The review deals with greases in which organic ureas of various compositions and structures are used as thickeners. The nature of compounds participating in the synthesis of organic ureas and the...

This review provides an analysis of recent scientific and engineering literature on chemical methods for CO₂ processing using heterogeneous catalysts. The following major uses of carbon dioxide are discussed: exhaustive hydrogenation; synthesis of hydrocarbons including light olefins; synthesis of oxygenates; and production of cyclic carbonates. Furthermore, the paper highlights the main design approaches for CO₂ conversion catalysts and formulates priorities for decarbonization using heterogeneous catalytic reactions.

The features of the Fischer-Tropsch synthesis in the presence of 100Fe: 8Al₂O₃: 3K₂O (parts by weight) catalyst nanoparticles under the slurry reactor conditions have been studied. The catalyst is prepared in situ and activated in the reactor. It has been found that during the preparation process, the catalyst reacts with the dispersion medium to form a structured system that is not liable to sedimentation. It is shown that the use of CO as a reducing agent makes it possible to increase the yield of liquid hydrocarbons by a factor of 1.5. An increase in the syngas pressure has almost no effect on the yield of liquid hydrocarbons; however, it gives the possibility of enhancing the catalyst efficiency up to 700 g/(kg Fe · h) at 40 atm. In conditions of a three-phase system, gasoline-fraction hydrocarbons, half of which consist of olefins, are mostly formed on the nanosized catalyst.

Lubricating greases based on pentaerythritol and trimethylolpropane esters and dioctyl sebacate have been synthesized using diureas as a thickener prepared by reactions of toluene...