二组分气体在固体上吸附的研究(Ⅶ)─—在不同复盖度下二组分气体在氧化铝上的吸附规律

测定了不同复盖度下的苯－正己烷和正庚烷－正己烷两个二组分气体在氧化铝上的组成吸附等温度，以及单组分气体在氧化铝上吸附的ＢＥＴ常数．结果表明，随着复盖度的增加，两个体系的组成吸附等温线都向下靠近它们各自的气液平衡曲线，可以近似地将二组分气相与吸附相的平衡看成二组分的气液两相平衡，两个体系的组成吸附等温线基本上都可以通过理想溶液的相对挥发度方程式模拟得到     

正庚烷均质压燃燃烧特性和排放特性的实验研究

为进一步了解高十六烷值燃料均质压燃的燃烧特性和排放特性，以正庚烷（n-heptane）为燃料，在一台改装的单缸直喷柴油机上进行正庚烷均质压燃台架实验．结果表明，正庚烷在均质压燃模式下表现出明显的双阶段着火特性；随着混合气浓度增大，缸内最大爆发压力和燃烧放热率峰值升高；随着发动机转速升高，燃烧放热率峰值先降低后升高，高转速的缸内最大爆发压力降低；当废气再循环率增大，缸内最大爆发压力和燃烧放热率峰值均降低，废气再循环使正庚烷均质压燃的运转工况范围向大负荷工况扩展，废气再循环率为75％正庚烷均质压燃运转的最高平均指示压力为0．41MPa．排放测试表明，正庚烷在均质压燃模式下的氮氧化物排放接近零，且可以实现无碳烟排放，但碳氢化合物和一氧化碳排放较高．     

NiO对Pt／WO3／ZrO2催化剂上正庚烷异构化反应的促进作用

考察了NiO掺杂的Pt／WO3／ZrO2催化剂在200℃时正庚烷临氢异构化反应性能．结果表明，少量NiO的加入能显著提高Pt／WO3／zrO2的催化活性，异构化选择性也有所增加，这是由于pt^0浓度和Pt分散度的增加以及临氢条件下具有更多的B酸位引起的．催化剂连续反应80h，正庚烷转化率和异构化选择性分别稳定在57％和98％．     

甲醇/正庚烷双燃料均质充量压缩着火燃烧

在单缸发动机上进行了甲醇/正庚烷双燃料均质充量压缩着火(HCCI)燃烧的试验研究,采用详细化学反应机理分析了它们的反应过程和中间产物历程.研究表明,甲醇和正庚烷浓度的变化主要通过影响第一阶段放热量和放热时刻,进而影响高温着火时刻.正庚烷当量比不变时,随着甲醇浓度增加,低温反应放热量减小,燃烧始点推迟;当总燃料当量比不变,增加正庚烷比例时,低温反应时刻提前,峰值放热率增加;正庚烷当量比和总燃料当量比之比在0.8左右时,高温着火时刻发生在上止点附近,此时气缸压力和峰值放热率最大.对排放影响因素分析表明,CO排放更多取决于燃烧温度,而HC主要取决于甲醇比例.数值模拟发现,OH摩尔分数在10-6数量级才触发冷焰反应,甲醇浓度的变化引起低温阶段nC7ket和OH最大浓度及时刻的改变,从而影响低温和高温反应.     

羟基金属聚合物交联蒙脱土(临安)及其催化特性

用羟基铝聚合物和它的金属同晶取代物交联临安产的蒙脱土。结果表明仅Fe~(3+)同晶取代了柱中Al~(3+)离子。这种新催化剂在异丙苯裂解时呈现较好的活性且能使丙烯二聚,随即发生环化脱氢的特性。浸渍上钯后,使正己烷加氢异构活性增加。从产物分布可知,此催化剂的异构物选择性很高。     

Fuel design real-time to control HCCI combustion

In order to achieve lower emissions and extensive load in the homogeneous charge com- pression ignition (HCCI) engine system, a novel fuel design concept that high-octane number fuel and high-cetane number fuel are mixed real-time to con- trol HCCI combustion is proposed in this study. HCCI combustion fueled with iso-octane/n-heptane mix- tures controlled real-time on a single-cylinder HCCI combustion engine is studied. The test results show that the equivalence ratio of n-heptane in mixtures decides ignition and controls the combustion phase of HCCI combustion. The addition of iso-octane ex- tends knocking limit in equivalence ratio somewhat, but knocking occurrence mainly depends on the total concentration of mixture. Although operating range in equivalence ratio becomes narrow with the increas- ing proportion of iso-octane, the maximum load of HCCI combustion fueled with iso-octane/n-heptane mixtures controlled real-time is increased about 80% more than that of pure n-heptane. When iso-octane/ n-heptane mixtures are controlled in optimized method, it is proved that the load of HCCI combustion can be fully extended and emissions can be de- creased remarkably, while at the same time the higher indicated thermal efficiencies are obtained over the extensive operation range.     

