Table 4. Compounds Identified by GC-MS/MS in the Product Oil from the Supercritical Water Liquefaction of Polypropylene at Conditions of 450 °C and Final Pressure of 33 MPa with a Residence Time of 60 min and Plastic:Water Ratio of 1:4^a.

retention time (min)	peak area (%)	compound	concentration (mg g–1 of PP)
2.085	0.99	cyclohexane	11.80
2.197	1.718	2-pentene, 4-methyl-	20.47
2.59	0.878	2-pentene, 2,4-dimethyl-	10.46
3.039	1.392	1,3-dimethylcyclopentane	16.59
3.258	1.538	3-methylhexene	18.33
3.694	1.059	1,1,3-trimethylcyclopentane	12.62
4.057	0.993	3-methyleneheptane	11.83
4.725	4.678	toluene	55.75
5.17	0.775	1,3-dimethylcyclohexane	9.24
5.882	1.31	2,4-dimethylhexane	15.61
6.134	1.246	cyclopentane, 1,1-ethylidene/cyclohexane, 1-ethyl-2-methyl	14.85
6.302	2.477	cyclopentane, 1,1,3,4-tetramethyl	29.52
6.754	1.076	3-ethylhexane	12.82
7.238	9.848	cyclohexane, 1,1,3-trimethyl	117.36
7.506	0.926	cyclohexane, 1-ethyl-1,3-dimethyl	11.03
7.623	2.13	6-methyl-1-octene	25.38
8.396	7.261	cyclohexane, 1,1,4-trimethyl	86.53
8.536	0.806	ethylbenzene	9.60
8.806	0.747	nonene	8.90
9.012	7.444	p-xylene	88.71
9.873	1.291	cyclohexane, 1,1,3,5-tetramethyl	15.38
10.063	0.72	1,2,3-cyclohexane	8.58
10.213	1.022	o-xylene	12.18
10.836	1.12	cyclopentane, 1-methyl-3(2-methyl-1-propenyl)	13.35
14.556	1.157	1-ethyl-3-methylbenzene	13.79
15.13	5.052	benzene, 1,2,3-trimethyl	60.20
16.759	2.738	benzene, 1,2,4-trimethyl	32.63
18.342	0.707	3,5-dimethyloctane	8.43
21.216	0.87	benzene, 4-ethyl-1,2-dimethyl	10.37
21.444	0.71	2,2-dimethyloctene	8.46
21.612	0.78	2-butyl-3-methyl-1-pentene	9.30
total	65.459		780.05

^aListed are the highest concentration compounds identified in the oil.