Journal of The Energy Institute最新文献_第2页

Numerical study on influences of intake temperature and swirl ratio on in-cylinder combustion and pollutant formation characteristics of ammonia/diesel dual-fuel engine 进气温度和涡流比对氨/柴油双燃料发动机缸内燃烧和污染物形成特性影响的数值研究

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-18 DOI: 10.1016/j.joei.2024.101860

In order to improve the combustion efficiency of ammonia fuel, and enhance the operational stability and emission level for ammonia engines, this study constructs an in-cylinder combustion numerical model of ammonia/diesel dual-fuel engine based on CONVERGE software, and investigates the effects of initial intake temperature and swirl intensity on in-cylinder combustion and pollutant formation characteristics of ammonia/diesel dual-fuel engine. The results show that increasing the intake temperature can improve the in-cylinder thermal atmosphere, advance the dual-fuel combustion reaction process, and increase the peak in-cylinder combustion pressure and temperature. The peak in-cylinder pressure increases from 6.05 to 6.44 MPa when the intake temperature is increased from 303 to 343 K. This is effective in improving the emissions of incomplete combustion for the ammonia/diesel dual-fuel engine. The in-cylinder unburned NH₃, CO and HC emissions are reduced by 20.2 %, 77.1 % and 88.21 %, respectively. Increasing the swirl ratio enhances the in-cylinder gas disturbance, reduces the amount of fuel attached to the wall, and improves the quality of in-cylinder fuel-gas mixture. It also accelerates the process of combustible mixture formation, advances the starting point of ammonia fuel consumption, and accelerates the initial reaction rate. When the swirl ratio is increased from 0.5 to 3.0, the in-cylinder unburned NH₃ emission is reduced by 14.85 %. Reasonable adjustment of intake temperature and swirl ratio helps to improve the distribution of direct injection fuel particles inside the cylinder, thereby optimizing the dual-fuel combustion process and enhancing engine performance.

为了提高氨燃料的燃烧效率，提高氨发动机的运行稳定性和排放水平，本研究基于 CONVERGE 软件构建了氨/柴油双燃料发动机缸内燃烧数值模型，研究了初始进气温度和漩涡强度对氨/柴油双燃料发动机缸内燃烧和污染物形成特性的影响。结果表明，提高进气温度可以改善缸内热气氛，推进双燃料燃烧反应过程，提高缸内燃烧压力和温度峰值。当进气温度从 303 K 提高到 343 K 时，缸内峰值压力从 6.05 MPa 提高到 6.44 MPa，从而有效改善了氨/柴油双燃料发动机的不完全燃烧排放。缸内未燃烧的 NH3、CO 和 HC 排放量分别减少了 20.2%、77.1% 和 88.21%。增加漩涡比可增强缸内气体扰动，减少附着在缸壁上的燃料量，并改善缸内燃料-气体混合物的质量。它还能加速可燃混合气的形成过程，提前氨燃料消耗的起点，加快初始反应速度。当漩涡比从 0.5 增加到 3.0 时，缸内未燃烧的 NH3 排放量减少了 14.85%。合理调节进气温度和涡流比有助于改善缸内直喷燃料颗粒的分布，从而优化双燃料燃烧过程，提高发动机性能。

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引用次数: 0

Effect of ammonia reforming on combustion and emission characteristics of a 4-valve engine with an active pre-chamber 氨气转化对带有主动前腔的四气门发动机燃烧和排放特性的影响

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-16 DOI: 10.1016/j.joei.2024.101861

