Journal of Analytical and Applied Pyrolysis最新文献_第6页

Hydrothermal carbonization of snow crab processing by-product: Hydrochar characterization 雪蟹加工副产品的水热碳化：水碳特征

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106767

Nadyana Incan , Kelly A. Hawboldt , Stephanie MacQuarrie

Fishery processing (crab) is an important industry in Atlantic Canada. However, up to half of the landed product ends as processing by-product with over 70 wt% water content. Often regarded as a “waste” this by-product has applications in soils, wastewater treatment, and other industries, an area of research largely unexplored. Hydrothermal carbonization (HTC) converts biomass into a more stable and useable material (hydrochar) and uses water as a medium. This valorization not only creates a profit stream but also reduces the environmental impacts of the crab by-product treatment and disposal. In this work, HTC hydrochar from snow crab (Chionoecetes opilio) processing by-product/feedstock is characterized with respect to key properties in an effort to delineate potential end use applications and the impact of process parameters (temperature, residence time, and water to biomass ratio) on these properties. The temperature range was 180–260 ℃, residence time of 0.5–3 h, and water to biomass ratio of 2–4 (wt:wt). The solids yield decreased as water ratio and temperature increased (time did not impact yield to the same extent). The hydrochar ash content increased from 33 to 45 wt% as water ratio and temperature increased to the maximums studied in this work. XRD analysis showed that the hydrochar retained chitin and CaCO₃. Trace analysis showed calcium was the most abundant mineral in the feedstock and hydrochar, consistent with the XRD CaCO₃ peak. Compared to the feedstock (11 m²/g), the hydrochar BET surface area increased with temperature and water ratio, reaching a maximum of 26 m²/g at 260 °C, water ratio 3 and 30 min. However, increasing the time to 3 h reduced the surface area to 13.47 m²/g. Hydrochar carbon content is similar or slightly higher than the feedstock due to competing polymerization reaction and CaCO₃ dissolution. Nitrogen decreased as temperature increased possibly due to protein degradation. Hydrochar and feedstock showed similar functional groups. The functional groups in the hydrochar have potential to facilitate chemosorption as a bioadsorbent.

渔业加工（螃蟹）是加拿大大西洋地区的重要产业。然而，多达一半的上岸产品最终成为含水量超过 70 wt% 的加工副产品。这种副产品通常被视为 "废物"，可用于土壤、废水处理和其他行业，但这一研究领域在很大程度上尚未开发。水热碳化（HTC）将生物质转化为更稳定、更可用的材料（水炭），并以水为介质。这种增值不仅创造了利润流，还减少了螃蟹副产品处理和处置对环境的影响。在这项工作中，对来自雪蟹（Chionoecetes opilio）加工副产品/原料的 HTC 水炭的主要特性进行了表征，以确定潜在的最终用途以及工艺参数（温度、停留时间和水与生物质比率）对这些特性的影响。温度范围为 180-260 ℃，停留时间为 0.5-3 h，水与生物质比率为 2-4（重量比）。固体产量随着水比和温度的增加而减少（时间对产量的影响程度不同）。随着水比和温度的增加，水煤灰含量从 33% 增加到 45%，达到了本次研究的最大值。XRD 分析表明，水碳保留了甲壳素和 CaCO3。痕量分析表明，钙是原料和水碳中含量最高的矿物质，这与 XRD CaCO3 峰值一致。与原料（11 m2/g）相比，水炭的 BET 表面积随温度和水比率的增加而增加，在 260 °C、水比率 3 和 30 分钟时达到最大值 26 m2/g。然而，将时间延长至 3 小时后，表面积降至 13.47 m2/g。由于竞争性聚合反应和 CaCO3 的溶解，水碳的碳含量与原料相近或略高于原料。氮含量随着温度的升高而降低，这可能是由于蛋白质降解所致。水碳和原料显示出相似的官能团。作为一种生物吸附剂，水碳中的官能团具有促进化学吸附的潜力。

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引用次数: 0

Exploring the potential of fast pyrolysis of invasive biomass species for the production of chemicals 探索入侵生物质物种快速热解生产化学品的潜力

