燃烧前CO2捕集技术在IGCC发电中的应用

由于整体煤气化联合循环（IGCC）发电本身的技术特点,使得其非常适合于进行燃烧前CO₂捕集。针对IGCC特点,提出了一种MDEA脱酸气结合湿法氧化法硫回收的燃烧前CO₂捕集流程。通过模拟计算,验证了流程的可行性。将其与IGCC发电系统集成,对比计算了有无燃烧前CO₂捕集的IGCC系统供电效率等相关参数,燃烧前CO₂捕集使IGCC供电效率降低约10个百分点。分析指出了导致包含燃烧前CO₂捕集的IGCC供电效率降低的3个因素：蒸汽消耗、燃料化学能损失和新增动力设备电耗,并据此确定了今后的优化方向。     

金属离子促进乙醇胺捕集二氧化碳研究

为了解决醇胺法燃烧后捕集二氧化碳再生能耗过高的问题,研究了一种向胺溶液中添加金属离子以降低其CO₂解吸能耗的方法,称之为金属离子络合物热缓冲自热利用技术。以广泛商业化应用的单乙醇胺（MEA）溶液为研究载体,并在MEA溶液中分别添加金属离子铜或镍, 通过建立含有金属离子的MEA捕集CO₂体系的化学反应模型,解释金属离子热缓冲剂效应的内在机理。机理显示在MEA-金属离子-CO₂-H₂O体系中,金属-MEA络合物作为一种有效的反应热缓冲剂,将有机胺吸收CO₂过程中释放的反应热（放热反应）存储于金属络合物的解离键能中（吸热反应）,在CO₂高温解吸中通过其络合放热反应将储存的能量释放出来用于CO₂解吸,形成自热再生低能耗CO₂捕集技术,从而降低了MEA再生的能耗。本文进行了综合的实验测定来评价金属离子对MEA溶液捕集CO₂过程的性能提升影响,包括CO₂反应热、解吸速率、吸收-解吸循环负载、汽液平衡溶解度等。实验结果表明铜离子或镍离子作为添加剂,能增加MEA的CO₂平衡循环负载14%~20%或7%~10%,同时能够降低MEA的CO₂反应热值6.6%~24%或6.0%~20%。     

骨架锌Zn-HZSM-5分子筛催化剂上甲醇制汽油反应动力学

通过水热晶化法,合成含有骨架杂原子Zn的Zn-HZSM-5分子筛催化剂,采用XRD、BET、NH₃-TPD表征催化剂结构和物化性能,在微型固定床反应器中测定催化剂的甲醇制汽油反应性能和反应动力学数据,研究Zn-HZSM-5分子筛催化剂的甲醇制汽油本征反应动力学。结果表明,杂原子Zn引入ZSM-5分子筛骨架后增加对产物汽油选择性有利的弱酸量。采用Chen and Reagan建立的甲醇制汽油三集总动力学模型,通过四阶龙格库塔法和最小二乘法对实验数据的回归,计算反应速率常数为k₁=1.154×10¹²exp (-97600/RT),k₂=0.687×10¹²exp (-105200/RT)和k₃=1.739×10⁷exp (-84700/RT)。以目标残差函数OF参数值为检验模型的标准,模拟值和实验值的相关系数R²均在0.993以上。因此Chen and Reagan建立的甲醇制汽油三集总动力学模型可以准确描述Zn-HZSM-5分子筛催化剂的甲醇制汽油反应动力学行为。     

Fe-HZSM-5分子筛催化剂的甲醇制汽油动力学研究

通过水热晶化法,合成含有骨架杂原子Fe的Fe-HZSM-5分子筛催化剂,采用XRD、BET和NH3-TPD对催化剂进行表征,在微型固定床反应器中测定催化剂的甲醇制汽油的反应性能和反应动力学数据,对Fe-HZSM-5分子筛催化剂的甲醇制汽油本征动力学进行研究。结果表明,ZSM-5分子筛骨架引入杂原子Fe,可以增加对产物汽油选择性有利的弱酸量。采用Chen and Reagan建立的甲醇制汽油三集总动力学模型,通过Runge-Kutta法和最小二乘法对实验数据的回归计算,获得反应速率常数为k1=0.921×1012exp(-108 600/RT)、k2=0.155×1012exp(-116 400/RT)和k3=1.008×107exp(-96 130/RT)。以目标残差函数OF参数值为检验模型的标准,模拟值和实验值的相关系数R2均超过0.99。因此,Chen and Reagan建立的甲醇制汽油三集总动力学模型可以准确描述Fe-HZSM-5分子筛催化剂的甲醇制汽油反应动力学行为。     

Recent progress in stability of perovskite solar cells

Perovskite solar cells have attracted significant attention in just the past few years in solar cell research fields, where the power conversion efficiency was beyond 22.1%. Now, the most important challenge for perovskite solar cells in practical applications is the stability issue. In this mini-review, we will summarize the degradation mechanism of perovskite solar cells, including the perovskite material itself and also the interfaces. While we also provide our opinion on improving the stability of perovskite solar cells.     

