Conveyor Belt Furnace Research Articles

Brazing of Ferritic Stainless Steel with Ni-25Cr-6P-1.5Si-0.5B-1.5Mo Amorphous Brazing Foil Having a Liquidus of 1243 K with Continuous Conveyor Belt Furnace in Low-Oxygen Atmosphere

Brazing of Ferritic Stainless Steel with Ni-25Cr-6P-1.5Si-0.5B-1.5Mo Amorphous Brazing Foil Having a Liquidus of 1243 K with Continuous Conveyor Belt Furnace in Low-Oxygen Atmosphere

Sputtered Phosphorus‐Doped poly‐Si on Oxide Contacts for Screen‐Printed Si Solar Cells

The impact of the phosphorus doping density in direct current‐sputtered polysilicon layers on surface passivation and contact resistance by fabricating polysilicon on oxide (POLO) contacts is studied, when applying doping densities ranging from 3 × 1019 to 4 × 1020 cm−3. Hydrogenation is performed either via a hydrogen‐releasing AlO x layer and postdeposition anneals in forming gas using a tube furnace at 400 °C, or by rapid firing of an AlO x /SiN y stack in a conveyor belt furnace at 810 °C. The study shows that the forming gas anneal of the weakly in situ phosphorus‐doped poly‐Si layers with AlO x enables a passivation quality with an implied open‐circuit voltage of up to 734 mV and a recombination current density down to 1.8 fA cm− 2. For fast firing, a high phosphorus concentration of 4 × 1020 cm−3 is required for comparably high passivation quality with a recombination current density down to 1.3 fA cm− 2. A p‐type POLO back‐junction solar cell featuring such ex situ doped sputtered POLO contacts with a cell efficiency of 22.4% and an open‐circuit voltage of 714 mV is fabricated. To our knowledge, this is the highest open‐circuit voltage published so far with sputtered POLO contacts.

Carrier Lifetime Stability of Boron-Doped Czochralski-Grown Silicon Materials for Years After Regeneration in an Industrial Belt Furnace

We examine the long-term stability of the carrier lifetime in boron-doped Czochralski-grown silicon materials with different boron and oxygen concentrations, which were regenerated in an industrial belt furnace. After firing and subsequent regeneration in an industrial conveyor-belt furnace, the silicon samples are exposed to long-term illumination at an intensity of 0.1 suns and a sample temperature of about 30 °C for more than two years. After regeneration, we observe a minor re-degradation (30–72% reduced compared to the degradation observed without regeneration step). We attribute this re-degradation to a non-completed regeneration within the belt furnace due to the short regeneration period. Our results show that the industrial process consisting of firing with subsequent regeneration in the same unit is very effective for industrially relevant silicon materials. Typical industrial silicon wafers with a resistivity of (1.75 ± 0.03) Ωcm and an interstitial oxygen concentration of (6.9 ± 0.3) × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">17</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">–3</sup> show lifetimes larger than 2 ms after regeneration and two years of light exposure.

In Situ Surface Temperature Measurement in a Conveyor Belt Furnace via Inline Infrared Thermography.

Measuring the surface temperature of objects that are processed in conveyor belt furnaces is an important tool in process control and quality assurance. Currently, the surface temperature of objects processed in conveyor belt furnaces is typically measured via thermocouples. However, infrared (IR) thermography presents multiple advantages compared to thermocouple measurements, as it is a contactless, real-time, and spatially resolved method. Here, as a representative proof-of-concept example, an inline thermography system is successfully installed into an IR lamp powered solar firing furnace, which is used for the contact firing process of industrial Si solar cells. This protocol describes how to install an IR camera into a conveyor belt furnace, conduct a customer correction of a factory calibrated IR camera, and perform the evaluation of spatial surface temperature distribution on a target object.

