FUEL
·
2024
·
IF 6.7
Qiang Gao,Hongyun Hu,Chan Zou,Yan Ding,Chao He,Xian Li,Hong Yao
Pyrolysis is regarded as a practical way for waste tires to achieve waste-to-resource objectives. However, the environmental risk of pollution emissions in product utilization caused by the migration of sulfur is an important issue in the waste tire disposal industry. This study introduced a solution to using the binary molten salt system (NaOH-Na 2 CO 3 ) as a heat transfer and desulfurization medium for the thermal utilization of waste tires. The results demonstrated that molten salts had in-situ desulfurization capability at 425 °C −575 °C and inhibited the migration of sulfur to gas–liquid-solid products with the total sulfur ratio reduced by 50 % − 67 %. The sulfur-containing radical intermediates could be extensively consumed by molten salt, leading to a low concentration level of H 2 S and COS in gaseous products. Simultaneously, molten salt blocked the traditional pathway of the sulfhydryl radical with inorganic additives, weakening the sulfur enrichment to char. Additionally, molten salt enhanced heat transfer during pyrolysis, facilitating the decomposition of thiazole and the polymerization of sulfur-containing benzene ring (2,3-dimethyl-thiophene to benzothiophene). The online monitoring further corroborated that COS release was preceded by H 2 S at high temperatures (>500 °C) along with the full degradation of the waste tires. Higher desulfurization efficiency of molten salt was achieved with feedstocks of small particle size, as it allows for adequate exposure of the reaction contact sites. This approach provides a new opportunity for in-situ desulfurization of waste tire pyrolysis via molten salt thermal treatment.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Ruolin Li,Yang Ren,Chengyang Cao,Chao He,Hongyun Hu,Xian Li,Hong Yao
Recently, waste tires gain a growing recognition of the potential as value-added fuel via pyrolysis. In the present study, molten salt was proposed to be used for the waste tires pyrolysis, aims to enhance heat transfer efficiency, and then reduce energy input for the mechanical shredding of waste tires into small particles before pyrolysis. In detail, the conversion and products formation behavior of two waste tires (of different particle sizes) were compared by a constructed molten salt thermal treatment system. Results show that H 2 and CH 4 contents of the pyrolysis gas increased substantially, and smaller tire particles produced more H 2 and CH 4 (up to 500%), while CO 2 content dropped to zero. Also, the contents of benzene increased remarkably with molten salt added (growth rate is between 1100% and 1800%) for electro-mobile tires, while caprolactam was disappeared. Specifically, benzene yield increases and then decreases with increasing particle size. In addition, molten salts were also effective in removing sulfur and ash from pyrolytic char, with more than 60% of the sulfur fraction being removed. These findings could provide theoretical support for the development of low-cost thermal treatment technology for waste tires.
研究领域:
能源与环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2025
·
IF 7.1
Qiang Gao,Hongyun Hu,Chan Zou,Yang Hu,Huan Liu,Xian Li,Hong Yao
Molten salt thermal treatment of solid waste is a promising way for energy recovery and pollutant removal. However, the migration of nitrogen during pyrolysis of waste tires poses a challenge for cleaner production. This study investigated nitrogen conversion pathways during waste tires pyrolysis using a binary NaOH-Na 2 CO 3 salt at 425, 500, and 575 °C. The results demonstrated that amine-N and pyrrole-N were the main N-containing species in waste tires. Compared to conventional pyrolysis, the molten salt enhanced the deamination of the amine-N while increasing levels of NH 3 and aniline. Owing to the catalytic benefits of molten salt, the C-N bond cleavage of amine-N was initiated by electron transfer involving the combination of NH 2 -Phenyl structures with Na + . The hydrocracking of Phenyl-NH-Phenyl in amine-N was facilitated by the available H radicals (or H 2 ). Furthermore, molten salt obstructed the contact of C(N) sites on the char surface, causing the suppression of HCN production. The SH radicals might be consumed by OH – ions, which disabled the formation path of benzothiazole from aniline and SH radicals. Comparatively, pyrrole-N showed limited reactivity and remained in char. This work contributes to nitrogen regulation during the molten salt treatment of solid waste.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2021
·
IF 6.609
Hua Tang,Hongyun Hu,Aijun Li,Baojun Yi,Xian Li,Dingding Yao,Hong Yao,Haoran Yuan