Ammonia (NH₃), as a hydrogen carrier and carbon-free fuel, offers an attractive opportunity for engines to achieve carbon neutrality. Turbulent jet ignition (TJI) combined with ammonia reforming shows the great capacity in ammonia-fueled engines. In this study, the effects of reforming strategy in an ammonia-fueled TJI are numerically studied, addressing the reforming ratio and reforming region. The results show that when only using reformate in the pre-chamber, the promoting effect of jet flame is more effective on the initial combustion phase. There are still very high NH₃ emissions due to the low reactivity in the main chamber. Further using reformate both in the pre-chamber and the main chamber, all the combustion stages (ST-CA10, CA10-50, CA50-90) can be shortened almost linearly with the increase of reforming ratio. Besides, the unburned NH₃ can be reduced to an acceptable level when the reforming ratio reaches 200 ‰ (hydrogen energy ratio of 18.50 %). The main reason is that the jet-induced strong flow field is coincident with the whole combustion stage. Further increasing the reforming ratio (pure hydrogen) in the pre-chamber, a high combustion efficiency and acceptable NH₃ emission can be achieved at a low hydrogen energy ratio (7.08 %). However, knocking combustion will happen at high reforming ratio with a low knock intensity. The results can provide some guidance for making the best-promoting benefit of the limited hydrogen in ammonia TJI engines with different reforming strategies.

氨（NH3）作为一种氢载体和无碳燃料，为发动机实现碳中和提供了一个极具吸引力的机会。湍流喷射点火（TJI）结合氨气重整显示了氨气燃料发动机的巨大潜力。在本研究中，针对重整比和重整区域，对氨燃料 TJI 中重整策略的影响进行了数值研究。结果表明，如果只在前腔使用重整液，喷射火焰对初始燃烧阶段的促进作用更为有效。由于主燃烧室的反应活性较低，NH3 的排放量仍然很高。进一步在前室和主室中使用重整液，所有燃烧阶段（ST-CA10、CA10-50、CA50-90）都能随着重整比的增加而几乎线性地缩短。此外，当重整比达到 200 ‰（氢能比为 18.50 %）时，未燃烧的 NH3 可以减少到可接受的水平。主要原因是射流引发的强流场与整个燃烧阶段相吻合。进一步提高前室的重整比（纯氢），可在低氢能比（7.08 %）下实现高燃烧效率和可接受的 NH3 排放。然而，在高重整比、低爆震强度的情况下，会出现爆震燃烧。这些结果为采用不同重整策略的氨 TJI 发动机充分利用有限的氢气提供了指导。

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引用次数: 0

Desulfurization of pyrolytic oils from waste tire pyrolysis in a fluidized bed reactor with boron nitride adsorbents 利用氮化硼吸附剂在流化床反应器中对废轮胎热解产生的热解油进行脱硫

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-16 DOI: 10.1016/j.joei.2024.101862

The study focused on producing hexagonal boron nitride (hBN) as an adsorbent which provides high efficiency in desulfurization processes. The synthesized hBN is used for sulfur removal from liquid fuel derived from end-of-life tires (ELTs). Characterization of hBN was performed using FTIR, XRD, TGA, and SEM-EDS analyses. Liquid fuel was produced in a fluidized bed reactor at 550 °C under a nitrogen gas flow. Post-desulfurization, the fuel's density, water content, and calorific value increased, while sulfur content and flash point decreased, with sulfur content showing a significant reduction of 79.23 %. The desulfurized fuel (PS-A) exhibited better combustion characteristics and closely resembled diesel fuel performance, though it slightly reduced engine effective efficiency by 1.06 % compared to diesel. Both PS-A and pre-desulfurized fuel (PS-B) significantly reduced soot emissions by 23.28 % and 20.81 %, respectively, compared to diesel. Additionally, CO emissions were lower for PS-A and PS-B, with reductions of 4.35 % and 2.00 %, respectively. However, CO₂ emissions increased by 1.60 % for PS-A and 0.86 % for PS-B, attributed to higher fuel consumption. Overall, hBN effectively reduced sulfur content and improved several fuel properties of pyrolytic liquids. The study highlights the environmental and economic benefits of enhancing ELT-derived liquid fuels and suggests potential applications in real systems, serving as a foundation for new technologies and projects.

