Production of p-Cymene from Crude Sulphate Turpentine with Commercial Zeolite Catalyst Using a Continuous Fixed Bed Reactor

Abstract

Crude sulphate turpentine (CST), containing α-pinene, 3-carene, other terpene isomers, and organic sulphur compounds, was used as feedstock in the production of cymenes with commercial zeolite catalysts. The catalysts used were not sensitive to sulphur, and the desulphurisation step was not needed prior to cymene synthesis. The experiments were performed in a continuous fixed bed reactor. Promising results were obtained after initial optimization at temperatures close to 300 °C with faujasite Y zeolite under 5 bar N 2 pressure. Cymenes were produced with 54% yields from model compound α-pinene and with 28% yields from CST. The mechanistic route of the reaction can be divided into three steps: (1) ring opening, (2) rearrangement, and (3) dehydrogenation. The final step in the formation of p-cymene can occur via dehydrogenation or disproportion; here the effect of reaction conditions and catalyst plays a crucial role. Article pubs.acs.org/OPRD

Conversion of polar and non-polar algae oil lipids to fatty acid methyl esters with solid acid catalysts – A model compound study

“…However, in general Nafion type fluorinated polystyrene sulphonic acid resins show higher acidity (Brönstead) compared to basic ion exchange resins like Amberlyst 15 or Smopex however they have lower acid capacity (acidic concentration). (Bringué et al, 2006;Samms et al, 1996) Zeolites have Brönstead and Lewis acid sites and their acid strength varies depending on Si/Al ratio and structure (Linnekoski et al, 2014).…”

Production of Industrially Useful and Renewable p‐Cymene by Catalytic Dehydration and Isomerization of Perillyl Alcohol

“…However, these conditions resulted in accumulation of even more oligomers (99%). Previous studies that utilized heterogeneous catalysts such as zeolites and acid‐activated clays also encountered significant oligomerization, which was attributed to regions of strong Brønsted acidity on the catalytic surface (Du et al, 2005; Fernandes et al, 2007; Golets et al, 2015; Linnekoski et al, 2014; Lycourghiotis et al, 2018; Makarouni et al, 2018). Thus, we speculated that the strong Brønsted acidity of p TsOH (pKa −1.3; Berkowitz and Grunwald, 1961) favored oligomerization over dehydroisomerization, thereby resulting in production of oligomers as opposed to the production of 1 .…”

Xylochemicals and where to find them

“…Mentha piperita oil (14-32%), [217] Mentha canadensis oil (8-16%) [218] P Me Me limonene (R)-(-)-limonene: orange oil (92%) [219] (3.8wt% of orange peel), [220] lemon, bergamot, dill, mint, among others, [219] (S)-(-)-limonene: oaks and pines, Eucalyptus stageriana [221] P Me Me Me α-terpinene Chenopodium ambrosioides oil (63%), [209] majoram oil (10%), [222] terpene fraction of orange oil, [69] american turpentine oil [69] P Me Me Me γ-terpinene majoram oil (14%), [222] cardamom oil (up to 11%) [223] P Me Me Me α-pinene spruce needle oil, [224] sulfate turpentine (65%) [207] P Me Me β-pinene from turpentine, from αpinene [69] Please do not adjust margins Please do not adjust margins Carum carvi oil (50-70%), [225] (R)-(-)carvone: oil of spearmint (up to 69%) [69,226]…”

“…ascaridole Chenopodium oil (67%), [205] Peumus boldus oil (31%) [206] P Me Me Me p-cymene sulfate turpentine, [207] Origanum acutidens oil (ca. 2%), [208] Chenopodium ambrosioides oil (26%) [209] P Me…”