VACUUM
·
2024
·
IF 3.8
Hailin Zheng,Min Zheng,Xianxing Huang,Mingjie Liang,Kang Li
Chemical-looping combustion (CLC) technology is considered a promising combustion method with inherent CO 2 capture. In this study, the sol-gel method and combustion synthesis were employed to produce precursor materials (P) of CuO-based oxygen carriers (OCs). The effects of vacuum drying conditions on both NO x emissions from precursor combustion and oxygen carrier cycle reaction characteristics were investigated. Vacuum-dried precursors emitted less NO x during the precursor calcination process. At a heating rate of 1 °C/min, the vacuum-dried precursors exhibited an average reduction of 24.13 % in NO x emissions compared with those prepared through atmospheric pressure drying. An increased amount of Cu 2 (OH) 3 NO 3 in the precursor results in greater heat release during the self-propagating high-temperature combustion synthesis used to synthesize the oxygen carrier. Furthermore, the complete combustion of the nitrogen-containing precursor leads to a reduction in the emission of NO x . CuO-based OCs exhibited stable redox reactions over 10 cycles. Vacuum drying enhanced CH 4 conversion and CO 2 yield of OC1 by 14.04 % and 13.21 %, respectively, compared to atmospheric pressure drying. The results indicate that the CuO-based OCs obtained through vacuum-dried significantly enhance redox properties. This study shows that vacuum-dried reduces NO x emissions from nitrogen precursors and enhances the cyclic efficiency of OCs from precursor combustion.
研究领域:
能源科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Bo Feng,Tingman Zhao,Jiada Du,Jiyuan Hu,Yun Shi,Jingkai Zhao,Jianmeng Chen
Methane selective catalytic reduction (CH 4 -SCR) technology has shown promise for controlling NO x emissions from natural gas generator sets. This study presents a highly efficient Ce 30 In 15 /HBEA catalyst featuring dual active sites, Al-O – (InO + )-Si site for CH 4 activation and ceria oxygen vacancy (Ce 3+ -□) site for NO x activation. However, the CH 4 -SCR activity of this catalyst decreased in the presence of H 2 O, SO 2 , C 3 H 6 , and CO 2 . The inhibitory effects on CH 4 -SCR activity followed by the sequence: H 2 O > SO 2 > C 3 H 6 > CO 2 . In particular, H 2 O combined with Al-O – (InO + )-Si to form inactive In(OH) 3-z z+ species and occupied Ce 3+ -□, preventing Ce 4+ -NO 3 – /NO 2 – formation. In/Ce sulfate formation via the reaction between SO 2 and In/Ce active sites hindered CH 4 and NO x adsorption and activation. The formed carbon deposits covered the active sites on the catalyst surface due to incomplete C 3 H 6 oxidation . In comparison, the dual active sites were almost unaffected by CO 2 . Overall, this study provides a basis for the rational design of novel catalysts for CH 4 -SCR.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 10
·期 11
·6065-6072
·
IF 12.732
Junxiao Chen,Xue Fang,Zhouhong Ren,Weiye Qu,Xiaolei Hu,Zhen Ma,Liwei Chen,Xi Liu,Yaxin Chen,Xingfu Tang
Selective catalytic reduction (SCR) of NOx with NH3 has been widely used for NOx emission control, but commercial catalysts inevitably suffer severe deactivation in SO2-containing stack gases at low temperatures because the ammonium bisulfate (NH4HSO4, ABS) formed in SCR blocks the surface active sites. We resolve this issue by developing a TiO2-supported single-atom Mo catalyst (Mo1/TiO2) that decomposes ABS at ∼225 °C, far lower than the dew point of ABS (∼260 °C). Single Mo atoms paired with the neighboring surface Ti atoms function as Mo–Ti acid–base dual sites, which respectively adsorb the NH4+ and HSO4− of ABS. After the oxidation of NH4+ by surface lattice oxygen on the Mo sites, electrons left behind on the dual sites are localized around the Fermi level, which allows them to transfer to the adsorbed HSO4− on the Ti sites, thus releasing SO2 at low temperatures. The Mo1/TiO2 catalyst with Mo–Ti acid–base dual sites enables the decomposition of ABS at low temperatures, and thus this work provides a way to effectively control NOx emission particularly from industrial boilers.
研究领域:
环境科学
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催化化学
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材料科学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2022
·
IF 8.129
Hao Chen,Xin Su,Fengyu Sun,Jingjing He,Zhanming Chen,Peng Zhang,Hongming Xu
In this study, the combustion and emission characteristics of a diesel engine fueled with diesel cyclopentanol blends were experimentally studied through the engine bench test and real-time vehicle test. The results indicated that the cyclopentanol addition weakened the premixed combustion process and accelerated the diffusion combustion process, resulting in an increased peak cylinder pressure and peak combustion temperature . In addition, with the increase of cyclopentanol addition, the ignition delay prolonged, the combustion duration shortened and the heat released more concentratedly. The addition of cyclopentanol decreased both the PM number and volume concentrations significantly, while increased the NOx emission due to the increased peak combustion temperature. At 2000 r/min, CP10 had little effect on inhibiting the nucleation ultrafine particles (≤ 50 nm). Urban, rural and highway roads were considered for on-road real-time vehicle test. The results were consistent with the engine bench test. For urban, rural, and highway areas, the average PN emissions of CP20 were 4.948 × 10 6 , 4.707 × 10 6 , and 3.314 × 10 6 per cm 3 , respectively, while those for diesel were 5.755 × 10 6 , 5.547 × 10 6 , and 4.058 × 10 6 per cm 3 , respectively.
研究领域:
机械工程
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汽车工程
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环境科学
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燃烧科学
✓ 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）