这项研究的重点是生产六方氮化硼（hBN）作为一种吸附剂，它在脱硫过程中具有很高的效率。合成的 hBN 用于从报废轮胎（ELT）中提取的液体燃料中脱硫。利用傅立叶变换红外光谱、XRD、TGA 和 SEM-EDS 分析对 hBN 进行了表征。液体燃料是在流化床反应器中于 550 °C 氮气流下生产的。脱硫后，燃料的密度、含水量和热值增加，而硫含量和闪点降低，其中硫含量显著降低了 79.23%。脱硫燃料（PS-A）的燃烧特性更好，与柴油的性能非常接近，但与柴油相比，发动机的有效效率略微降低了 1.06%。与柴油相比，PS-A 和预脱硫燃料（PS-B）分别显著减少了 23.28% 和 20.81% 的烟尘排放。此外，PS-A 和 PS-B 的二氧化碳排放量也较低，分别减少了 4.35 % 和 2.00 %。然而，由于燃料消耗量增加，PS-A 和 PS-B 的二氧化碳排放量分别增加了 1.60 % 和 0.86 %。总之，hBN 有效降低了硫含量，并改善了热解液的多项燃料特性。该研究强调了提高 ELT 衍生液体燃料的环境和经济效益，并提出了在实际系统中的潜在应用，为新技术和新项目奠定了基础。

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引用次数: 0

Synergistic effects of multi-walled carbon nanotubes and Mn0.4Cu0.6Fe2O4 on mercury removal with high efficiency and sulfur resistance 多壁碳纳米管和 Mn0.4Cu0.6Fe2O4 在高效脱汞和抗硫方面的协同效应

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-16 DOI: 10.1016/j.joei.2024.101863

Although ferrite-based adsorbents are the potential mercury removal materials for the high thermal stability, they usually suffer from a low efficiency in flue gas environment, especially under SO₂ condition. In the present paper, the multi-walled carbon nanotubes (MWCNTs) are utilized to improve the adsorption capacity of the Mn_0.4Cu_0.6Fe₂O₄ adsorbents as well as inhibit the influence of flue gas composition. The influences of temperature, adsorbent type and the flue gas composition on Hg⁰ removal efficiency are evaluated by experiments. The physical adsorption property of MWCNTs provides a platform for Hg⁰ oxidation by Mn_0.4Cu_0.6Fe₂O₄. The synergistic effect between MWCNTs and Mn_0.4Cu_0.6Fe₂O₄ enhances the mercury removal efficiency as well we the sulfur resistance. The results find that the adsorbent of Mn_0.4Cu_0.6Fe₂O₄ containing 14 % MWCNTs has a high mercury removal efficiency of 95.6 % at 120 °C even under 1000 ppm SO₂ concentration. The kinetic behaviors of adsorbent adsorption are analyzed by theoretical models. The mechanisms of porous carbon-containing modifier to improve the mercury removal performance of Mn_0.4Cu_0.6Fe₂O₄ are explored carefully. The present ferrite-based adsorbent exhibits promising prospects for the practical industrial applications of the low temperature mercury removal from coal-fired flue gas.

虽然亚铁基吸附剂具有较高的热稳定性，是一种潜在的脱汞材料，但它们在烟气环境中通常效率较低，尤其是在二氧化硫条件下。本文利用多壁碳纳米管（MWCNTs）来提高 Mn0.4Cu0.6Fe2O4 吸附剂的吸附能力，并抑制烟气成分的影响。实验评估了温度、吸附剂类型和烟气成分对 Hg0 去除效率的影响。MWCNTs 的物理吸附特性为 Mn0.4Cu0.6Fe2O4 氧化 Hg0 提供了一个平台。MWCNTs 与 Mn0.4Cu0.6Fe2O4 的协同效应提高了汞的去除效率和抗硫能力。结果发现，含有 14% MWCNTs 的 Mn0.4Cu0.6Fe2O4 吸附剂在 120 °C、1000 ppm 二氧化硫浓度条件下的汞去除率高达 95.6%。理论模型分析了吸附剂吸附的动力学行为。仔细探讨了多孔碳改性剂改善 Mn0.4Cu0.6Fe2O4 汞去除性能的机理。该铁氧体基吸附剂在燃煤烟气低温脱汞的实际工业应用中具有广阔的前景。

