Conventional Heating Method Research Articles

Nano fibrous carbon produced from chromium bearing tannery solid waste as the bitumen modifier

Bitumen binders play a major role in reducing the aging and oxidation property of bitumen. Carbon nanomaterials act as an effective bitumen modifier due to its stiffness and strength. Thus, nano fibrous carbon (NFC) was prepared from Chrome Tanned Buffing Dust (a solidwaste generated from leather industries) with proper care of avoiding oxidation of Cr(III) to Cr(VI) through pulse pyrolysis system. Morphology analysis using TEM confirmed the nano fibrous structure of NFC. XRD pattern of NFC depicts the graphitic phases of carbon along with the Cr2O3. Prepared NFC has been used as bitumen modifier and the blending of NFC with bitumen were done using both conventional and microwave heating methods to study the proper blending methods to enhance the bitumen properties. Thermogram of the modified bitumen showed that the decomposition temperature increases by increasing the percentage of NFC (5–25%) in both the heating methods, but comparatively the thermal stability is more in microwave mixing than in conventional mixing. The morphology analysis of the modified bitumen showed that non-uniform blending in conventional type of heating and homogeneously blended mixture in microwave type of heating. The penetration value and ductility decreases while softening point and kinematic viscosity increases by increasing the quantity of NFC from 5 to 25% in modified bitumen. Microwave heat mixing method yielded better modified bitumen with NFC than conventional heating method in terms of stability, uniform blending and physical properties. The non-leachability of the Cr(III) in the NFC modified bitumen was confirmed through total chromium analysis in the leachate. But, chromium analysis in leachate of NFC immersed in acetate buffer for one month showed leaching of Cr(III) 5.5 μg/L in the 25% NFC modified bitumen block mixed using conventional heating method.

CONVENTIONAL EXTRACTION OF BETALAIN COMPOUNDS FROM BEETROOT PEELS WITH AQUEOUS ETHANOL SOLVENT

Consumer concern over artificial food additives has stimulated production of pigments from natural sources. The aim of this study was to examine the effects of process variables on the content of colour compounds (betaxanthin and betacyanin) in beetroot peel juice extracted by conventional method. In this research, the extraction processes were carried out according to the central composite design with different process variables. Quantitative measurements of the basic colour compounds in beetroot extract were performed using spectrophotometer. From our experiment, it was found that the most adequate extraction conditions, which gave the highest yield of colour compounds (952.5 mg l–1 of betaxanthin and 1361 mg l–1 of betacyanin), were extraction time 1 h, operating temperature 20 ºC, and solvent ratio 0.8 w/v. Being a conventional heating method, it is a simple and cost efficient process with relatively high yield.

Effect of two-step microwave heating on the gelation properties of golden threadfin bream (Nemipterus virgatus) myosin

The effects of different microwave heating (MH) methods on gelation properties of golden threadfin bream myosin and related mechanism were investigated in this study. Compared with conventional heating and one-step MH methods, myosin gel developed by 100 W coupled with 300 W MH method (MH100 + MH300) had stronger gel strength (p < 0.05) with more immobilized water (p < 0.05). Raman analysis suggested that this two-step method promoted the suitable unfolding of myosin before aggregation formation, and contributed to stabilizing the ordered secondary structure. Confocal laser scanning microscopy images revealed that 100 W microwave followed by 300 W MH produced a compact networked structure with small cavities and a thick cross-linked gel wall. Furthermore, from a perspective of molecular forces, the improvement of gelation properties by the MH100 + MH300 method were mainly involved in the enhancement of regular hydrophobic interaction and stabilization of weak protein-water hydrogenbonds.

Catalytic microwave synthesis of biphenyl urea over mesoporous ZrO2-Al2O3

Solid acids such as ZrO2, Al2O3 and ZrO2-Al2O3 were prepared and analyzed for their physico-chemical properties like surface acidity and acid site distribution by NH3-TPD, crystalline nature by powder XRD, functionality by FT-IR, morphology by TEM and elemental analysis by ICP-OES methods. These solid acids were used as catalysts in the solvent free synthesis of biphenyl urea using microwave irradiation technique starting from aniline and dimethyl carbonate. Surface acidity and the phase of the solid acid were found to have a significant role in the synthesis of biphenyl urea. Up to (98%) yield of biphenyl urea with 100% selectivity was obtained in just 12 min. The activity of ZrO2-Al2O3 was compared with Mo(VI)/ZrO2 which is a solid super acid. For comparison, the reactions were also carried out by using conventional heating method. Kinetic studies were carried out to determine energy of activation of the solid acids. These solid acid catalysts were found to be reactivable and reusable when used for up to six reaction cycles.

