Gaseous By-products Research Articles

Development of dimethyl ether synthesis processes using by-product gas from a steel-making plant: Single-vs. two-step processes

This work addresses the development of a DME synthesis process from a mixture of coke oven gas (COG) and FINEX tail gas (FTG) from a steel-making plant. Two different syngas-to-DME processes were considered: one using two separate reactors for the methanol synthesis over Cu–ZnO–Al2O3 (CZA) and the methanol dehydration over ferrierite (FER) zeolite catalysts, and the other using a single reactor by physically mixing the two catalysts. Kinetic models were developed for each catalyst and the kinetic parameters were estimated by fitting the experimental data at various conditions of temperatures, pressures, space velocities, and feed compositions. The process modeling results showed that the single reactor achieved a CO conversion of 88.1% and a DME production rate of 450 kg/h, while the corresponding values for the method employing two separate reactors were 38.6% and 240 kg/h, respectively. This difference is attributable to the spontaneous conversion of the produced MeOH to DME, by the coexistence of the two catalysts, which shifted the equilibrium of MeOH production forward. The comparison between the open-loop and recycled cases showed that the carbon efficiency could be more than doubled for both reactor configurations when the unreacted gas was recycled. Finally, the single-reactor configuration employing the recycled stream produced DME at a rate of 825.9 kg/h with the complete consumption of CO and a CO2 conversion of 76%. This indicated that such a process would maximize the use of by-product gas and increase the economic feasibility of steel-making plants.

Reduction of tar from biomass gasification using a dielectric barrier discharge reactor

A non-thermal plasma reactor was used to investigate its effectiveness in reducing the by-products from biomass gasification. Biomass is used for generating heat and power through gasification, which is a process of converting solid fuel to gaseous fuel at temperatures of 700 to 900 °C by operating a reactor in sub-stoichiometric conditions. This gas mixture can be utilized for liquid fuel synthesis or for fuel cells. However, the by-product of gasification consists of tar, which consists of oxygenates, ringed-aromatics, phenolic compounds, and polyaromatic hydrocarbons (PAH). Depending on the composition, the condensation temperature can be as high as 450 °C, fouling downstream equipment. In this study, a dielectric barrier discharge (DBD) reactor with a coil as the inner electrode was used to reduce toluene, a model tar compound. Toluene was injected into a mixing chamber that was heated to 900 °C, evaporating the toluene, and is entrained by nitrogen into the DBD reactor. High voltage is injected into the DBD reactor to initiate ionization, decomposing the toluene into lighter hydrocarbons. A sampling bottle submerged in an ice bath collects the residual toluene, and the resulting decomposition rate is as high as 70%.

Simulation and optimization of a combined cycle power plant with low heating value fuel gas

Combined cycle power plant (CCPP) usually plays an important role in balancing byproduct gas generation and consumption in integrated iron and steel plant. The low heat value fuel gases, such as blast furnace gas (BFG) or mixed gas with Coke oven gas (COG) and BFG, are preferred to be used in high-efficient CCPP for power generation. In practice, the general heat value of mixed gas can be set in the range of 3500–4400[Formula: see text]kJ/Nm3. This paper presents a methodology to simulate operating parameters of CCPP with BFG. A generic model of gas turbine with open loop stage cooling employing air is used to simulate the performance of gas turbines cycle under different compressor pressure ratios and turbine inlet temperatures (TIT). The isentropic efficiencies for gas compressor and gas turbine are supposed to be constants and set corresponding to published industrial experience. The steam cycle is composed of classical double-pressure heat recovery steam generator (HRSG) and steam turbines according to gas turbine outlet temperature. Specific work, gas turbine cycle efficiency, cogeneration thermal efficiency and coolant air flow requirements are evaluated to find the optimal compressor pressure ratio and TIT. The research results are useful to select the optimum operating parameters of CCPP with BFG. Performance features were estimated with the help of compression ratios 12.5–20 and combustor exit temperature 1150–1350[Formula: see text]C.

