CO2 recovery from flue gas by PSA process using activated carbon

An experimental study was performed for the recovery of CO₂ from flue gas of the electric power plant by pressure swing adsorption process. Activated carbon was used as an adsorbent. The equilibrium adsorption isotherms of pure component and breakthrough curves of their mixture (CO₂ : N₂ : O₂=17 : 79 : 4 vol%) were measured. Pressure equalization step and product purge step were added to basic 4-step PSA for the recovery of strong adsorbates. Through investigation of the effects of each step and total feed rate, highly concentrated CO₂ could be obtained by increasing the adsorption time, product purge time, and evacuation time simultaneously with full pressure-equalization. Based on the basic results, the 3-bed, 8-step PSA cycle with the pressure equalization and product purge step was organized. Maximum product purity of CO₂ was 99.8% and recovery was 34%.     

CO oxidation from syngas (CO and H<Subscript>2</Subscript>) using nanoporous Pt/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalyst

The concept of “waste-to-wealth” is spreading awareness to prevent global warming and recycle the restrictive resources. To contribute towards sustainable development, hydrogen energy is obtained from syngas (CO and H₂) generated from waste gasification, followed by CO oxidation and CO₂ removal. In H₂ generation, it is key to produce more purified H₂ from syngas using heterogeneous catalysts. In this respect, we prepared Pt/Al₂O₃ catalyst with nanoporous structure using precipitation method, and compared its catalytic activity with commercial alumina (Degussa). Based on the results of XRD and TEM, it was found that metal particles did not aggregate on the alumina surface and showed high dispersion. Optimum condition for CO conversion was 1.5 wt% Pt loaded on Al₂O₃ support, and pure hydrogen was obtained after removal of CO₂ gas.     

Modeling and economic analysis of CO<Subscript>2</Subscript> separation process with hollow fiber membrane modules

The main purpose of the study was to develop a model using ASPEN and Excel simulation method to establish optimum CO₂ separation process utilizing hollow fiber membrane modules to treat exhaust gas from LNG combustion. During the simulation, optimum conditions of each CO₂ separation scenario were determined while operating parameters of CO₂ separation process were varied. The characteristics of hollow fibers membrane were assigned as 60 GPU of permeability and 25 of selectivity for the simulation. The simulation results illustrated that 4 stage connection of membrane module is required in order to achieve over 99% of CO₂ purity and 90% of recovery rate. The resulted optimum design and operation parameters throughout the simulation were also correlated with the experimental data from the actual CO₂ separation facility which has a capacity of 1,000 Nm³/day located in the Korea Research Institute of Chemical Technology. Throughout the simulation, the operating parameters of minimum energy consumption were evaluated. Economic analysis of pilot scale of CO₂ separation plant was done with the comparison of energy cost of CO₂ recovery and equipment cost of the plant based on the simulation model. This work was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.     

Optimal operation of the pressure swing adsorption (PSA) process for CO<Subscript>2</Subscript> recovery

The operation of PSA (Pressure Swing Adsorption) processes is a highly nonlinear and challenging problem. We propose a systematic procedure to achieve the optimal operation of a PSA process. The model of the PSA process for CO₂ separation and recovery is developed first and optimization is performed to identify optimal operating conditions based on the model. The effectiveness of the model developed is demonstrated by numerical simulations and experiments using CO₂ and N₂ gases and zeolite 13X. Breakthrough curves and temperature changes in the bed are computed from the model and the results are compared with those of experiments. The effects of the adsorption time and reflux ratio on the product purity and the recovery are identified through numerical simulations. The optimization problem is formulated based on nonlinear equations obtained from simulations. The optimal operating conditions identified are applied to experiments. The results show higher recovery of CO₂ under optimal operating conditions.     

