The effects of the gas medium and heterogeneous factors on the gas-phase oxidative cracking of dilute ethane mixtures at atmospheric pressure, temperatures of up to 750°C, and an initial reactant...

It was found that, in the gas-phase oxidative cracking of C2-C5light alkanes, the ratio between ethylene and CO in the products depends on both the residence time in a reactor and the process...

The gas-phase oxidative cracking of ethane in very dilute gas mixtures ([C₂H₆]₀ ≤ 10%) has been investigated at atmospheric pressure, temperatures of up to 750°C, reaction times of up to 4 s, and initial reactant ratios of [O₂]₀: [C₂H₆]₀ = 0.2–1.

A combination of analytical methods (including CHNS-O elemental analysis, X-ray diffraction, ¹H and ¹³C NMR spectroscopy, MALDI-TOF and ICP mass spectrometry) was used to determine the elemental composition and average molecular and structural parameters of asphaltenes isolated from a heavy oil sample from the Ashalchinskoye field and vacuum residue samples from two different Russian oil refineries. The study identified differences in the nano-aggregate size of asphaltenes in heavy oil and vacuum residues, and evaluated the effects of the composition and molecular structure of asphaltenes on the composition and properties of the heavy petroleum feedstock samples.

The characterization of the feedstock is an important analytical task in the modeling and development of processes for upgrading of petroleum residues. This work presents the results of fractionation of the vacuum petroleum residue by extraction using a mixture of CO₂ and toluene as a solvent. Fractionation was carried out by changing the ratio of components in the mixture by successively increasing the concentration of toluene in the composition of the CO₂ stream from 0% to 50%. As a result of separation of the vacuum residue, nine fractions of the extract with a yield of 83.1% were obtained. Graphical abstract