An efficient process for sustainable and scalable hydrogen production from green ammonia

This study comprehensively investigates hydrogen production from green ammonia reforming, including synthesis of catalysts, reactor development, process integration, and techno-economic analysis. In-house developed Ru/La–Al2O3 pellet catalyst having perovskite structure showed high catalytic activity of 2827 h−1 at 450 °C and stability over 6700 h at 550 °C, exceeding the performance of the majority of powder catalysts reported in the literature. A scalable 12-faceted reactor adopting the as-produced catalyst was designed to enhance heat transfer, producing over 66 L min−1 of hydrogen with state-of-the-art ammonia reforming efficiency of 83.6 %. Near-zero CO2 emission of hydrogen extraction from green ammonia was demonstrated by-product gas recirculation as a combustion heat source. A techno-economic assessment was conducted for system scales from 10 kW to 10 MW, demonstrating the effect of reduced minimum hydrogen selling prices from 7.03 USD kg−1 at small modular scales to 3.98 USD kg−1 at larger industrial scales. Sensitivity analyses indicate that hydrogen selling prices may reduce even further (up to 50 %). The suggested hydrogen production route from green NH3 demonstrates superior CO2 reduction ranging from 78 % to 95 % in kg CO2 (kg H2)−1 compared to biomass gasification and steam methane reforming. These findings can be used as a basis for following economic and policy studies to further validate the effectiveness of the suggested system and process for H2 production from NH3.

Integration of waste biomass thermal processing technology with a metallurgical furnace to improve its efficiency and economic benefit

The article presents innovative technology which integrates a metallurgical pusher-type furnace with a waste heat recovery system that consisted of a reactor for torrefaction and pyrolysis of waste biomass. The technology is designed for utilizing both liquefied and gaseous by-products (torgas, pyrolysis gas and condensate denoted as TPC) obtained from torrefaction and pyrolysis of waste biomass. TPC is considered to be applied as an additional fuel for a metallurgical furnace as an example of effective energy management in metallurgical industry. In detail, the technology contains waste heat recovery unit installed on the furnace smoke stack as the heat source for the pyrolysis/torrefaction reactor. The analysis was carried out for a pusher furnace, fed optionally with either natural gas or coke gas. Share of this gaseous/liquid TPC fuel from waste in the total fuel mixture fed to the furnace was varied from 5 to 15% by volume. Practical usefulness of TPC fuel was tested on a specially constructed test stand. Financial analysis in energy consumption and economy of using the obtained TPC fuel for co-combustion with coke gas in the metallurgical pusher furnace was carried out on the basis of data from a steel sheet roller combined with the pusher furnace located in one of large steel works. It was shown that the use of this TPC fuel derived from thermal treatment of waste biomass and other organic substances can be considered an effective method of reducing production costs in the analyzed steel company and can lead to increase in the attractiveness of their products and thus strengthen their competitiveness on the global market.Graphic abstract

Visualization of Bubble Nucleation and Growth Confined in 2D Flakes.

The nucleation and growth of bubbles within a solid matrix is a ubiquitous phenomenon that affects many natural and synthetic processes. However, such a bubbling process is almost "invisible" to common characterization methods because it has an intrinsically multiphased nature and occurs on very short time/length scales. Using in situ transmission electron microscopy to explore the decomposition of a solid precursor that emits gaseous byproducts, the direct observation of a complete nanoscale bubbling process confined in ultrathin 2D flakes is presented here. This result suggests a three-step pathway for bubble formation in the confined environment: void formation via spinodal decomposition, bubble nucleation from the spherization of voids, and bubble growth by coalescence. Furthermore, the systematic kinetics analysis based on COMSOL simulations shows that bubble growth is actually achieved by developing metastable or unstable necks between neighboring bubbles before coalescing into one. This thorough understanding of the bubbling mechanism in a confined geometry has implications for refining modern nucleation theories and controlling bubble-related processes in the fabrication of advanced materials (i.e., topological porous materials).

Respiratory Disorders, Pulmonary Functions and Radiological Abnormalities among Workers Exposed to Welding Fumes