Synthesis of nanocrystalline barium titanate: Effect of microwave power on phase evolution

Nanocrystalline BaTiO3 (BT) powder was synthesised using a polymer precursor route and the influence of conventional, microwave and combined hybrid heating methods on phase formation was investigated. A single-phase tetragonal BT (t-BT) nanocrystalline powder of about 20 nm primary particle size and decreased agglomeration were formed when high levels of microwave energy were used. This was accomplished at a lower processing condition of 700 °C for 30 min compared to conventional processing, which required 900 °C for 5 h, resulting in potential savings in time and energy. During the nano BT synthesis, the role of microwaves was determined by subjecting the samples to identical thermal histories, i.e. exactly the same time-temperature profiles, while using a range of different levels of microwave power. Significant reduction in the activation energy for the formation of the tetragonal phase was observed with increasing levels of microwave power and the results are explained in terms of a possible non-thermal mechanism. Furthermore, under otherwise identical thermodynamic conditions of temperature, time and (atmospheric) pressure, the co-occurrence of hexagonal crystal structure at < 200 W of additional microwave power along with formation of tetragonal crystal structure at ≥ 200 W and single phase tetragonal crystal structure at ∼1200 W was observed, demonstrating a new method of controlling the phase evolution during the synthesis of nanostructured barium titanate powder. The methodology could be applied to synthesise a variety of functional ceramic powders with tailored levels of crystallographic phases.

Monoterpene-based metallophthalocyanines: Sustainable synthetic approaches and photophysical studies

Tetra-substituted zinc(II) and copper(II) phthalocyanines bearing peripheral alkoxy-monoterpene groups were prepared by conventional vs. non-conventional synthetic approaches (ultrasound and microwave irradiation). The synthesis of (1[Formula: see text]-(–)-myrtenol (a) and (1[Formula: see text],2[Formula: see text],5[Formula: see text]-([Formula: see text]-menthol (b) derived phthalonitrile precursors was performed through ipso-nitro aromatic substitution reactions, with optimal conditions being obtained using ultrasound irradiation, which allowed us to achieve full conversions in 4.5 h, with isolated yields up to 74%. The subsequent cyclotetramerization of monoterpene-based phthalonitriles was carried out using Zn(II) or Cu(II) salts as metal templates, and also using conventional and non-conventional heating methods. Microwave-assisted synthesis was shown to be the most efficient approach, providing complete conversions in 1 h, yielding the target monoterpene-based metallophthalocyanines in up to 70% isolated yields. Furthermore, photophysical and photochemical studies revealed that Zn(II) phthalocyanines possess fluorescence quantum yields in the range of [Formula: see text] 0.27–0.29, while Cu(II) phthalocyanines exhibited room temperature phosphorescence. In addition, the monoterpene-based Zn(II) phthalocyanines led to high singlet oxygen quantum yields ([Formula: see text] 0.55–0.69).

Microwave-Assisted Noncatalytic Esterification of Fatty Acid for Biodiesel Production: A Kinetic Study

This study developed a microwave-mediated noncatalytic esterification of oleic acid for producing ethyl biodiesel. The microwave irradiation process outperformed conventional heating methods for the reaction. A highest reaction conversion, 97.62%, was achieved by performing esterification with microwave irradiation at a microwave power of 150 W, 2:1 ethanol:oleic acid molar ratio, reaction time of 6 h, and temperature of 473 K. A second-order reaction model (R2 of up to 0.997) was established to describe esterification. The reaction rate constants were promoted with increasing microwave power and temperature. A strong linear relation of microwave power to pre-exponential factors was also established, and microwave power greatly influenced the reaction due to nonthermal effects. This study suggested that microwave-assisted noncatalytic esterification is an efficient approach for biodiesel synthesis.

