Related Experiment Video
Updated: Jan 22, 2026

Preparation of Biopolymer Aerogels Using Green Solvents
Published on: July 4, 2016
Using switchable solvent as a solvent and catalyst for in situ transesterification of spent coffee grounds for
Hoang Chinh Nguyen1, My Linh Nguyen2, Fu-Ming Wang1
1Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
Abstract:
This study developed a novel in situ transesterification process by combining the solvent and catalyst functions of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) for biodiesel synthesis from spent coffee grounds (SCG). The influence of reaction parameters on the reaction was investigated. The maximum biodiesel yield of 96.13% was observed at DBU-to-SCG and methanol-to-SCG ratios of 20 and 10 mL/g, respectively; a reaction temperature of 130 °C; and a reaction time of 60 min. Notably, the polarity of DBU could be reversibly regulated, thus facilitating excellent product separation. Moreover, DBU could be effectively reused for 10 cycles to yield high biodiesel conversion. DBU-catalyzed in situ transesterification of SCG is a promising, ecofriendly, and economically viable biodiesel production process.
Related Concept Videos
Solvents
A...
Titration in Nonaqueous Solvents
Chemical Shift: Internal References and Solvent Effects
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
Taping Over Different Ground Profiles
Connective Tissue Fibers and Ground Substance
Dehydration Synthesis
Dehydration synthesis (also called a condensation reaction) is the chemical process in which two molecules covalently link together to form a new molecule, along with the release of a water molecule. Many physiologically important compounds form by dehydration synthesis reactions, such as complex carbohydrates, proteins, DNA, and RNA.
Synthesis of carbohydrates
Sugar molecules are covalently linked together by dehydration synthesis. During the reaction, the hydroxyl (-OH) group from...