Thermo-chemical recycling of waste tire to generate pyrolytic char as alternative carbon black is a promising route for waste disposal and environmental sustainability. However, impurities in waste tire (like Zn, Si, Ca and S) are probably enriched in the pyrolytic char, and removal of those impurities is of great importance for char recycling. To avoid generating large amount of waste acids and polluted gases in the traditional impurities removing process, molten salt (Na 2 CO 3 -NaOH) thermal treatment was creatively proposed in the current work. The influence of operational temperatures (in the range of 350 to 450 °C) was investigated in relation to the efficiency of impurity removal. Results show that the removal efficiency of impurity components was firstly increased but then weakened by increasing treating temperature from 350 to 450 °C, while the highest removal rate was obtained at 400 °C. Generally, the current system could effectively remove more than 80% of ash and 70% of sulfur at 400 °C, with the recovery rate of char between 71% and 83%. Specifically, calcium carbonate/sulfate was removed from the char due to its good solubility in the molten salts. In addition, molten salts showed good activity to convert char contained inorganic sulfides and ·SH radicals into salts-soluble Na 2 S. Similarly, silicon and zinc were tended to be transformed into soluble silicate and zincate, which had higher solubility in the used molten salt. In addition, the agglomerated char particles were separated into smaller and more uniform size during molten salt thermal treatment.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Chengyang Cao,Yang Ren,Hao Wang,Hongyun Hu,Baojun Yi,Xian Li,Linling Wang,Hong Yao
Solar-powered pyrolysis of waste tires has been extensively studied because it can rapidly convert waste tires into valuable gas products using sustainable energy. However, the emitted sulfurous pollutants during this fast pyrolysis process would significantly reduce the economic feasibility of disposal waste tires. In order to investigate and regulate the sulfur transformation behavior, a large-load thermogravimetric analyzer and an optical rapid thermal processor were adopted to characterize and simulate the solar-powered fast pyrolysis behavior. The sulfur fixation effect of CaO was also evaluated in this study. Results showed that CaO addition could increase the emission of H 2 and CO by promoting the cracking of organic compounds in tar. In comparison, it could decrease the CO 2 emission by adsorption or transformation. Also, an excellent sulfur fixation rate in char was achieved with 10 wt% CaO addition, but accompanied by increasing emission tendency of SO 2 , especially at 650 °C-6000 °C/min. It was attributed to the competition reaction between H 2 S and SO 2 in the gas phase and interaction between CaS and CaSO 4 in the condensed phase. Our findings could be beneficial to develop an in-situ sulfur removal method during the pyrolysis of waste tires in the industry.
研究领域:
能源与环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2016
·
IF 3.652
Kuan Ding,Zhaoping Zhong,Bo Zhang,Jia Wang,Addy Min,Roger Ruan
Pyrolysis of waste tire with HY, HZSM-5 (HZ) and purified attapulgite (PA) catalysts to produce valuable aromatic hydrocarbons has been carried out in a Pyrolyzer- Gas Chromatograph/Mass Spectrum (Py-GC/MS) reactor. Likewise, d -limonene and polybutadiene rubber (BR), which played important roles in the pyrolysis process of waste tire, has also been pyrolyzed in the Py-GC/MS reactor with these catalysts. Based on the product distribution, the catalytic pyrolysis mechanisms of d -limonene were proposed, while those of BR were extended. With these mechanisms, the catalytic pyrolysis characteristics of waste tire could be explained reasonably. Results showed that HY promoted a dramatic increase of aromatics from pyrolysis of d -limonene and BR, leading to the considerable growth of aromatics in the degraded products of waste tire. The shape selectivity of HZ to mono-cyclic aromatics performed effectively in the pyrolysis of BR, yet it exhibited a weak performance in the pyrolysis of d -limonene. As a result, upon the catalytic pyrolysis of waste tire, HZ was inferior to HY in the aromatization ability. However, the selectivity of HZ to BTXE (benzene, toluene, xylene and ethylbenzene) was superior to that of HY. PA performed a weaker catalytic ability in promoting the production of aromatics during the pyrolysis of d -limonene, BR and waste tire.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Science China-Technological Sciences
·
2022
·Vol. 65
·期 10
·2337-2347
·
IF 3.903
Hou ShengPing,Zhang Da,Xie ZhiPeng,Kang Yao,Tang ZhengGang,Dai YongNian,Lei Yong,Chen Jian,Liang Feng