Enhanced CO2 absorption and desorption efficiency using DETA functionalized nanomagnetite/water nano-fluid

The main objective of this research is based on the enhancement in CO2 solubility in water using amine-functionalized Fe3O4 nano-particle at low pressure. The performance of prepared nano-fluid is investigated in CO2 absorption/desorption process in an isothermal batch reactor in the temperature range of 293.15–308.15 K, nano-particle loading ranged from 0 to 0.5 wt.%, and pressure range 120–240 kPa. The prepared nano-fluids are evaluated in terms of CO2 absorption capacity, molar fraction of CO2 in liquid phase and regeneration efficiency of conventional heating method and proposed sonication procedure. The absorption capacity was evaluated to be 0.051, 0.075, 0.082 and 0.087 mol CO2/Kg nano-fluid for the weight percentages of 0, 0.1, 0.3 and 0.5, respectively at 308.15 K and 200 kPa. Thus, increasing the concentration of functionalized nano-particles significantly improves the absorption capacity. The superior improvement of about 77 % was attained using the prepared nano-fluid at 293.15 K. Additionally, the proposed sonicated based regeneration procedure could significantly reduce the demand of regeneration energy (about 23.2 %). Based on the experimental data, the higher CO2 solubility, lower reduction in cyclic absorption/desorption capacity and higher energy efficiency of whole process are achievable using the functionalized nano-fluid and regeneration with the proposed sonication-based procedure.

Microwave assisted tuning of optical and magnetic properties of zinc oxide nanorods—efficient antibacterial and photocatalytic agent

Microwave radiations play an important role in chemical reactions for reducing overall time and cost. The method has many advantages over conventional heating methods like phase purity, high crystallinity, enhanced reaction selectivity, narrow size distribution, energy saving, and high product yield. Microwave-assisted sol–gel route is used to prepare zinc oxide (ZnO) nanorods. X-ray diffraction results show peaks corresponding to Zn (OH)2 and ZnO at low microwave (MW) powers, i.e., at 136, 264, and 440 W. Whereas, increase in MW powers to 616 and 800 W results in dissociation of Zn (OH)2 to ZnO thus forming single-phase ZnO with wurtzite structure. The presence of absorption bands at 461 and 496 cm−1, in FTIR analysis, match to stretching modes of ZnO. Nanorods with diameter ~90 nm and with length of ~210 nm are observed in SEM micrographs at MW power of 800 W. Increased values of transmission (i.e., from 80.98 to 87.49%) are observed with the increase of MW powers from 136 to 800 W. Direct energy band gap of ZnO nanorods is observed in the range of 3.109–3.274 eV. Ferromagnetic behavior instead of diamagnetic nature of ZnO nanorods arises due to bound magnetic polarons (BMP) effect. At 800 W ZnO nanorods show high saturation magnetization (i.e., 0.104 emu/g). Antimicrobial activity is tested against B. Subtilis and E. Coli with 19 mm and 17 mm zone of inhibition, respectively. ZnO nanorods are found efficient photocatalyst for degradation of methylene blue (MB). It is worth to describe that combined optical and magnetic properties’ tuning is studied in this research work.

Tetralin and Decalin H-Donor Effect on Catalytic Upgrading of Heavy Oil Inductively Heated with Steel Balls

The Toe-to-Heel Air Injection (THAI) combined with catalytic upgrading process in situ (CAPRI) has demonstrated it can simultaneously extract and upgrade heavy oil in situ. This paper reports the investigation of augmenting temperature deficit and suppressing coke formation in the CAPRI section through the incorporation of induction heating and H-donor solvents. An induction-heated catalytic reactor was designed and developed, heated with steel balls in a mixed bed of NiMo/Al2O3 catalyst (66% v/v) to 425 °C temperature, 15 bar pressure and 0.75 h−1 LHSV (Liquid Hourly Space Velocity). The catalyst surface area, pore volume and pore size distribution were determined by using nitrogen adsorption–desorption, while the location of coke deposits within the microstructure of the pelleted spent catalyst was analyzed with X-ray nano-Computed Tomography (X-ray nano-CT). Findings showed that induction heating improved the catalyst performance, resulting in a 2.2° American Petroleum Institute (API) gravity increase of the upgraded oil over that achieved with the conventional heating method. The increment in API gravity and viscosity reduction in the upgraded oils with nitrogen gas only, N2 and H-donor solvents, and hydrogen gas environments can be summarized as follows: decalin &gt; H2 gas &gt;= tetralin &gt; N2 gas. Meanwhile, the improvement in naphtha fraction, middle distillate fractions and suppression of coke formation are as follows: decalin &gt; H2 gas &gt; tetralin &gt; N2 gas. The X-ray nano-CT of the spent catalyst revealed that the pellet suffers deactivation due to coke deposit at the external surface and pore-mouth blockage, signifying underutilization of the catalyst interior surface area.