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106817

Enara Fernandez , Maider Amutio , Maite Artetxe , Gartzen Lopez , Laura Santamaria , Julian E. Lopez , Martin Olazar , Juan F. Saldarriaga

The pyrolysis of five invasive plants crowded in Colombia (Liquidambar styraciflua, Sambucus nigra, Cecropia telenitida, Ruta greveolens, and Clusia orthoneura) has been studied for the first time in order to assess their potential for the production of liquid and solid fuels and chemical products. The volatiles produced from the fast pyrolysis of these biomass species at three different temperatures (500, 600 and 700 ºC) were analyzed by Py-GC/MS. In spite of the different nature of the feedstock, the bio-oil produced from the pyrolysis of all the biomasses at the three temperatures studied is mainly composed of phenols (with a relative content in the 19–26.5 % range), acids (14.6–19.5 %), ketones (13.4–19.2 %) and levoglucosan (6.7–15.4 %). Temperature has a moderate effect, leading to a decrease in the relative content of all component families, except aldehydes and hydrocarbons, when it is increased. Biochars produced at 500 ºC show high calorific values, as well as low H/C and O/C ratios, which prove their high stability in the soil. These results are clear evidence that the valorization of these invasive plants by pyrolysis may be an effective strategy for the mitigation of their associated impacts.

为了评估哥伦比亚五种入侵植物（Liquidambar styraciflua、Sambucus nigra、Cecropia telenitida、Ruta greveolens 和 Clusia orthoneura）生产液体和固体燃料及化学产品的潜力，我们首次对这些植物进行了热解研究。Py-GC/MS 分析了这些生物质在三种不同温度（500、600 和 700 ºC）下快速热解产生的挥发物。尽管原料性质不同，但所有生物质在三种温度下热解产生的生物油主要由酚类（相对含量在 19-26.5 % 之间）、酸类（14.6-19.5 %）、酮类（13.4-19.2 %）和左旋葡聚糖（6.7-15.4 %）组成。温度的影响不大，当温度升高时，除醛和碳氢化合物外，所有组分族的相对含量都会降低。在 500 ºC 温度下生产的生物炭显示出较高的热值以及较低的 H/C 和 O/C 比值，这证明它们在土壤中具有较高的稳定性。这些结果清楚地证明，通过热解使这些入侵植物增值可能是减轻其相关影响的有效策略。

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引用次数: 0

Biochar: Preserving the long-term catalytic activity of biosynthesized PdNPs/AuNPs in Cr(VI) reduction 生物炭：保持生物合成的 PdNPs/AuNPs 在还原 Cr(VI) 过程中的长期催化活性

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106816

Ling Tan , Chao Long , Hongfei Lai , Xiaowei Huo , Wenjia Yu , Guotong Wei , Ting Tong , Chaoyu Tian

Palladium nanoparticles (PdNPs) and gold nanoparticles (AuNPs) synthesized within yeast biomass can be effectively preserved in yeast biochar while maintaining their catalytic activity. Herein, we observe well-preserved PdNPs/AuNPs within yeast biochars, alongside the retention of cell morphology. Notably, the crystal structures of AuNPs within biochars exhibit similarity to that of uncarbonized samples, suggesting minimal influence of carbonization on nanoparticle structure. XPS analysis reveals the transformation of organic bacterial cells into heterocyclic aromatic-carbon material during pyrolytic carbonization. Chemical states analysis indicates the prevalence of metallic Pd(0)/Au(0) with limited PdO_x/AuO_x content in yeast biochars. FTIR analysis highlights increased aromaticity of biochars with typical bands for aromatic ring, and new bands appeared in Pd/Au-loaded biochars possibly attribute to PdO_x/AuO_x. Moreover, yeast biochars exhibit significantly improved Cr(VI) removal capacities compared to yeast biomass. Specifically, we detect complete removal within 18 h for CYPd and CYPdG biochars, contrasting with less than 65 % removal efficiency in yeast biomass. These findings underscore the potential of carbonization in enhancing the long-term catalytic activity of biosynthesized PdNPs/AuNPs for efficient Cr(VI) reduction, offering promising avenues for environmental remediation strategies.