Introduction: The welding process produces visible smoke that containsharmful metal fume and gas by-products which may have deleterious effectson the respiratory system. Aim of Work: To study the prevalence of respiratorysymptoms and diseases, and to detect the changes in pulmonary functions andchest X rays among welders. Materials and Methods: This cross-sectionalstudy was conducted in the Shuaiba industrial area, Kuwait. Two hundred andthirty-five welders and 155 unexposed workers were interviewed using theBritish Medical Research Council questionnaire; clinical examination (generaland local to the chest) was done. Workers underwent measurements of lungfunctions, and chest X rays were performed and interpreted, according to theILO classification of pneumoconiosis. Cases suggestive of pneumoconiosisunderwent high-resolution CT scanning. Results: Exposure to weldingfumes significantly increased the prevalence of chronic cough in the earlymorning, it was 1.74 times fold higher compared with unexposed workers.Chronic bronchitis was more prevalent among welders, but the result wasnot statistically significant. Metal fume fever was experienced by 23.4% ofthe studied welders, the majority reported one or two attacks per year, and attacks usually lasted for one or two days. The frequency of sick leaves wassignificantly higher among welders (35.74%) compared with unexposedworkers (14.19%), and was mainly due to respiratory diseases, followedby musculoskeletal disorders, and injuries. Lung function indices (LFIs)(FVC, FEVI, FEV1%, PEFR, FEF75%, FEF50%, and FEF25%) showed significantdecrements among welders after adjusting for age, height, weight, andsmoking, moreover, increase in the duration of exposure to welding fumes wassignificantly associated with a decrease in lung functions after allowing for theeffect of confounders. Findings suggestive of pneumoconiosis were observedamong welders. Conclusion: Welding fumes had significant adverse effects onthe respiratory system of welders and safety measures should be encouragedamong workers.

Carbon deposition mechanism and structural changes for zeolite-templated carbons

The process of synthesizing a zeolite/carbon composite (ZCP) is the first chemical event for preparing a zeolite-templated carbon (ZTC) via the chemical vapor deposition (CVD) process. The purpose of this work was to investigate the effect of CVD time duration (up to 446 min) at 600 °C and then heat treatment at 800 °C on the structure of the pyrolytic carbon formed. The CVD process with 13X zeolite as the template was performed in a thermogravimetric analyzer (TGA) using a low acetylene concentration (2 % by vol. In N 2 ). A thermogravimetric analyzer connected to a mass spectrometer (TG-MS) characterized the in-situ mass change that a zeolite particle underwent during a TGA run, while the MS monitored the decrease in C 2 H 2 concentration and the appearance of C 2 H 2 decomposition products (H 2 , CH 4 , C 6 H 6 ). Optical analysis and SEM/EDS of the macro- and micro-morphology of the ZCP indicated that pyrolytic carbon was deposited gradually in the nano-pores, starting from the edge of the spherically shaped zeolite. The XPS and XRD analysis indicated that the pyrolytic carbon deposited in the nano-pores was mainly connected by C–C and C C bonds, whereas some quasi-crystal graphitic carbon was formed at the zeolite's external surface. Finally, three stages of carbon formation were identified during the CVD process in the TGA and the mass-time profile generated by the TGA curve was well predicted by a diffusion-reaction equation model. Findings from this work provided useful insight for designing, and optimizing a CVD process used for the synthesis of ZCP. • One particle zeolite was used to synthesis ZCP in a TGA analyzer by the CVD process. • TG-MS monitored the mass change of ZCP and the evolution of gaseous by-products. • DRE model was presented to predict the mass increase of ZCP with time. • Mechanisms of carbon deposition in the zeolite nano-pores has been revealed.

석유화학 NCC 공정의 부생수소 가스 정제용 PSA 흡착제 특성

In this study, four types of adsorbents for PSA process suitable for the purification of low-purity by-product hydrogen gas generated in the petrochemical NCC process were selected and their characteristics were reviewed by performing SEM-EDS, XRD, and BET analysis. SEM-EDS analysis showed that P1 was an organic C component, P2 was Si, Al, Ca, Na component, P3 was Si component, and P4 was Al component. In particular, in the case of P2, a Si/Al ratio of 1.2, a Na/Al ratio of 0.20, and a Ca/Al ratio of 0.32 were detected. For XRD analysis, P1 is amorphous and graphite, P2 is a mixture of zeolite 10X and 13X, P3 is amorphous silica gel, and P4 is a typical Al₂O₃ crystal structure. BET synthesis analysis of adsorbents showed that P1 had the most well-developed micropores and P2, P3, and P4 had larger mesopore volumes.

