Modification of gas condensate gasoline by single atomic alcohols with the use of cavitation

The process of modification of gas condensate gasolines with monohydric alcohols with subsequent cavitation treatment of these mixtures has been investigated. The expediency of using alcohol additives in fuels and the relevance of introducing into gasoline production such chemical technologies that use cavitation processing of raw materials and selective energy supply to the reaction zone have been substantiated. The expediency of the production of high-octane gasolines on the basis of a combination of the processes of mechanical mixing of hydrocarbon gasolines with alcohols and the processes of cavitation treatment of alcohol-gasoline mixtures is also substantiated. The description of the laboratory setup and the experimental methodology is given. The influence of the intensity of cavitation treatment on the increase in the octane number is studied and it is proved that there is some optimal intensity at which a constant value of the octane number of the mixture is achieved. With an increase in the content of bioethanol in the mixture, the number of cavitation cycles (intensity) required to achieve the steady-state value of the octane number decreases from 8 cycles of gas condensate without bioethanol to 4 cycles with a bioethanol content of 3% and more. To achieve the octane number of the mixture corresponding to gasoline A-92 and A-95, it is necessary to add 2% and 5% bioethanol, respectively. It is shown that the use of cavitation can increase the octane number up to 2.6 points in comparison with simple mechanical mixing of alcohol and gasoline. A comparison is made of the efficiency of using bioethanol and isobutanol for modifying gas condensate gasoline in a cavitation field. The effect of cavitation on the octane number was studied with a change in the concentration of alcohol in the mixture. A new way of modifying low-octane motor gasolines with bio-ethanol and other mixtures of alcohols of biochemical origin, which contain water impurities, is shown

Solvent Extraction of Boric Acid: Comparison of Five Different Monohydric Alcohols and Equilibrium Modeling with Numerical Methods

Solvent extraction is one of the common methods for the recovery of boric acid (or boron) from aqueous solutions. A wide variety of different compounds including monohydric alcohols has been tested, and there is wide recognition that they are rather ineffective compared to other extractants such as diols. Nevertheless, monohydric alcohols find application in industrial processes, demonstrating their efficiency. The intention of this study is to clarify this discrepancy and to provide an overall picture of monohydric alcohols as an extractant for boric acid. Five different monohydric alcohols are the object of this study: n-octanol, 2-ethyl-1-hexanol, 2-butyl-1-octanol, 2-octanol and 3,7-dimethyl-3-octanol. A special focus of this work is the examination of the effect of the structure of the carbon chain and the effect of the composition of the aqueous phase on the extraction efficiency. As well as the extraction efficiency for boric acid, other important properties are examined such as the viscosity of the organic phase, the solubility of alcohols in the aqueous phase and the co-extraction of salts used as a salting-out agent (NaCl, Na2SO4, MgCl2, LiCl, LiNO3). Finally, a numerical algorithm is developed to calculate the relationship between the number of theoretical stages and the phase ratio at equilibrium for selected extraction systems.

Contribution of the Hydroxyl Group on Interfacial Heat Conduction of Monohydric Alcohols: A Molecular Dynamics Study

Monohydric alcohols have been used as promising phase change materials (PCMs) for low-temperature latent heat storage. However, the heat storage/retrieval rates are limited due to the low thermal conductivity of such alcohols. In this work, nonequilibrium molecular dynamics (NEMD) simulations were performed to study the microscopic heat conduction in example monohydric alcohols, i.e., 1-dodecanol (C12H26O), 1-tetradecanol (C14H30O), and 1-hexadecanol (C16H34O). A simplified ideal crystal model was proposed to exploit the potential for improving the thermal conductivity of monohydric alcohols. The effect of ideal crystalline structures, especially the contribution of the hydroxyl group, on the microscopic heat conduction process was analyzed. The thermal conductivity of the ideal crystals of the various monohydric alcohols was predicted to be more than twice as compared to that of their respective solids. The major thermal resistance in the ideal crystals was found around the molecular interfaces, as a result of the excellent heat conduction performance along the linear molecular chains. The calculated vibrational density of states (VDOS) and interfacial heat transfer were then investigated. When the interfaces are surrounded by hydroxyl groups as walls, strong hydrogen bond (HB) interactions were observed. The interfacial heat transfer coefficient of the ideal crystalline structures of 1-tetradecanol was found to reach up to ∼735.6 MW/m2 W. It was elucidated that the high interfacial heat transfer rate is clearly related to the stronger intermolecular interactions.