As the quantity of waste tires increases, more pyrolysis carbon black (CBp), a type of low value-added carbon black, is being produced. However, the application of CBp has been limited. Therefore, it is necessary to identify and expand applications of CBp. This work focuses on the preparation of activated carbon (AC) from CBp using the physicochemical activation of carbon dioxide (CO 2 ) and potassium hydroxide (KOH). Thereafter, AC is applied to the electrode of the electrical double-layer capacitor (EDLC). The AC prepared by CO 2 /KOH activation exhibited a hierarchical pore structure. The specific surface area increased from 415 to 733 m 2 g −1 , and in combination with low ash content of 1.51%, ensured abundant ion diffusion channels and active sites to store charge. The EDLC comprising the AC (AC-2) electrode prepared by excitation of CO 2 (300 sccm) and KOH had a reasonable gravimetric specific capacitance of 192 F g −1 at 0.5 A g −1 , and exhibited a good rate capability of 73% at 50 A g −1 in a three-electrode system. Moreover, the EDLC device comprising the AC-2 electrode delivered excellent cycling stability (capacitance retention of 106% after 10000 cycles at 2 A g −1 in a two-electrode system). Furthermore, a symmetric supercapacitor based on an AC electrode that exhibits a supreme energy density of 4.7 Wh kg −1 and a maximum power density of 6362.6 W kg −1 is demonstrated.
研究领域:
材料科学
·
环境科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2022
·
IF 8.816
Chan Zou,Yang Ren,Songgeng Li,Hongyun Hu,Chengyang Cao,Hua Tang,Xian Li,Hong Yao
Pyrolysis is a technical means for waste tires recycling, which can promote the enrichment of carbon black and facilitate the subsequent recovery. However, carbon black particles aggregated and the inorganic impurities tended to be enriched in pyrolytic char during the waste tire pyrolysis process, which is not conducive to the substitution of commercial carbon black by pyrolytic char. In the present study, a novel method using molten salts thermal treatment was proposed for the impurities removal from pyrolytic chars with different characteristics. In addition, the proper thermal treatment conditions were further estimated to obtain better performance for the physical–chemical properties improvement of pyrolytic char. Six kinds of char samples were chosen to conduct molten salts thermal treatment (MSTT) experiments at 350, 400, and 450 °C. The experimental results show that MSTT can effectively remove the impurities of different pyrolytic chars, and the most optimum reaction conditions are at 400 °C, 2 h of reaction time, and molten salt/char ratio of 10:1. In addition, after MSTT, the pyrolytic char was depolymerized, and the average particle size reduced from 36.63 μm to 19.08 μm, the specific surface area increased from 49 m 2 /g to 73 m 2 /g. At the same time, the graphite carbon content of the pyrolytic char increased from 24.41% to 70.90%, and the hydroxyl content on the pyrolytic char surface increased significantly. In summary, the physical–chemical properties of waste tire pyrolytic char were improved by MSTT, which is close to the carbon black N550 level.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ECS Journal of Solid State Science and Technology
·
2022
·Vol. 11
·期 6
·061004
·
IF 2.483
Dazhi Zhang,Zhaojie Ma,Yixin Zhang,Yunhui Xu,Honglai Liu,Jianjun Wu,Peipei Li
Hard-carbon materials are considered as the most promising anodes in various energy storage system applications including lithium, sodium, potassium ion batteries and supercapacitors. Given the huge bulk of the waste tires produced by the rapid development of automobile industry, recycling waste tires to generate value-added products is crucially important for the development of a more sustainable world. In this work, we demonstrate how waste tire-derived pyrolytic char can be transformed into activated carbon for supercapacitor electrodes. The process consists of the acidification of the waste tire-derived pyrolytic char with mixed acids (HCl and HF) and the followed activation with KOH. The activated carbon exhibited a hierarchical meso-/micro-porous network with specific surface area 524 m2 g−1. A traditional three-electrode system was used to investigate the electrochemical performances of the activated carbon as a supercapacitor electrode material, which displayed a specific capacitance of ∼408 F g−1 at 0.25 A g−1 in an electrolyte of 6 M KOH, with capacitance retention of up to 97% after 10,000 charge/discharge cycles. This work offers an innovative and simple approach to yield higher performance activated carbon from waste tires for use in energy storage devices.