Preparation of mesoporous MCM‐41 supported zinc sorbents by microwave in‐situ oxidation for H2S removal in coal gas

AbstractZn‐based MCM‐41 supporter sorbents were prepared using the microwave in‐situ oxidation method. Other sorbents were heated using a conventional heating method to contrast the performance for H2S removal. The sorbents were tested at 500°C in fixed reactor and dried simulated Texaco coal gas was employed for the sulphurized atmosphere. The results show that sorbents prepared by microwave oxidation had a better toleration for the adsorption of H2S. A 13.2% improvement occurred in the sulphur capacity of the sorbents heated by the microwave method. XRD, SEM with EDS‐element mapping, TEM, N2 adsorption, and XPS were used to characterize the properties of the sorbents. Due to the selective heating of the microwave and the superiority of the in‐situ oxidation method, the sorbents heated by microwave exhibited more appropriate structures for sulphurization. Meanwhile, the even heating environment supplied by the microwave resulted in a more uniform distribution of the active component. The microwave also had an effect on the chemical bond and reduced the binding energy of the active component, which enhanced the reactivity between the H2S and the sorbents. The preferable features generated by microwave in‐situ oxidation accelerate the replacement of S to O, and therefore the Zn‐based MCM‐41 sorbents prepared by the microwave method have an increased capability for H2S removal in high temperature coal gas.

Comparison of the Effects of Ohmic and Conventional Heating Methods on Some Quality Parameters of the Hot-smoked Fish Pâté

ABSTRACTThis research investigates the effect of ohmic and conventional heating methods on the nutritional characteristics of hot-smoked fish pâté, including proximate composition, total volatile base nitrogen (TVB-N) level, thiobarbituric (TBA) value, pH, and mineral content. The hot-smoked pâté samples exposed to different heating methods were examined during storage periods. The technological aspects of the ohmic and conventional heating methods, including process time, energy efficiency, and energy consumption, were also evaluated. TVB-N levels of samples treated by Ohmic heating were considerably higher than those of samples treated by conventional heating at the end of storage. Meanwhile, lower TBA and pH values were detected in ohmic heated fish pâté (OH) compared to conventional heated fish pâté (CH). These quality parameters were within the permissible limits for all the samples of hot-smoked fish pâté. However, ohmic heating had a significant reduction on process time, energy efficiency, and energy consumption compared to conventional heating method. Temperature and electrical conductivity of the hot-smoked fish pâté during the ohmic heating was highly correlated (R2 = 0.999). Ohmic heating, as a volumetric heating technique, promises to be an appropriate alternative to conventional heating for processing hot-smoked fish pâté, although further research is required.

Microwave-assisted continuous-flow synthesis of mixed-ligand UiO-66(Zr) frameworks and their application to toluene adsorption

Mixed-ligand metal–organic frameworks (MIXMOFs) containing two or more organic linkers that exhibit functionalities can show improved selective gas adsorption and separation properties with respect to those of the conventional MOFs. In this study, the mixed-ligand UiO–66(Zr) framework was rapidly prepared by employing a microwave-assisted continuous-flow method, which can be easily scaled up for efficient mass production. A microfluidic syringe pump system was used to introduce the precursor solutions of zirconium metal salt and ligand mixture (terephthalic acid and 2-amino terephthalic acid) into a polytetrafluoroethylene tubular reactor kept under microwave irradiation. MIXMOFs were obtained within 10min, a much shorter time than the reaction time required by the conventional heating method. The prepared samples were characterized by N2 porosimetry, field-emission scanning electron microscopy, Fourier transform infrared spectrometry, thermogravimetric, and powder X-ray diffraction analyses to elucidate the effects of the ligand ratios. Furthermore, the toluene adsorption–desorption tests were conducted using the synthesized mixed-ligand UiO–66(Zr) adsorbents at different temperatures.

The physicochemical properties of chitosan prepared by microwave heating.