在酵母生物质中合成的钯纳米颗粒（PdNPs）和金纳米颗粒（AuNPs）可以有效地保存在酵母生物炭中，同时保持其催化活性。在此，我们观察到酵母生物炭中的 PdNPs/AuNPs 保存完好，同时细胞形态也得以保留。值得注意的是，生物炭中 AuNPs 的晶体结构与未碳化样品的晶体结构相似，这表明碳化对纳米粒子结构的影响微乎其微。XPS 分析表明，在热解碳化过程中，有机细菌细胞转变为杂环芳香碳材料。化学状态分析表明，酵母生物炭中普遍含有金属钯（0）/金（0），而钯氧化物/金氧化物含量有限。傅立叶变换红外分析表明，生物酵母的芳香性增强，具有典型的芳香环条带，而 Pd/Au 负载生物酵母中出现的新条带可能归因于 PdOx/AuOx。此外，与酵母生物质相比，酵母生物酵素对六价铬的去除能力明显提高。具体来说，我们发现 CYPd 和 CYPdG 生物酵母在 18 小时内就能完全去除六价铬，而酵母生物质的去除效率不到 65%。这些发现强调了碳化在增强生物合成的 PdNPs/AuNPs 的长期催化活性以高效还原六价铬方面的潜力，为环境修复策略提供了前景广阔的途径。

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引用次数: 0

The preparation, layered characterization and potential applications of corncob biochar 玉米芯生物炭的制备、分层表征和潜在应用

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106808

Lichao Ge , Lei Yao , Yang Wang , Mingjin Zuo , Yanquan Liu , Kefeng Wu , Weixuan Zhang , Chang Xu

To investigate the characteristics of biochar produced from different parts of corncob, biochar was prepared using corncob as a raw material at constant temperatures of 500 °C, 600 °C, and 700 °C, and the biochar was divided into three parts based on its macroscopic structure: an inner layer (CC-N), a middle layer (CC-Z), and an outer layer (CC-W). The composition and physicochemical changes of the biochar samples were evaluated via FTIR, XRD, Raman, and SEM. The results revealed that the microstructure of corncob is heterogeneous, with CC-N resembling withered leaves, CC-Z resembling blocks, and CC-W resembling sheets. The specific surface area and average pore size of the biochar significantly decreased from the inner layer to the outer layer. The functional group structures of the three parts of the biochar are similar, but the infrared spectrum of CC-N has the greatest peak intensity. The degree of graphitization and thermal stability of CC-N were lower than those of CC-Z and CC-W. Higher-temperature pyrolysis promoted the graphitization of char and improved its thermal stability. This research provides important theoretical support for the preparation of activated carbon and high-quality solid biofuels from different layers of corncob.

为研究不同部位玉米芯制备的生物炭的特性，以玉米芯为原料，在 500 ℃、600 ℃ 和 700 ℃ 的恒温条件下制备生物炭，并根据生物炭的宏观结构将其分为三部分：内层（CC-N）、中层（CC-Z）和外层（CC-W）。通过傅立叶变换红外光谱、X 射线衍射、拉曼和扫描电镜评估了生物炭样品的组成和理化变化。结果表明，玉米芯的微观结构是异质的，CC-N 像枯叶，CC-Z 像块状，CC-W 像片状。从内层到外层，生物炭的比表面积和平均孔径明显减小。生物炭三个部分的官能团结构相似，但 CC-N 的红外光谱峰强度最大。CC-N 的石墨化程度和热稳定性低于 CC-Z 和 CC-W。高温热解促进了炭的石墨化，提高了其热稳定性。该研究为利用不同层的玉米芯制备活性炭和优质固体生物燃料提供了重要的理论支持。

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引用次数: 0

Conversion of kraft lignin to hydrocarbons using an integrated molten salt pyrolysis/catalytic hydrotreatment approach 利用熔盐热解/催化加氢处理综合方法将牛皮纸木质素转化为碳氢化合物

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106813

Balaji Sridharan , Ilse Oude Nijeweme , Erwin Wilbers , Gerco Gerritsen , Josef G.M. Winkelman , Robbie H. Venderbosch , Hero J. Heeres