Separation characteristics of tetrapropylammoniumbromide templating silica/alumina composite membrane in CO<Subscript>2</Subscript>/N<Subscript>2</Subscript>, CO<Subscript>2</Subscript>/H<Subscript>2</Subscript> and CH<Subscript>4</Subscript>/H<Subscript>2</Subscript> systems

Nanoporous silica membrane without any pinholes and cracks was synthesized by organic templating method. The tetrapropylammoniumbromide (TPABr)-templating silica sols were coated on tubular alumina composite support ( γ-Al₂O₃/ α-Al₂O₃ composite) by dip coating and then heat-treated at 550 °C. By using the prepared TPABr templating silica/alumina composite membrane, adsorption and membrane transport experiments were performed on the CO₂/N₂, CO₂/H₂ and CH₄/H₂ systems. Adsorption and permeation by using single gas and binary mixtures were measured in order to examine the transport mechanism in the membrane. In the single gas systems, adsorption characteristics on the α-Al₂O₃ support and nanoporous unsupport (TPABr templating SiO₂/ γ-Al₂O₃ composite layer without α-Al₂O₃ support) were investigated at 20–40 °C conditions and 0.0–1.0 atm pressure range. The experimental adsorption equilibrium was well fitted with Langmuir or/and Langmuir-Freundlich isotherm models. The α-Al₂O₃ support had a little adsorption capacity compared to the unsupport which had relatively larger adsorption capacity for CO₂ and CH₄. While the adsorption rates in the unsupport showed in the order of H₂> CO₂> N₂> CH₄ at low pressure range, the permeate flux in the membrane was in the order of H₂≫N₂> CH₄> CO₂. Separation properties of the unsupport could be confirmed by the separation experiments of adsorbable/non-adsorbable mixed gases, such as CO₂/H₂ and CH₄/H₂ systems. Although light and non-adsorbable molecules, such as H₂, showed the highest permeation in the single gas permeate experiments, heavier and strongly adsorbable molecules, such as CO₂ and CH₄, showed a higher separation factor (CO₂/H₂=5-7, CH₄/H₂=4-9). These results might be caused by the surface diffusion or/and blocking effects of adsorbed molecules in the unsupport. And these results could be explained by surface diffusion. This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University.     

Kinetic study on carbonation of crude Li<Subscript>2</Subscript>CO<Subscript>3</Subscript> with CO<Subscript>2</Subscript>-water solutions in a slurry bubble column reactor

Investigations were conducted to purify crude Li₂CO₃ via direct carbonation with CO₂-water solutions at atmospheric pressure. The experiments were carried out in a slurry bubble column reactor with 0.05 m inner diameter and 1.0 m height. Parameters that may affect the dissolution of Li₂CO₃ in the CO₂-water solutions such as CO₂-bubble perforation diameter, CO₂ partial pressure, CO₂ gas flow rate, Li₂CO₃ particle size, solid concentration in the slurry, reaction temperature, slurry height in the column and so on were investigated. It was found that the increases of CO₂ partial pressure, and CO₂ flow rate were favorable to the dissolution of Li₂CO₃, which had the opposite effects with Li₂CO₃ particle size, solid concentration, slurry height in the column and temperature. On the other hand, in order to get insight into the mechanism of the refining process, reaction kinetics was studied. The results showed that the kinetics of the carbonation process can be properly represented by 1−3(1−X)^2/3+2(1–X)=kt+b, and the rate-determining step of this process under the conditions studied was product layer diffusion. Finally, the apparent activation energy of the carbonation reaction was obtained by calculation. This study will provide theoretical basis for the reactor design and the optimization of the process operation.     

A superstructure‐based optimal synthesis of PSA cycles for post‐combustion CO2 capture

Recent developments have shown pressure/vacuum swing adsorption (PSA/VSA) to be a promising option to effectively capture CO₂ from flue gas streams. In most commercial PSA cycles, the weakly adsorbed component in the mixture is the desired product, and enriching the strongly adsorbed CO₂ is not a concern. On the other hand, it is necessary to concentrate CO₂ to high purity to reduce CO₂ sequestration costs and minimize safety and environmental risks. Thus, it is necessary to develop PSA processes specifically targeted to obtain pure strongly adsorbed component. A multitude of PSA/VSA cycles have been developed in the literature for CO₂ capture from feedstocks low in CO₂ concentration. However, no systematic methodology has been suggested to develop, evaluate, and optimize PSA cycles for high purity CO₂ capture. This study presents a systematic optimization‐based formulation to synthesize novel PSA cycles for a given application. In particular, a novel PSA superstructure is presented to design optimal PSA cycle configurations and evaluate CO₂ capture strategies. The superstructure is rich enough to predict a number of different PSA operating steps. The bed connections in the superstructure are governed by time‐dependent control variables, which can be varied to realize most PSA operating steps. An optimal sequence of operating steps is achieved through the formulation of an optimal control problem with the partial differential and algebraic equations of the PSA system and the cyclic steady state condition. Large‐scale optimization capabilities have enabled us to adopt a complete discretization methodology to solve the optimal control problem as a large‐scale nonlinear program, using the nonlinear optimization solver IPOPT. The superstructure approach is demonstrated for case studies related to post‐combustion CO₂ capture. In particular, optimal PSA cycles were synthesized, which maximize CO₂ recovery for a given purity, and minimize overall power consumption. The results show the potential of the superstructure to predict PSA cycles with up to 98% purity and recovery of CO₂. Moreover, for recovery of around 85% and purity of over 90%, these cycles can recover CO₂ from atmospheric flue gas with a low power consumption of 465 k Wh tonne^?1 CO₂. The approach presented is, therefore, very promising and quite useful for evaluating the suitability of different adsorbents, feedstocks, and operating strategies for PSA, and assessing its usefulness for CO₂ capture. Published 2009 American Institute of Chemical Engineers AIChE J, 2010     

