The Removal of Biomass Tar Derived Producer Gas by Means of Thermal and Catalytic Cracking Methods

Tar derived from biomass gasification system needs to be eliminated before applying biomass producer gas for avoiding equipment and its gas problems. In this study, thermal and catalytic cracking methods of biomass tar along with microwave assistance in heat transfer were experimented at various temperatures during 650-1,200 °C and residence at 0.24-0.5 s. The results present that high tar removal efficiency by approximately 90 % under thermal cracking treatment and about 98 % with catalytic cracking method. It also shows that the catalytic cracking especially modified catalyst could be lowered carbon deposition on catalyst surface.

Sonication, a Potential Technique for Extraction of Phytoconstituents: A Systematic Review

Traditional extraction techniques have lost their optimum performance because of rising consumer demand and novel technologies. In this regard, several techniques were developed by humans for the extraction of plant materials from various indigenous sources, which are no longer in use. Many of the techniques are not efficient enough to extract maximum plant material. By this time, evolution in extraction has led to development of various techniques including microfiltration, pulsed electric fields, high pressure, microwave assistance, enzyme assistance, supercritical fluid, subcritical fluid and ultrasonication. These innovations in food processing/extraction are known as “Green Food Processing”. These technologies were basically developed by focusing on three universal parameters: simplicity, energy efficiency and economy. These green technologies are practical in a number of different food sectors, mostly for preservation, inhibition of microorganisms, inactivation of enzymes and extraction of plant material. Like the others, ultrasonication could also be used for the said purposes. The primary objective of this review is to confine the potential use of ultrasonication for extraction of oils, pectin and phytochemicals by reviewing the literature systematically.

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

Microwave-assisted (MWA) multicomponent reactions (MCRs) have successfully emerged as one of the useful tools in the synthesis of biologically relevant heterocycles. These reactions are strategically employed for the generation of a variety of heterocycles along with multiple point diversifications. Over the last few decades classical MCRs such as Ugi, Biginelli, etc. have witnessed enhanced yield and efficiency with microwave assistance. The highlights of MWA-MCRs are high yields, reduced reaction time, selectivity, atom economy and simpler purification techniques, such an approach can accelerate the drug discovery process. The present review focuses on the recent advances in MWA-MCRs and their mechanistic insights over the past decade and shed light on its advantage over the conventional approach.

Boosting electrochemical properties of CoCo2O4 porous nanowire arrays by microwave-assisted synthesis for battery-supercapacitor hybrid devices

Cobalt oxide (CoCo2O4) porous nanowires are synthesized by a microwave assisted hydrothermal process (MHP) and the followed annealing. It is found that the introduction of microwave assistance led to an...

A study comparing Conventional Heating and Microwave Assistance Heating to Recover Metals from Municipal Solid Waste using Microwave-Assisted Leaching Technique

This study investigates and compares microwave-heating radiation with conventional heating. Incinerated municipal solid waste (IMSW) bottom ash (BA) and fly ash (FA) was utilized to recover various metals including Co, Cr, Cu, Fe, Mn, Zn,Pb, Al, Cd, Ba, Mg and V using various acid leaching agents i.e. HCl, HNO3 and H3PO4 were utilized and several parameters were altered in order to determine the most effective conditions. The current study concluded that microwave assisted leaching method is effective to recover most of the metals. In addtion, metals from MSWBA were much easier to recover in contrast with MSW-FA. 71% of Co, 75.69% of Cr, 56.19% of Cd, 35.23% of Ba and 30.2% of Pb, using 2M of HCl and 3M of H3PO4. While 1.48% of Cr, 0.93% of Fe, 1.19% of Mn, and 1.18% of Al were extracted using HCL and H3PO4 from MSWFA. It was also confirmed that higher power and longer contact time had a positive effect on metal recovery. From cost analysis point of view, microwave assisted leaching was fraction of the cost for conventional heating, making this method comparatively sustainable, energy efficient and safe.

Optimization of process conditions for microwave-assisted flax water retting by response surface methodology and evaluation of its fiber properties

Microwave-assistance was used to increase the degumming efficiency in flax water retting. Different pre-soaking times, microwave times, and microwave power were investigated in this study. The relationships between degumming rate and process parameters were established via response surface methodology (RSM). The optimum process parameters were a pre-soaking time of 25.5 h, a microwave time of 18.5 min, and a microwave power setting of 570 W. Under these optimal conditions, the degumming rate was 83.85% ± 1.13%, which was 1.33 times higher than that of natural hot water retting (P < 0.05). Moreover, the tensile properties and color of the resulting fibers showed that they had tensile properties similar to those of the natural hot water retting fibers. However, the color values for the natural hot water retting fibers were higher than those of the fibers treated with microwave-assisted flax water retting.

Highly Dual Antifouling and Antibacterial Ultrafiltration Membranes Modified with Silane Coupling Agent and Capsaicin-Mimic Moieties

Dual antifouling and antibacterial polysulfone(PSf)/polyethersulfone(PES) hybrid membranes were developed by the synergy of capsaicin-mimic N-(5-methyl acrylamide-2,3,4 hydroxy benzyl) acrylamide (AMTHBA) and vinyl triethylene (b-methoxy ethoxy) silane (VTMES). First, AMTHBA as a natural antimicrobial agent was incorporated into a casting solution via “microwave-assistance (MWA) in situ polymerization-blending” process to construct a hydroxyl-rich environment. Then, VTMES crosslinked to a hydroxyl-rich polymer matrix via hydrolytic condensation, and the influence of VTMES content on the hybrid membrane properties was systematically investigated. When the VTMES added amount was 1.0 wt %, the hybrid membrane achieved an optimal separation performance including a steady-state humic acid (HA) (5 mg/L) permeation flux of 326 L·m−2·h−1 and a rejection percentage of 97%. The antibacterial tests revealed that the hybrid membranes exhibited sustained bactericidal activity and effective inhibition of bacterial adhesion. Besides, the dual-functional membranes were clean as new after two-cycles filtration (with a cleaning efficiency of ~90%), indicating that the network silicone film on the surface benefits the foulant repellence. Hopefully, the dual-functional membranes constructed in this study can be applicable to the pretreatment stage of water treatment.