%)			VOCs emission source (%)
	Car	Motorcycle 2-stroke	Motorcycle 4-stroke	Filling unit	Aromatic unit
Alkanes	44	63	41	94	85
Aromatics	40	29	50	5	15
Alkenes	10	5	7	1	0