Synthesis of sulfonated catalyst from bituminous coal to catalyze esterification for biodiesel production with promoted mechanism analysis

Sulfonation of Natural Carbonaceous Bentonite as a Low-Cost Acidic Catalyst for Effective Transesterification of Used Sunflower Oil into Diesel; Statistical Modeling and Kinetic Properties

“…The CB composed of inorganic aluminosilicate layers intercalated with organic kerogen. During the interaction between H 2 SO 4 and the interlayer kerogen, the present sulfur ions and their trioxide species attack the aromatic rings of kerogen causing destruction for their double bonds and incorporation for the active acidic −SO 3 H group , (Figure ). Additionally, the other oxidation effect occurs for the hydroxyl groups which cause alteration of them to active carboxyl groups (COOH). , For the aluminosilicate layers, the reaction with H 2 SO 4 causes modification for their surface with acidic sulfate anions which are attached to the surface by inner-sphere and outer-sphere complexes …”

“…Additionally, the other oxidation effect occurs for the hydroxyl groups which cause alteration of them to active carboxyl groups (COOH). 36,37 For the aluminosilicate layers, the reaction with H 2 SO 4 causes modification for their surface with acidic sulfate anions which are attached to the surface by inner-sphere and outer-sphere complexes. 25 Generally, the transesterification process involved reaction between the TGs of the vegetable oils and the used alcohol molecules creating monoesters is the existence of the used catalyst (S-CB) (Figure 8).…”

Insight into the Effect of Sulfonation Techniques on the Adsorption Properties of −SO3H Surface-Functionalized Coal as Adsorbent for Malachite Green Dye: Steric and Energetic Investigation

“…This in turn causes remarkable destruction of the present oxygen–hydrogen bond and the formation of H 2 O molecules (Figure ). During this reaction, another interaction occurs between the protonated oxygen and lone pair electrons resulting in a new π bond with the incorporated sulfur ions creating protonated trioxide . The sulfur ions and the formed sulfur trioxide exhibit significant electronegativity therefore it acts as effective electrophiles during the performed sulfonation reactions .…”

“…24 As a geological term, coal refers to a sedimentary rock of high worldwide natural reserves and is composed of different types of organic components (cellulose, resin, lignite, and macerals) and inorganic ashes. 22,25,26 As a material, it was identified as a series of natural polycyclic aromatic hydrocarbons, and the aromatic rings in its structure are linked with each other by types of oxygen-bearing functional groups (carbonyl, carboxyl, phenolic, and hydroxyl groups). 27,28 The existence of such active oxygen-bearing chemical groups, especially the carboxylic and phenolic groups, makes it a promising adsorbent for different species of water-dissolved chemical compounds.…”

“…As a geological term, coal refers to a sedimentary rock of high worldwide natural reserves and is composed of different types of organic components (cellulose, resin, lignite, and macerals) and inorganic ashes. ,, As a material, it was identified as a series of natural polycyclic aromatic hydrocarbons, and the aromatic rings in its structure are linked with each other by types of oxygen-bearing functional groups (carbonyl, carboxyl, phenolic, and hydroxyl groups). , The existence of such active oxygen-bearing chemical groups, especially the carboxylic and phenolic groups, makes it a promising adsorbent for different species of water-dissolved chemical compounds . The previous studies demonstrate that the physicochemical properties of coals as adsorbents depend essentially on their surface properties such as the dominant chemical groups, surface area, and porosity properties. , Therefore, several studies were introduced to follow the impact of the different surface modification processes on the chemical and textural properties of coal.…”