Lignite is a source of valuable products: wax, tar, and humic material. In turn, valuable constituents of wax include saturated hydrocarbons, aliphatic saturated acids and alcohols, complex esters of carboxylic acids, azulene, and sterols. Some of its components are biologically active. In the present work, fractions rich in biologically active components are derived. By saponification, wax from Tyulgan lignite is divided into saponifiable and nonsaponifiable components. By the synthesis of inclusion compounds with urea, each component is divided into three fractions. The first is obtained at room temperature, while the second is obtained on cooling to +4°C. The third consists of molecules that do not form adducts with urea. In addition, both components of the wax are treated with different initial concentrations of the reaction mass. It is found that reaction of the wax components with urea solution concentrates the biologically active minor constituents. These constituents may be concentrated by a factor of 1.20–17.77; in particular, the factor is 11.07 for hexacosanoic acid and 17.77 for tetracosanoic acid. It is also found that saturated fatty acids with a urea/sample ratio greater than 4 : 1 tend not to form inclusion compounds. This trend grows weaker with elongation of the aliphatic fragment of the guest molecule.
Moiseev et al. (Sun,) studied this question.