Circumventing fuel-NOx formation in catalytic combustion of gasified biomass

It has been shown that it is possible to decrease fuel-NO_x produced from NH₃ using catalytic combustion of a synthetic gasified biomass at fuel-lean conditions. In a certain temperature regime where the conversion of fuel components, such as CO, H₂ and CH₄, is low and conversion of NH₃ is high, it is suggested that the formed NO_x is reduced by the remaining fuel components, mainly hydrocarbons. With oxide catalysts only ca. 10% of the NH₃ was converted to NO_x, the rest to N₂. It has also been shown that the ignition sequence of CO, H₂ and CH₄ varied for different catalysts and different experimental conditions, and that methane coupling and methanation reactions occurred before ignition of CH₄.     

天然气大气式灶具的CO排放特性预测

CO是城市燃气燃烧过程中生成的主要污染物之一,必须对其排放量进行严格的控制。随着我国气源多样化格局的形成,不同组分的天然气在同一管网中运输,可能会引发末端设备的互换性问题,造成CO排放量的不稳定。为此,通过实验分析了天然气组分与大气式灶具CO排放特性之间的关系,并提出CO排放特性的预测公式。实验分为3个阶段:(1)在设计的大气式基准燃烧器上,测试了2 kPa条件下CH_4掺混单一组分时CO的排放特性,确定了C_2H_6、C_3H_8、C_4H_(10)、N_2和H_2各自对CO排放量的影响;(2)进行以CH_4为主要成分的多组分随机掺混配气CO的排放实验测试,并对实验结果进行多元线性回归分析,确定CO排放量与天然气各组分含量之间的数学关系;(3)选取3台结构型式具有代表性的实际天然气灶具,进行不同组分天然气的CO排放特性测试,验证提出的数学关系式的通用性。实验验证结果表明:实验回归得到的计算公式具有一定的通用性,可以很好地预测天然气组分变化时燃烧器的CO排放性能。     

Exploitation of methane in the hydrate by use of carbon dioxide in the presence of sodium chloride

The replacement process of CH4 from CH4 hydrate formed in NaCl solution by using pressurized CO2 was investigated with a self-designed device at temperatures of 271.05,273.15 and 275.05 K and a constant pressure of 3.30 MPa.The mass fraction of the NaCl solution was either 0.5 wt% or 1.0 wt%.The effects of temperature and concentration of NaCl solution on the replacement process were investigated.Experimental results showed that high temperature was favorable to the replacement reaction but high NaCl concentration had a negative effect on the replacement process.Based on the experimental data,kinetic models of CH4 hydrate decomposition and CO2 hydrate formation in NaCl solution were established.The calculated activation energies suggested that both CH4 hydrate decomposition and CO2 hydrate formation are dominated by diffusion in the hydrate phase.     

微细通道内氢气辅助甲烷催化氧化的数值模拟

对微圆管内低浓度氢气、甲烷混合气在铂表面的催化氧化进行了数值模拟,重点研究了添加氢气对甲烷反应的影响机理.结果表明,氧气占据空位活性中心抑制了甲烷的吸附,导致较高的催化着火温度;氢气的掺入可以降低甲烷氧化反应的起始温度和着火温度;在铂催化剂表面,甲烷的催化氧化发生在氢气的燃烧过程中,氢气在燃烧过程中消耗氧气,为甲烷的反应提供必需的空位活性中心(Pt(s));甲烷的着火主要受其自身的激发,甲烷着火以前,壁面活性中心几乎全被氧占据,而甲烷着火以后,O(s)和Pt(s)同为主要壁面组分.     

南海北部二氧化碳对天然气水合物形成与分布的影响

南海北部天然气富含CO₂等非烃气体,非烃气体对于水合物既有建设性,也有破坏性。含CO₂的天然气向上运移渗漏到浅层,条件适当时,CO₂可作为碳源,被还原成CH₄,在浅层形成水合物成藏。选取南海北部的几组不同CO₂、N₂含量的气体组分进行的实验表明,含CO₂的天然气形成水合物的温度比纯甲烷水合物要高,致使水合物的赋存深度增加,从而拓展了水合物稳定带的厚度。高含CO₂的天然气藏发生强渗漏并运移至上覆甲烷水合物层时,CO₂可能会置换甲烷水合物中的甲烷,使原有的水合物矿藏遭受破坏或甲烷饱和度下降。     

