Synthesis of pillared clays assisted by microwaves

Microwave pyrolysis of rice straw: Products, mechanism, and kinetics

“…Microwave heating is also a selective and energysaving technology without direct contacts with the heated materials (Jones et al, 2002). Therefore, it is widely used in many applications such as sample pretreatment (Roig, 1995), synthesis (de Andresa et al, 1999), digestion (Bettinelli et al, 2000), extraction (Perez Cid et al, 2001), and sludge stabilization (Chen et al, 2005;Hsieh et al, 2007). The technology of pyrolysis induced by microwave heating has been researched to treat various feedstocks such as oil shale (El harfi et al, 2000), oil-palm stone (Guo and Lua, 2000), paper (Miura et al, 2001), plastic waste (Ludlow-Palafox and Chase, 2001), sewage sludge (Menendez et al, 2002), rock phosphate (Bilali et al, 2005), scrap tire (Appleton et al, 2005), coffee hulls (Menendez et al, 2007), wood (Chen et al, 2008), rice straw (Huang et al, 2008), corn stalk bale (Zhao et al, 2010), oil palm biomass (Salema and Ani, 2011), and microalgae (Hu et al, 2012).…”

Effect of Ultrasound on the Structural and Textural Properties of Al–Fe Pillared Clays in a Concentrated Medium

“…Variants of the traditional method have been researched in order to decrease the water volume and timing of the synthesis. Thus, it has become possible to decrease the volume of water by the use of concentrated suspensions, both clay (10,15,20,40, 50 and 100 wt%) and a pillaring agent (chlorhydrol concentrate) [4][5][6][7][8][9]. Also, the time of intercalation of calcium montmorillonite with chlorhydrol (commercial format of basic aluminum chloride solution) has been reduced through the use ultrasound for a period of a few minutes, having obtained Al-PILC with a high thermal stability and textural properties superior to those of clay modified with an exchange time of 24 h. In general, during the intercalation, treatment with ultrasound [10][11][12] and microwaves [4,[13][14][15] has proved an adequate method for reducing the contact time between the clay and the pillaring agent.…”

Adsorption properties of microwave synthesized inorgano–organo montmorillonite

“…This difference in the amount of water released is probably resulting from the different structures of Al-species in the interlayer. As microwave irradiation has a calcination effect as reported by various researchers, [15,16,18] the amount of Al may alter the calcination in the parent clays by microwave irradiation. Therefore, more pillars are possible to be obtained in the case of s1.…”

“…However, the microwave irradiation is used in certain steps such as calcination [15,16] and intercalation [17] , as well as in both intercalation and calcination. [18] In the present study, we propose the use of microwave irradiation in the aging and intercalation steps. Aging is required for the completion of oligomerization in the pillaring solution and it is generally carried out by keeping the reaction mixture containing the pillaring solution for at least 24 h at room temperature.…”