Effect of low-sulfur fuels upon NH3 and N2O emission during operation of commercial three-way catalytic converters

The use of low-sulfur fuel is known to improve the performance of the three-way catalytic converter (TWC). However, in this work we report how low-sulfur operation of commercial TWC also favors formation of N₂O and NH₃ as by products. We found that low-sulfur rich operation above 300 °C increases the production of NH₃, inhibiting the formation of N₂O characteristic of high-sulfur operation. During lean operation, the production of N₂O near the stoichiometric point is not significantly affected by the sulfur level. The large production of N₂O observed during light-off is not affected by SO₂ when the operation is lean, but under rich conditions N₂O is produced up to 575 °C. The increased production of NH₃ and N₂O in TWC as a result of the introduction of low-sulfur gasoline is an area that requires further analysis because of its implication upon public health in large urban settings.     

电控汽油机爆震故障分析和排除方法研究

针对目前电控汽油机出现爆震故障产生的因素进行研究,对常用的诊断排除故障的方法进行了对比分析,目的是研究解决电控发动机爆震故障的方法。通过对两则典型的汽车爆震故障诊断排除案例,总结归纳出预防和排除两类常见爆震故障的方法和步骤。实践结果表明了文中方法的可行性和实用性。     

酸催化合成烷基化油的研究进展

综述了分别以硫酸、氢氟酸等无机酸、固体酸和离子液体为催化剂合成烷基化油的最新研究进展,并对这些催化剂的结构和酸性能对烷基化油的组成和性质的影响规律进行了分析和评述。指出离子液体作为绿色催化剂用于烷基化油的合成表现出易与产物分离、催化活性高、烷基化产物中C8组分含量高、辛烷值高等突出优点,是较有应用前景的烷基化油合成用催化剂。     

利用C_5开发叔戊基甲醚

介绍了利用C_5生产汽油抗爆剂叔戊基甲醚的工艺进程。其中KOCH公司开发的催化蒸馏工艺是目前最先进的工艺。我国当前尚未有工业化生产叔戊基甲醚的装置。利用流化催化裂化C_5生产叔戊基甲醚是急待开发的课题。     

Hollow porous carbon microspheres obtained by the pyrolysis of TiO2/poly(furfuryl alcohol) composite precursors

Disordered carbon materials with high porosity were prepared through the pyrolysis of TiO₂/poly(furfuryl alcohol) composites, obtained by the sol-gel method. The composites were prepared starting from titanium tetra-isopropoxide (TTIP) and furfuryl alcohol (FA) as precursors. Two different synthetic procedures for our composites were carried out, based on the addition of furfuryl alcohol (FA) before or after the TiO₂ nanoparticles formation. Also, different TTIP/FA ratio was tested. The hybrid materials obtained by both synthetic routes were pyrolyzed, under argon flow, at 900 °C producing novel TiO₂/carbon composites. All samples were characterized by XRD, FT-IR, DR-FTIR, Raman spectroscopy and TEM. Results indicated the effective FA polymerization on TiO₂ (anatase) nanoparticles, and polymer conversion to disordered carbon after the pyrolysis, simultaneously with TiO₂ anatase-rutile phase transition. The resulting TiO₂/carbon composites were treated with HF solution aiming the oxide dissolution, yielding an extremely porous carbon material as insoluble fraction. The morphology of these porous carbon materials is strongly dependent on the synthetic route adopted for the composite precursor, varying from carbon foam to highly ordered hollow microspheres.     

超临界乙醇提质生物油的汽油机试验研究

配制了典型的模型油模拟提质产物中的中质成分(沸点为80~200℃),在1台单缸4冲程汽油机上对模型油、模型油-汽油混合燃料及汽油进行试验研究.结果表明:调整化油器结构适当增加供油量,在不改变发动机其他特性的条件下,燃用模型油的动力略微下降,下降幅度在5%以内,能耗率平均下降了8.47%;HC和CO排放远远低于汽油,平均下降了42.97%和66.7%,但NOX和CO2排放明显上升,相对汽油平均分别上升了29.47%和20.17%.对汽油机不作任何调整,燃用模型油体积分数10%(B10)和20%(B20)的混合燃料的动力特性及排放特性一般介于汽油与模型油之间.     

