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Recycling critical metals from spent Li-ion batteries (LIBs) is important for the overall sustainability of future batteries. This study reports an improved sulfation roasting technology to efficiently recycle Li and Co from spent LiCoO

The presence of organic impurities hinders the resource utilization of industrial waste salt (IWS). In this study, pyrolysis treatment was chosen to remove these organic impurities. The optimal process parameters for the pyrolysis of organic impurities were as follows: a temperature of 500 °C and a holding time of 20 min. Under these optimal conditions, the total organic carbon (TOC) removal rate was 96.32%, inducing a decrease in the TOC mass fraction from 1.88 to 0.08%. Fourier transform infrared spectroscopy (FTIR) results obtained during this process showed that prolonging the pyrolysis time (10-70 min) for IWS resulted in a gradual decrease in the relative content of characteristic functional group, such as C-O in ether groups, and the disappearance of functional group, such as benzophenone carbonyl group and ester carbonyl. Organic impurities can release gas-containing compounds that destroy the initially smooth IWS surface, and the resulting particles with rough and irregular shapes fuse into large or lumpy particles during the pyrolysis process. GC‒MS results clearly showed that the number of different semivolatile organic compounds in the IWS was reduced from 35 to 19 as a result of the pyrolysis process. Correspondingly, organic impurities with molecular formulas containing 5-10 carbon atoms converted into compounds containing 6-20 carbon atoms. These findings provide theoretical support for IWS resource utilization.

Using oxalic acid as a reducing agent, hydroquinone (HQ), graphene (GO), and acidified carbon nanotubes (CNTs) were compounded directly to synthesize reduced graphene oxide (rGO)/CNTs/HQ hydrogels by a one-step hydrothermal method, and the phase composition and electrochemical properties were studied. During the hydrothermal reaction, the π bond in the hydroquinone molecule will be compounded with the large π bond on the surface of rGO due to the π-π interaction. At the same time, CNTs play a role of spacer and support in rGO/CNTs/HQ and improve the conductivity of rGO/CNTs/HQ. The prepared rGO/CNTs/HQ has a mass-specific capacitance of 219 Fg−1 at 0.5 Ag−1; at 10 Ag−1, the mass-specific capacitance retains 81%, confirming its excellent rate performance; After 2000 cycles, the mass ratio capacitance retains 94%, and the cycle performance is excellent.

In this paper, a two-step hydrothermal method was used to prepare NiCo2S4/N-CNT nanocomposites with excellent cycling performance. N-doped carbon nanotubes occur coordination effect; it is conducive to enhancing the overall electrochemical effects of NiCo2S4. Besides, the introduction of carbon nanotubes (CNTs) greatly improved the cycling stability of the materials. Electrochemical tests show that the NiCo2S4/N-CNT composite materials have an ultra-high specific capacitance of 1428 F g−1 at 1 A g−1, while the capacitance of pure NiCo2S4 is 733.5 F g−1. After 4000 charge and discharge cycles, the capacitance of NiCo2S4/N-CNT electrode materials still maintains 80.2%, while the retention rate of NiCo2S4 materials is only 60.2%. Compared with the electrochemical performance of NiCo2S4 materials reported by most people, it has greatly improved. Therefore, the NiCo2S4/N-CNT composite material is a promising electrode material.

This paper presents a simple method to prepare carbon-coated spinel nickel–cobalt–sulfide metal hollow spheres with excellent electrochemical properties, which can be considered as promising materials for supercapacitors. A type of Ni–Co coordination polymer sphere is identified as a precursor metal template as well; the prepared coordination polymer precursor sphere is vulcanized to obtain the NiCo2S4 hollow metal sphere. After that, glucose modified on the surface of the hollow metal sphere is the source of carbon. After hydrothermal sulfuration treatment the carbon-coated NiCo2S4 hybrid material is obtained, which is sintered in a tube furnace to improve the crystallinity of the materials. The compound materials reveal advanced specific capacitance (1367 F g−1 at 1 A g−1) and advantageous cycling stability (approximately 89.2% maintained after 6000 cycles at 10 A g−1).

