本研究針對台灣大客車柴油引擎積碳問題，創新性地採用甲醇製氫技術進行清除積
碳，並系統性評估其對燃油效率與空氣污染排放的改善效果。研究結果顯示，氫氣助燃技術能夠有效提升大客車燃油經濟性並顯著降低主要污染物排放，為台灣交通運輸領域的低碳轉型提供了重要的技術解決方案。隨著台灣城市化進程加速，大客車作為公共運輸的重要組成部分，面臨著引擎積碳導致的燃油效率下降和空氣污染加劇問題。傳統的清除積碳方法包括化學清洗、燃料添加劑使用及機械清潔等，但這些方法存在明顯限制：化學清洗成本高昂且可能造成環境二次污染；燃料添加劑效果有限且需長期使用；機械清潔則需拆解引擎部件，操作複雜且耗時。因此，尋求創新且高效的解決方案顯得尤為迫切。
本研究採用碧氫科技開發的甲醇製氫設備，使用 58 wt%甲醇水溶液作為原料，通過催化轉換在 270°C 相對低溫下運作，產生純度達 73-74%的氫氣。該技術具有多項優勢：採用現場即時產氫並使用模式，無需高壓儲存設備，降低安全風險；設備相對輕巧，適合現場操作。研究選用 6 台相同規格的馨盛汽車柴油引擎 HINO J08E-TE (EURO4)大客車，分為兩組不同長度路線進行實驗：甲路線（苗栗火車站至大甲站，單程 49.4 公里，每日行駛197.6 公里）和乙路線（苗栗站至外埔漁港，單程 19.7 公里，每日行駛 157.6 公里）。每組包含 2 台實驗組車輛進行清除積碳和 1 台對照組車輛。氫氣除碳作業程序為每台車輛進行40 分鐘的氫氣注入，期間車輛保持怠速狀態。使用 BE-2000 手提式車輛與引擎廢氣分析儀測量 HC、CO、CO₂、NOx 等污染物排放變化，並記錄 30 天內的燃油消耗數據。
實驗結果顯示，氫氣清除積碳技術對大客車燃油效率有顯著改善效果。在甲路線測試
中，實驗組 A 的燃油效率最高提升 17%，實驗組 B 提升 20%，清除積碳後第一個月效果最為明顯。在乙路線測試中，實驗組 C 提升 12.5%，實驗組 D 提升 9.7%。改善效果在長距離行駛路線上更為顯著，但隨時間推移會逐漸減弱，約 3 個月後回復至原來水準。
空污排放測試結果顯示，氫氣清除積碳技術對污染物減排有顯著效果。碳氫化合物
（HC）排放平均減少 86%，一氧化碳（CO）排放平均減少 69%，二氧化碳（CO₂）平均減少 18%。氮氧化物（NOx）的改善效果相對有限。特別值得注意的是，甲路線車輛的減排效果普遍優於乙路線，顯示該技術在長距離行駛條件下表現更佳。
未來研究建議包括：擴展至新型引擎，比較不同世代引擎的除碳效果差異；調整產氫
量、清洗時間等關鍵參數，尋找最佳操作條件；增設懸浮微粒（PM）測量能力，驗證清除積碳後碳化物的去向；建立更完整的經濟效益評估模型，考慮不同氫氣供應方式的經濟性。

This study addresses the carbon deposit problem in Taiwan's bus diesel engines by innovatively employing methanol-to-hydrogen technology for carbon removal and systematically evaluating its improvement effects on fuel efficiency and air pollution emissions. The research results demonstrate that hydrogen-assisted combustion technology can effectively enhance bus fuel economy and significantly reduce major pollutant emissions, providing an important technical solution for the low-carbon transformation of Taiwan's transportation sector.With the acceleration of Taiwan's urbanization process, buses, as an important component of public transportation, face the challenges of declining fuel efficiency and increasing air pollution caused by engine carbon deposits. Traditional carbon removal methods include chemical cleaning, fuel additive usage, and mechanical cleaning, but these methods have obvious limitations: chemical cleaning is costly and may cause secondary environmental pollution; fuel additives have limited effectiveness and require long-term use; mechanical cleaning requires disassembly of engine components, which is complex and time-consuming in operation. Therefore, seeking innovative and efficient solutions has become particularly urgent.

This study employs methanol-to-hydrogen equipment developed by Green Hydrotec,inc, using a 58 wt% methanol-water solution as raw material. Through catalytic conversion operating at the relatively low temperature of 270 °C, it generates hydrogen with a purity of 73-74%. This technology has multiple advantages: it adopts an on-demand production mode without requiring high-pressure storage equipment, reducing safety risks; the equipment is relatively compact and suitable for on-site operation.

The research selected 6 buses with identical specifications, featuring Shin Sheng Automotive diesel engines HINO J08E-TE (EURO4), and divided them into two groups with different route lengths for experiments: Route A (Miaoli Railway Station to Dajia Station, 49.4 km one-way, driving 197.6 km daily) and Route B (Miaoli Station to Waipu Fishing Port, 19.7 km one-way, driving 157.6 km daily). Each group included 2 experimental vehicles for carbon removal and 1 control group vehicle.

The hydrogen decarbonization procedure involved 40-minute hydrogen injection for each vehicle while maintaining idle state. A BE-2000 portable exhaust gas analyzer was used to measure changes in pollutant emissions including HC, CO, CO2, NOx, and fuel consumption data was recorded for 30 days.