Concentrator In2O3:F/(n+pp+)c-Si/Al solar cells with Al-alloyed BSF and Ag-free multi-wire metallization using transparent conductive polymers

Cost-effective low concentrator c-Si-based PV systems have been under development for more than 30 years without any significant commercial break-through. One primary reason for that is the cost and availability of Si cells for such applications. We have developed high efficiency low concentrator crystalline silicon (c-Si) solar cells using the standard SiNx/(n+pp+)c-Si/Al structures with a P-doped n+-emitter and screen-printed Al-alloyed Al-p+ back-surface-field (BSF). Ag-free multi-wire metallization has been applied using transparent conductive polymers. We have investigated seven groups of solar cell structures based on both Cz-Si and mc-Si and produced by the BSF formation processes with various peak firing temperatures (TF) in a conveyor belt furnace. TF was varied in the range of 820,940 °C in 20 °C steps. Surface morphology of the structures has been examined by scanning electron microscope. External quantum efficiency, reflection spectra, sheet resistance, Suns-Voc and current–voltage dependence under illumination have been studied. The structures obtained at TF = 860 °C have been used for fabrication of low concentrator solar cells based on an indium fluorine oxide (IFO)/(n+pp+)c-Si/Al structure. Transparent conductive IFO films, acting as passivating and antireflection electrodes, were grown by ultrasonic spray pyrolysis. A copper wire contact pattern was attached by low-temperature lamination simultaneously to the front (IFO) and rear (Al) layers using transparent conductive polymer films (laminated grid cell (LGCell) design). The best LGCells from Cz-Si/mc-Si showed an efficiency of 18.3–19.2%/15.9–16.7% in the operating range of 1–12suns/1–10 suns.

Role of Firing Temperature, Sheet Resistance, and Contact Area in Contact Formation on Screen-Printed Metal Contact of Silicon Solar Cell

Formation of an Ohmic contact requires a suitable firing temperature, appropriate doping profile, and contact dimensions within resolution limits of the screen-printing process. In this study, the role of the peak firing temperature in standard rapid thermal annealing (RTA) six-zone conveyor belt furnace (CBF) and two inexpensive alternate RTA systems [a custom-designed, three-zone, 5″-diameter quartz tube furnace (QTF) and a tabletop, 3″-diameter rapid thermal processing (RTP)] has been investigated. In addition, the role of sheet resistance and contact area in achieving low-resistance ohmic contacts has been examined. Electrical measurements of ohmic contacts between silver paste/n +-emitter layer with varying sheet resistances and aluminum paste/p-doped wafer were carried out in transmission line method configuration. Experimental measurements of the contact resistivity (ρ c) exhibited the lowest values for CBF at 0.14 mΩ cm2 for Ag and 100 mΩ cm2 for Al at a peak firing temperature of 870°C. For the QTF configuration, lowest measured contact resistivities were 3.1 mΩ cm2 for Ag and 74.1 mΩ cm2 for Al at a peak firing temperature of 925°C. Finally, for the RTP configuration, lowest measured contact resistivities were 1.2 mΩ cm2 for Ag and 68.5 mΩ cm2 for Al at a peak firing temperature of 780°C. The measured contact resistivity exhibits strong linear dependence on sheet resistance. The contact resistivity for Ag decreases with contact area, while for Al the opposite behavior is observed.

ANALISA STRUKTUR MIKRO DAN SIFAT MEKANIK PADA COPPER-IRON MELALUI PROSES MECHANICAL MILLING DAN CONTINUOUS SINTERING

&lt;em&gt;Mechanical Alloying (MA) / Mechanical Milling (MM) is a process of processing of solid metal powders including the union and re-destruction of powder particles by using high-energy ball mill. The difference depends on whether material transfer is involved or not during processing. The study was conducted by analyzing the effect of the mechanical milling process by comparing the microstructure and mechanical properties of the copper-iron between the ones before milling (sample 1) and after milling for 2 hours (sample 2). The sample was made into a green compact cold pressing process with an emphasis system using mechanical mechanisms and dual emphasis techniques. Sintering process using continuous type machine with conveyor belt mesh and furnace type is muffle. After that cooled with natural water jacket process. Vicker hardness testing and strength testing (tensile strength test) is performed to determine the mechanical properties of copper-iron alloys that occur. The mean value of sample 1 hardness (before milling) was 39.8 HV. The mean value of sample hardness 2 (after milling) was 74.9 HV. The value of the yield strength (σ) of sample 1 is 17.597MPa, and the value of ductility (ε) is 0.119. The value of the yield strength (σ) of sample 2 is 18.547MPa, and the value of ductility (ε) is 0.073. The observation of micro structure was done to know the physiological surface of the alloy formed and to know the distribution of the composition. Observation of sample microstructure 1 shows solid phase formation ε (silver color) is an area of iron element formed with large size. Solid phase γ (orange color) is an area of copper element formed with large size. The visible elements are copper (Cu) and iron (Fe) which have a large percentage formed with large size (&amp;gt; 50 μm), and the pore is also large (&amp;gt; 50 μm). For carbon element (C), it looks gray, with a small amount. For other elements, such as zinc (Zn), phosphorus (P), and Tin (Sn), generally, they are at the grain boundary of iron (Fe) and copper (Cu) elements. Observation of sample microstructure 2 shows solid phase formation ε (silver color) showing iron area area formed with smaller size. The solid phase γ (white color) shows the copper element area formed with a smaller size. The elements seen are copper (Cu) and iron (Fe) with a small size (&amp;lt;50 μm), and small pores occur. From the test results and analysis showed that by shrinking the size of metal powder by milling for 2 hours can increase the hardness and yield strength of the product. Although the product becomes more brittle which is indicated by the decreased ductility value.&lt;/em&gt;

