酯交换法合成碳酸甲乙酯催化剂的研究进展

碳酸甲乙酯（EMC）是一种环境友好型的不对称碳酸酯，因其独特的结构性质被广泛用作溶剂或有机合成中间体，特别是随着锂离子电池的迅猛发展，其作为电池电解液主要成分市场需求量急增。文中简单介绍了光气法、氧化羰化法和酯交换法合成碳酸甲乙酯的研究进展。重点针对最具发展前景的酯交换法合成EMC工艺路线中所用催化剂进行了综述；讨论和分析了该路线所用催化剂的类型、结构、性质及性能，并对当前研究中存在的问题进行了归纳和分析总结。最后本文分析并展望了酯交换法合成EMC催化剂的研究方向及新型合成工艺发展趋势，提出研发经济、高效、稳定且制备工艺简单的非均相催化剂，并与反应精馏技术耦合是今后的主要发展趋势，期望为EMC的高效合成提供参考和借鉴。     

甲烷在钯基催化剂上脱氢的分子模拟

为探明甲烷在钯基二聚体催化剂上脱氢反应过程的微观机理,对甲烷燃烧催化剂的设计与使用提供指导。在M06L/6-311++G(d,p)+SDD//M06L/6-311G(d,p)+LANL2DZ基组水平上,采用密度泛函理论(DFT)对甲烷在钯基二聚体催化剂(Pd_2、PdPt和PdNi)上的脱氢过程进行了研究。对比了甲烷在催化剂Pd_2、PdPt和PdNi上反应的能垒(E_b)、活化能(E_a)及反应速率常数(k),结果表明:CH_2→CH是甲烷在二聚体Pd_2反应的速率控制步骤(RDS),而CH_3→CH_2是催化剂PdPt和PdNi反应的RDS;钯基二聚体催化剂对甲烷脱氢的催化活性顺序为PdPtPd_2PdNi;抗积炭性能顺序为PdNiPd_2PdPt。PdPt适用于要求催化效率较高的项目,而抗积炭性能较好的PdNi催化剂可用于大型工业催化。     

超支化镍系催化剂构效关系及催化乙烯齐聚机理

采用1.0G超支化大分子（1.0G）、3-取代水杨醛和NiCl₂·6H₂O为原料，依次经席夫碱反应和络合反应合成了3种新型具有不同取代基位阻的超支化水杨醛亚胺配体及其镍系催化剂，利用红外光谱（FTIR）、核磁共振氢谱（¹H NMR）、紫外光谱（UV-vis）、电喷雾质谱（ESI-MS）及电感耦合等离子体质谱（ICP-MS）等方法对合成出产物的结构进行表征。考察了配体空间位阻、溶剂种类、助催化剂种类及反应条件对催化乙烯齐聚性能的影响。研究结果表明，配体空间位阻对催化乙烯齐聚性能有较大的影响，当以甲苯为溶剂、甲基铝氧烷（MAO）为助催化剂，在最佳反应条件下，超支化邻苯基水杨醛亚胺镍系催化剂催化乙烯齐聚的活性为2.81×10⁵g/(mol Ni·h)，对高碳烯烃（C₁₀₊）的选择性为34.28%。此外，在超支化水杨醛亚胺镍系催化剂催化性能评价的基础上，对其催化乙烯齐聚的机理进行研究。     

Synergistic effect on hydrolytic sodium borohydride adding waste Al for hydrogen generation

Synergistic effect of sodium borohydride (NaBH₄) mixed with waste aluminum in hydrolytic system were investigated to improve the hydrogen generation (HG) efficiency. The alkaline aqueous originated from NaBH₄ hydrolysis impels the passive aluminum hydroxide film of Al surface to be dissolved, thus, mutual effect of HG amount increasing by 88% and 50% for Al powder and waste Al can, respectively. To add acid catalyst in the mutual mixture system prompts to significantly accelerate HG rate from 100 ml/min˙g to 400 ml/min˙g but raising temperature is not obviously found. It is speculated that exothermic effect dominates the NaBH₄ hydrolytic reaction and eliminates the temperature effect. In this study, the mutual hydrolyzed reaction of NaBH₄ and waste Al provides ecofriendly environment, low cost and enables to achieve higher HG rate and further uses for portable/mobile fields.     