The promotional effect of K on the catalytic activity of Ni/MgAl<Subscript>2</Subscript>O<Subscript>4</Subscript> for the combined H<Subscript>2</Subscript>O and CO<Subscript>2</Subscript> reforming of coke oven gas for syngas production

A K-promoted 10Ni-(x)K/MgAl₂O₄ catalyst was investigated for the combined H₂O and CO₂ reforming (CSCR) of coke oven gas (COG) for syngas production. The 10Ni-(x)K/MgAl₂O₄ catalyst was prepared by co-impregnation, and the K content was varied from 0 to 5 wt%. The BET, XRD, H₂-chemisorption, H₂-TPR, and CO₂-TPD were performed for determining the physicochemical properties of prepared catalysts. Except under the condition of a K/Ni=0.1 (wt%/wt%), the Ni crystal size and dispersion decreased with increasing K/Ni. The coke resistance of the catalyst was investigated under conditions of CH₄: CO₂: H₂: CO:N₂=1 : 1 : 2 : 0.3 : 0.3, 800 °C, 5 atm. The coke formation on the used catalyst was examined by SEM and TG analysis. As compared to the 10Ni/MgAl₂O₄ catalyst, the Kpromoted catalyst exhibited superior activity and coke resistance, attributed to its strong interaction with Ni and support, and the improved CO₂ adsorption characteristic. The 10Ni-1K/MgAl₂O₄ catalyst exhibited optimum activity and coke resistance with only 1wt% of K.     

Separation of COCO2N2 gas mixture for high-purity CO by pressure swing adsorption

A pressure swing adsorption (PSA) process for separating CO from a COCO₂N₂ mixture is proposed. The adsorbent used in this process is active carbon supported copper, which has been developed by this laboratory. By cycling the pressure of a bed of this adsorbent between ambient pressure and 20–30 Torr at room temperature, high purity CO can be obtained from the COCO₂N₂ gas mixture with a high recovery. The CO product purity depends crucially on the step of CO cocurrent purge after adsorption in the cycle and the regeneration of sorbent.     

Increasing carbon utilization in Fischer-Tropsch synthesis using H2-deficient or CO2-rich syngas feeds

Fischer-Tropsch technology has become a topical issue in the energy industry in recent times. The synthesis of linear hydrocarbon that has high cetane number diesel fuel through the Fischer-Tropsch reaction requires syngas with high H₂/CO ratio. Nevertheless, the production of syngas from biomass and coal, which have low H₂/CO ratios or are CO₂ rich may be desirable for environmental and socio-political reasons. Efficient carbon utilization in such H₂-deficient and CO₂-rich syngas feeds has not been given the required attention. It is desirable to improve carbon utilization using such syngas feeds in the Fischer-Tropsch synthesis not only for process economy but also for sustainable development. Previous catalyst and process development efforts were directed toward maximising C₅₊ selectivity; they are not for achieving high carbon utilization with H₂-deficient and CO₂-rich syngas feeds. However, current trends in FTS catalyst design hold the potential of achieving high carbon utilization with wide option of selectivities. Highlights of the current trends in FTS catalyst design are presented and their prospect for achieving high carbon utilization in FTS using H₂-deficient and CO₂-rich syngas feeds is discussed.     