Highly performance composite material nitrogen-doped mesoporous hollow carbon nanospheres and Ni-Co coordination polymer metal precursor (N-MHCNS700@Ni-Co-MOF) obtained by using hydrothermal reaction Ni-Co coordination polymer metal precursor to assist hollow carbon nanospheres as templates. Then the composite material (N-MHCNS700@Ni-Co-MOF) is calcined under nitrogen to obtain nitrogen-doped mesoporous hollow carbon nanospheres and nickel cobalt metal oxide (N-MHCNS700@NiCo2O4). Material characterization is used to analyze the morphology and structure of the material. The hybrid materials exhibit high specific capacitance (166 mAh g−1 at 1 A g−1) and great cyclic stability (approximately 85.6% retained after 5,000 cycles at 10 A g−1). The composite material also have outstanding power density of composite (624.9 W kg−1) and the energy density (42.8 Wh kg−1). Therefore, composite materials can be applied to electrode materials for high-performance supercapacitor.

Fayalite is widely used in various fields based on its structural characteristics and only exists in weak reducing environments. Excess ZVI (zero-valent iron) is used to regulate oxygen fugacity when synthesizing fayalite. This paper investigates the function of ZVI during the formation of fayalite. The results indicate that ZVI plays two main roles: it is used as an oxygen scavenger to keep the atmosphere in a weakly reduced state and it is used as a reducing agent to reduce Fe3+ to Fe2+, which produces an Fe1−αO intermediate. The formation of Fe1−αO is a critical step in Si-O-Fe formation. The XPS and XRD results not only provide proof of this process but also indicate that fayalite formation is actually an exchange process between Fe(II) and Si(IV). These data provide theoretical support for basic research on copper slag and other research related to fayalite.

Metal sulfides with spinel structures have been considered as promising materials for supercapacitors and attracted increasing attentions of researchers over the past few years. However, inherent defects of metal sulfides such as poor electric conductivity and cyclic stability limit the practical application. Herein, we present a facile strategy to fabricate N-doped carbon coated spinel copper cobalt sulfide hollow spheres with remarkable electrochemical performance. A kind of Cu–Co coordination polymer spheres was utilized as template and metal precursor, polydopamine modified on the surface of the spheres was the source of N-doped carbon. The optimized hybrid materials exhibit high specific capacitance (1228 F g−1 at 1 A g−1) and outstanding cyclic stability (retaining 81.5% of the initial capacitance after 10000 cycles at 20 A g−1). The result demonstrates that this hybrid material is a promising electrode material to realize high performance supercapacitors.

The MnO/C composites were obtained by co-precipitation method, which used Mn3O4 nanomaterials as precursors and dopamine solution after ultrasonic mixing and calcination under N2 atmosphere at different temperatures. By studying the difference of MnO/C nanomaterials formed at different temperatures, it was found that with the increase of calcination temperature, the materials appear obvious agglomeration. The optimal calcination temperature is 400 °C, and the resulting MnO/C is a uniformly dispersed slender nanowire structure. The specific capacitance of MnO/C nanowires can reach 356 F g−1 at 1 A g−1. In the meantime, the initial capacitance of MnO/C nanowires remains 106% after 5000 cycles. Moreover, the asymmetric supercapacitor was installed, which displays a tremendous energy density of 30.944 Wh kg−1 along with a high power density of 10 kW kg−1. The composite material reveals a promising prospect in the application of supercapacitors.

Recovering P via struvite crystallization is an effective way to utilize the resources in swine wastewater. At present, the main challenges of traditional struvite crystallization process are the long reaction time and insufficient removal efficiency. In this study, a novel method to promote struvite crystallization process through ultrasound (US) combined with seed materials is proposed to overcome these defects. We systematically study the effects of US, seed materials, and ultrasonic power on nutrient recovery. The experimental results show that under the conditions of pH 9.5 and MgCl2:P molar ratio1.4:1, the addition of 2 g/L pre-synthesized struvite as the seed materials can increase the P removal rate to 91.56%, whereas, the addition of 80 W ultrasonic power for 15 min can make the P removal rate reach 94.18%. Meanwhile, the combination of US and struvite seed crystals can achieve a maximum P removal efficiency value of 97.66% in which 10 min for the reaction time is enough. The products are characterized using XRD, SEM, and FTIR to determine the phosphorus removal mechanism of ultrasonic power combined with seed induction. The shearing effect of US is found beneficial to affect the surface morphology of the seed crystals, which provides more nucleation sites to enhance crystal nucleation and growth. The removal efficiency comparison reveals that this combined technology performs an excellent removal effect.