Thermochemical conversion of underutilized lignocellulosic streams such as kraft lignin from the pulp and paper industry has the potential to produce sustainable chemicals and biofuels. We here report a process to continuously convert softwood-based lignoboost lignin to hydrocarbons using a three-step approach: i) liquefaction/dispersion of the lignin in a suitable molten salt, ii) pyrolysis of the liquefied/dispersed lignin in a molten salt mixture (ZnCl₂, KCl, and NaCl), to obtain a crude lignin oil and iii) upgrading of the lignin oil using a catalytic hydrotreatment to yield hydrocarbons. Step 1 and 2 were integrated using a twin screw extruder with different heating sections at a scale of 20 g/h lignin input. Besides char, a lignin oil, mainly composed of monomeric phenolics, and propylene were the major products. The highest yield of the latter two products was around 32 wt% (23 wt% crude lignin oil and 9 wt% propylene). The lignin oil was subsequently converted to hydrocarbons using a two-step catalytic hydrotreatment approach (stabilization step using CoMo/Al₂O₃ catalyst and a further deep hydrotreatment over a NiMo/Al₂O₃ catalyst). The final liquid product contained less than 0.5 wt% of oxygen and was shown to be rich in (cyclo)alkanes and aromatic hydrocarbons. The carbon yield for the overall conversion of lignin to hydrocarbons was 23 %.

对未充分利用的木质纤维素流（如来自纸浆和造纸工业的牛皮纸木质素）进行热化学转化，具有生产可持续化学品和生物燃料的潜力。我们在此报告一种采用三步法将软木基木质素连续转化为碳氢化合物的工艺：i) 将木质素液化/分散在合适的熔盐中；ii) 将液化/分散的木质素热解在熔盐混合物（ZnCl2、KCl 和 NaCl）中，以获得粗木质素油；iii) 使用催化加氢处理对木质素油进行升级，以获得碳氢化合物。第 1 步和第 2 步采用双螺杆挤压机进行，挤压机有不同的加热段，木质素输入量为 20 克/小时。除了木炭，主要由单体酚组成的木质素油和丙烯也是主要产品。后两种产品的最高产量约为 32 wt%（粗木质素油 23 wt%，丙烯 9 wt%）。木质素油随后采用两步催化加氢处理法（使用 CoMo/Al2O3 催化剂进行稳定化处理，然后在 NiMo/Al2O3 催化剂上进行深度加氢处理）转化为碳氢化合物。最终液体产品的含氧量低于 0.5 wt%，并富含（环）烷烃和芳香烃。木质素到碳氢化合物的整体转化率为 23%。

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引用次数: 0

Nickel doped enhanced LaFeO3 catalytic cracking of tar for hydrogen production 掺镍增强型 LaFeO3 催化裂解焦油制氢

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106825

Wang-mi Chen , Bei-dou Xi , Mei-ying Ye , Ming-xiao Li , Jia-qi Hou , Yu-fang Wei , Cheng-ze Yu , Fan-hua Meng , Xin Dai

The transformation of biomass into green energy was pivotal for sustainable development, yet the efficient conversion of biomass-derived tar into hydrogen-rich syngas remained a significant challenge. This study addressed the catalytic demand for hydrogen production from tar, focusing on the development of LaNi_xFe_1-xO₃ perovskites as catalysts. A series of LaNi_xFe_1-xO₃ perovskites with varying nickel doping levels (x=0, 0.25, 0.5, 0.75, 1) were synthesized to evaluate their catalytic performance in converting toluene, a representative tar component, into hydrogen. The LaNi_0.5Fe_0.5O₃ catalyst demonstrated the highest hydrogen yield (14.5 L/6 h) and volume percentage (82.9 V/V%), highlighting the optimal nickel doping level for enhancing hydrogen production. The hydrogen production performance of LaNi_xFe_1-xO₃ was significantly affected by nickel doping. In particular, a small amount of nickel doping can significantly enhance the hydrogen production capacity of LaFeO₃ and maintain good reaction stability. The enhanced performance was attributed to the high oxygen storage capacity of perovskite, which facilitated the removal of surface carbon and promotes the methanation reaction. Notably, the total content of defect oxygen and surface adsorbed oxygen/hydroxyl groups significantly impacted the hydrogen production efficiency. These findings indicated that LaNi_0.5Fe_0.5O₃ was an effective catalyst for converting biomass-derived tar into hydrogen-rich syngas, offering a promising solution to the catalytic demand in the hydrogen production system.