Development of Pilot-Scale CO2 Methanation Using Pellet-Type Catalysts for CO2 Recycling in Sewage Treatment Plants and Its Validation through Computational Fluid Dynamics (CFD) Modeling

In this study, a pilot-scale reactor was designed and compared using computational fluid dynamics (CFD) for a high-efficiency CO2 methanation reaction. The trends of the CO2 methanation catalyst efficiency at a pilot or industrial scale could be lower than those measured at the laboratory scale, owing to the flow of fluid characteristics. Therefore, the CO2 methanation reactor was designed based on the results of the CFD analysis to minimize the above phenomenon. Ni–Ce–Zr was used to manufacture a CO2 methanation catalyst in the form of pellets. The catalyst successfully produced about 43.3 Nm3/d of methane from the reactor. This result shows that CO2 methanation, which is known as an exothermic reaction, was stable at the pilot scale. It is believed that the self-supply of energy will be possible when this CO2 methanation technology is applied to industrial processes generating large amounts of CO2 and H2 from by-product gases.

The Influence of Sample pH on the Determination of Selected Carboxylic Acids by Isocratic Ion Chromatography

Validated isocratic ion chromatography method with suppressed conductivity detection has been developed for the simultaneously determination of common inorganic anions (F-, Cl-, NO3-, PO43-, SO42-), as well as formate and acetate. Liquid samples originate from absorption of gaseous by-products from coal combustion with and without the addition of medium-density fireboards. The influence of sample pH changes on carboxylic acids determination has been tested.

Post-Plasma Catalysis for Trichloroethylene Abatement with Ce-Doped Birnessite Downstream DC Corona Discharge Reactor

Trichloroethylene (TCE) removal was investigated in a post-plasma catalysis (PPC) configuration in nearly dry air (RH = 0.7%) and moist air (RH = 15%), using, for non-thermal plasma (NTP), a 10-pin-to-plate negative DC corona discharge and, for PPC, Ce0.01Mn as a catalyst, calcined at 400 °C (Ce0.01Mn-400) or treated with nitric acid (Ce0.01Mn-AT). One of the key points was to take advantage of the ozone emitted from NTP as a potential source of active oxygen species for further oxidation, at a very low temperature (100 °C), of untreated TCE and of potential gaseous hazardous by-products from the NTP. The plasma-assisted Ce0.01Mn-AT catalyst presented the best CO2 yield in dry air, with minimization of the formation of gaseous chlorinated by-products. This result was attributed to the high level of oxygen vacancies with a higher amount of Mn3+, improved specific surface area and strong surface acidity. These features also allow the promotion of ozone decomposition efficiency. Both catalysts exhibited good stability towards chlorine. Ce0.01Mn-AT tested in moist air (RH = 15%) showed good stability as a function of time, indicating good water tolerance also.

Microstructure and Mechanical Properties of Nb-API X70 Low Carbon Steel

The oil and gas production has grown steadily, and the care with its transportation grid needs to be maintained and expanded. The pipeline used in the transport of gas and oil by-product requires materials with high mechanical strength, toughness, and fatigue resistance. The chemical composition and distribution, amount, and morphology of the final microconstituents of the steel are of paramount importance once it will directly influence the mechanical properties. The fracture toughness is one of the most important mechanical properties for the suitability of the steel for pipeline usage, and is most of the literature with pipelines study does not present tests such as crack tip opening displacement (CTOD), with a steady and controlled crack growth behavior, to evaluate its fracture toughness. This study compares the fracture toughness of the API 5L X70 steel between two plates of steel with different Nb content, 0.06 and 0.09 Nb wt.% by CTOD tests. The mechanical response was correlated to the grain size and distribution. The CTOD parameter was used to assess the fracture toughness at 25 °C and − 60 °C. The microstructures and microconstituents of the two plates of steel were similar. The matrices were composed of ferrite, with bands of secondary products, including degenerated pearlite. Results showed a prone to the formation of a bimodal microstructure, coarse and fine grains, due to the addition of Nb. High-Nb steel presented better fracture toughness than normal-Nb steel at low-temperature.

Unified Metallic Catalyst Aging Strategy and Implications for Water Treatment.