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引用次数: 0

Effect of Cu incorporation on Fe-based catalysts for selective CO2 hydrogenation to olefins 铜掺入对选择性二氧化碳加氢制烯烃的铁基催化剂的影响

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-05 DOI: 10.1016/j.joei.2024.101849

The process of converting CO₂ into sustainable chemical feedstock and fuels through reaction with renewable hydrogen has been regarded as a promising direction in energy research. The enhancement of CO₂ hydrogenation efficiency to produce valuable hydrocarbons (specifically olefins) on Fe catalysts through Cu modification has been extensively researched. However, there is ongoing vigorous debate regarding the impact of these modifications on catalytic properties and the underlying mechanism. When compared to unprompted iron-based catalysts for CO₂ hydrogenation, the choice of desired products, such as C₂-C₄ and C₅₊, is relatively low. So, promoters are frequently employed to customize and enhance product distribution. This study investigates how adding Cu to Fe-based supported catalysts affects their performance in converting CO₂ to hydrocarbons, with a specific emphasis on the interaction between Fe and Cu. To achieve this goal, catalysts were created using co-precipitation methods, varying the distribution of Fe and Cu within them. A set of composite catalysts underwent testing in a fixed bed setup using a reactant gas mixture at 350 °C and 30 bar pressure. Analysis techniques such as XRD, SEM, TEM, NH₃-TPD, H₂-TPR, and N₂ adsorption-desorption isotherms revealed the presence of iron-copper interaction within the composite catalysts. This interaction between the two components synergistically enhances the catalytic activity in CO₂ hydrogenation.

通过与可再生氢气反应将二氧化碳转化为可持续化学原料和燃料的过程一直被视为能源研究中一个前景广阔的方向。在铁催化剂上通过铜改性提高 CO2 加氢效率以生产有价值的碳氢化合物（特别是烯烃）已得到广泛研究。然而，关于这些改性对催化特性的影响及其内在机理的争论仍在继续。与用于 CO2 加氢的未催化铁基催化剂相比，C2-C4 和 C5+ 等所需产物的选择相对较少。因此，经常使用促进剂来定制和增强产物分布。本研究探讨了在铁基支撑催化剂中添加 Cu 如何影响其将 CO2 转化为碳氢化合物的性能，并特别强调了铁和 Cu 之间的相互作用。为实现这一目标，研究人员采用共沉淀方法制造催化剂，并改变其中铁和铜的分布。在 350 °C 和 30 bar 压力下，使用反应物气体混合物在固定床装置中对一组复合催化剂进行了测试。XRD、SEM、TEM、NH3-TPD、H2-TPR 和 N2 吸附-解吸等温线等分析技术显示，复合催化剂中存在铁-铜相互作用。这两种成分之间的相互作用协同增强了二氧化碳加氢的催化活性。

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引用次数: 0

CoCe composite catalyst for CO2 hydrogenation: Effect of pore structure 用于二氧化碳加氢的 CoCe 复合催化剂：孔结构的影响

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-05 DOI: 10.1016/j.joei.2024.101856

In order to realize the dual carbon goals of “carbon peaking” and “carbon neutrality”, the design and development CO₂ hydrogenation catalyst with high performances is of great significance. In this study, the CoCe composite catalysts were prepared by different methods and used to CO₂ catalytic hydrogenation. The physicochemical properties of the prepared catalysts were characterized by XRD, BET, TEM/HRTEM, and H₂-TPD. The characterization results indicated that the studied CoCe composite catalytsts with different pore structure can be prepared by different preparation methods. The suitable preparation method can promote Co species to be dissolved into the CeO₂ lattice to form Ce-O-Co solid solution, which can promote the corresponding Co species to be reduced by H₂ to form active Co⁰ species. The large specific surface area and developed ordered mesoporous structure of the CoCe-HT catalyst precursor, which was prepared by hard-template method, are conducive to the formation of active Co⁰ species and activation of H₂ to produce reactive H species. The CO₂ hydrogenation activity of the studied CoCe composite catalysts follows the following order: CoCe-HT > CoCe-CP > CoCe-CA > CoCe-HY. The CoCe-HT catalyst showed high CO₂ hydrogenation conversion of 53.9 % and good using stability at 360 °C for 600 min. However, the CoCe-CA prepared by complex method has a poor use stability.