The aim of this study was to compare the physicochemical properties of chitosan prepared by microwave and water bath heating with an equivalent quantity of heat intake. The structure and physicochemical properties of the chitosan obtained by these two methods were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffractometry (XRD), gel permeation chromatography (GPC), and scanning electron microscopy (SEM). The FTIR and XRD patterns show that there was no significant difference in the structure of chitosan produced by the two heat sources. The results showed that chitosan with 73.86% deacetylation was successfully prepared by microwave heating within 60 min, while a longer time of 180 min was required for the preparation of chitosan with the same deacetylation degree (74.47%) using the conventional heating method under the same heating rate. Even under the same temperature conditions, microwave technology can greatly reduce the reaction time by approximately 1/3, while the chitosan produced by microwaves can obtain relatively low molecular weight and viscosity. These results showed that microwaves may efficiently promote complete chemical reactions by the friction heating mechanism generated by molecular vibration beyond a rapid heating source, turning into a more efficient, energy‐saving, and environmentally friendly method for the further use of rigid shrimp shells and highly crystalline crustacean materials.

Research on the Influence of Microwave Filler on the Performance of Recycled Asphalt Mixture

In order to study the effect of different microwave fillers on the performance of microwave reclaimed asphalt mixture, carbon black with 10% by volume of asphalt and steel fiber with 6% volume fraction of asphalt were respectively formed by microwave induction method 30%, 40%, 50%. Recycled Asphalt Mixture (RAP) with water-immersed Marshall, uniaxial penetration, four-point bending fatigue for water stability, high temperature stability, fatigue resistance the study. The results show that the asphalt mixture test piece formed by microwave heating has better high temperature stability, water stability, fatigue resistance than the test piece formed by the conventional heating method. the microwave-induced reclaimed asphalt mixture with 40% RAP content has the best high temperature stability. For the performance of high temperature stability, it is better to add steel wool fiber as microwave microwave filler, and the carbon black is used as microwave. Compared with steel fiber, the filler is superior to the water-stable and anti-fatigue of the recycled asphalt mixture under microwave induction.

Isomerization of α-pinene with a hierarchical mordenite molecular sieve prepared by the microwave assisted alkaline treatment

Abstract To develop effective catalysts for α-pinene isomerization reaction is important to get high valuable products. A hierarchical mordenite molecular sieve is prepared using alkaline treatment assisted by the microwave radiation. After the alkaline treatment, the relative crystalline decreases by ~20% and mesopores are introduced in the mordenite molecular sieve. Compared to conventional heating method, microwave assisted alkaline treatment exhibits a selective etching of zeolitic silicon atoms. Aluminum atoms adjacent to silicon atoms are extracted to form Al–OH hydroxyl groups. These extracted aluminum atoms are reconnected to zeolitic silicon atoms. Mordenite after microwave assisted alkaline treatment has a good dispersion of mesopores, higher retention of BrOnsted acid sites in 12-membered rings, and lower concentration of Lewis acid sites. The isomerization reaction of α-pinene suggests that alkaline treatment increases the accessibility of acid sites for α-pinene molecules. The hierarchical porosity increases the conversion of α-pinene from 46.1 to 94.7%. The yields for camphene and limonene increase by 17.0 and 5.4%, respectively. Disproportionation of limonene is inhibited when using microwave assisted alkaline treated mordenite due to a low concentration of Lewis acid sites. These results are important to propose a facile post modification method to realize a selective extraction of zeolitic framework atoms.

Microwave-Assisted Synthesis of 2-(5-(5-(4-Substituted phenyl)-2-(5-methoxy- 2H-chromen-3-yl)-1H-imidazol-1-yl)alkyl)-1H-benzo[de]isoquinoline- 1,3(2H)-dione Derivatives and their Antimicrobial Activity

A method for the synthesis of several imidazoles containing isoquinoline scaffolds under conventional and microwave irradiation methods. In the microwave irradiation method gives higher yields with in shorter reaction time as compared to conventional heating method, using green solvents and eco-friendly reaction conditions. All the synthesized derivatives were characterized by IR, NMR and Mass spectral analysis. Furthermore, the title compounds were screened for their in vitro antimicrobial activity against bacteria such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Klebsiella pneumonia as well as fungi such as Aspergillus niger, Aspergillus flavus and Fusarium oxysporum. The compounds 8a, 8d, 8e and 8h exhibited better antimicrobial activity against all organisms.

Ultrasound-assisted regeneration of zeolite/water adsorption pair.

