This article reports experimental data of density and ultrasonic velocity at the range from 278.15 to 323.15 K and atmospheric pressure of ethers used as additives in fuels (methyl tert-butyl ether ethyl tert-butyl ether, tert-amyl ether and diisopropyl ether). From the experimental data, temperature dependent polynomials were fitted and theoretical models were used to correlate these properties. The MTC Lattice Gas EOS is used to correlate simultaneously vapour pressures and volumetric properties. Free Length Theory is applied to estimate the ultrasonic velocity of the chemicals as a function of temperature, satisfactory predictions were obtained. The dependence of temperature showed by these magnitudes reveals a strong interaction at low values.

Aromatic saturation is an important reaction for improving the cetane number of diesel streams. NiMo sulfide catalysts supported on alumina (Alu), silica−alumina (Si−Al), and alumina-Y zeolite (AluZ) were prepared with similar dispersions and variable acidities. These catalysts were tested in the hydroconversion of tetralin, indan, decalins, and alkylbenzenes to evaluate the effect of the support acidity in the overall activity and the distribution of products. NiMo/Alu generated essentially hydrogenated products while the presence of an acid component on the support increased not only isomerization and cracking reactions but also hydrogenated compounds formation, especially on tetralin, indan, and butylbenzene hydroconversions over NiMo/AluZ catalyst. The better hydrogenation activity of NiMo/AluZ for these reactions was associated with the presence of strong acid sites that contribute to creating protonated species which would migrate to the sulfide phase. Such species would be easier to hydrogenate due to the lower stability of the aromatic ring.

This work presents experimental liquid densities and ultrasonic velocities for a collection of substituted aromatic compounds (isobutylbenzene, 1,3, 5-trimethylbenzene, butylbenzene, isopropylbenzene, p-xylene, m-xylene and o-xylene) at the range of temperature 278.15-323.15 K and atmospheric pressure of a collection of halogenated and aromatic hydrocarbons. Fitting equations were applied to data in order to correlate for later computer-based design. The estimation of the studied properties was made by the application of different theoretical procedures. An equation of state based on the generalised Van der Waals theory which combines the Staverman-Guggenheim combinatorial term of lattice statistics with an attractive lattice gas expression and the free length theory (FLT) showed a good response at the studied conditions.

IR operando study of cyclohexene reaction on HY zeolite (Si/Al = 15) was performed to determine the role of the OH groups located in the different zeolitic cages and the silanol groups (SiOH). A parallel between the product yield and type and amount of OH groups poisoned by coking and pyridine pulses was established. The role of silanol and zeolitic OH groups during cyclohexene conversion and the coverage rate of surface groups of the dealuminated HY zeolite, were evaluated by FT-IR operando study.At the beginning of the reaction, zeolite exhibited a very intense deactivation due to coke formation. Coke is initially deposited on strong acid sites, inhibiting the H-transfer activity.Further, coke formation decreased. At this stage of the reaction, pyridine addition markedly decreased the isomerization activity. In parallel, it is noted that mainly SiOH, OH groups at hexagonal prisms, and perturbed OH groups in sodalite cages were mainly affected, indicating that these groups are responsible for the isomerization steps. These results showed that even weakly acidic sites are active sites for isomerization reaction.Strong and weakly acidic OH groups of HY zeolite into the different routes...