为了实现 "碳调峰 "和 "碳中和 "的双碳目标，设计和开发高性能的二氧化碳加氢催化剂具有重要意义。本研究采用不同方法制备了 CoCe 复合催化剂，并将其用于 CO2 催化加氢。通过 XRD、BET、TEM/HRTEM 和 H2-TPD 对所制备催化剂的理化性质进行了表征。表征结果表明，所研究的不同孔结构的 CoCe 复合催化剂可通过不同的制备方法制备。合适的制备方法可以促进 Co 物种溶解到 CeO2 晶格中形成 Ce-O-Co 固溶体，从而促进相应的 Co 物种被 H2 还原形成活性 Co0 物种。硬模板法制备的 CoCe-HT 催化剂前驱体具有较大的比表面积和发达的有序介孔结构，有利于形成活性 Co0 物种并活化 H2 生成活性 H 物种。所研究的 CoCe 复合催化剂的 CO2 加氢活性按以下顺序排列：CoCe-HT；CoCe-CP；CoCe-CA；CoCe-HY。CoCe-HT 催化剂的二氧化碳加氢转化率高达 53.9%，在 360 °C 下 600 分钟的使用稳定性良好。然而，用复合方法制备的 CoCe-CA 的使用稳定性较差。

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引用次数: 0

Fuel consumption and exhaust emissions from Euro 6d vehicles fueled by innovative LPG/DME blend 以创新型液化石油气/二甲醚混合物为燃料的欧 6d 车辆的燃料消耗量和尾气排放量

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-05 DOI: 10.1016/j.joei.2024.101851

The aim of this research was to investigate the exhaust emissions from vehicles when fueled by a new and fully renewable fuel if made of bio-LPG and renewable dimethyl ether (DME), in comparison with standard gasoline. For this purpose, DME was mixed with liquefied petroleum gas (LPG) and used to fuel three bi-fuel LPG/gasoline spark-ignition engines light-duty vehicles. The suitable fuel blend was selected based on several octane tests using CFR engines. Exhaust emissions were tested over the WLTC and over the hot-start CADC cycles, as well as on the road. All Euro 6 standards were well fully met over the WLTC with both fuels. Switching from gasoline to LPG/DME fueling, the CO and NOx emission factors increased for two vehicles, whereas THC and NMHC decreased. Regarding particulates, for two vehicles the emission factors decreased, too. Generally, when the vehicles were driven on the CADC, lower gaseous emissions were observed compared to WLTC: excluding one vehicle, when switching from gasoline to LPG/DME fueling, the overall emission profiles reflected those of the same vehicles run on the WLTC. The unregulated particulate emissions measured over both testing cycles reflect what was detected for the regulated ones. Except for PN10, which was not measured, all regulated emissions were found to meet the (most severe) Euro 7 standards proposed at first by the European Commission. RDE tests showed that all vehicle emissions obtained from on-road tests were also found to meet the RDE standards, regardless of the fueling. Concerning CO₂ emissions, LPG/DME fueling guaranteed a systematic decrease for all vehicles and cycles, both on road and in the laboratory. The present investigation aims at demonstrating that the innovative LPG/DME 80 %/20 % (m/m) blend not only can be deemed as potentially suitable for GHG emissions reduction, as long as both DME and propane are obtained from renewable sources, but even compliant with EN 589 and both Euro 6 and part of preliminary Euro 7 exhaust emission proposal.