The design of nanocomposite materials with special stable structure has become the consensus of researchers working on the exploitation of new materials for effective energy storage equipment. Herein, for the purpose of solving the problem of low capacity and short cycle life of the materials used for supercapacitors, we use Co3(VO4)2 with orthohexagonal nanosheet structure as the transition template, utilizing ion exchange reaction to prepare Co3S4 with a two-dimensional structure. At the same time, the surface of Co3S4 nanosheets were anchored by some Zn0.76Co0.24S nanoparticles through hydrothermal reaction. The prepared Co3S4/Zn0.76Co0.24S composite displays a satisfactory specific capacitance of 1832.1 F g−1 at a current density of 1 A g−1 and an outstanding conductivity. After 4000 times of continuous charge and discharge cycles, it still presents a good capacitance (94.6% retention). The tests on the assembled Co3S4/Zn0.76Co0.24S//AC device show an energy density of 55.6 Wh kg−1, while the power density is 690.9 W kg−1. With such a remarkable electrochemical performance, the prepared Co3S4/Zn0.76Co0.24S composite is considered as an excellent candidate for supercapacitors application.

For the past few years, transition metal oxides have attracted significant attention for supercapacitor due to their high theoretical capacity, low costs, and abundant natural reserves. In this work, we present a facile strategy to fabricate spinel zinc manganese oxide/carbon hybrid materials with rod-like structures from mixed-MOFs. Through two-steps calcining the mixed-MOFs constituted by metal ion and 1, 3, 5-Benzenetricarboxylic acid in different condition, the mixed-MOFs have converted to ZnMn2O4/carbon nanorods. The 1D rod-like nanostructure inherited from the MOFs was preserved intact during the process. Due to the porous 1D nanostructure and synergistic effect between the transition metal oxide and carbon, the specific capacitance of hybrid materials reaches to 589 F g−1 at 1 A g−1 within the potential window of 0–1.2 V. Meanwhile, the hybrid materials display superior capacitive behavior at high current density (278 F g−1 at 20 A g−1) and outstanding cycling stability (98.1% retention after 2000 cycles at 10 A g−1). The results imply that the MOFs-derived hybrid materials could be potential electrode materials.

The interfacial microstructure and mechanical properties of B4C-SiC-TiB2 composite joints diffusion bonded with Ti foil interlayer were investigated. The joints were diffusion bonded in the temperature range of 800–1200 °C with 50 MPa by spark plasma sintering. The results revealed that robust joint could be successfully obtained due to the interface reaction. B4C reacted with Ti to form nanocrystalline TiB2 and TiC at the interface at 800–1000 °C. Both the reactions between SiC and Ti and between TiB2 and Ti were not observed during joining. A full ceramic joint consisted of micron- and submicron-sized TiB2 and TiC, accompanied with the formation of micro-crack, was achieved for the joint bonded at 1200 °C. Joint strength was evaluated and the maximum shear strength (145 ± 14.1 MPa) was obtained for the joint bonded at 900 °C. Vickers hardness of interlayer increased with increasing the joining temperature.

Swine wastewater contains phosphorus, ammonia nitrogen, and heavy metals that affect the struvite purity produced from the wastewater and increase the ecological hazards. In addition, struvite crystallization process is highly dependent on the usage of magnesium sources. Thus, it is necessary to explore the effects of three magnesium sources, including MgCl2, Mg(OH)2 and MgO, on the phosphorus recovery and minimizing Cu and Fe contents via struvite crystallization process. The observations revealed that the predominant parts of Cu and Fe precipitate in the form of hydroxide during pH adjustment. Meanwhile, when using MgCl2 as the magnesium source, the optimal removal efficiency of phosphorus reached 94.55%, followed by MgO and Mg(OH)2. Simultaneously, 90.60% Cu and 98.80% Fe precipitate under MgCl2 as magnesium source. The redissolution behavior of Cu occurs when MgO and Mg(OH)2 are used as magnesium sources, increasing the Cu concentration. The smallest operation cost is from MgCl2 as magnesium source. The potential environmental impact analyzed by life cycle assessment method shows that MgCl2 in struvite crystallization process saves more fossil energy and protects resource while lessens the nature's eutrophication risk. The technical, economic, and environmental assessments confirm MgCl2 as a promisable source of magnesium in struvite crystallization process for achieving cleaner production goal.

