CAS 121-65-3 4-Dodecylbenzenesulfonic acid - Vaccine Lab / Alfa Chemistry

4-Dodecylbenzenesulfonic Acid as a Catalyst for the Catalytic Reaction of Oleic Acid Esterification

Esterification of oleic acid for biodiesel production catalyzed by 4-dodecylbenzenesulfonic acid Alegría A, et al. Applied Catalysis B: Environmental, 2015, 179, 530-541.

4-dodecylbenzenesulfonic acid (DBSA), a hydrophobic catalyst, exhibited excellent catalytic activity in the esterification of oleic acid with methanol, proving to be a viable catalyst for biodiesel production from raw materials with high free fatty acid (FFA) content.
The study employed DBSA as a catalyst in the esterification process, investigating the influence of various operating conditions, including temperature, catalyst/acid molar ratio, methanol/oleic acid molar ratio, water content, and the presence of triglycerides. The esterification was carried out in a thermostatically controlled 5 mL reactor, with methanol added at zero reaction time. The reaction mixture was stirred at 600 rpm, and the progress was monitored by titrating the remaining oleic acid with potassium hydroxide in ethanol. The study found that the reaction rate increased with the hydrophobicity of the catalyst. DBSA, being more hydrophobic than sulfuric acid and p-TSA, demonstrated superior catalytic activity in both esterification and transesterification reactions.

4-Dodecylbenzenesulfonic Acid as a Catalyst for the Synthesis of Biodiesel

Biodiesel production using 4-dodecylbenzenesulfonic acid as catalyst Alegría A, et al. Applied Catalysis B: Environmental, 2014, 160-161, 743-756.

4-Dodecylbenzenesulfonic acid proves to be a highly effective catalyst for biodiesel production, offering faster reaction rates, higher conversions, and resistance to common issues like saponification.
DBSA offers a unique advantage in biodiesel production due to its hydrophobic moiety. This structural characteristic enhances its catalytic efficiency, leading to higher transesterification rates compared to other acid catalysts like sulfuric acid. Conversions exceeding 95% can be achieved under mild reaction conditions within 3 hours, showcasing DBSA's superiority. Additionally, DBSA does not cause saponification reactions, further improving the biodiesel yield and quality.
Experimental Procedure
Biodiesel was synthesized through the transesterification of triglycerides with methanol using DBSA as the catalyst. Various experiments were conducted to determine the effects of temperature, catalyst/oil molar ratio, and methanol/oil molar ratio on the conversion rate. The reaction was carried out in a thermostatic bath at controlled temperatures, with the progress monitored using 1H NMR analysis. The study revealed that higher temperatures and catalyst concentrations significantly increased the conversion rates, while excessive methanol initially slowed the reaction but later contributed to higher conversions at elevated temperatures.
The kinetic analysis demonstrated that the transesterification reaction followed pseudo first-order kinetics, with an activation energy of 66.3 kJ/mol. At 90°C, conversions exceeding 98% were achieved in less than 2 hours. The presence of free fatty acids (FFAs) and small amounts of water did not significantly affect the reaction kinetics or equilibrium, indicating DBSA's robustness in handling inedible feedstock with varying quality.

Catalog Number	ACM121653-2
CAS	121-65-3
Structure
Synonyms	P-Dodecylbenzenesulfonic acid
IUPAC Name	4-dodecylbenzenesulfonic acid
Molecular Weight	326.49
Molecular Formula	C18H30O3S
Canonical SMILES	CCCCCCCCCCCCC1=CC=C(C=C1)S(=O)(=O)O
InChI	InChI=1S/C18H30O3S/c1-2-3-4-5-6-7-8-9-10-11-12-17-13-15-18(16-14-17)22(19,20)21/h13-16H,2-12H2,1H3,(H,19,20,21)
InChI Key	KWXICGTUELOLSQ-UHFFFAOYSA-N
Melting Point	82 °C
Flash Point	85 °F
Purity	95%
Density	1.06 g/mL at 20 °C (lit.)
Complexity	351
Covalently-Bonded Unit Count	1
Defined Atom Stereocenter Count	0
EC Number	204-489-3
Exact Mass	326.19156599
Heavy Atom Count	22
Hydrogen Bond Acceptor Count	3
Hydrogen Bond Donor Count	1
Isomeric SMILES	CCCCCCCCCCCCC1=CC=C(C=C1)S(=O)(=O)O
MDL Number	MFCD00066677
Monoisotopic Mass	326.19156599
Rotatable Bond Count	12
Topological Polar Surface Area	62.8 Å²