In-depth investigation of spin-on doped solar cells with thermally grown oxide passivation

Solar cell industrial manufacturing, based largely on proven semiconductor processing technologies supported by significant advancements in automation, has reached a plateau in terms of cost and efficiency. However, solar cell manufacturing cost (dollar/watt) is still substantially higher than fossil fuels. The route to lowering cost may not lie with continuing automation and economies of scale. Alternate fabrication processes with lower cost and environmental-sustainability coupled with self-reliance, simplicity, and affordability may lead to price compatibility with carbon-based fuels. In this paper, a custom-designed formulation of phosphoric acid has been investigated, for n-type doping in p-type substrates, as a function of concentration and drive-in temperature. For post-diffusion surface passivation and anti-reflection, thermally-grown oxide films in 50–150-nm thickness were grown. These fabrication methods facilitate process simplicity, reduced costs, and environmental sustainability by elimination of poisonous chemicals and toxic gases (POCl3, SiH4, NH3). Simultaneous fire-through contact formation process based on screen-printed front surface Ag and back surface through thermally grown oxide films was optimized as a function of the peak temperature in conveyor belt furnace. Highest efficiency solar cells fabricated exhibited efficiency of ∼13%. Analysis of results based on internal quantum efficiency and minority carried measurements reveals three contributing factors: high front surface recombination, low minority carrier lifetime, and higher reflection. Solar cell simulations based on PC1D showed that, with improved passivation, lower reflection, and high lifetimes, efficiency can be enhanced to match with commercially-produced PECVD SiN-coated solar cells.

Ex-situ and in-situ investigations of thermal anti-oxidation treatments of stainless steels by reflection mode EXAFS

Different thermal treatments were performed for the anti-oxidation of steel surfaces, and the processes were investigated ex-situ and in-situ by surface sensitive reflection mode EXAFS experiments at the Cr and Fe K-edges. While the samples for the ex-situ studies were heat-treated in a conveyor belt furnace at temperatures between 600 and 900 °C in inert carrier gases (N2 or Ar) using different additives such as hydrogen (H2) and monosilane (SiH4), the in- situ anti-oxidation treatments have been performed in a high vacuum environment (p < 10-6 mbar). While the ex-situ experiments suggest that SiH4-additives are needed for the reduction of the steel to a metallic state, the in-vacuum treatments appear successful for temperatures above approx. 900 °C.

Thermal anti-oxidation treatment of CrNi-steels as studied by EXAFS in reflection mode: the influence of monosilane additions in the gas atmosphere of a continuous annealing furnace

Surface sensitive, reflection mode EXAFS spectroscopy at the Cr and Fe K-edges was used to study the surfaces of stainless steel (EU alloy grade 1.4301 X5CrNi18-10) after different heat treatments. The thermal treatments were performed in a conveyor belt furnace at temperatures between 600 and 900 °C in different gas atmospheres containing inert carrier gases (N2 or Ar) and different additives such as hydrogen (H2) and monosilane (SiH4). The ex-situ EXAFS results show that the iron and chromium in the steel can only be reduced to a metallic state, if SiH4 was used as a reducing additive for temperatures of 900 °C. Lower temperatures and process atmospheres without silane always result in strongly oxidized steel surfaces.