雾霾成因及严寒地区乙醇汽油对雾霾影响

本文通过分析雾霾的组成成分及其形成机理,分别研究了乙醇汽油燃烧产物气溶胶粒子、颗粒物、附加产物(醛酮等)和水分对严寒地带区域性雾霾形成的影响.研究结果表明,乙醇汽油燃烧产物对雾霾的影响也是比较严重的,在严寒地区冬季不建议过量使用乙醇汽油.     

自由活塞汽油直线发电机燃烧过程特性

为了获得自由活塞汽油直线发电机工作过程中的燃烧特性,根据试验测得的活塞运动曲线对其燃烧过程进行了CFD仿真研究,并对比传统发动机分析了两种发动机活塞运动规律差异对燃烧过程的影响规律。研究发现:与传统发动机相比,自由活塞汽油发电机缸内最高燃烧压力和平均温度均较小,且最高燃烧压力保持时间较短,这有助于减少NO污染物;自由活塞直线发电机燃烧放热率呈现"缓和长"的特点,燃烧放热过程等容度较低;自由活塞直线发电机较少的混合气在上止点前完成燃烧,压缩行程负功较小,但由于后燃较严重,其指示效率较传统发动机低。     

Chemiresistor sensor using elastomer-functionalized carbon nanotube nanocomposites for the detection of gasoline spills

Two types of multi-walled carbon nanotube (MWNT)-based elastomer nanocomposites are used as a sensor material for the detection of gasoline spills by applying the interdigitated electrode (IDE) device. MWNT-g-polyisoprene (PI) and Si-MWNT/natural rubber (NR) are prepared by applying “grafting-from” and “grafting-to” process, respectively. When compared based on the identical condition of gasoline sensing test, the maximum response value to the exposure of gasoline is 17.5 for MWNT-g-PI sensor and 12.9 for Si-MWNT/NR sensor, which reach the maximum in less than 3 min. The MWNT-g-PI sensor selectively detects gasoline, and its response is completely reversible. It shows that the longer chain length of PI brings about the larger response of MWNT-g-PI sensor to gasoline. The sensitivity of MWNT-g-PI sensor highly depends on both how much gasoline is exposed to the sensor and what bias voltage is applied to the IDE device. The IDE sensor using MWNT-g-PI nanocomposites effectively detects gasoline spills.     

Breakthrough Technologies for the Biorefining of Organic Solid and Liquid Wastes

Organic solid and liquid wastes contain large amounts of energy, nutrients, and water, and should not be perceived as merely waste. Recycling, composting, and combustion of non-recyclables have been practiced for decades to capture the energy and values from municipal solid wastes. Treatment and disposal have been the primary management strategy for wastewater. As new technologies are emerging, alternative options for the utilization of both solid wastes and wastewater have become available. Considering the complexity of the chemical, physical, and biological properties of these wastes, multiple technologies may be required to maximize the energy and value recovery from the wastes. For this purpose, biorefining tends to be an appropriate approach to completely utilize the energy and value available in wastes. Research has demonstrated that non-recyclable waste materials and bio-solids can be converted into usable heat, electricity, fuel, and chemicals through a variety of processes, and the liquid waste streams have the potential to support crop and algae growth and provide other energy recovery and food production options. In this paper, we propose new biorefining schemes aimed at organic solid and liquid wastes from municipal sources, food and biological processing plants, and animal production facilities. Four new breakthrough technologies—namely, vacuum-assisted thermophilic anaerobic digestion, extended aquaponics, oily wastes to biodiesel via glycerolysis, and microwave-assisted thermochemical conversion—can be incorporated into the biorefining schemes, thereby enabling the complete utilization of those wastes for the production of chemicals, fertilizer, energy (biogas, syngas, biodiesel, and bio-oil), foods, and feeds, and resulting in clean water and a significant reduction in pollutant emissions.