Conversion of CH<Subscript>4</Subscript> and CO<Subscript>2</Subscript> to syngas and higher hydrocarbons using dielectric barrier discharge

The conversion of methane to syngas and other hydrocarbons in dielectric barrier discharge plasma under the presence of CO₂ was investigated. Effects of the input voltage on the conversion of methane and CO₂ and the ratio of syngas were analyzed experimentally. The results of numerical simulations showed good quantitative agreement with those of experiments.     

Adsorption characteristics analysis of CO<Subscript>2</Subscript> and N<Subscript>2</Subscript> in 13X zeolites by molecular simulation and N<Subscript>2</Subscript> adsorption experiment

The adsorption characteristics of CO₂ and N₂ in 13X zeolites have been studied by the molecular simulation and N₂ adsorption experiment. It is found that the simulation results by Dreiding force fields are in an agreement with the published data. The influence of the σ and ε parameters of O_Z and Na⁺ on the adsorption performance is discussed. Then the optimized force field parameters are obtained. Specific surface area (S _B ) is calculated by simulation and experiment. Its relative error is just only 4.3 %. Therefore, it is feasible that S _B of 13X zeolites is obtained by the simulation methods. Finally, the impacts of pressure and temperature on adsorption characteristics are investigated. At low pressure, CO₂ adsorption in 13X zeolites belongs to the surface adsorption. As the pressure increase, the partial multilayer adsorption appears along with the surface adsorption. N₂ adsorption in 13X zeolites is different from that of CO₂. At low temperature of 77 K, two primary peaks are caused by the surface adsorption and multilayer adsorption respectively regardless of pressure variation. When the temperature is 273 K, the energy distribution curve appears undulate at low pressures. Then it becomes stable with the pressure increase. The surface adsorption plays an important role at the relative high pressures. The results will help to provide the theory guide for the optimization of force field parameters of adsorbents, and it is very important significance to understand the adsorption performance of zeolites.     

Reduction of CO<Subscript>2</Subscript> to CO via reverse water-gas shift reaction over CeO<Subscript>2</Subscript> catalyst

CeO₂ catalysts with different structure were prepared by hard-template (Ce-HT), complex (Ce-CA), and precipitation methods (Ce-PC), and their performance in CO₂ reverse water gas shift (RWGS) reaction was investigated. The catalysts were characterized using XRD, TEM, BET, H₂-TPR, and in-situ XPS. The results indicated that the structure of CeO₂ catalysts was significantly affected by the preparation method. The porous structure and large specific surface area enhanced the catalytic activity of the studied CeO₂ catalysts. Oxygen vacancies as active sites were formed in the CeO₂ catalysts by H₂ reduction at 400 °C. The Ce-HT, Ce-CA, and Ce-PC catalysts have a 100% CO selectivity and CO₂ conversion at 580 °C was 15.9%, 9.3%, and 12.7%, respectively. The highest CO₂ RWGS reaction catalytic activity for the Ce-HT catalyst was related to the porous structure, large specific surface area (144.9 m²?g^?1) and formed abundant oxygen vacancies.     

Mg(OH)<Subscript>2</Subscript> Films Prepared by Ink-Jet Printing and Their Photocatalytic Activity in CO<Subscript>2</Subscript> Reduction and H<Subscript>2</Subscript>O Conversion

Mg(OH)₂ films on Al substrates were fabricated by ink-jet printing, and they were applied as photocatalysts in solar fuels production (H₂ and CH₃OH) from CO₂ and H₂O conversion. The films were fabricated by means of a deposition of a solution composed of magnesium complex nanoparticles over aluminum foils, which were submitted to a heat treatment to promote the crystallization of Mg(OH)₂. The films were characterized by razing incidence X-ray diffraction (GZXD), Fourier-transform infrared spectroscopy (FTIR), Scanning electronic microscopy, X-ray photoelectron spectroscopy (XPS), and N₂ physisorption by BET method. The Mg(OH)₂ was detected in all the samples synthesized with 1 to 40 layers. According to XPS and FTIR analysis, it was detected the presence of carbonates related to Mg₃O(CO₃)₂ and Al⁰ and Al³⁺ due to the substrate. The highest photocatalytic activity was reached using 30 layers of Mg(OH)₂ for H₂ and CH₃OH generation, which it was 268 and 15 µmol g^??1h^??1, respectively. These results were associated to the presence of adequate amounts of MgO and Al₂O₃ that promote an efficient transfer of the photogenerated electrons between them. Furthermore, the formation of porous structures with high surface area and relative high roughness promoted an increase in the mass transport between the gas and liquid phase, which increase the effectiveness of the photocatalysts.     

