Sulfonated functionalization of carbon derived corncob residue via hydrothermal synthesis route for esterification of palm fatty acid distillate

Abstract

Low-cost biodiesel was successfully produced through esterification of palm fatty acid distillate over corncob residue-derived heterogeneous solid acid catalyst. The sulfonated functionalized carbon derived from corncob was synthesized via hydrothermal carbonization followed by chemical activation using concentrated sulfuric acid. This technique allows efficient carbonization process and able to maintain active polar species of the catalyst hence effectively improves the acid strength of prepared catalyst. The esterification of palm fatty acid distillate over HTC-S catalyst was optimized via the one-variable-at-a-time technique, and 92% free fatty acid conversion with a biodiesel yield of 85% was achieved at optimum conditions of 2 h reaction time, 70°C reaction temperature, 3 wt% catalyst loading, and 15:1 methanol-to-oil molar ratio. Various of catalyst regeneration techniques have been studied and sulfuric acid treatment is found to be the most effective approach for restoring the active sites for spent HTC-S catalyst in comparison to washing solvent and thermal treatment. The HTC-S catalyst regenerated via sulfuric acid treatment is capable to convert PFAD to biodiesel with free fatty acid conversion > 90% for two consecutive cycles. The synthesized PFAD-derived biodiesel has complied with the international biodiesel standard ASTM D6751.

Optimizing the catalytic activities of methanol and thermotolerant Kocuria flava lipases for biodiesel production from cooking oil wastes

“…These drawbacks have gained significant attention in the search for different heterogeneous catalyst technologies for biodiesel synthesis. Recently, several studies stated solid basic or acidic heterogeneous catalysts for biodiesel production including, solid ferric hydrogen sulphate [Fe(HSO 4 ) 3 ] 10 , KF and NaNO 3 catalysts 11 , Calcined dolomite 12 , Calcium lanthanum mixed oxide 13 , Bi 2 O 3 –La 2 O 3 14 , calcium methoxide 15 , g-Al 2 O 3 /KI 16 , metal-doped methoxide 17 , sucrose-derived solid acid 18 , natural CaO 19 , sulfonated functionalized carbon 20 , ZrO 2 21 , Methoxy-functionalized mesostructured stable carbon 22 , sand dollar 8 . The application of these heterogeneous catalysts for biodiesel production overwhelms the homogeneous catalysts drawbacks due to their feasibility, easily recovered processes, tolerance to feedstock moisture and free fatty acid contents and reusability 13 .…”

Sulfonated SnO2 nanocatalysts via a self-propagating combustion method for esterification of palm fatty acid distillate

“…The catalyst deactivation can be suppressed by employing catalyst regeneration and reactivation steps. 45 Although the sulfur was leached out into the biodiesel, the concentration detected was lower than the maximum limit (25 ppm) in ASTM D6751-02. 46 Overall, these ndings suggested that the reduction of the esterication activity in the spent sulfonated SnO 2 -spc catalyst aer four consecutive runs was due to the accumulation of carbon species, loss of acidic sites and leaching of S species.…”

A-Review on Nanorods-An Overview from Synthesis to Emerging, Device Applications and Toxicity (A-Review)

“…Such nanorods are strong and are made from iron, cobalt, and stable spinel ferrite materials. Since of the weak driving fields 21 the materials are adopted. Magnetic characteristics include chemical stability, biocompatibility and superparamagnetic characteristics.…”

“…Its optimization has been observed to be dependent on its adsorbing capability. The adsorbing capability of the material in use is dependent on the pH, sonication time, adsorbent mass as well as other factors which should be considered 21 .…”