The ${\bf ALU}^{+}$ Concept: $N$-Type Silicon Solar Cells With Surface-Passivated Screen-Printed Aluminum-Alloyed Rear Emitter

Aluminum-doped p-type (Al-p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> ) silicon emitters fabricated by means of screen-printing and firing are effectively passivated by plasma-enhanced chemical-vapor deposited (PECVD) amorphous silicon (a-Si) and atomic-layer-deposited (ALD) aluminum oxide (Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) as well as Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> stacks, where the silicon nitride (SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> ) layer is deposited by PECVD. While the a-Si passivation of the Al-p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> emitter results in an emitter saturation current density J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> e of 246 fA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , the Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /SiN <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> double layers result in emitter saturation current densities as low as 160 fA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , which is the lowest J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> e reported so far for screen-printed Al-doped p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> emitters. Moreover, the Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> as well as the Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /SiN <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> stacks show an excellent stability during firing in a conveyor belt furnace at 900 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C. We implement our newly developed passivated Al-p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> emitter into an n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> np <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> solar cell structure, the so-called ALU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> cell. An independently confirmed conversion efficiency of 20% is achieved on an aperture cell area of 4 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , clearly demonstrating the high-efficiency potential of our ALU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> cell concept.

Pulling more performance by walking

As things get hotter to produce sintering results, conveyor belt furnace manufacturers have to raise their game to keep market share…

Rapid thermal technologies for high-efficiency silicon solar cells

This paper shows that rapidly formed emitters in less than 6 min in the hot zone of a conveyor belt furnace or in 3 min in an rapid thermal processing (RTP) system, in conjunction with a screen-printed (SP) RTP Al-BSF and passivating oxide formed simultaneously in 2 min can produce very simple high-efficiency n + -p-p + cells with no surface texturing, point contacts, or selective emitter. It is shown for the first time that an 80Ω/□ emitter and SP Al-back surface field (BSF) formed in a high throughput belt furnace produced 19% FZ cells and greater than 17% CZ cells with photolithography (PL) contacts. Using PL contacts, we also achieved 19% efficient cells on FZ, > 18% on MCZ, and ∼ 17% boron-doped CZ by emitter and SP Al-BSF formation in < 10 min in a single wafer RTP system. Finally, manufacturable cells with 45 Ω/□ emitter and SP Al-BSF and Ag contacts formed in the conveyor belt furnace gave 17% efficient cells on FZ silicon. Compared to the PL cells, the SP cell gave ∼2% lower efficiency along with a decrease in J sc and fill factor. This loss in performance is attributed to a combination of the poor blue response, higher series resistance and higher contact shading in the SP devices.

Hydrogen passivation of defects in EFG ribbon silicon

To enhance the bulk lifetime of multicrystalline silicon material, gettering of impurities and hydrogen passivation of defects are investigated. In edge-defined film-fed grown (EFG) ribbon silicon, an aluminium-enhanced hydrogenation of defects by silicon nitride has been reported. On thin wafers, the formation of a full area aluminium back surface field will lead to wafer bending due to different thermal expansion coefficients of aluminium and silicon. To circumvent this problem, remote plasma-enhanced chemical vapour deposited (PECVD) silicon nitride (SiN x ) as passivation scheme for the front and rear surface is proposed. In this work, the bulk passivation by hydrogenation is investigated using two different hydrogen passivation techniques: (i) passivation in a remote hydrogen plasma and (ii) passivation due to a post-deposition anneal of remote PECVD-SiN x in a lamp-heated conveyor belt furnace. Measurements of the bulk lifetime show that the lifetime improvement due to remote hydrogen plasma passivation degrades under illumination with white light. In contrast, the hydrogen passivation by a post-deposition SiN x anneal is only effective if a phosphorous-doped emitter is present below the SiN x layer during the hydrogenation. This lifetime improvement is stable under illumination.

Hydrogenation of defects in edge-defined film-fed grown aluminum-enhanced plasma enhanced chemical vapor deposited silicon nitride multicrystalline silicon