研究领域:
材料科学
·
能源存储
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Shiwei Yang,Shiqin Zheng,Youjia Zhang,Chenyang Zhang,Jiangyi Chen,Xin Pan,Xianbao Wang,Shimin Wang,Li Wan
Given the annual generation of approximately 1.5 billion tons of waste tires, there is an urgent need for sustainable and environmentally friendly recycling technologies to facilitate the circular economy. Here, this work developed a novel methodology for the synthesis of rubber aerogel (RA) using waste tire rubber powder. The fabrication process employs cost-effective freeze-drying technology to combine rubber powder with polyvinyl alcohol (PVA), glutaraldehyde (GA), and xanthan gum (XG) to successfully fabricate RA with a 3D network porous structure. The density and porosity of RA obtained under the relatively optimized experimental parameters were 0.0697 g/cm 3 and 94.36 %, respectively. Furthermore, the size of RAs was adjusted by molds to meet specific application requirements. RAs exhibit good compression characteristics, with a Young’s modulus of 162.9 kPa. They also demonstrated excellent thermal insulation characteristics, and remained stable at temperatures below 200 ℃. The RAs modified through surface modification technique, had a water contact angle of 146° and demonstrated hydrophobic stability. This study presented a sustainable and environmentally-friendly technological approach for recycling waste tires, and established the groundwork for the development of RAs as a heat preservation material, oil adsorbent and other potential applications.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2022
·
IF 6.137
Xiaojing Sun,Xiaoxi Ni,Xilin Wang,Dongyan Xu
Red mud (RM) is an attractive catalyst precursor due to its valuable components. In this study, we successfully synthesized a zero-valent iron-based composite catalyst by carbothermal reduction of RM with carbon black obtained by pyrolysis of the scrap tire as the reductant for the first time and evaluated the catalytic performance of the as-prepared catalyst for activating H 2 O 2 to degrade methylene blue (MB) in an aqueous solution. The characterization results signified that a gradual transformation of iron-related species, i.e. Fe 2 O 3 → Fe 3 O 4 → FeO → Fe 0 , might occur by varying the carbothermal reduction temperature. The Fe@RM catalyst reduced at 900 °C exhibited much higher MB degradation efficiency than those reduced at 850 °C and below, proving that the stabilized zero-valent iron nanoparticles are more effective than iron oxides in the heterogeneous Fenton-like processes. The response surface methodology (RSM) based on Central composite design (CCD) was employed to design and optimize individual and interactive effects of the independent parameters. Chemical quenching tests ascertained the contributions of free radicals (•OH and O 2 − • ) and singlet oxygen ( 1 O 2 ) reactive oxygen species to MB decomposition in the Fenton-like process. The present results demonstrate the promising reutilization of RM and scrap tires as low-cost raw materials for preparing zero-valent iron heterogeneous catalysts being active for the Fenton-like oxidation of organic pollutants in wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2022
·
IF 7.693
Shun Chen,Bo Zhang,Hao Zheng,Xingyang He,Ying Su,Hui Xu,Yan Zhu,Yingyuan Pan,Jizhan Chen
This work explored polymerization activating fine waste tire powder modified asphalt at a lower mixing temperature. Different from common temperatures of more than 190 °C, traditional waste tire powder could not achieve the excellent properties of modified asphalt at 170 °C. Through styrene and methyl methacrylate monomers polymerized on the surface of 400-mesh waste tire powder, polymerized waste tire powder was successfully fabricated through changes in morphology and surface potential. Polymerized waste tire powder modified asphalt was 15 wt%. It was determined by dynamic shear rheology and nanoindentation. The excellent dispersion of polymerized waste tire powder in asphalt was proved by fluorescence microscopy. Compared with waste tire powder modified asphalt, the hardness of polymerized waste tire powder modified asphalt decreased by 21.27 %, and the viscoelasticity decreased by 92.26 %. It indicated polymerized waste tire powder modified asphalt performed good hardness and viscoelasticity regulation. This work inspired a new idea for modified asphalt and reclaiming waste tires, which would have good economic and environmental benefits.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）