将生物质转化为绿色能源对于可持续发展至关重要，然而将生物质衍生焦油高效转化为富氢合成气仍是一项重大挑战。本研究针对焦油制氢的催化需求，重点开发了作为催化剂的 LaNixFe1-xO3 包晶。研究人员合成了一系列具有不同镍掺杂水平（x=0、0.25、0.5、0.75、1）的 LaNixFe1-xO3 包晶，以评估它们在将焦油的代表性成分甲苯转化为氢气过程中的催化性能。LaNi0.5Fe0.5O3 催化剂的产氢量（14.5 升/6 小时）和体积百分比（82.9 V/V%）最高，凸显了提高产氢量的最佳镍掺杂水平。LaNixFe1-xO3 的制氢性能受到镍掺杂的显著影响。尤其是少量的镍掺杂可以显著提高 LaFeO3 的制氢能力，并保持良好的反应稳定性。性能的提高归因于过氧化物的高储氧能力，这有利于表面碳的去除并促进甲烷化反应。值得注意的是，缺陷氧和表面吸附氧/羟基的总含量对制氢效率有显著影响。这些研究结果表明，LaNi0.5Fe0.5O3 是一种将生物质衍生焦油转化为富氢合成气的有效催化剂，为解决制氢系统的催化需求提供了一种可行的解决方案。

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引用次数: 0

Machine learning assisted prediction of specific surface area and nitrogen content of biochar based on biomass type and pyrolysis conditions 基于生物质类型和热解条件的机器学习辅助预测生物炭的比表面积和氮含量

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106823

Zhantao Song , Xiong Zhang , Xiaoqiang Li , Junjie Zhang , Jingai Shao , Shihong Zhang , Haiping Yang , Hanping Chen

Predicting and optimizing the physicochemical properties of biochar is crucial for its applications. The characteristics of biomass and pyrolysis conditions are the main factors influencing these properties. However, the numerous components of biomass and the pyrolysis conditions contribute to the substantial challenge in predicting the physicochemical properties, particularly the specific surface area and the nitrogen content of biochar. In this work, machine learning methods including random forest (RF), gradient boosting decision tree (GBDT) and extreme gradient boosting (XGB) (all with R² exceeding 0.97) were used to predict and analyze specific surface area of biochar (SSA), N content of biochar (N-char), and yield of biochar (Yield-char). Compositions of biomass and pyrolysis conditions were selected as input variables. The partial dependence plot analysis showed the impact way of each influential factor on the target variable and the interactions among these factors in the pyrolysis process. The feature importance of these models indicated that the influencing factors toward predicting three targets (sorted by importance) were specified as follows: pyrolysis temperature, nitrogen content, and fixed carbon for Yield-char; N and ash for N-char; ash and pyrolysis temperature for SSA. This work provided new insights for understanding pyrolysis process of biomass.

预测和优化生物炭的物理化学特性对其应用至关重要。生物质的特性和热解条件是影响这些特性的主要因素。然而，生物质的多种成分和热解条件给预测生物炭的理化性质，尤其是比表面积和氮含量带来了巨大挑战。本研究采用随机森林（RF）、梯度提升决策树（GBDT）和极端梯度提升（XGB）等机器学习方法（R2 均超过 0.97）来预测和分析生物炭的比表面积（SSA）、生物炭的氮含量（N-char）和生物炭的产量（Yield-char）。生物质成分和热解条件被选为输入变量。偏倚图分析表明了热解过程中各影响因素对目标变量的影响方式以及这些因素之间的相互作用。这些模型的特征重要度表明，预测三个目标的影响因素（按重要度排序）具体如下：产状炭的热解温度、氮含量和固定碳；N-炭的氮和灰分；SSA的灰分和热解温度。这项工作为了解生物质热解过程提供了新的见解。

