2.2.4. Analytical and Calculation Methods

Hydrocarbon composition of the feedstock and products was determined according to ASTM D 5134-13(2017) standard. Octane numbers of the feeds and products were calculated from their hydrocarbon composition and by blending octane numbers of the individual components. In order to evaluate the efficiency of isomerization and the yields of iso- and cyclo-paraffins, the thermodynamic equilibrium concentration (ATECT) was calculated according to Equation (1).

$$\text{ATEC}\_{\text{T}} = \frac{(\mathbf{c}\_{i-\text{Cx}})\_{\text{T}}}{(\mathbf{C}\_{i-\text{Cx}})\_{\text{T} \text{HT}}} \ast 100 \tag{1}$$

where (ci-Cx)T is the concentration of the isomer at the actual temperature in the C6 fraction of product, and (Ci-Cx)ThT is the equilibrium concentration of the isomer.

The Pt content of the catalysts was determined by the inductively coupled plasma (ICP) method; the platinum dispersion of catalysts was determined by CO pulse chemisorption, and CO consumption was detected by a thermal conductivity detector. The Al and Si contents of H-Mordenite were also determined by the ICP method. The specific surface areas were determined by the Brunauer–Emmett–Teller (BET) method from the corresponding nitrogen adsorption isotherm. The chlorine content of catalysts was measured by the Volhard method [26]; the sample was dissolved in concentrated sulfuric acid and Cl ions were precipitated with silver nitrate solution. Excess silver solution was back titrated with a thiocyanate solution to give the amount of chlorine in the original sample. The chlorine contents of products were determined according to the ASTM D4929–19 (Standard Test Method for Determination of Organic Chloride Content in Crude Oil). The oxygen-containing compounds were detected by GC-MS. The water contents of the feedstock and products were determined by Coulometric Karl Fischer titration.