A novel process for extracting lithium from coal fly ash by low-temperature salt activation with ammonium fluoride was proposed in this study. The glass phase in coal fly ash was converted to water-soluble fluoride salts after the salt activation process, which was followed by the extraction of lithium from the glass phase via water leaching. The effects of activation temperature and SiO2/NH4F mass ratio on the extraction of lithium were investigated in detail. The results showed that more than 90% of lithium was recovered under the optimized conditions: 155 °C of activation temperature, 1:1.35 of SiO2/NH4F mass ratio. A possible reaction mechanism for lithium extraction was also proposed based on thermodynamic, thermogravimetry, X-ray diffraction, scanning electron microscopy, and solid nuclear magnetic resonance analyses. This work provides a unique platform reference for further studies on the efficient extraction of resources with similar mineral compositions.

Integrating LiMn2O4(LMO) and different carbon materials to build a mixed cathode system can provide fast transport channels to improve the conduction of both electrons and ions. In this paper, our work studied in situ low-temperature hydrothermal synthesis of LMO nanocomposites based on graphene oxide (GO)/carbon nanotubes (CNTs) hydrogel. Compared with the pure LMO nanoparticles, GO/CNTs/LMO (GCLMO) composites greatly improved electrochemical performance in specific capacity, cycle performance and rate ability. The electrochemical test results showed that the specific capacitance of GCLMO nanocomposites reached 396 F/g at the current density of 0.5 A/g, which was much higher than 221 F/g of pure LMO. Even at the current density of 10 A/g, the specific capacitance was still as high as 309 F/g. Besides, after 2000 cycles, the specific capacitance retention of the composite was 93%. Electrochemical data showed that GCLMO composite is an ideal cathode material for supercapacitors.

Human urine consists of large amounts of phosphorus (P) and potassium (K), which are essential chemical elements for living species and plants growth. In this study, we investigate the effects of reflux rate on crystallization promotion to simultaneously recover P and K from urine. The effects of potassium ion presence in the formation of magnesium ammonium phosphate (MAP) in the fluidized bed reactor (FBR) is also studied. The largest removal efficiency of P at 96.57% and K at 68.40% can be achieved under the optimal conditions of: pH 9.5, P:Mg:N molar ratio of 1:1.4:1.2, and reflux rate of 12 L min–1. The purity of produced MAP and magnesium potassium phosphate (MPP) are both promoted, owing to the improved formation frequency among particles, when reflux rate is increased. During the MAP production process, MgKPO4 is initially nucleation and growth under turbulence environmental in FBR. Afterwards, with the presence of NH4+ in solution, K + ion can be replaced by NH4+ and formed the MAP due to more stability of MgNH4PO4 compound than MgKPO4. The cost analysis demonstrates that FBR system can provide a profit of $2.01/m3 on urine treatment. The investigation can shed lights on efficient removal and recovery process of P and K elements from urine through changing various reflux rates for further development.

s In this work, specific morphology of Mn3O4 supercapacitor electrode material was synthesized in a fast, efficient, and mass-produced two-step hydrothermal method. 20–30 nm Mn3O4 particles were successfully anchored on 500–600 nm Mn3O4 nanorods. The products were tested by XRD, XPS, SEM, TEM, CV, EDS, EIS, and galvanostatic charge/discharge to prove that the material exhibits good electrochemical performance. At a current density of 0.5 A/g, its specific capacitance could reach 233.41 F/g. This could maintain 10,000 cycles galvanostatic charge/discharge with 108.4% retention. When the current density was 0.5 A/g, the power density of the electrode material was 250 W kg−1 and the energy density was 32.42 W h kg−1. The synergistic effect of nanoparticles and nanorods enhance the electroactive sites of material and increase the energy storage and specific capacitive.