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引用次数: 0

Quantitative 13C-IS pyrolysis-GC-MS lignin analysis: Overcoming matrix effects in animal feed and faeces 13C-IS 热解-GC-MS木质素定量分析：克服动物饲料和粪便中的基质效应

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106802

Romy J. Veersma , Gijs van Erven , Corentin Lannuzel , Sonja de Vries , Mirjam A. Kabel

Recently, a pyrolysis-GC-MS methodology for specific lignin quantification and structural characterisation was developed, relying on the use of uniformly ¹³C-labeled polymeric lignin isolate as internal standard (IS). The ¹³C-IS py-GC-MS method has been validated for grasses, woods, and applied in various showcases. To study the fate of lignin in animals, this method still requires careful validation in animal feeds and, especially complex faecal samples, hence the aim of this work. Hereto, faecal material was collected from pigs fed with wheat straw as lignin source and subjected to the py-GC-MS analytical platform for thorough examination of IS pyrolysis behaviour in terms of response and structural features. Next, ^13C-ISpy-lignin contents and corrected Klason lignin contents were compared. Most importantly, we revealed that pyrolysis behaviour of ¹³C-IS lignin and ¹²C-sample lignin was differently affected in the faecal matrix, resulting in the ultimate underestimation of ^13C-ISpy-lignin contents. In-depth examination and evaluation of matrix constituents showed that predominantly matrix ash was responsible for the effects observed. We further demonstrated that said matrix effects can be overcome by water extraction of the samples prior to analysis. Our validation and approach extend the use of the specific ¹³C-IS py-GC-MS methodology for accurate quantitative lignin analysis to biomass samples with complex matrices like pig faeces, and now call for application in future digestibility studies.

最近，研究人员开发了一种热解-气相色谱-质谱（GC-MS）方法，用于特定木质素的定量和结构表征，该方法依赖于使用统一的 13C 标记聚合木质素分离物作为内标（IS）。13C-IS py-GC-MS 方法已在草类和木材中得到验证，并应用于各种展示。为了研究木质素在动物体内的去向，该方法仍需要在动物饲料，特别是复杂的粪便样本中进行仔细验证，因此这也是本研究的目的所在。为此，收集了以小麦秸秆为木质素来源的猪的粪便材料，并将其置于 py-GC-MS 分析平台上，从反应和结构特征方面对 IS 热解行为进行彻底检查。然后，比较了 13C-ISpy 木质素含量和校正克拉森木质素含量。最重要的是，我们发现 13C-IS 木质素和 12C 样品木质素在粪便基质中的热解行为受到不同的影响，导致 13C-ISpy 木质素含量最终被低估。对基质成分的深入研究和评估表明，主要是基质灰分造成了所观察到的影响。我们进一步证明，在分析前对样品进行水提取可以克服上述基质效应。我们的验证和方法将特定 13C-IS py-GC-MS 方法用于精确定量木质素分析的范围扩大到了猪粪等基质复杂的生物质样品，并有望在未来的消化率研究中得到应用。

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引用次数: 0

Pressurized hydrogasification and cobalt-catalyzed hydrogasification behaviors of naphthalene as a coal-based model compound 萘作为煤基模型化合物的加压加氢气化和钴催化加氢气化行为

