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Nowadays, it is widely recognized that biomass combustion processes can contribute to the mitigation of greenhouse gas emissions, and thus, these processes have become a viable option as an alternative energy source for the power industry. Among various biomasses, the herbaceous biomass is regarded as an abundant and relatively inexpensive fuel. However, it contains high ashes (especially high levels of alkali metals), leading to operation troubles such as slagging and fouling inside a heat exchanger or deterioration in efficiency. Accordingly, we herein propose an economical method to remove the inherent ashes in the biomass using 16.6 M acetic acid pretreatment at 60 °C for 10 min. Seven different biomasses were investigated to validate the effects of method. The Kenaf shows the total mineral rejection of 93.48%. In particular, the potassium and sodium elements in the Kenaf, which are major factors influencing fouling and slagging in a boiler, were removed up to 99.46 and 100%, respectively. Furthermore, the proposed wet treatment was more effective for biomass with higher surface areas.

Mesoporous silica and titania supraparticles with controllable pore size, particle size, and macroscopic morphology were readily synthesized by a novel synthetic pathway using meniscus templating on a superhydrophobic surface, which is much simpler than well-known emulsion systems. Moreover, we first report that despite the very large radius of droplet curvature on a millimeter scale, supraparticles kept the round cap morphology due to addition of sucrose as a shape preserver as well as a pore-forming agent. In addition, mesoporous silica and titania supraparticles provided good adsorption performance for Acid Blue 25 and Cr(VI), and were easily separated from the solution by using a scoop net after adsorption tests.

Synthetic methods of mesoporous silica using surfactants or ionic liquids as a template have several disadvantages to commercialization such as low economic feasibility and low sustainability. Thus, the development of more ecofriendly and economical synthetic pathways for commercialization of mesoporous silica remains a challenge in the field of mesoporous silica synthesis. In this study, we first report a synthetic method of mesoporous silica (KIE-11) using deep eutectic solvent (DES) of choline chloride/urea as a templating agent and solvent without alcohol and water, except for water needed for hydrolysis of tetraethyl orthosilicate. KIE-11 has high surface area (up to 877 m2/g) and pore volume (up to 1.74 cm3/g), and its pore size can be easily tailored from 3.3 nm up to 24.5 nm with narrow pore size distribution by only changing the aging conditions. On the basis of various analyses of KIE-11, we deduced pore formation mechanism of mesoporous silica by DES. In addition, we used KIE-11 as a catalyst support for additive-free formic acid dehydrogenation at room-temperature, and KIE-11-supported catalysts showed excellent catalytic activity (TOF: 860.7 mol H2 mol Pd−1 h–1). Comparing to surfactant or ionic liquid-templated methods, the DES-templated synthetic method is much cheaper, more ecofriendly, and more energy efficient. Therefore, this work is expected to open a new avenue for cheap and green synthesis of mesoporous silica on an industrial scale.