Heterogeneous catalysis holds great promise for oxidizing or reducing a range of pollutants in water. A well-recognized, but understudied, barrier to implement catalytic treatment centers around fouling or aging over time of the catalyst surfaces. To better understand how to study catalyst fouling or aging, we selected a representative bimetallic catalyst (Pd-In supported on Al2O3), which holds promise to reduce nitrate to innocuous nitrogen gas byproducts upon hydrogen addition, and six model solutions (deionized water, sodium hypochlorite, sodium borohydride, acetic acid, sodium sulfide, and tap water). Our novel aging experimental apparatus permitted single passage of each model solution, separately, through a small packed-bed reactor containing replicate bimetallic catalyst "beds" that could be sacrificed weekly for off-line characterization to quantify impacts of fouling or aging. The composition of the model solutions led to the following gradual changes in surface composition, morphology, or catalytic reactivity: (i) formation of passivating species, (ii) decreased catalytic sites due to metal leaching under acid conditions or sulfide poisoning, (iii) dissolution and/or transformation of indium, (iv) formation of new catalytic sites by the introduction of an additional metallic element, and (v) oxidative etching. The model solution water chemistry captured a wide range of conditions likely to be encountered in potable or industrial water treatment. Aging-induced changes altered catalytic activity and provided insights into potential strategies to improve long-term catalyst operations for water treatment.

Increase in SARS-CoV-2 infected biomedical waste among low middle-income countries: environmental sustainability and impact with health implications.

Studies have shown that severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) is a highly infectious disease, with global deaths rising to about 360,438 as of 28 May 2020. Different countries have used various approaches such as lockdown, social distancing, maintenance of personal hygiene, and increased establishment of testing and isolation centers to manage the pandemic. Poor biomedical waste (BMW) management, treatment, and disposal techniques, especially SARS-CoV-2 infected BMW, may threaten the environmental and public health in most developing countries and, by extension, impact the economic status of individuals and the nation at large. This may increase the potential for the transmission of air/blood body fluid-borne pathogens, increase the growth of microorganisms, risk of mutagenesis, and upsurge of more virulent strain. In contrast, uncontrolled substandard burning could increase the potential spread of nosocomial infection and environmental exposure to toxic organic compounds, heavy metals, radioactive, and genotoxic bio-aerosols which might be present in the gaseous, liquid, and solid by-products. The paucity of understanding of pathophysiology and management of the SARS-CoV-2 pandemic has also necessitated the need to put in place appropriate disposal techniques to cater for the sudden increase in the global demand for personal protective equipment (PPE) and pharmaceutical drugs to manage the pandemic and to reduce the risk of preventable infection by the waste. Therefore, there is a need for adequate sensitization, awareness, and environmental monitoring of the impacts of improper handling of SARS-CoV-2 infected BMWs. Hence, this review aimed to address the issues relating to the improper management of increased SARS-CoV-2 infected BMW in low middle-income countries (LMICs).

Reforming of converter gas with coke oven gas for thermochemical energy storage and carbon dioxide emission reduction

During traditional processing and utilizing of converter gas, a common by-product gas of steel production, the recycling of waste heat is insufficient, carbon emission is high, and the added value of the gas is low. The reforming of converter gas with coke oven gas is proposed to utilize the gas more efficiently. The reforming recycles the waste heat of the gas by thermochemical energy storage technology and converts CH4 and CO2 into H2 and CO, which improves the recovery rate of the waste heat and gas added value, and reduces the direct emission of CO2. Thermodynamic equilibrium calculation and regression analysis were used to investigate the effects of the temperature, pressure, and mole fraction of coke oven gas on the results of the reforming. The results show that atmospheric pressure and the temperature range of 850 °C–1000 °C are suitable for the reforming, at which the conversion rates of CH4 and CO2 are more than 90% and 75%, respectively. The ratio of H2 to CO is determined by the mole fraction of coke oven gas. Then, the reforming process was investigated by experiments which simulated the reforming process in converter flue. The experimental results show that the in-suit catalysis of converter dust can significantly improve the conversion rates of CH4 and CO2 and the conversion rates can reach a high level at about 1000 °C. Then, the waste heat utilization of the reforming was investigated, and it was concluded that 35–40% of the waste heat is converted into chemical energy in the reforming. After the waste heat power generation of the product gas, the total recovery rate of waste heat is 60–65%. Finally, the amount of coke oven gas reformed by a fixed amount of converter gas without additional heating was calculated. The results show that when the preheating temperature of coke oven gas is 500 °C the range of 850 °C–900 °C is appropriate for the reforming, at which the conversion rate of CO2 is approximately 50% and about 40% of the waste heat was converted to chemical energy. For a steel plant with an annual output of 20 million, the direct emission of CO2 can reduce by 2.13 × 108 Nm3, and waste heat of 3.24 × 106 GJ can be converted into chemical energy.