Experimental study of n-heptane ignition delay with carbon dioxide addition in a rapid compression machine under low-temperature conditions

The ignition delay of n-heptane homogeneous charge compression ignition(HCCI) combustion under high levels of carbon dioxide addition was quantitatively measured at elevated pressure from low to intermediate temperatures in a rapid compression machine.The experiments were conducted in the compressed temperature range 613-750 K.Both the compression ratio and fuel/air equivalence ratio were varied to investigate their effects on the ignition delay of n-heptane.Carbon dioxide was subsequently added to study the influence of the carbon dioxide level on the ignition delay of n-heptane under low-temperature conditions.It was found that carbon dioxide had different effects on the two-stages of ignition delay of n-heptane under low-temperature conditions:the concentration of carbon dioxide had little effect on the first-stage ignition time;a certain concentration of carbon dioxide accelerated the first-stage ignition but had a significantly larger impact on the second-stage ignition delay,thus increasing the overall ignition delay time.The results also showed that the first-stage ignition delay of n-heptane is only a function of temperature under low-temperature conditions.The mass of n-heptane in the combustible mixture,the equivalence ratio,and the pressure at the top dead center had little effect on the first-stage ignition time of n-heptane.     

杂原子MnAlβ分子筛负载Pt双功能催化剂的正庚烷临氢异构化性能

采用静态水热法合成一系列Mn骨架改性的杂原子β分子筛,将其作为载体通过浸渍法负载Pt制备双功能催化剂,用X线衍射(XRD)、比表面积测定(BET)、电感耦合等离子发射光谱(ICP)、NH3程序升温脱附(NH3-TPD)、CO-化学吸附等手段对催化剂进行表征,并在常压固定床反应器上考察催化剂的正庚烷临氢异构化反应性能。结果表明:由骨架Mn改性的β分子筛负载Pt的催化剂显示出良好的催化活性,选择性明显高于通过Mn浸渍或Mn交换β分子筛得到的催化剂。催化剂最佳的组成为Pt负载量0.4%,n(MnO)/n(SiO2)=0.011,在230℃、空速2.7 h-1、氢料摩尔比值7.9时,正庚烷的转化率为62.1%,异构化选择性达到92.0%。骨架中引入杂原子Mn不仅可以调节孔道结构,还可以提高催化剂表面Pt的分散度,从而提高催化剂的异构化选择性。     

边界参数对HCCI发动机燃烧影响的模拟研究

为了研究边界参数对柴油均质压燃(HCCI)发动机燃烧过程的影响,应用CHEMKIN化学动力学软件包中的SENKIN程序以及正庚烷(n-heptane)氧化反应简化模型,模拟了不同进气温度、进气压力和当量比等边界参数对HCCI发动机燃烧及排放特性的影响.结果表明,在相同当量比条件下,增压可以拓宽HCCI发动机负荷工况范围,同时保持氮氧化物排放基本不变;过浓或过稀的混合气导致CO排放增加;混合气浓度分层增加NO排放.     

镓镍皂石的合成、交联、表征及催化性能的研究

采用水热法首次合成出自然界不存在的两种不同镓含量的镓镍皂石（ＧａＮｉＳ）－ 用多烃基铝低聚物交联，制得交联粘土（ＡｌＰＧａＮｉＳ）－ 经ＸＲＤ 表征了样品的晶相，元素分析确定了样品的化学组成与结构式－ 同时又采用红外光谱分析和程序升温还原（ＴＰＲ） 表征了样品－ＮＨ３ＴＰＤ 和ＰｙＩＲ 结果表明，样品均含有Ｂ 酸和Ｌ 酸中心，ＡｌＰＧａＮｉＳ 表面Ｌ 酸中心所占的份额大，ＡｌＰＧａＮｉＳ的酸量高于ＨＧａＮｉＳ－ 在异丙苯裂解反应和正己烷加氢异构反应上考察了样品的催化性能－ 结果表明，交联镓镍皂石催化活性较高，异构选择性较好