Fluorinated and non-fluorinated conjugated polymers showing different photovoltaic properties in polymer solar cells with PFNBr interlayers

Photovoltaic properties of the two polymers (named as PBQ-0F and PBQ-4F) were investigated by employing [6, 6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM) as the acceptor and a water-alcohol-soluble polymer interlayer material (named as PFNBr) to fabricate photovoltaic devices. For the PBQ-0F:PC₇₁BM blend, the device using Ca/Al as cathode showed very similar efficiency as the device using PFNBr/Al as cathode, while for the PBQ-0F:PC₇₁BM blend, photovoltaic performance of the device can be distinctly improved by replacing Ca/Al with PFNBr/Al. As a result, the best PCE of the PBQ-4F:PC₇₁BM based devices reached 9.04%, which is much higher than that of the PBQ-0F:PC₇₁BM based devices. The results obtained from the quantum chemistry calculations and water contact angle measurements demonstrate that these two polymers are low polar materials, and also the films based on them have hydrophobic surfaces. Since PFNBr has an amphipathic structure (hydrophobic backbone and hydrophilic side chain) and the blend films of PBQ-4F:PC₇₁BM and PBQ-4F:PC₇₁BM have different surface energies, the PFNBr organization atop these two blend types of should be different, which will affect device photovoltaic performance.     

Methylammonium Chloride as a Double-Edged Sword for Efficient and Stable Perovskite Solar Cells

The additive engineering strategy promotes the efficiency of solution-processed perovskite solar cells (PSCs) over 25%. However, compositional heterogeneity and structural disorders occur in perovskite films with the addition of specific additives, making it imperative to understand the detrimental impact of additives on film quality and device performance. In this work, the double-edged sword effects of the methylammonium chloride (MACl) additive on the properties of methylammonium lead mixed-halide perovskite (MAPbI_3-xCl_x ) films and PSCs are demonstrated. MAPbI_3-xCl_x films suffer from undesirable morphology transition during annealing, and its impacts on the film quality including morphology, optical properties, structure, and defect evolution are systematically investigated, as well as the power conversion efficiency (PCE) evolution for related PSCs. The FAX (FA = formamidinium, X = I, Br, and Ac) post-treatment strategy is developed to inhibit the morphology transition and suppress defects by compensating for the loss of the organic components, a champion PCE of 21.49% with an impressive open-circuit voltage of 1.17 V is obtained, and remains over 95% of the initial efficiency after storing over 1200 hours. This study elucidates that understanding the additive-induced detrimental effects in halide perovskites is critical to achieve the efficient and stable PSCs.     

CO2辅助好氧菌煤炭脱硫工艺的实验

生物脱硫技术具有环境和过程友好等特点,在煤炭脱硫领域具有重要的应用开发前景。本文主要研究了嗜酸氧化亚铁硫杆菌（Acidithiobacillus ferrooxidans）和嗜酸氧化硫硫杆菌（Acidithiobacillus thiooxidans）混合菌群对高硫煤生物的脱硫工艺,分别考察了空气氧化环境、CO₂辅助气氛下的脱硫效果。实验结果表明,A. ferrooxidans和A. thiooxidans混合菌群在空气氧化环境下具有良好的脱硫能力,两种嗜酸好氧菌表现出一定的协同作用,无机硫脱除率可达70%;而CO₂辅助能够显著提高有氧条件下菌群的脱硫效率,无机硫脱除率可达90%以上。通过扫描电镜（SEM）、红外光谱（FTIR）、X射线衍射（XRD）、X射线光电子能谱技术（XPS）等表征手段对脱硫后的煤炭结构变化和发酵脱硫机制进行研究,引入的CO₂一方面为两种好氧菌在发酵条件下提供碳源,促使菌群快速生长增殖;另一方面部分CO₂溶于水使发酵溶液中碳酸根离子浓度发生改变,实现降低发酵脱硫产物黄钾铁矾在煤粒表面的沉积密度,促进生物脱硫过程的进行。     

断裂对页岩气保存条件的影响机制——以渝东南地区五峰组-龙马溪组为例

上扬子地区广泛发育多套烃源岩,其中渝东南地区五峰组—龙马溪组具有有机质页岩厚度大、TOC丰度高、有机质成熟度适中等特点,整体具备页岩气发育的气源条件;但各钻井含气性差异显著,可见区域构造对页岩气的后期保存存在重要影响。以渝东南地区为例,通过野外地质调查、岩心观测、含气性分析等手段,研究区域构造分布对页岩气赋存条件的影响,并认为：渝东南地区主要断裂均为逆断裂,且靠近褶皱核部的断裂盘地层变形更为明显,属于相对受伤盘;濯河坝向斜西翼的主控断裂——王家湾—大河口逆冲断裂两盘差异明显：向斜核部、断裂下盘构造缝高度发育,整体含气性较差,是页岩气保存条件的欠佳区域,不利于页岩气成藏。通过分析发现,区域应力背景控制褶皱体系,褶皱变形程度决定断裂分布和组合样式,断裂形态决定地层变形和裂缝发育,从而进一步控制页岩气的保存和富集。因此,全面分析构造匹配模式,是研究不同地区页岩气保存能力的先决条件。