褐煤、小麦秸秆和废塑料在亚临界水液化制液体燃油中硫的变迁行为研究

The distribution and transformation of sulfur in products during hydrothermal liquefaction of lignite, wheat straw and plastic waste in sub-critical water were investigated in an autoclave. The influence of blending ratio, temperature, initial nitrogen pressure, residence time and additives on sulfur distribution was studied systematically. The results showed that most of sulfur existed as organic sulfur and transferred into the residue, and only a small part of sulfur transferred into oil and gas during hydrothermal liquefaction of lignite, wheat straw and plastic waste in sub-critical water. The results also showed that lower temperature(less than 300 ℃) was favorable for obtaining oil with low sulfur content. It can be also seen from the results that the best condition to obtain the oil with low sulfur content should be implemented at a lignite/wheat straw/plastic waste blending ratio of 5:4:1, an initial nitrogen pressure of 3 MPa and a residence time of 30 minutes. Furthermore, the results indicated that adding tourmaline during hydrothermal liquefaction of lignite, wheat straw and plastic waste was beneficial to production of oil with low sulfur content.     

亚/超临界乙醇-水体系中杜氏盐藻直接液化制备生物油

在间歇式高温高压反应釜中,以乙醇-水混合溶剂为介质,研究了在亚/超临界条件下杜氏盐藻直接液化制备生物油的工艺,探索了乙醇-水介质中不同乙醇体积分数和液化温度对盐藻液化率和产油率的影响,采用FT-IR和GC-MS方法分析了生物油的主要成分。结果表明,在亚/超临界乙醇-水体系中,当乙醇的体积分数为40%、液化温度为320℃时,杜氏盐藻的液化率为98.24%,产油率高达64.68%。在亚/超临界乙醇-水体系下,杜氏盐藻中各主要生化组分都能被有效液化。以亚/超临界乙醇-水为介质直接液化杜氏盐藻制备生物油时,随着介质中乙醇体积分数的增加,所得生物油中的酸性物质含量显著减少,酯类物质含量不断增加,从而提高了生物油的品质。     

Mim-NH_2/TBAB离子液体基二元均相催化体系在温和条件下高效催化转化CO_2

以功能化氨基咪唑离子液体(Mim-NH_2)为催化剂,四丁基溴化铵(TBAB)为助催化剂,将两者通过物理混合制成一种高效二元均相催化剂用于催化CO_2和环氧丙烷(PO)的环加成反应生成碳酸丙烯酯(PC),并系统考察了催化剂/助催化剂的物质的量比、CO_2压力以及反应温度对PC产率的影响。研究发现,Mim-NH_2和TBAB对CO_2的环加成反应有良好的协同催化效应,从而在无金属、无溶剂、温和的条件下高效催化转化CO_2。当Mim-NH_2/TBAB的物质的量比为1:1时,在75℃以及0.35MPa的CO_2压力下,反应48h后PC的产率高达98%以上。     

BrØnsted酸性离子液体在萃取氧化二苯并噻吩中的应用

 以具有BrØnsted酸性的吡咯烷酮离子液体N-甲基-2-吡咯烷酮氟硼酸盐([Hnmp]BF₄)为萃取剂和催化剂, 含30%质量分数H₂O₂的双氧水为氧化剂, 二苯并噻吩(DBT)的正辛烷溶液作为模型油, 同时进行萃取脱硫和氧化脱硫, 考察了n(H₂O₂)/n(S)、DBT初始浓度和反应温度对脱硫率的影响. 结果表明, [Hnmp]BF₄-H₂O₂体系产生的羟基自由基能将DBT氧化成相应的砜而进入离子液体相, 从而脱除了模型油中的S; 当n(H₂O₂)/n(S)=3、反应温度为60℃、模型油与离子液体等体积时, 在60min内可将油相中的S质量浓度为1550μg/ml 的DBT完全氧化脱除; DBT初始浓度越高, S的完全脱除就越困难. 离子液体重复再生使用7次后, 脱硫率明显降低.     

Vanadium-catalyzed extractive oxidesulfurization of commercial diesel in ionic liquid with combined oxidizing agents

A series of vanadium catalysts were synthesized and employed in pyridinium phosphate [HPy][H₂PO₄] with various oxidants for extractive catalytic oxidesulfurization (ECODS) of diesel. The VO(acac)₂ showed high catalytic activity with HNO₃/H₂SO₄ and ionic liquid via microwave radiations in the MECODS of diesel. The sulfur removal could reach 98.9% in 210?s at 500?W, which was superior to that of the simple ECODS (89.3%) under optimal conditions (V_diesel?=?20?mL, VIL/Vdiesel volume ratio?=?0.075, m(VO(acaca)₂)/m_diesel?=?0.5?wt%, V(HNO₃)/V(H₂SO₄)?=?1 and T?=?80?°C). The catalytic system could be regenerated six times without significant loss of activity.     

