從實驗室規模至模廠規模試驗，均已證實兩段式NOx Scrubber 的可行性，但實廠要 運用兩段式式NOx Scrubber，須面臨強氧化劑與還原劑使用量大與儲存不易的問題。在 電化學反應器中，同時可以在陽極產生氧化劑並在陰極產生還原劑，如以薄膜將電化學 反應槽分隔，可將此電化學反應器做為產生與再生氧化劑與還原劑之用。因此本研究提 議將兩段式式NOx Scrubber 與電化學反應器兩種程序結合，此將可在現場產生並再生氧 化劑與還原劑，充分有效地使用於兩段式NOx Scrubber 所需的氧化與還原洗滌液中。且 由於氧化劑與還原劑是在現地製造使用，不須儲存場地，可避免其存放期間易變質的問 題，故可以解決實廠運用兩段式NOx Scrubber 所面臨的問題。本計劃目的在發展一個結 合兩段式NOx Scrubber 與電化學氧化還原劑產生/再生器之整合系統，本計劃將針對以 下問題進行探討: 1.以間接與直接電化學法產生的氧化還原劑，用於測試其用於兩段式 NOx Scrubber 的效果，並測試將洗滌廢液分別導回電化學反應器之再生效果。 2.分析電 化學法產生自陽極氧化槽的氧化劑與產生自陰極還原槽的還原劑之組成成分，並探討其 在兩段式NOx Scrubber 的氧化與還原機制。 3.評估幾種電極材料，測試其在本系統應 用之導電性與抗極化能力，以評估其作為電化學氧化還原劑再生器的極板使用之可行 性。 4.測試改進電化學氧化還原劑再生器，其極板腐蝕、電流密度、電流效率、洗滌溶 液pH、ORP 等操作參數。 5.測試改進結合兩段式NOx Scrubber 與電化學氧化還原劑再 生器系統之整體操作參數，以得出一套完整可行的建議系統。本計劃預期能得出具高 NOx 去除率，無須氧化還原劑儲存槽，可回收再生程序廢液等優點之兩段式NOx Scrubber 整合系統，並獲得該整合系統的最佳操作參數，以提供實廠設計應用。 From bench to pilot scale, a two-stage NOx scrubber was confirmed to be a feasible process for NOx absorption. However the usage and storage of mass chemicals and the treatment of wasted solution are the major concerns for its practical application. Since oxidizing and reducing agents are produced on anode and cathode respectively in a special designed electrochemical reactor, the reactor can be used to produce and regenerate the redox agents when a membrane was set to separate the oxidizing and reducing agents in electrolyte solution. Hence we propose to integrate a two-stage NOx scrubber with an electrochemical reactor as an integrated system used for NOx absorption while the redox agents are supplied from on-site regeneration facility. The system can avoid the drawbacks of mass storage and easily degradable of the Redox agents, and the treatment of the wasted scrubbering solution. With this design, the application of the two-stage NOx scrubber becomes more feasible both functionally and economically. In this study, the following tasks will be explored. 1. To test the performance of the NOx scrubber with solutions made by indirect and direct electrochemical reactor for Redox agents regeneration; 2. To explore constitutes in the reduction agents made by regeneration reactor and their reaction mechanism in NOx reduction; 3. To find appropriate electrode materials for the Redox reactor hence the system may avoid polarization that causes high resistance; 4. To improve the operation parameters of the integrated NOx control system, the considered parameters include current density, power efficiency, conductivity, pH and ORP; 5. To test and obtain a set of optimal operational parameters of the integrated NOx scrubber system including the parameters of two-stage NOx scrubber and the electrochemical reactor for the Redox agents regeneration.
