Waste Seashells as a Highly Active Catalyst for Cyclopentanone Self-Aldol Condensation

Abstract

For the first time, waste-seashell-derived CaO catalysts were used as high-performance solid base catalysts for cyclopentanone self-condensation, which is an important reaction in bio-jet fuel or perfume precursor synthesis. Among the investigated seashell-derived catalysts, Scapharca Broughtonii-derived CaO catalyst (S-shell-750) exhibited the highest dimer yield (92.1%), which was comparable with commercial CaO (88.2%). The activity sequence of different catalysts was consistent with the CaO purity sequence and contact angle sequence. X-ray diffraction (XRD) results showed that CaCO3 in waste shell were completely converted to CaO after calcination at 750 °C or above for 4 h. CO2 temperature-programmed desorption (CO2-TPD) results indicate that both the amount and strength of base sites increase significantly when the calcination temperature climbs to 750 °C. Therefore, we can attribute the excellent performance of S-shell-750/850/950 catalysts to the higher CaO content, relatively low hydrophilicity, and stronger acidity and basicity of this catalyst. This study developed a new route for waste shell utilization in bio-derived ketone aldol condensation.

Diatomite Stabilized KOH: An Efficient Heterogeneous Catalyst for Cyclopentanone Self‐condensation

“…Moreover, Al 2 O 3 (5.10 %), Na 2 O (0.33 %), CaO (0.30 %) were found as minor impurity components over KOH/diatomite. According to the literature, these minor components can also catalyze the reaction [25] . Thus, it can be concluded that there is synergistic effect between KOH and these impurity components of diatomite.…”

Progress on Modified Calcium Oxide Derived Waste-Shell Catalysts for Biodiesel Production

“…It was discovered that the waste shells are beneficial for the production of a wide range of value-added chemicals and products, such as 1,2,3-triazoles [44], cyclopentanone [45], 7,8-dihydro-4H-chromen-5(6H)-one [46], dimethyl carbonate [47], steam gasification [48], wastewater treatment [49], soil improvement [50], Portland cement replacement [51] and artificial stone [52]. Xiong et al [44] studied the synthesis of 1,2,3-triazoles catalyzed by waste oyster shell powders (OSPs)-supported CuBr catalyst (OSPs-CuBr).…”

“…The authors reported that the prepared OSPs-CuBr catalysts showed high catalytic activity with cost-effectiveness for the larger-scale synthesis of 1,4-disubstituted 1,2,3-triazoles. Sheng et al [45] investigated the multiple characteristics of the Scapharca Broughtonii shell, conch shell and oyster shell derived catalyst for cyclopentanone self-aldol condensation. Dimer obtained from the self-aldol condensation pathway of cyclopentanone can be used as a high-density fuel or perfume precursor.…”

Synthesis of Diesel and Jet Fuel Range Cycloalkanes with Cyclopentanone and Furfural

“…Cyclopentanone can be obtained (at high carbon yields of 62-95.8%) through the aqueous phase selectively hydrogenation and rearrangement of furfural [34][35][36][37][38]. High density fuels were prepared by self aldol condensation of cyclopentanone and hydrodeoxygenation [39][40][41][42]. In some studies, diesel and jet fuel range cycloalkanes were produced by the aldol condensation of furfural and cyclopentanone [43][44][45][46], followed by HDO.…”