Novel utilization of waste marine sponge (Demospongiae) as a catalyst in ultrasound-assisted transesterification of waste cooking oil

Abstract

This study demonstrates the potential of Na-silica waste sponge as a source of low cost catalyst in the transesterification of waste cooking oil aided by ultrasound. In this work an environmentally friendly and efficient transesterification process using Na-loaded SiO2 from waste sponge skeletons as a solid catalyst is presented. The results showed that the methyl esters content of 98.4±0.4wt.% was obtainable in less than an hour (h) of reaction time at 55°C. Optimization of reaction parameters revealed that MeOH:oil, 9:1; catalyst, 3wt.% and reaction duration of 30min as optimum reaction conditions. The catalyst is able to tolerant free fatty acid and moisture content up to 6% and 8%, respectively. In addition, the catalyst can be reused for seven cycles while maintaining the methyl esters content at 86.3%. Ultrasound undoubtedly assisted in achieving this remarkable result in less than 1h reaction time. For the kinetics study at 50-60°C, a pseudo first order model was proposed, and the activation energy of the reaction is determined as 33.45kJ/mol using Arrhenius equation.

Synthesis, characterization and performance of silica impregnated calcium oxide as heterogeneous catalyst in biodiesel production

“…The band at 3429 and 1652 cm À1 can be attributed to the presence of OeH stretching and bending mode of adsorbed water molecules bound to the silica surface, respectively (Hindryawati and Maniam, 2015). The predominant absorbance peak of silica was indicated by the strong band at 1053 cm À1 , which could be assigned to asymmetric stretching of siloxane bond (SieOeSi).…”

MCM-41 Derived from Freshwater Sponge Silica as Support for HPW Applied in the Esterification of Oleic Acid

“…As bandas largas de vibração em 3444 cm -1 são atribuídas ao grupo silanol Si-OH, [19][20][21]28 referente ao grupo hidroxila interno e externo da estrutura e ao modo de vibração de O-H da água, que se confirma pela ocorrência de outra banda próxima a 1635 cm -1 , referentes à deformação angular de moléculas de água. 19,21,28 Também, se observa uma banda em 948 cm -1 atribuída ao estiramento assimétrico dos grupos O-H, provenientes dos silanóis de superfície. [32][33][34] De forma geral, essas bandas são relativas à sílica amorfa (cauxi) que também aparece na peneira molecular.…”

“…) apresenta reflexão alargada e intensa, centrada em 2  21,9°, típica de partículas de sílica amorfa, ou melhor, de estrutura desordenada de SiO2,28,30 que pode ser considerado um material reativo para o processo de síntese de MCM-41 19,28. Também se observa reflexões estreitas de fase cristalina em 2  26,5, 45,8, 50,1, 59,9 e 67,8 de SiO2 residual de quartzo não removido pelo tratamento químico.…”

Catalytic applications of waste derived materials

“…The same group prepared a similar material from waste sponge skeletons as a silica source. 64 These were impregnated with aqueous NaOH at a Na : Si molar ratio of 2, and the resulting material dried and calcined at 500 C to form predominantly amorphous SiO 2 and Na 2 SiO 3 . This was also active in waste cooking oil trans-esterication, leading to 98% FAME yield aer only 30 min at 55 C for an identical reaction mixture.…”