Conversion of Polyethylene Waste into Gaseous Hydrocarbons via Integrated Tandem Chemical–Photo/Electrocatalytic Processes

The chemical inertness of polyethylene makes chemical recycling challenging and motivates the development of new catalytic innovations to mitigate polymer waste. Current chemical recycling methods yield a complex mixture of liquid products, which is challenging to utilize in subsequent processes. Here, we present an oxidative depolymerization step utilizing diluted nitric acid to convert polyethylene into organic acids (40% organic acid yield), which can be coupled to a photo- or electrocatalytic decarboxylation reaction to produce hydrocarbons (individual hydrocarbon yields of 3 and 20%, respectively) with H2 and CO2 as gaseous byproducts. The integrated tandem process allows for the direct conversion of polyethylene into gaseous hydrocarbon products with an overall hydrocarbon yield of 1.0% for the oxidative/photocatalytic route and 7.6% for the oxidative/electrolytic route. The product selectivity is tunable with photocatalysis using TiO2 or carbon nitride, yielding alkanes (ethane and propane), whereas electrocatalysis on carbon electrodes produces alkenes (ethylene and propylene). This two-step recycling process of plastics can use sunlight or renewable electricity to convert polyethylene into valuable, easily separable, gaseous platform chemicals.

Techno-economic analysis of co-production of bio-hydrogenated diesel from palm oil and methanol

A bio-hydrogenated diesel (BHD) or green diesel is produced from refined bleached deodorized palm oil (RBDPO) via a heterogeneous catalytic reaction which requires high hydrogen to oil volumetric ratio for a complete conversion of oil. In this regard, a hydrogen recovery process is required to reduce a high amount of hydrogen loss in a gas by-product. This work proposes coupling the conventional BHD process with a production of methanol, a valuable co-product, and performs its techno-economic evaluation in comparison with the stand-alone BHD process. The results showed that the BHD process coupled with the methanol synthesis can recover by 46.3% of discharged hydrogen and reduce 14% of carbon dioxide and carbon monoxide emissions from the production process. Furthermore, methanol synthesis could improve the internal rate of return (IRR) by 23.2%, shorten the payback period by 2.81 years, and increase the net present value (NPV) by 54.41 million USD relative to the BHD process. Finally, environment potential impact of both processes are analyzed. The most significant on the environment is hydro-processing stage and both processes provide same environmental results.

Pressureless sinterability study of ZrB2–SiC composites containing hexagonal BN and phenolic resin additives

This research is dedicated to the role of different amounts of hexagonal BN (hBN: 0, 1.5, 3, and 4.5 wt%) on the pressureless sinterability of ZrB2–25 vol% SiC ceramics. Phenolic resin (5 wt%) with a carbon yield of ~40 % was incorporated as a binder to the powder mixtures and after initial cold pressing, the final sintering process was performed at 1900 °C for 100 min in a vacuum furnace. The as-sintered specimens were characterized by X-ray diffractometry, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The results disclosed that the incorporation of 1.5 wt% hBN could increase the relative density to ~92%, while the sample with zero hBN content just reached ~81% of full densification. Appropriate hBN content not only facilitated the particle rearrangement during the cold pressing, but also removed the harmful oxide impurities during the final sintering. Nevertheless, the addition of higher amounts of hBN remarkably lessened the densification because of more delamination of the non-reacted hBN flakes and release and entrapment of more gaseous by-products induced by the reacted hBN phases.

Combustion Using Oxygen-Lancing in a Reheating Furnace.

Fuel economy has been a primary issue in the steel industry because it uses large amounts of energy, such as the gaseous fuel of byproduct gas. Furthermore, reheating throughput capacity has been a key issue because it can improve furnace efficiency, leading to fuel economy. Many attempts have tried improving fuel economy using oxygen in a reheating furnace. Oxygen-lancing technology was developed to increase fuel economy and maintain the same level of NOx concentration simultaneously. Mechanisms that inject oxygen into flames locally causing flame quenching and at the same time suppressing the increase in NOx concentration due to recirculation of reheating furnace-burned gases are key to this study. Various oxygen concentrations for its lancing were used to investigate its effects on furnace temperature and NOx concentration in a test furnace. It was determined that 30% of oxygen was optimal regarding fuel economy and NOx concentrations. Oxygen was injected into the flame using two lancing pipes at 11° in a design capacity of 125 MW. The results showed a 3–5% increase in fuel economy and the same level of NOx concentration in the furnace.