Influence of operating temperature on CO<Subscript>2</Subscript>-NH<Subscript>3</Subscript> reaction in an aqueous solution

Although aqueous ammonia solution has been focused on the removal of CO₂ from flue gas, there have been very few reports regarding the underlying analysis of the reaction between CO₂ and NH₃. In this work, we explored the reaction of CO₂-NH₃-H₂O system at various operating temperatures: 40 °C, 20 °C, and 5 °C. The CO₂ removal efficiency and the loss of ammonia were influenced by the operating temperatures. Also, infrared spectroscopy measurement was used in order to understand the formation mechanism of ion species in absorbent, such as NH₂COO⁻, HCO₃⁻, CO₃²⁻, and NH₄⁺, during CO₂, NH₃, and H₂O reaction. The reactions of CO₂-NH₃-H₂O system at 20 °C and 40 °C have similar reaction routes. However, a different reaction route was observed at 5 °C compared to the other operating temperatures, showing the solid products of ammonium bicarbonates, relatively. The CO₂ removal efficiency and the formation of carbamate and bicarbonate were strongly influenced by the operating temperatures. In particular, the analysis of the formation carbamate and bicarbonate by infrared spectroscopy measurement provides useful information on the reaction mechanism of CO₂ in an aqueous ammonia solution.     

A Novel Process for Renewable Methane Production: Combining Direct Air Capture by K<Subscript>2</Subscript>CO<Subscript>3</Subscript>/Alumina Sorbent with CO<Subscript>2</Subscript> Methanation over Ru/Alumina Catalyst

CO₂ methanation over supported ruthenium catalysts is considered to be a promising process for carbon capture and utilization and power-to-gas technologies. In this work 4% Ru/Al₂O₃ catalyst was synthesized by impregnation of the support with an aqueous solution of Ru(OH)Cl₃, followed by liquid phase reduction using NaBH₄ and gas phase activation using the stoichiometric mixture of CO₂ and H₂ (1:4). Kinetics of CO₂ methanation reaction over the Ru/Al₂O₃ catalyst was studied in a perfectly mixed reactor at temperatures from 200 to 300 °C. The results showed that dependence of the specific activity of the catalyst on temperature followed the Arrhenius law. CO₂ conversion to methane was shown to depend on temperature, water vapor pressure and CO₂:H₂ ratio in the gas mixture. The Ru/Al₂O₃ catalyst was later tested together with the K₂CO₃/Al₂O₃ composite sorbent in the novel direct air capture/methanation process, which combined in one reactor consecutive steps of CO₂ adsorption from the air at room temperature and CO₂ desorption/methanation in H₂ flow at 300 or 350 °C. It was demonstrated that the amount of desorbed CO₂ was practically the same for both temperatures used, while the total conversion of carbon dioxide to methane was 94.2–94.6% at 300 °C and 96.1–96.5% at 350 °C.     

Cycle synthesis and optimization of a VSA process for postcombustion CO2 capture

A systematic analysis of several vacuum swing adsorption (VSA) cycles with Zeochem zeolite 13X as the adsorbent to capture CO₂ from dry, flue gas containing 15% CO₂ in N₂ is reported. Full optimization of the analyzed VSA cycles using genetic algorithm has been performed to obtain purity‐recovery and energy‐productivity Pareto fronts. These cycles are assessed for their ability to produce high‐purity CO₂ at high recovery. Configurations satisfying 90% purity‐recovery constraints are ranked according to their energy‐productivity Pareto fronts. It is shown that a 4‐step VSA cycle with light product pressurization gives the minimum energy penalty of 131 kWh/tonne CO₂ captured at a productivity of 0.57 mol CO₂/m³ adsorbent/s. The minimum energy consumption required to achieve 95 and 97% purities, both at 90% recoveries, are 154 and 186 kWh/tonne CO₂ captured, respectively. For the proposed cycle, it is shown that significant increase in productivity can be achieved with a marginal increase in energy consumption. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4735–4748, 2013     

