Efficient carbon-based solid acid catalysts for the esterification of oleic acid

The production of biodiesel by the esterification of oleic acid, as an example of free fatty acid (FFA), was explored by using a new solid acid catalyst derived from lignin, a highly abundant low-cost biomass material. The catalyst was synthesized from lignin-derived carbon fiber by straightforward sulfonation and contains 1.86 mmol/g of sulfonic acid (-SO3H) groups. The catalyst was characterized by a variety of techniques including PXRD, TGA, TPD-MS, SEM, and XPS to understand the surface chemistry and the result of sulfonation. It was found that the sulfonated lignin-derived carbon fiber (CF-SO3H) catalyst was very efficient at esterifying oleic acid at 80 oC in 4 hours, with 10 wt. % catalyst (in terms of oleic acid content) and at a 10:1 molar ratio of methanol: oleic acid with a yield of 92%. Furthermore, the catalyst can be reused with no significant loss in activity after 4 cycles. Hence, synthesizing solid acid catalysts from lignin-derived carbon fiber affords a novel strategy for producing biodiesel via ‘green chemistry’.

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The Role of Carbon-based Solid Acid Catalysts in Organic Synthesis

Advances in Organic Synthesis - Advances in Organic Synthesis: Volume 14 ◽

10.2174/9789811803741121140007 ◽

2021 ◽

pp. 235-291

Author(s):

Jay Soni ◽

Ayushi Sethiya ◽

Shikha Agarwal

Keyword(s):

Organic Synthesis ◽

Solid Acid ◽

Solid Acid Catalysts ◽

Acid Catalysts ◽

Carbon Based

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Preparation of Carbon-Based Solid Acid Catalysts Using Rice Straw Biomass and Their Application in Hydration of α-Pinene

Catalysts ◽

10.3390/catal10020213 ◽

2020 ◽

Vol 10 (2) ◽

pp. 213 ◽

Cited By ~ 2

Author(s):

Zhaozhou Wei ◽

Deyuan Xiong ◽

Pengzhi Duan ◽

Shilei Ding ◽

Yuanlin Li ◽

...

Keyword(s):

Low Temperature ◽

Rice Straw ◽

Photoelectron Spectroscopy ◽

Solid Acid ◽

Solid Acid Catalysts ◽

Side Reactions ◽

Acid Catalysts ◽

High Porosity ◽

Ft Ir ◽

Carbon Based

Carbon-based solid acid catalysts were prepared using rice straw (RS) waste, and the effects of carbonization temperature and sulfonation temperature on the catalytic activity were investigated. The properties of the catalysts were characterized using thermo gravimetric (TG), scanning electron microscope (SEM), Brunauer–Emmet–Teller (BET), Fourier transform infrared spectroscopy (FT-IR), temperature-programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS), and their activities were investigated through the hydration of α-pinene. The conversion of α-pinene and the selectivity of α-terpineol reached 67.60% and 57.07% at 80 °C and atmospheric pressure in 24 h, respectively. The high catalytic capacity of the catalyst is attributed to the high acid site density and high porosity of the catalyst. TPD analysis and FT-IR spectroscopy showed that the catalyst produced by low-temperature carbonization at 300 °C followed by low-temperature sulfonation at 80 °C had abundant strong acid sites (0.82 mmol/g), which can effectively inhibit the side reactions of hydrated α-pinene. The total acidity reached 2.87 mmol/g. N2-physisorption analysis clearly indicated that the obtained catalysts were mesopore-predominant materials, and the SBET and VTotal of catalysts reached 420.9 m2/g and 4.048 cm3/g, respectively. Preparation of the catalyst involves low energy consumption, and its cheap raw materials make the whole process simple, economical, and environmentally friendly.

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