Table 4. Typical Tar Composition from Gasificationa.
| tar compound | typical composition by weight (%) | tar class |
|---|---|---|
| benzene | 37.9 | 3 |
| toluene | 14.3 | 3 |
| other one-ring aromatic HC | 13.9 | 3 |
| naphthalene | 9.6 | 4 |
| other two-ring aromatic HC | 7.8 | 4 |
| three-ring aromatic HC | 3.6 | 4 |
| four-ring aromatic HC | 0.8 | 5 |
| phenolic | 4.6 | 2 |
| heterocyclic | 6.5 | 2 |
| others | 1 |
a
Note: benzene is not usually classified as a tar compound, and only compounds having a molecular weight greater than that of benzene are considered as tar. Statistical information was not found, and only typical values were available in the literature.