这项研究的目的是调查车辆在使用由生物液化石油气和可再生二甲醚（DME）制成的新型完全可再生燃料时的尾气排放情况，并与标准汽油进行比较。为此，将二甲醚与液化石油气（LPG）混合，用于为三辆双燃料 LPG/ 汽油火花点火发动机轻型汽车提供燃料。根据使用 CFR 发动机进行的辛烷值测试，选择了合适的混合燃料。对废气排放进行了 WLTC 和热启动 CADC 循环测试以及道路测试。两种燃料在 WLTC 循环中均完全符合所有欧 6 标准。从汽油改用液化石油气/二甲醚燃料后，两辆车的一氧化碳和氮氧化物排放系数增加，而四氢大麻酚和非甲烷总烃则减少。在微粒方面，两辆车的排放系数也有所下降。一般来说，当车辆在 CADC 上行驶时，观察到的气体排放量低于 WLTC：除一辆车外，当从汽油燃料切换到 LPG/DME 燃料时，总体排放曲线反映了相同车辆在 WLTC 上行驶时的排放曲线。在两个测试周期中测得的非规范颗粒物排放反映了规范颗粒物的检测结果。除了未测量的 PN10 外，所有受管制的排放物均符合欧盟委员会最初提出的（最严格的）欧 7 标准。RDE 测试表明，无论使用何种燃料，从道路测试中获得的所有车辆排放也都符合 RDE 标准。在二氧化碳排放量方面，无论是在道路上还是在实验室中，液化石油气/二甲醚燃料都能保证所有车辆和循环的二氧化碳排放量都有系统地减少。本次调查旨在证明，只要二甲醚和丙烷都来自可再生资源，创新的液化石油气/二甲醚混合燃料（80%/20% (m/m)）不仅可被视为减少温室气体排放的潜在选择，甚至还符合 EN 589 标准以及欧 6 和部分初步欧 7 废气排放建议。

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引用次数: 0

Exploring the catalytic conversion of aromatic model compounds of coal pyrolysis over Ca(OH)2 探索煤热解芳香模型化合物在 Ca(OH)2 上的催化转化

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-04 DOI: 10.1016/j.joei.2024.101850

The distribution of pyrolysis products from aromatic model compounds in coal catalyzed by Ca(OH)₂ was investigated at the molecular level. The composition and relative abundance of the pyrolysis products from coal were analyzed using Py-GC/MS. The rapid pyrolysis products of coal at 600 °C consisted of phenols (15.94 %), non-phenolic oxygenated compounds (25.31 %), aliphatics (49.03 %), aromatic compounds (21.74 %), and other compounds (0.03 %). Six representative aromatic model compounds (2-methoxy-4-methylphenol, p-cresol, 2,4-dimethylphenol, o-cresol, guaiacol, and catechol) were selected. The pyrolysis process of model compounds was primarily the cleavage of C-O and C-C bonds, which resulted in the formation of methoxy and methyl radicals. The results revealed that Ca(OH)₂ undergoes acid-base reactions with -OH, thereby increasing the stability of the model compounds. Notably, the impact of Ca(OH)₂ on the composition and distribution of pyrolysis products was significantly more pronounced in aromatic compounds containing both -OCH₃ and -OH compared to those containing solely -OH. The formation pathways of pyrolysis products involving guaiacol and Ca(OH)₂ were elucidated through density functional theory (DFT) calculations, demonstrating that Ca(OH)₂ could facilitate more free radicals release and the conversion of model compounds. This study contributes to the understanding of the transformation of aromatic compounds during coal pyrolysis at the molecular level.

在分子水平上研究了 Ca(OH)2 催化煤中芳香模型化合物热解产物的分布。使用 Py-GC/MS 分析了煤热解产物的组成和相对丰度。煤在 600 °C 时的快速热解产物包括酚类（15.94 %）、非酚类含氧化合物（25.31 %）、脂肪族（49.03 %）、芳香族化合物（21.74 %）和其他化合物（0.03 %）。选择了六种具有代表性的芳香族模型化合物（2-甲氧基-4-甲基苯酚、对甲酚、2,4-二甲基苯酚、邻甲酚、愈创木酚和邻苯二酚）。模型化合物的热解过程主要是 C-O 和 C-C 键的裂解，从而形成甲氧基和甲基自由基。结果表明，Ca(OH)2 与 -OH 发生酸碱反应，从而提高了模型化合物的稳定性。值得注意的是，在同时含有 -OCH3 和 -OH 的芳香族化合物中，Ca(OH)2 对热解产物组成和分布的影响要比只含有 -OH 的化合物明显。通过密度泛函理论（DFT）计算，阐明了愈创木酚和 Ca（OH）2 热解产物的形成途径，证明 Ca（OH）2 可促进更多自由基的释放和模型化合物的转化。这项研究有助于从分子水平理解煤热解过程中芳香族化合物的转化。