Gettering of impurities and hydrogen passivation of defects in edge-defined film-fed grown (EFG) multicrystalline silicon were studied by low-cost manufacturable technologies such as emitter diffusion by a spin-on phosphorus dopant source, back surface field formation by screen-printed aluminum, and a post-deposition anneal of plasma enhanced chemical vapor deposited (PECVD) silicon nitride antireflection coating. These processes were carried out in a high-throughput lamp-heated conveyor belt furnace. PECVD silicon nitride-induced hydrogenation of defects in EFG silicon was studied in conjunction with screen-printed aluminum back surface field formation to investigate the synergistic effect of aluminum gettering and silicon nitride hydrogenation of bulk defects. It was found that post-deposition anneal of PECVD silicon nitride at temperatures ranging from 450 to 850 °C, without the coformation of aluminum back surface field on the back, does not provide appreciable passivation or hydrogenation of bulk defects in EFG material. However, simultaneous anneal of PECVD silicon nitride and formation of aluminum back surface field at 850 °C significantly enhanced the hydrogenation ability of the PECVD silicon nitride film. PECVD silicon nitride deposition and a subsequent anneal, after the aluminum back surface field formation, was found to be less effective in passivating bulk defects. It is proposed that aluminum-enhanced hydrogenation from a PECVD silicon nitride film is the result of vacancy generation at the aluminum-silicon interface due to the alloying process. The affinity of hydrogen to react with vacancies provides a chemical potential gradient that increases the flux of atomic hydrogen from the silicon nitride film into the bulk silicon. In addition, vacancies can dissociate hydrogen molecules, increasing the atomic hydrogen content of the bulk silicon. This enhances defect passivation and improves the minority carrier lifetime.

TiO2 Coating by Atmospheric Pressure MOCVD in a Conveyor Belt Furnace for Industrial Applications

TiO2 Coating by Atmospheric Pressure MOCVD in a Conveyor Belt Furnace for Industrial Applications

How to achieve cost-effective sintering

Conveyor belt sintering furnaces presently used in iron powder metallurgy (PM) are classified, compared and contrasted according to their design features. If furnaces vary in their design but have comparable output capacities, the consumption of power, atmosphere gases, etc. as well as the finite operating cost per kilogram of sintered product are discussed. It is shown that the lowest operating cost is achieved by using conveyor belt furnaces which incorporate de-waxing zones which are heated by the protective gas issuing from the electrically heated sintering zone, the protective gas itself being produced by catalytic generation within the body of the furnace.

Advanced Copper/Polyimide Hybrid Technology

In the past, a unique hybrid IC processing approach which combines wet-metallized copper, air-fired (ruthenium-based) RuO 2 paste, and photoactive polyimide, was presented by the authors [1], Now, a further improved and advanced new copper/polyimide hybrid technology Mitsubishi Copper Polyimide Hybrid (MCPH) has been developed. The new MCPH was processed using a large (106 x 106 mm) Al 2 O 3 substrate, full copper system (all layers) with 50-µm fine lines. For the first layer, the full-additive process was adopted, while for the other layers, a semiadditive process was employed. The photoactlve polyimide interlayer insulation is screen printed, and after the exposure and development steps, is cured using a conveyor belt furnace. This new process has many excellent features, such as uniform coating thickness, better mass-production capability, etc. The MCPH fundamental processes were evaluated and established using an MCPH Test Element Group (TEG). This TEG has fine lines, small diameter vias and/or pads, matrix lines, etc. To compare characteristics, the same circuit as a conventional hybrid IC was fabricated by applying the MCPH technology. As a result, this functional MCPH (MCPH ES) is a compact size (less than 1/2 the circuit area), has excellent electrical parameters, and high reliability. This MCPH ES uses a flip-chip IC (2.9 mmx 3.4 mm) with 30 small solder bumps (100 µm, min. 170-µm pitch). Important MCPH process factors and/or reliability factors were fully evaluated by using the TEG and functional ES. Through various tests (thermal cycle, voltage loaded, humidity, pressure cooker, break-down or leak, etc.), the MCPH shows excellent reliability characteristics. Consequently, a unique MCPH has been developed using a simple, reliable, cost-effective and excellent massproduction multilayer-hybrid process.

Infrared Thermal Regeneration of Spent Activated Carbon from Water Reclamation

An infrared conveyor-belt furnace was evaluated and utilized to conduct a parametric study on the effects of temperature and residence time on spent granular carbon intraparticle structure and concomitant regeneration efficiencies, incorporating an appraisal of the efficacy of low-temperature long-residence-time regeneration conditions. In addition, a virgin carbon of the same type and particle size fraction as was used in the above regeneration study, was subjected to equivalent temperature and residence time conditions to serve as a control experiment designed to shed light on the effects of regeneration conditions on the activated carbon per se. The infrared furnace proved to be an effective system for the regeneration of spent carbon; and an optimum operating region of 800 °C/10 min to 850 °C/5 min was identified. Temperatures in excess of 850 °C, regardless of residence time, must be avoided since excessive structural and pore volume distribution degradation is effected.