PN(CH2)nP配体/Cr(III)/DMAO/AlEt3催化乙烯齐聚

合成并表征了N-(2-(二苯基膦酰)乙基)-N-甲基-1,1-二苯基膦胺(L1)、N-(2-(二苯基膦酰)乙基)-N-异丙基-1,1-二苯基膦胺(L2)和N-(3-(二苯基膦酰)丙基)-N-异丙基-1,1-二苯基膦胺(L3)3种新型PN(CH₂)_nP型配体。3种配体分别与CrCl₃(THF)₃、脱除挥发性组分的甲基铝氧烷(Dried methylaluminoxane,DMAO)和三乙基铝(Aluminumtriethyl,AlEt₃)组成催化体系,考察其催化乙烯齐聚的性能。结果表明：该类配体组成的催化体系,具有催化活性高和C₆～C₈线性α烯烃选择性高的特点;L2组成的催化体系,在4.0 MPa和100 ℃时,催化活性可达1.71×10.7 g/(mol Cr·h);在1.0 MPa和100 ℃时,1-己烯和1-辛烯总选择性达到93%。与配体L1相比,配体L2骨架N上的异丙基增加了催化剂空间体积,显著提高了催化活性及催化体系的热稳定性。     

基于包裹体PVTx数值模拟恢复油藏古温压——存在的问题、对策及应用实例

包裹体PVTx数值模拟是恢复油藏古温压的重要手段。由于无法精确地确定油包裹体的组成,以及油包裹体成分在地质演化过程中可能发生不可逆的次生变化,现有方法恢复的古温压存在不确定性。一般而言,与油包裹体伴生的盐水包裹体成分相对简单,且遭受次生蚀变影响的概率较低。因此,尝试将伴生的盐水包裹体作为独立的地质压力计在塔里木盆地顺南地区SN1井进行了应用研究。包裹体岩相学研究显示,SN1井高角度裂缝充填的方解石中,发育大量遭受过次生蚀变的含沥青烃包裹体及伴生的盐水包裹体。包裹体古温压恢复显示,伴生的盐水包裹体呈现异常高的均一温度（超过170℃）,均一压力波动范围大,且存在异常高压（39.1 MPa起,甚至超过165.8 MPa）。上述现象可能与热流体活动和原油充注后所经历的裂解增压过程有关。基于盐水包裹体均一压力的最低值,结合该地区埋藏史和热演化史分析,推测热液活动时间为海西期。上述认识与该地区NE向走滑断裂活动具有较好的时空匹配关系。综上所述,油包裹体伴生的盐水包裹体作为独立的地质压力计,可以用来恢复油藏古温压的演化轨迹,并限定古流体活动的时间,能够在一定程度上弥补现有方法的不足。     

MWD GAMMA 测量技术在地质导向钻井中的应用

MWD GAMMA测量是MWD无线随钻仪在完成井眼井斜、方位、工具面等定向参数测量的基础上,对MWD仪器的GAMMA测量功能加以开发应用。地质人员利用测量的地层自然伽马值可以及时分析地层岩性变化,进行地层对比,为地质决策提供科学的参考。目前,该技术已在濮侧平130井和桥69-平1井得到了成功应用。     

A highly active catalyst, Ni/Ce–ZrO2/θ-Al2O3, for on-site H2 generation by steam methane reforming: pretreatment effect

The steam treatment effect has been investigated over the doubly impregnated catalyst, Ni/Ce–ZrO₂/θ-Al₂O₃, in steam methane reforming (SMR). The catalyst was remarkably deactivated by steam treatment but reversibly regenerated by H₂-reduction. XRD results showed that the steam treatment resulted in the formation of NiAl₂O₄ which is inactive for SMR but it was reversibly converted to Ni by the reduction. The reversible oxidation-reduction of Ni state was also evidenced by XPS and it was observed that the formation of NiAl₂O₄ is more favorable at higher temperature. It is most likely that the alumina support is only partially covered with Ce–ZrO₂ and most Ni directly interacts with θ-Al₂O₃ which would probably make easy formation of NiAl₂O₄ in the presence of steam alone. The results imply that, during the start-up procedure in SMR, too high concentration of steam could deactivate seriously Al₂O₃ supported Ni catalysts.     

小尺寸无线随钻测量仪器DWD在深侧钻短半径水平井中的应用

针对塔河油田侧钻短半径水平井钻井施工的特点,讨论了小尺寸无线随钻测量仪DWD在这类井的测量施工中的施工难点及应采取的措施。结合T703CH井的实际施工,对DWD在深侧钻短半径水平井中的应用效果进行了分析。DWD在塔河地区深侧钻短半径水平井中的成功应用。为短半径水平井降低施工成本、提高施工效率、回避施工风险找到了一条有效的途径,具有一定的推广应用价值。