Evaluation of strategies for the subsequent use of CO<Subscript>2</Subscript>

If substantial amounts of CO₂, which according to actual scenarios may in the future be captured from industrial processes and power generation, shall be utilized effectively, scalable energy efficient technologies will be required. Thus, a survey was performed to assess a large variety of applications utilizing CO₂ chemically (e.g., production of synthesis-gas, methanol synthesis), biologically (e.g., CO₂ as fertilizer in green houses, production of algae), or physically (enhancement of fossil fuel recovery, use as refrigerant). For each of the processes, material and energy balances were set up. Starting with pure CO₂ at standard conditions, expenditure for transport and further process specific treatment were included. Based on these calculations, the avoidance of greenhouse gas emissions by applying the discussed technologies was evaluated. Based on the currently available technologies, applications for enhanced fossil fuel recovery turn out to be most attractive regarding the potential of utilizing large quantities of CO₂ (total capacity > 1000 Gt CO₂) and producing significant amounts of marketable products on one hand and having good energy and material balances on the other hand \(\left( {{{t_{CO_2 - emitted} } \mathord{\left/ {\vphantom {{t_{CO_2 - emitted} } {t_{CO_2 - utilized} < 0.2 - 0.4}}} \right. \kern-\nulldelimiterspace} {t_{CO_2 - utilized} < 0.2 - 0.4}}} \right)\). Nevertheless, large scale chemical fixation of CO₂ providing valuable products like fuels is worth considering, if carbon-free energy sources are used to provide the process energy and H₂ being essential as a reactant in a lot of chemical processes (e.g., production of DME: \({{t_{CO_2 - emitted} } \mathord{\left/ {\vphantom {{t_{CO_2 - emitted} } {t_{CO_2 - utilized} > 0.34}}} \right. \kern-\nulldelimiterspace} {t_{CO_2 - utilized} > 0.34}}\)). Biological processes such as CO₂ fixation using micro-algae look attractive as long as energy and CO₂ balance are considered. However, the development of effective photo-bioreactors for growing algae with low requirements for footprint area is a challenge.     

Simultaneous MS-IR Studies of Surface Formate Reactivity Under Methanol Synthesis Conditions on Cu/SiO<Subscript>2</Subscript>

The coverages and surface lifetimes of copper-bound formates on Cu/SiO₂ catalysts, and the steady-state rates of reverse water-gas shift and methanol synthesis have been measured simultaneously by mass (MS) and infrared (IR) spectroscopies under a variety of elevated pressure conditions at temperatures between 140 and 160 °C. DCOO lifetimes under steady state catalytic conditions in CO₂:D₂ atmospheres were measured by ¹²C–¹³C isotope transients (SSITKA). The values range from 220 s at 160 °C to 660 s at 140 °C. The catalytic rates of both reverse water gas shift (RWGS) and methanol synthesis are ~100-fold slower than this formate removal rate back to CO₂ + 1/2 H₂, and thus they do not significantly influence the formate lifetime or coverage at steady state. The formate coverage is instead determined by formate’s rapid production/decomposition equilibrium with gas phase CO₂ + H₂. The results are consistent with formate being an intermediate in methanol synthesis, but with the rate-controlling step being after formate production (for example, its further hydrogenation to methoxy). A 2–3 fold shorter life time (faster decomposition rate) was observed for formate under reactions conditions, with both D₂ and CO₂ present, than in pure Ar or D₂ + Ar alone. This effect, due in part to the effects of the coadsorbates produced under reaction conditions, illustrates the importance of using in situ techniques in the study of catalytic mechanisms. The carbon which appears in the methanol product spends a longer time on the surface than the formate species, 1.8 times as long at 140 °C. The additional delay on the surface is attributed in part to readsorption of methanol on the catalyst, thus obscuring the mechanistic link between formate and methanol.     

Experimental investigations on combustion characteristics of syngas composed of CH<Subscript>4</Subscript>, CO,and H<Subscript>2</Subscript>

The residual gas and remained raw gas in dual gas resources polygeneration system are quite complex in components (mainly CH₄, CO, and H₂), and these results to the distinguished differences in combustion reaction. Experimental investigations on basic combustion characteristics of syngas referred above are conducted on a laboratory-scale combustor with flame temperature and flue gas composition measured and analyzed. Primary air coefficient (PA), total air coefficient (TA), and components of the syngas (CS) are selected as key factors, and it is found that PA dominates mostly the ignition of syngas and NO _x formation, while TA affects the flue gas temperature after high temperature region and NO _x formation trend to be positive as H₂/CO components increase. The results provide references for industrial utilization.