结构特征对沉积岩工程性质的影响

岩石力学特性的估计在各种岩土工程中非常重要, 这些特征主要受岩石微细结构特征的影响. 为了将织构系数与力学性能联系起来, 测量了干容重、有效孔隙率、点荷载指数、施密特回弹硬度、单轴抗压强度和织构系数. 根据ASTM和ISRM标准从Kalidromo (希腊中部)采集了包括9块石灰岩和11块泥岩在内的20块沉积岩样品, 进行了全面的实验室测试, 对其矿物学和岩石学性质、结构特征及X射线衍射进行了研究, 并对所得结果进行了统计描述和分析. 纹理系数的最大值为0.13, 最小值为0.50. 颗粒含量较高岩石的值最高. 采用回归分析的方法研究了结构系数与工程性能之间的关系. 建立了经验方程并选取了最佳的决定系数, 结果表明, 所有工程特性与纹理系数具有良好的相关性.     

Mathematical modeling of a multi-stage naphtha reforming process using novel thermally coupled recuperative reactors to enhance aromatic production

In this study, a novel thermally coupled reactor containing the naphtha reforming process in the endothermic side and the hydrogenation of nitrobenzene to aniline in the exothermic side has been investigated. Considering the higher thermal efficiency as well as the smaller size of the reactor, utilizing the recuperative coupled reactor is given priority. In this novel configuration, the first and the second reactor of the conventional naphtha reforming process have been substituted by the recuperative coupled reactors which contain the naphtha reforming reactions in the shell side, and the hydrogenation reaction in the tube side. The achieved results of this simulation have been compared with the results of the conventional fixed-bed naphtha reforming reactors. Acceptable enhancement can be noticed in the performance of the reactors. The production rate of the high octane aromatics and the consumption rate of the paraffins have improved 17% and 72%, respectively. The conversion of the nitrobenzene is acceptable and the effect of the number of the tubes also has been taken into account. However, the performance of the new configuration needs to be tested experimentally over a range of parameters under practical operating conditions.     

Integrated and inherently safe design and operation of a mobile power generation: Process intensification through microreactor reformer and HT-PEMFC

In the present study, due to various advantages of process miniaturization, the integrated design and operation of a mobile power generation system consisting of a microreactor reformer and a proton exchange membrane fuel cell (PEMFC) are investigated. The hydrogen fuel is supplied through autothermal steam-reforming of methanol in a microreactor leading to a safer, as well as more efficient, and economical operation. A high-temperature polymer membrane fuel cell with external accessories is applied for power generation. Then, simulation-optimization programming is applied for simultaneously optimizing the process design and operation at the same level. The result shows that the implemented procedure ensures the economic and flexible operation of the process while satisfying the safety constraints. The maximum gross power and net power generation are 109.3 and 91.9, respectively, while the cost of hydrogen production reduces from 13 to 20 $/kg to 7.7 $/kg. The fuel (methanol) consumption can be as low as 0.42 L/kWh.