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106773

Sumin Gu , Shuai Yan , Jun Feng , Rong Zhang , Xuan Qu

The pressurized hydrogasification/catalytic hydrogasification behaviors of naphthalene as a coal-based model compound were investigated for the first time in a batch reactor. The composition of products was roundly analyzed by gas chromatography (GC), gas chromatography–mass spectrometer (GC-MS) and laser desorption time-of-flight mass spectrometry (TOF-MS). Based on the product analysis results, the detailed reaction pathways for naphthalene hydrogasification and the effects of cobalt on reaction pathways were elucidated. Naphthalene first destabilized during hydrogasification. Subsequently, the destabilized naphthalene either underwent stepwise hydrocracking by active hydrogen atoms to ultimately produce benzene and methane, or formed naphthalene free radicals to initiate condensation. Cobalt can regulate products distribution to boost methane, benzene and toluene yield by facilitating active hydrogen generation, despite it had a limited ability to facilitate the naphthalene destabilization at temperature below 700 °C. Whereas above 750 °C, cobalt can promote naphthalene destabilization, thereby remarkably enhancing the conversion of naphthalene. Furthermore, cobalt intensified condensation leading to a shift of molecular mass distribution of condensation products from 252 ∼ 500 Da to 750 ∼ 2000 Da. These phenomena supported similar findings in coal catalytic hydrogasification. The rise in temperature, initial H₂ pressure (P₀), and cobalt content all facilitated the cobalt catalyzed naphthalene hydrocracking to gaseous product, with temperature exerting a particularly significant effect. This trend was similar with cobalt catalyzed coal hydrogasification. For example, when temperature increased from 650 ℃ to 750 ℃, naphthalene conversion improved from 21.2 % to 49.6 %, and gas yield rose from 2.6 % to 29.4 % at 1 % Co and 1.3 MPa P₀. The investigation serves to shed light on the molecular-level understanding of the mechanism underpinning coal hydrogasification.

首次在间歇反应器中研究了煤基模型化合物萘的加压加氢气化/催化加氢气化行为。通过气相色谱（GC）、气相色谱-质谱（GC-MS）和激光解吸飞行时间质谱（TOF-MS）对产物成分进行了全面分析。根据产物分析结果，阐明了萘加氢气化的详细反应途径以及钴对反应途径的影响。萘在加氢气化过程中首先脱稳。随后，失稳的萘在活性氢原子的作用下发生逐步加氢裂化，最终生成苯和甲烷，或者形成萘自由基，引发缩合反应。钴可以通过促进活性氢的生成来调节产物的分布，从而提高甲烷、苯和甲苯的产量，尽管它在温度低于 700 °C 时促进萘脱稳的能力有限。而在 750 °C 以上，钴能促进萘的脱稳，从而显著提高萘的转化率。此外，钴还能促进缩合，使缩合产物的分子质量分布从 252 ∼ 500 Da 变为 750 ∼ 2000 Da。这些现象证实了煤催化加氢气化的类似发现。温度、初始 H2 压力 (P0) 和钴含量的升高都有助于钴催化萘加氢裂化成气态产物，其中温度的影响尤为显著。钴催化煤加氢气化也有类似的趋势。例如，在 1 % Co 和 1.3 MPa P₀ 条件下，当温度从 650 ℃ 升至 750 ℃ 时，萘的转化率从 21.2 % 提高到 49.6 %，气体产率从 2.6 % 提高到 29.4 %。这项研究有助于从分子层面了解煤炭加氢气化的机理。

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引用次数: 0

A new insight into H-donor’s positive effect on thermal cracking process at molecular level 从分子水平重新认识 H-载体对热裂解过程的积极影响

IF 5.8 2区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Analytical and Applied Pyrolysis

Pub Date : 2024-10-01 DOI: 10.1016/j.jaap.2024.106776

Li Jiguang, Cai Xinheng, Hou Huandi, Ren Jiahao, Xu Ke, Wang Wei

Thermal cracking reactions of vacuum residue (VR) at 420 ℃ with different reaction time were carried out to evaluate an industrial H-donor’s effect on thermal cracking process at molecular level. The mass distribution, conversion ratio, asphaltene and coke yields were analyzed to evaluate the changing rules. Aromatic structures of H-donor were analyzed and its typical structures were speculated, and the bond energy of those model compounds were calculated. It can be concluded that the >460℃ fractions from a refinery stream have abundant H-donors. From analyzing the structures of asphaltenes for the feed and products, it can be learned that H-donors not only can modify the asphaltene structures but also can improve the asphaltene solubility.

对真空残渣（VR）在 420 ℃、不同反应时间下的热裂解反应进行了研究，以评估工业 H-载体在分子水平上对热裂解过程的影响。分析了质量分布、转化率、沥青质和焦炭产率，以评估其变化规律。分析了 H-载体的芳香结构，推测了其典型结构，并计算了这些模型化合物的键能。可以得出结论，炼油厂馏分流中的 460℃馏分含有丰富的 H-载体。通过分析进料和产品中沥青质的结构，可以得出结论：H-载体不仅能改变沥青质的结构，还能提高沥青质的溶解度。

引用次数: 0