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引用次数: 0

Robust online monitoring system for PCDD/Fs in a full-scale MSWI by Deans switch: Efficiently separation and purification 通过迪恩斯开关，对大规模 MSWI 中的多氯二苯并对二恶英和多氯二苯并呋喃进行在线监测：高效分离和净化

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-03 DOI: 10.1016/j.joei.2024.101852

Existing online monitoring system for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), technically named Thermal Desorption-Gas Chromatography-Tunable Laser Ionization-Time of Flight Mass Spectrometry (TD-GC-TLI-TOFMS), has been applied in several incinerators in China. TD-GC-TLI-TOFMS can realize rapid detection of PCDD/Fs emissions from incineration sources. However, the long-term measurement of unclean flue gas will pollute the instruments in TD-GC-TLI-TOFMS, and interfere with the peak output of the target 1,2,4-trichlorobenzene (1,2,4-TrCBz). In this study, Deans switch (DS) was utilized for the first time in an online monitoring system for PCDD/Fs to separate 1,2,4-TrCBz signal from impurity signals, which improved the anti-interference capability of the system. Laboratory standard gas experiments showed that after adding a DS device between GC and TLI pulse valve, when the pressure set in DS was 4 psi and switched before or near the peak output of 1,2,4-TrCBz, the change of 1,2,4-TrCBz signal intensity was minimal. The impurities near the target peak were removed, and TLI-TOFMS was highly stable during continuous measurement. Moreover, the maximum intensity peak time of 1,2,4-TrCBz was stable after using DS in different switching time intervals. When connecting DS to TD-GC-TLI-TOFMS for field validation on the tail flue gas of a municipal solid waste incinerator (MSWI), results showed that a better 1,2,4-TrCBz signal could be obtained with a 69.52 % reduction of impurity peaks at the moments closer to the target peak. Furthermore, DS improved the sensitivity of the system to low concentration variations of 1,2,4-TrCBz in the flue gas. The robust system developed in this study can be better applied to incineration factories with poor combustion or suboptimal purification technology, facilitating online PCDD/Fs monitoring.

现有的多氯二苯并对二恶英和多氯二苯并呋喃（PCDD/Fs）在线监测系统，专业名称为热脱附-气相色谱-可调激光电离-飞行时间质谱联用仪（TD-GC-TLI-TOFMS），已在国内多个焚烧厂应用。TD-GC-TLI-TOFMS 可以实现对焚烧源中多氯二苯并对二恶英和多氯二苯并呋喃排放的快速检测。然而，长期测量不洁烟气会污染 TD-GC-TLI-TOFMS 中的仪器，干扰目标物 1,2,4-三氯苯（1,2,4-TrCBz）的峰值输出。本研究首次在多氯二苯并对二恶英/多氯二苯并呋喃在线监测系统中使用了迪恩斯开关（DS），将 1,2,4-TrCBz 信号从杂质信号中分离出来，提高了系统的抗干扰能力。实验室标准气体实验表明，在气相色谱仪和 TLI 脉冲阀之间增加 DS 装置后，当 DS 设定的压力为 4 psi，并在 1,2,4-TrCBz 峰输出之前或附近切换时，1,2,4-TrCBz 信号强度的变化很小。目标峰附近的杂质被清除，TLI-TOFMS 在连续测量过程中高度稳定。此外，在不同的切换时间间隔内使用 DS 后，1,2,4-TrCBz 的最大强度峰时间也很稳定。将 DS 与 TD-GC-TLI-TOFMS 连接起来对城市固体废物焚化炉（MSWI）的尾气进行现场验证时，结果表明可以获得更好的 1,2,4-TrCBz 信号，在更接近目标峰的时刻杂质峰减少了 69.52%。此外，DS 还提高了系统对烟气中 1,2,4-TrCBz 低浓度变化的灵敏度。本研究开发的稳健系统可更好地应用于燃烧不充分或净化技术不理想的焚烧厂，从而促进多氯二苯并对二恶英和多氯二苯并呋喃的在线监测。