离子液体用于甲烷直接转化的研究

合成了5种酸性离子液体,以PdCl2为催化剂、K2S2O8为氧化剂、离子液体、三氟乙酸(TFA)和三氟乙酸酐(TFAA)为介质作为甲烷直接转化体系。讨论了离子液体对甲烷转化率的影响,并考察了离子液体在甲烷直接转化过程中的稳定性。利用GC、GC-MS和FTIR等仪器对反应产物进行分析。研究结果表明:离子液体[mim]+HSO4-在甲烷转化体系中能够稳定存在,并可以提高催化剂PdCl2的活性,二者能够起到一定的协同作用共同促进甲烷转化。     

[bmim]OH和[A336][FeCl_4]混合离子液体氧化吸收硫化氢

为了降低非水相催化氧化硫化氢体系的运行成本,将碱性的氢氧化1-丁基-3-甲基咪唑([bmim]OH)离子液体与价格较低的酸性三辛基甲基铵四氯铁酸盐([A336][FeCl_4])离子液体分别按照0.2∶1、0.5∶1、0.8∶1、1∶1和2∶1的比例混合,用所得到的混合离子液体进行硫化氢氧化吸收实验,系统研究了混合离子液体的水溶性、密度、红外光谱、黏度和酸性强度等性能,并对其硫容和反应产物进行了分析。研究结果表明:(1)[A336]FeCl_4季铵盐离子液体的酸性强度和价格均低于[bmim]Fe Cl4离子液体,可以降低离子液体非水相催化氧化硫化氢体系的成本;(2)混合离子液体不仅同时具有[bmim]OH和[A336][FeCl_4]的骨架结构,且其p H值、黏度和硫容均随[bmim]OH量的增加而增加;(3)混合离子液体明显弱于[A336][FeCl_4]离子液体的酸性强度,有利于硫化氢的吸收,其黏度随温度上升而剧烈下降的性质有利于中、高温脱硫。结论认为,当[bmim]OH/[A336][FeCl_4]的物质的量之比在0.5∶1~1∶1时,可以构建成本较低、酸性适中、黏度较低、硫容较高的中、高温脱硫体系。     

填料塔离子液体气相内脱水实验研究

以1-丁基-3-甲基咪唑醋酸盐([BMim][Ac])离子液体为吸收剂,用空气和水蒸气的混合气模拟含水湿气,在θ金属网环填料塔中进行脱水实验。探究了离子液体流量、液体含水量、液体温度、空气流量以及进气含水量对脱水效果的影响,获得了最佳实验参数条件。实验结果表明,气体露点降随液体流量和进气含水量的增加而增大,随液体含水量、液体温度和空气流量的增加而减小。在液体流量9L/h、气体流量1m~3/h、液体中水质量分数1%、湿气中水质量浓度18.26g/m~3、温度20℃的条件下,气体露点降在40℃以上,干气露点低于-20℃,取得了良好的脱水效果,在工业气体脱水、室内空气干燥等领域展现出良好的应用前景。     

Revealing the catalytic mechanism of an ionic liquid with an isotope exchange method

The alkylation mechanism catalyzed by an ionic liquid (as a Lewis acid) may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear.In this paper,an isotope exchange method is used to investigate the catalytic mechanism of AlCl 3 /butyl-methyl-imidazolium chloride ionic liquid in the alkylation of benzene with 1-dodecene.The proposed catalytic mechanism was confirmed by analysis of ionic liquid before and after reaction and of the alkylation products of deuterated benzene (C 6 D 6) with 1-dodecene.The proposed mechanism consists of the equilibrium reaction between [Al 2 Cl 7 ] +H + and [AlHCl 3 ] + +[AlCl 4 ],in which the Br nsted acid [AlHCl 3 ] + is supplied by the reaction of 2-H on the imidazolium ring and [Al 2 Cl 7 ].The alkylation reaction is initiated by the Br nsted acid [AlHCl 3 ] + which reacts with 1-dodecene to form a carbonium ion,then the carbonium ion reacts with benzene to form an unstable σ complex,leading to the formation of 2-phenyldodecane.     

富有机质页岩增产改造氧化液浸泡离子溶出行为

页岩储层富含有机质、黄铁矿等还原性组分,因而氧化溶蚀致裂是极具潜力成为一种新的页岩油气层增产改造技术。以往研究侧重于页岩氧化后孔隙结构及传质能力的变化,但对页岩氧化过程水溶液性质变化关注不多,而水溶液性质又与压裂液返排、黏土水化作用、水相圈闭损害缓解等密切相关。选取四川盆地龙马溪组富有机质页岩粉体样品,实验测试了页岩粉体样品与蒸馏水、不同浓度氧化液浸泡过程水溶液离子组成、pH、电导率和浊度等参数,精细描述了页岩氧化反应过程。实验结果表明,页岩氧化液浸泡时溶液中Fe³⁺、Ca^2+、Mg²⁺等离子的浓度大幅度增加、pH降低、电导率和浊度增加。分析认为,氧化液选择性溶解页岩中黄铁矿、有机质等还原性组分和(铁)白云石、方解石等碳酸盐矿物,释放出离子;或将矿物集合体分散成粒径更小的微粒,从微观层面上“破碎”页岩中部分矿物,形成溶蚀孔和微裂缝,有利于提高页岩渗透率;宜合理调控入井氧化液浓度和氧化处理时间,优化设计处理工艺;页岩氧化改造后的返排液处理,可沿用现行的页岩压裂返排液处理方法和工艺。     

Synthesis of amphiphilic peroxophosphomolybdates for oxidative desulfurization of fuels in ionic liquids

Three amphiphilic peroxophosphomolybdates [C₄mim]₃PMo₄O₂₄, [C₈mim]₃PMo₄O₂₄ and [C₁₆mim]₃PMo₄O₂₄ were synthesized and characterized. These catalysts were used for extraction and catalytic oxidative desulfurization of fuel with H₂O₂ as an oxidant and ionic liquid [C₄mim]BF₄ as an extractant. It was found that [C₁₆mim]₃PMo₄O₂₄ showed the highest catalytic activity and the sulfur content could decrease to 7.5 ppm. In contrast, the desulfurization system shows very low performance without H₂O₂ or ionic liquid. The detailed reaction conditions were optimized including reaction time, temperature, the dosage of H₂O₂ and catalyst, and different sulfur compounds. After the reaction, the catalysts and the ionic liquid can be cycled 8 times with a little decrease in desulfurization efficiency.