In this work, N-tetradecyl-isopropanolamine (NTIA) is synthesized and used as a new collector on the flotation separation process of scheelite from calcite to further improve the efficiency of the selective flotation. The effects of NTIA on minerals are investigated through microflotation experiments. Flotation experimental results show that NTIA provides good flotation and separation effects on the scheelite in a wide range of pulp pH (6.0–10.0). At pH 7.0, the flotation recovery of scheelite reaches 96.89%, while calcite to only 10%. Moreover, it also reveals an efficient separation effect for artificial mixed minerals of scheelite and calcite under certain conditions. The adsorption behavior of NTIA on scheelite is further studied using wettability test, infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and zeta potential analysis. The results demonstrate that the surface of scheelite is preferentially modified, increasing its hydrophobicity after treatment with NTIA. Meanwhile, under the action of hydrogen bonding and strong electrostatic field in the hydrophilic N–H group of NTIA, the NTIA molecules are absorbed on the scheelite surface.

We report a mild strategy to synthesize reduced graphene oxide/spinel nickel manganese oxide (rGO/NiMn2O4) nanorods composites. The rGO/NiMn2(C2O4)3 precursors were prepared via coprecipitation method in ethanol-water system and the composites were obtained by calcining the precursors in air. The hybrid materials have been characterized by X-ray powder diffraction, Raman spectra, X-Ray photoelectron spectroscopy, high-resolution transmission electron microscopy and field emission scanning electron microscopy. Different electrochemical measurements have been used in a three electrode system to study the electrochemical performance such as cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The typical hybrid materials (30 wt% rGO) display a high specific capacitance (693.00 F g−1 at 1 A g−1) and prominent cycling stability (91.38% capacitance retention after 2000 cycles at 5 A g−1), indicating that the composites possess potential application as excellent electrode material.

Arsenic is the most important hazardous trace element in copper concentrates. In order to separate arsenic from the smelting processes, a pyrometallurgical treatment with additives was developed to deal with high-arsenic copper smelter flue dust high in copper sulfate. Under the optimized conditions of mixing 30 wt% pyrite and roasting at 550 °C under an inert atmosphere for 30 min, more than 92% arsenic was volatilized as a high purity arsenic trioxide by-product while most copper was retained in the calcine to be returned to smelting as a high-copper feed. The high separation of arsenic is due to the transformation from the limited vaporization of arsenate to volatile arsenic trioxide by pyrite at above 460 °C. Two reaction paths of pyrite were identified as follows: one followed the pattern FeS2 → Fe2O3 → FeAsO4 → Fe3O4/Fe2O3 and the other was FeS2 → FeS + S2 (g) → Fe3O4/Fe2O3.

A novel approach was developed to prepare hollow polypyrrole (PPy) nanospheres and nitrogen-doped graphene/hollow PPy nanospheres (NG/H-PPy) composites. In this process, uniform poly (methyl methacrylate-butyl methacrylate-methacrylic acid) (PMMA-PBMA-PMAA) latex microspheres as sacrificial templates were synthesized by using an emulsion polymerization method. Then, hollow PPy nanospheres were obtained on the surface of PMMA-PBMA-PMAA microspheres by in situ chemical oxidative polymerization. Finally, H-PPy was embedded in NG layers successfully through a simple approach. The nanobeads have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectra, and Fourier transform infrared spectra (FTIR). Different electrochemical methods including cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) have been applied to study the electrochemical properties. The specific capacitance of NG/H-PPy composites based on the three-electrode system is as high as 575 F g−1 at a current density of 1 A g−1 and enhanced stability about 90.1 % after 500 cycles, indicating that the composite has an impressive capacitance and excellent cycling performance.

The Mesozoic ore-bearing high-Mg monzodioritic–granodioritic rocks in the Tongling mining district (East China) have been described as having adakitic affinities, and their origin has been attributed to partial melting of delaminated eclogite at depth in the mantle, followed by interaction of the resultant granitic magma with mantle peridotite. Here we present petrological data and in situ Sr isotopic data for zoned plagioclase that are inconsistent with the eclogite-derived model and instead propose a model that involves magma mixing of siliceous crustal melts and basaltic magma that was derived from metasomatized mantle in a back-arc extensional regime. The principal geochemical signatures of these Mesozoic rocks include a high-K calc-alkaline affinity, high values of Mg#, high Sr–Ba abundances, high Sr/Y and La/Yb ratios, e Nd ( t ) = − 13.1 to − 9.0, and I Sr = 0.70707–0.70824. The magma mixing model is supported by (1) the common existence of mafic microgranular enclaves (MMEs) and the disequilibrium textures of plagioclase and amphibole, (2) the 87 Sr/ 86 Sr ratios of embayed high-Ca cores of plagioclase that are distinctly lower than in the euhedral low-Ca overgrowth rims, (3) the negative correlations between whole-rock Nd and Sr isotopic ratios, and (4) the significant differences in the values of e Hf ( t ) (− 9.5 to − 26) within different zircons from the same intrusion.