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引用次数: 0

NH3 co-firing strategy in 500 MW tangential utility boiler: Impact of blending methods 500 兆瓦切向公用事业锅炉中的 NH3 联合燃烧策略：混合方法的影响

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute

Pub Date : 2024-10-03 DOI: 10.1016/j.joei.2024.101854

Ammonia co-firing is increasingly regarded as an effective strategy to reduce CO₂ emissions in coal-fired boilers. In this study, we introduce and evaluate two innovative fuel blending methods for ammonia-coal co-firing in a commercial 500 MW utility boiler: burner blending and in-boiler blending. Using computational fluid dynamics simulations, we investigated the effects of 20 % ammonia co-firing on heat transfer efficiency, fuel burnout rate, and pollutant emissions. The results show that while ammonia co-firing effectively reduces CO₂ emissions, it also leads to decreases in the furnace and furnace exit-gas temperatures due to the lower flame temperature and increased moisture production. Specifically, the total heat absorption by the water walls and heat exchangers decreased by 4.58 % in the burner blending method and 2.27 % in the in-boiler blending method compared to that with pure coal combustion. Although ammonia co-firing suppresses the generation of thermal NO, overall NO emissions increase significantly due to the substantial release of fuel NO. However, the in-boiler blending method demonstrated superior NO reduction, reducing NO emissions by 13.48 ppm compared to the burner blending method. In addition, the in-boiler blending method showed better combustion stability, achieving faster ignition and reducing the amount of unburned carbon in fly ash by 0.97 %, compared to that with the burner blending method. This is likely due to the higher concentration of combustible gases near the burner in the in-boiler blending system. These findings indicate that the in-boiler blending method is more effective than the burner blending method for ammonia-coal co-firing in a 500 MW utility boiler. This provides valuable insights into the implementation of ammonia co-firing in commercial boilers as part of efforts to achieve carbon neutrality.

氨煤共烧越来越被视为燃煤锅炉减少二氧化碳排放的有效策略。在本研究中，我们介绍并评估了在商用 500 兆瓦公用事业锅炉中进行氨煤共烧的两种创新燃料混合方法：燃烧器混合和锅炉内混合。通过计算流体动力学模拟，我们研究了 20% 氨水共燃对传热效率、燃料燃尽率和污染物排放的影响。结果表明，虽然氨气联合燃烧可有效减少二氧化碳排放，但由于火焰温度降低和水分产生增加，氨气联合燃烧也会导致炉膛和炉膛出口气体温度降低。具体而言，与纯煤燃烧相比，燃烧器掺烧法和锅炉内掺烧法的水壁和热交换器总吸热下降了 4.58%，锅炉内掺烧法下降了 2.27%。虽然氨水共燃抑制了热氮氧化物的产生，但由于燃料氮氧化物的大量释放，总体氮氧化物排放量显著增加。然而，与燃烧器掺烧法相比，锅炉内掺烧法能更好地减少氮氧化物的排放，氮氧化物排放量减少了 13.48 ppm。此外，与燃烧器掺烧法相比，沸腾炉内掺烧法的燃烧稳定性更好，点火速度更快，飞灰中的未燃碳量减少了 0.97%。这可能是由于沸腾炉内掺烧系统中燃烧器附近的可燃气体浓度更高。这些研究结果表明，在 500 兆瓦公用事业锅炉的氨煤共烧中，锅炉内掺烧方法比燃烧器掺烧方法更有效。这为在商业锅炉中实施氨气联合燃烧提供了宝贵的见解，是实现碳中和努力的一部分。

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引用次数: 0