- 學位論文
具多孔材重組產氫系統純化器對於CO轉化特性研究
Study on purifier with a porous material installed in a hydrogen production reformer for CO removal
摘要
本研究設計一組甲醇重組產氫系統，針對系統中具多孔介質純化器對於CO轉化特性進行研究探討。研究方法於優先氧化段置入多孔介質，以不同O2/CO比與多孔介質放置位置，針對溫度分佈與產出氣體濃度進行探討。本論文主要分為兩部分，包括於各重組段以不同參數作測試，並於優先氧化段以不同操作條件對於CO轉化特性進行研究。 在第一部分，主要先在自發熱重組段，以不同O2/CH3OH比與H2O/CH3OH比探討溫度特性及重組性能的影響及比較；隨即將測試出來的較佳參數所產出之重組氣體，導入高、低溫水氣轉移段，設定其H2O/CO比、控制其水氣轉移段較佳溫度，藉由水氣轉移反應產出氫氣與二氧化碳，降低一氧化碳濃度；經水氣轉移的重組氣體最後導引至優先氧化段，將CO降低至ppm級。此目標達成後，此產氫系統再經過四小時耐久測試，且將冷凝之水溶液送檢分析，檢驗液體中的甲醇成分。最後將本重組產氫系統與燃料電池系統整合進行耐久測試，系統操作四小時的過程中，產氫系統重組溫度與氣體濃度皆能穩定供應，燃料電池可拉載至40安培，穩定輸出功率在1050W左右。 第二部分，則於優先氧化段置入多孔介質，探討其對CO轉化特性與背壓對產出氣體濃度之影響。經實驗測試結果，發現置入多孔材介質，其溫度分佈較為均勻，並以原系統與前端與中段放入多孔介質作比較，其CO濃度可從95ppm降至75ppm。另外，本實驗並進行分段導氧測試，發現將導致其觸媒中段氧化甚為劇烈，溫度最高可達535oC，其CO濃度最低只能到285ppm，且甲烷濃度也從0.26%上升至0.64%。另發現系統背壓會影響燃料進料、O2/CH3OH比，進而影響產出氣體濃度的穩定性。故在整合系統時，必須注意背壓的改變，並調整燃料進料，以維持進料的穩定供應，避免其對於產出氣體濃度的影響。
並列摘要
This study investigated the reforming of methanol with porous material for CO conversion. The research method was to use different O2/CO ratio and porous material position in the PrOX to observe the temperature distribution and reformate gas concentration. This study employed different parameters to carry out reforming tests and study the CO conversion in PrOX reactor. In the experiments, temperature distribution and reforming performance in autothermal reformer were investigated under different O2/CH3OH and H2O/CH3OH ratios. And then, the reformate gas produced in the ATR reformer was conducted into the high temperature (HT) and low temperature (LT) water gas shifting (WGS) reactors, in which setting suitable H2O/CO ratio to control the temperature and reduce CO concentration. When H2O enter the WGS reactor, it increased hydrogen and carbon dioxide and reduced carbon monoxide contents. After it came through PrOX reactor, CO content in the reformate gas from WGS reduced to lower than 100 ppm. When the target reached, system was performed a four-hour durable test. At last, the hydrogen production reforming system and PEMFC were also combined to make a durability test. A power 1050 W was generated from the fuel cell. Finally, PrOX with PM for CO conversion improvement was experimented. It was found that the temperature distributed better than that of original system when installed PM. And CO concentration reduced from 95 ppm to 75 ppm. In addition, one can find that the temperature is as high as 535 oC when the air was adding at middle catalyst. Under this condition, the CO concentration reached 285 ppm and CH4 increase from 0.26% to 0.64%. After a series of experiments, it was also found that the system pressure could affect fuel feeding and O2/CH3OH ratio to affect reformate gas concentration when the hydrogen production reformer was combined with fuel cell system. Therefore, the fuel supplied to the reformer must be regulated according to the back pressure of the system to maintain the stable production of reformate gas.