The use of ultrasound to enhance the regeneration of zeolite 13X for efficient utilization of thermal energy was investigated as a substitute to conventional heating methods. The effects of ultrasonic power and frequency on the desorption of water from zeolite 13X were analyzed to optimize the desorption efficiency. To determine and justify the effectiveness of incorporating ultrasound from an energy-savings point of view, an approach of constant overall input power of 20 or 25W was adopted. To measure the extent of the effectiveness of using ultrasound, the ultrasonic-power-to-total power ratios of 0.2, 0.25, 0.4 and 0.5 were investigated and the results compared with those of no-ultrasound (heat only) at the same total power. To analyze the effect of ultrasonic frequency, identical experiments were performed at three nominal ultrasonic frequencies of ~28, 40 and 80kHz. The experimental results showed that using ultrasound enhances the regeneration of zeolite 13X at all the aforementioned power ratios and frequencies without increasing the total input power. With regard to energy consumption, the highest energy-savings power ratio (0.25) resulted in a 24% reduction in required input energy and with an increase in ultrasonic power, i.e. an increase in acoustic-to-total power ratio, the effectiveness of applying ultrasound decreased drastically. At a power ratio of 0.2, the time required for regeneration was reduced by 23.8% compared to the heat-only process under the same experimental conditions. In terms of ultrasonic frequency, lower frequencies resulted in higher efficiency and energy savings, and it was concluded that the effect of ultrasonic radiation becomes more significant at lower ultrasonic frequencies. The observed inverse proportionality between the frequency and ultrasound-assisted desorption enhancement suggests that acoustic dissipation is not a significant mechanism to enhance mass transfer, but rather other mechanisms must be considered.

Microwave heating motivated performance promotion and kinetic study of iron oxide sorbent for coal gas desulfurization

High temperature coal gas desulfurization is an efficient and environment-friendly process for clean coal technologies. In this study, microwave heating is adopted as the energy source to prepare iron oxide desulfurization sorbents and the effect on the properties of the sorbents is investigated. Sorbent synthesized through the conventional heating method is obtained as well for comparison. Characterization techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), scanning electron microscope (SEM) and N2 adsorption are used to evaluate the as-prepared sorbents. Results from XAS and XRD show that Fe2O3 crystal possesses smaller volume and shorter length in bonds Fe-O and Fe-Fe, suggesting that there is a better dispersion of crystallites under microwave irradiation. According to XPS results, microwave irradiation induces sorbents with higher contents of surface lattice O2−, which is contributive to increasing the absorption efficiency and desulfurization reactivity towards the removal of H2S. With the help of thermogravimetry devices, kinetic studies produce the result that both the desulfurization and regeneration processes adapt the model of unreacted shrinking core. The reaction rates are limited via surface chemical reaction at first and then controlled by internal diffusion control in the later stage. Sorbents produced by microwave heating, on the whole, show a better H2S removal performance due to their facilitated chemical reaction and mass transfer, suggesting the potential of the preparation of improved industrial sorbents.

Conception, implementation and evaluation of induction wire heating system applied to hot wire GTAW (IHW-GTAW)

A notable advantage of the GTAW process with the use of a hot wire is the higher deposition rate, which can be twice as high as that achieved with a cold wire for the same welding current. In the conventional procedure, the wire is heated through the passage of current to create heat by the Joule Effect. However, due to the interaction of the magnetic fields generated by the currents which circulate through the wire and the arc, the deflection of the arc (by magnetic blow) occurs. This paper describes the conception, construction and evaluation of a wire heating system based on electromagnetic induction, aimed at minimizing or even eliminating the problems inherent to the conventional heating technique of passing a current. The induction heating method was applied in the hot wire GTAW process (resulting in the IHW-GTAW technique), using different values for the welding current (100, 150 and 200 A) and coil currents between 20 and 120 A. For the same welding current, a gain of up to 220 % could be achieved in the deposition rate by preheating the wire with the IHW-GTAW technique, when compared with the rate achieved with the cold wire (CW-GTAW) method, showing a high heating efficiency. No magnetic blow or arc instability was observed with the induction heating method. In addition, because it can operate without the need for permanent contact of the wire with the molten pool (as the secondary arcing observed with the conventional heating method does not occur), other applications are envisaged, such as GTAW with tangential wire feeding, GTAW with dynamic feeding, hot wire techniques using laser and GMAW processes, as well as brazing.