Chia-Chieh Shen

Cyclic hydrogenation of an LmNi5-based alloy with different hydrogen loadings

Abstract Cyclic hydrogenation of an LmNi 5 -based alloy up to 3000 cycles at room temperature was conducted. Based on the ( P – C – T ) curve of the activated alloy, the initial charging pressures were set at four different values so that the saturated hydrogen loadings in equilibrium were controlled at H/M=1.0, 0.75, 0.50, and 0.25. The cyclic hydrogenation test was made for each loading. The absorption kinetic curves, hydrogen contents, and ( P – C – T ) curves after 1000, 2000, and 3000 cycles of testing were collected and compared with those of the activated sample. It is observed that the maximum hydrogenation capacities are reduced to 0.95, 0.92, 0.82, and 0.74 for the loadings of 0.25, 0.50, 0.75, and 1.0, respectively. The plateaus for the loadings of 0.25 and 0.50 do not change much, but are lowered and become more sloped for the loadings of 0.75 and 1.0, indicating that non-homogeneous chemical modification has been induced. The X-ray diffraction patterns show broadening of the peaks for all samples, and even the presence of some second phase for the loading of 1.0. The degradation is explained based on reduction of grain size, phase separation, and accumulation of strain energy in the alloy.

Measurement of internal temperature, flow and pressure in micro-methanol-reformer using multifunction micro-sensors

Methanol has many advantages, such as safe for storage and transportation and low reforming temperature. Methanol can be use to provide hydrogen for fuel cell. In this research, the multifunction micro-sensors are integrated using the micro-electro-mechanical systems (MEMS) technology for the in-situ monitoring of temperature, flow and pressure within micro reformer. The multifunction micro-sensors are embedded inside the micro reformer successfully and the calibration curves of micro temperature, flow and pressure sensors are finished. In the future, the further temperature, flow and pressure data obtained demonstrate that operation occurred in the micro reformer.

Application of flexible micro temperature sensor in oxidative steam reforming by a methanol micro reformer.

Advances in fuel cell applications reflect the ability of reformers to produce hydrogen. This work presents a flexible micro temperature sensor that is fabricated based on micro-electro-mechanical systems (MEMS) technology and integrated into a flat micro methanol reformer to observe the conditions inside that reformer. The micro temperature sensor has higher accuracy and sensitivity than a conventionally adopted thermocouple. Despite various micro temperature sensor applications, integrated micro reformers are still relatively new. This work proposes a novel method for integrating micro methanol reformers and micro temperature sensors, subsequently increasing the methanol conversion rate and the hydrogen production rate by varying the fuel supply rate and the water/methanol ratio. Importantly, the proposed micro temperature sensor adequately controls the interior temperature during oxidative steam reforming of methanol (OSRM), with the relevant parameters optimized as well.