稠油地下改质开采技术及发展趋势

稠油作为全球重要的非常规原油资源，是保障我国能源安全、重大工程需求的重要资源。目前常规的热采稠油油藏陆续进入开采后期，高能耗、高污染、高成本问题日趋严重，亟需依靠技术换代实现开发方式升级。稠油地下改质是通过向油藏中注入改质催化剂，使其与稠油发生化学反应，实现稠油地下不可逆降黏并高效采出的一种开采方式，是近十年来最受瞩目的下一代稠油开采技术之一。本文从技术机理、改质催化剂及开采效果影响因素三方面阐述了技术内涵，通过系统调研国内外相关学者和企业的代表性成果，按照催化剂种类、反应温度和降黏效果等进行综合性分类统计，对比了现有矿场试验的开采方式和采油效果，指出制约技术应用的两个关键问题，并展望了技术未来发展方向。     

剂油比对煤焦油沥青质加氢过程的影响

以中低温煤焦油沥青质为原料,采用NiMoW/γ-Al_2O_3商业催化剂,在反应温度380℃、反应压力8 MPa和反应时间1.5 h条件下,分别在不同剂油质量比(1∶25、1∶20、1∶15、1∶10)条件下进行加氢实验,通过采用元素分析、FT-IR、XRD、~1H-NMR和XPS等分析表征手段,考察不同剂油质量比对中低温煤焦油沥青质加氢转化过程的影响。结果表明,随着剂油质量比的增加,沥青质转化率提高,加氢产物分布也发生大幅变化,沥青质和芳香分轻质化转化为饱和分。但随着剂油质量比的进一步提高,同时也发生了更多的裂化反应和缩合反应,剂油质量比在合适范围能够很好地起到加氢轻质化且抑制结焦的效果。     

新型硫酸法C_4烷基化工艺的模拟

提出了一种新型硫酸法C4烷基化生产工艺,丁烯原料在气相状态下进入反应器,与液相异丁烷、浓硫酸混合后,部分丁烯溶于液相,在液相中进行反应;通过控制反应器的压力,部分液相吸收反应热而汽化,使反应温度基本稳定;经气液分离、酸烃分离及产品分馏后,气相丁烯、异丁烷、浓硫酸分别构成循环。采用Aspen Plus过程模拟软件对新工艺过程进行模拟计算的结果表明,在反应器进口压力0.2 MPa、压降4.5 k Pa的条件下,反应器进出口温度均在7.2℃左右,可通过调节反应器压力实现温度的控制;反应器进口液相中烷烯质量比为145∶1,可减少副反应的发生;与传统硫酸法C4烷基化工艺相比,新工艺耗电量可降低30%。     

Cross-linking of cellulose and poly(ethylene glycol) with citric acid

A novel approach to modifying native cellulosic fibres with poly(ethylene glycol) (PEG) impregnation and simultaneous cross-linking by citric acid (CA) was investigated. To understand the contributions of different components in the system, control references with just CA and cellulosic fibres (filter paper) were studied. The effect of sodium hypophosphite as a catalyst was also assessed. The results revealed that ester bonds are indeed formed in the cellulose–PEG–CA reaction system, as indicated by weight percentage gain (WPG) and FTIR analysis. The best results were achieved by using 5% CA and 10% PEG (calculated as weight-% from cellulose). In the reaction, the environmentally friendly CA prevents PEG from being leached out of cellulose during washing, resulting in promising future applications in dimensionally stabilized products based on cellulosic fibres.     

Fuel conversion characteristics of black liquor and pyrolysis oil mixtures: Efficient gasification with inherent catalyst

Alkali metals inherent in black liquor (BL) have strong catalytic activity during gasification. A catalytic co-gasification process based on BL with pyrolysis oil (PO) has the potential to be a part of efficient and fuel-flexible biofuel production systems. The objective of the paper is to investigate how adding PO into BL alters fuel conversion under gasification conditions. First, the conversion times of single fuel droplet were observed in a flat flame burner under different conditions. Fuel conversion times of PO/BL mixtures were significantly lower than PO and comparable to BL. Initial droplet size (300–1500 μm) was the main variable affecting devolatilization, indicating control by external heat transfer. Char oxidation was affected by droplet size and the surrounding gas composition. Then, the intrinsic reactivity of char gasification was measured in an isothermal thermogravimetric analyser at T = 993–1133 K under the flow of CO₂–N₂ mixtures. All the BL-based samples (100% BL, 20% PO/80% BL, and 30% PO/70% BL on mass basis) showed very high char conversion. Conversion rate of char gasification for PO/BL mixtures was comparable to that of pure BL although the fraction of alkali metal in char decreased because of mixing. The reactivities of BL and BL/PO chars were higher than the literature values for solid biomass and coal chars by several orders of magnitude. The combined results suggest that fuel mixtures containing up to 30% of PO on mass basis may be feasible in existing BL gasification technology.     

催化裂化催化剂制备过程中水资源的综合利用

在催化裂化催化剂制备过程中会产生大量废水,这些废水来源于分子筛和催化剂的交换、过滤、洗涤及后改性过程中引入的铵盐、新鲜水及或酸碱等交换介质的残存液。通过分析过程中废水产生的原因及性质,将废水按不同性质分类收集,并采用不同的处理方法,重新回用于制备体系中,提高水资源循环利用率,降低外排废水量。