Polyaniline (PANI) is a promising electroactive material for pseudocapacitor due to the existence of the electronic conjugation structure. Here we demonstrate a novel approach to prepare hollow polyaniline nanospheres. In this process, uniform poly (methyl methacrylate- butyl methacrylate - methacrylic acid) (PMMA-PBMA-PMAA) latex microspheres as self-sacrificial templates were rapidly prepared through an emulsion polymerization method. Then the hollow PANI (H-PANI) nanospheres were obtained directly through an in-situ chemical oxidative polymerization of aniline in the presence of PMMA-PBMA-PMAA microspheres, which can be explained by the “dissolution” of templates and phase separation between the constituent polymers. The structure and morphology of the nanophase materials have been characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectra. The specific capacitance of H-PANI is 485.5 F g−1 at 1 A g−1 and there is 69% performance attenuation after 500 cycles, which show a promising electrochemical performance.

The interactions between Fe

A simple and convenient one-step hydrothermal process for synthesizing nitrogen-doped graphene/p-aminophenol composite by using ethylenediamine, p-aminophenol, and graphene oxide is described. The p-aminophenol does not only act as a spacer to prevent the graphene sheets from aggregating and restacking during the hydrothermal process but also enhances the contribution of pseudocapacitance, which further improves the performance of the electrode materials. The field emission scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and electrochemical workstation are used to characterize the materials. The as-produced composite material shows superior specific capacitance of 365.7 F g−1 at a scan rate of 10 mV s−1 and excellent electrochemical cycle stability.

A new route to prepare core/shell structured polypyrrole (PPy)/hydroquinone nano-beads have been proposed via an in-situ chemical oxidative polymerization. The core template, p-benzoquinone, is demonstrated to work as an oxidizing agent for the in-situ polymerization of PPy, and to be reduced to 1,4-hydroquinone after the reaction. The structure and morphology of the nano-beads have been characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectra. The cyclic voltammetry (CV), impedance and galvanostatic charge/discharge analysis demonstrate that PPy contributes electronic conductive channels for hydroquinone and hydroquinone works as a pseudocapacitance component. The prepared PPy/hydroquinone nano-beads exhibit brilliant electrochemical properties of a specific capacitance of 91.6 F g −1 at a scan rate of 5 mV s −1 and enhanced stability of about 63.1 F g −1 after 500-cycle scanning at a current density of 0.5 A g −1 .

Traditional ethylene glycol production is heavily dependent on oil. In the background of richness of coal and scarcity of oil, more and more coal to ethylene glycol (CTEG) plants have been successfully operated to relieve the shortage of ethylene glycol in China. Thus, it is an urgent work to answer the following question: between oil-based and coal-based ethylene glycol routes, which is the better choice? A comparative techno-economic analysis of oil-based and coal-based ethylene glycol processes is conducted to identify the opportunities and challenges of CTEG industry. Results show that CTEG process has prominent advantage in total production cost, which is about 16% lower than that of oil to ethylene glycol (OTEG) process. However, it is criticized by many shortcomings, such as higher energy consumption, lower exergy efficiency, higher total capital investment, and higher CO2 emissions compared with OTEG process. Facing with these restrictive problems of CTEG process, several possible measures are proposed to improve the technoeconomic performance. In addition, the effects of several key economic parameters on the competitiveness of OTEG and CTEG processes are investigated and compared. Results show that the development of CTEG industry has a cost advantage and is promising due to the abundant reserve and low-price of coal in China. However, it should reduce the energy consumption and emissions before the large-scale development of CTEG industry.