METHOD OF PREPARING BITUMEN Russian patent published in 1998 - IPC

FIELD: oil refining industry highway engineering and other industries. SUBSTANCE: bitumen is prepared by oxidizing petroleum residue with hydrocarbon additive comprising polyalkyl benzene resin with atmospheric air at elevated temperature. Hydrocarbon additive is mixture of polyalkylbenzene resin oil stillage residue resulting from regeneration of dimethyl formamide (0.6-0.7) to (0.4-0.3) weight, the ratio of components is as following, wt. %: petroleum residue, 97.5-94.5; polyalkylbenzene resin, 1.5-3.3; and stillage residue resulting from dimethyl formamide regeneration, 0.65-2.2. To petroleum residue heated to 200-230 is added initially half of the desired amount of hydrocarbon additive and oxidized till softening temperature of semiproduct of 37- 39 C is attained, second half of additive is then added and oxidation is continued till the desired product is obtained. In this case, amount of products deposited on apparatus walls and connecting pipes is significantly reduced and yield of the desired product is thus increased. EFFECT: more efficient preparation method. 6 ex, 3 tbl