Mass spectrometric investigation of the hydrocarbon composition of pyrolysis products

Conclusions

• 1. The hydrocarbon composition of the raw material and products of pyrolysis boiling within a wide temperature range-light oil (low boiling to 195°C), green oil (195–350°C), and hydraulic resin (270–500°C)-was investigated by the methods of molecular mass spectroscopy.

• 2. It was shown that the initial kerosene-gas oil fraction is represented chiefly by saturated hydrocarbons (44% paraffin and 38.9% naphthene), containing from one to four rings in the molecule. Aromatic hydrocarbons are represented chiefly by alkylbenzenes (7.8%), indans, and tetralins (3.6%), and dinaphthenebenzenes (1.6%).

• 3. It was established that the light oil of pyrolysis consists of 98% of aromatic hydrocarbons: alkyl- and alkenylbenzenes and alkylnaphthalenes. Alkylbenzenes (75.9% of the light oil) are represented chiefly by benzene and toluene; the content of alkenylbenzenes comprises 14.8 mole %.

• 4. The structure-group composition of the green oil of pyrolysis was determined. The content of aromatic hydrocarbons of various degrees of hydrogen unsaturation, from C_nH_2n−6 to C_nH_2n−22 (90.6% on the basis of green oil), represented chiefly by naphthalene and its methyl derivatives, was determined. The content of unsaturated aliphatic hydrocarbons is low and comprises 2.7% monoolefins, 1.8% diolefins and cycloolefins, and 8.2% aromatic hydrocarbons with multiple bonds in the cycloalkyl substituent-indenes.

• 5. The hydrocarbon composition of hydraulic resin was established. It was shown that it contains chiefly condensed hydrocarbons with two, three, and four aromatic rings: naphthalenes 35.3%, acenaphthenes 13%, phenanthrenes and anthracenes 20.2%, benzoacenaphthenes 6.1%, and pyrenes 6.6%. The resin contains 8.7% hydrocarbons with one benzene ring; alkylbenzenes, indans, and indenes.