[1] 111 年民眾日常使用運具狀況調查 摘要分析. 交通部統計處.
[2] 吳宗憲. (2017). 戰後臺灣公路運輸政策與公營客運之變遷. 國立中央大學歷史研究所碩士論文, (頁 10-13).
[3] 李家儂. (2006). 交通運輸與土地使用整合規劃之演變～大眾運輸導向發展的都市發展模式. 土地問題研究季刊, 70-83.
[4] 美國環境保護署（EPA）. (2024年8月15日). Diesel Fuel Standards and Rulemakings. 擷取自 https://www.epa.gov/diesel-fuel-standards/diesel-fuel-standards-and-rulemakings
[5] 曹誠蔡鳳田,劉莉,曹磊. (2011). 不同駕駛操作方法下的汽車運行燃料消耗量分析. 汽車節能(1), 31-34.
[6] 曾平毅張瓊文,黃嘉承,林彥妤. (2008). 臺北市幹道自由車流速率特性之初探. 臺北市: 安全與執法研討會
[7] 雷敏宏. (2005). 中國 專利號碼 CN100410167C
[8] 蔡宇洲宋廉永,張榮桂,陳力之,王建凱. (2017). 台灣 專利號碼 TW201722847A
[9] 羅志臣王勤. (2010). 中國 專利號碼 CN101760345A.
[10] 蘇昭銘, 郭子義, 謝界田, 王詮勳. (2023). 無所不在的公車——臺灣地區公路客運的發展與未來展望. 2023 臺灣博物季刊 157　42 卷．第1 期, 6-13.
[11] BalmerT.Robert. (2011). Chapter 13 - Vapor and Gas Power Cycles. 於 BalmerT.Robert, Modern Engineering Thermodynamics (頁 503-509). Burlington, MA, USA: Academic Press (Elsevier).
[12] CARBONCLEAN LT 25 LTR. (2024). 擷取自 Wilhelmsen公司網站: https://www.wilhelmsen.com/product-catalogue/products/marine-chemicals/cleaning-chemicals/cleaning-and-maintenance/carbonclean-lt-25-ltr/
[13] Chen, W., Li, Q., & Zhang, Y. (2020). Hydrogen-assisted carbon removal in GDI engines: A comparative study. Journal of Automotive Engineering, 12(4), 頁 45-58.
[14] DanielsenNGuttorm. (2017). Modeling and Analysis of a 2-Stage Turbocharger. 挪威科技大學(NTNU).
[15] Davis Belmiro Satria, Novandra Rhezza Pratama, M. Dachyar. (2022). Time Reduction of Oxyhydrogen Carbon Clean Process at Automobile Workshop in Indonesia Using Business Process Reengineering. Depok City, West Java Province, Indonesia : Department of Industrial Engineering, Faculty of Engineering, Universitas Indonesia .
[16] Dietmar Filsinger、Georgios Iosifidis、Loic Durbiano、Christian Kirschner、Jan Ehrhard. (2023). On Advanced Turbocharger Technology and Development . IHI Corporation.
[17] (2016). Downsized, Boosted Gasoline Engines. International Council on Clean Transportation.
[18] Ghodbane Hassina, Khaldi Fouad,Deraadji Bahloul. (2023). Optimizing Low-Load Performance: Investigating Diesel-Hydrogen Dual Fuel Engine Combustion Traits. IJR Proceedings, 15(1), 頁 112-125.
[19] Gregory K. Lilik , Hedan Zhang , Jose´ Martin Herreros , Daniel C. Haworth , Andre´ L. Boehman. (2010). Hydrogen assisted diesel combustion. Hydrogen assisted diesel combustion. International Journal of Hydrogen Energy, 35(9), pp. 4382-4398.
[20] Lee, Rob ; Pedley, Joanna ; Hobbs, Christine. (1998). Fuel Quality Impact On Heavy Duty Diesel Emissions:-A Literature Review. SAE transactions, 1952-1970.
[21] Liu, M., Wang, Y., & Zhang, R. (2017). Dynamic evolution of carbon deposit properties in internal combustion engines. Tribology International, 112, 頁 23-31.
[22] M. Diaby, M. Sablier , A. Le Negrate , M. El Fassi , J. Bocquet. (2009). Understanding carbonaceous deposit formation resulting from engine oil degradation. Carbon, 47(1).
[23] Marek Wozniak, Sergiusz Zakrzewski, Gustavo Ozuna, Krzysztof Siczek, Paweł Just, Constantin Onescu. (2023). Deposition effect of carbon deposits on charge flow in EGR valve equipped CI engine. World Wide Journal of Multidisciplinary Research and Development, 192(1), 頁 26-35.
[24] PechlivanoglouGeorgios. (2007). Hydrogen Enhanced Combustion History, Applications and Hydrogen Supply by Plasma Reforming. University of Oldenburg. .
[25] Rodica Baranescu, Bernard Challen. (1999). Diesel Engine Reference Book. Butterworth-Heinemann Ltd.
[26] Sepehr Bapiri, Cem Sorusbay. (2019). Investigating the Effects of Variable Valve Timing on Spark Ignition Engine Performance. Advances in Science and Technology Research Journal, 13(2), 頁 100–111.
[27] Shou-Pin Yu,Ming-Wei Lai,Chen-Yeon Chu,Chia-Ling Huang,Chiu-Yue Lin,Vasily I. Borzenko,Dmitry O. Dunikov,Alexey N. Kazakov. (2016). Integration of low-pressure hydrogen storage cylinder and automatic controller for carbon deposit removal in car engine. International Journal of Hydrogen Energy.
[28] Thi Minh Hao Dong, Thanh Hai Truong. (2019). Deposit Formation in Diesel Engine and Its Effects. World Wide Journal of Multidisciplinary Research and Development, 5(10).
[29] Thomas Leroy, Jonathan Chauvin, Nicolas Petit. (2009). Controlling In-Cylinder Composition on Turbocharged Variable-Valve-Timing Spark Ignition Engines. European Control Conference (ECC09).
[30] Variable Geometry Turbo for Gas Engines. (2023). 擷取自 Garrett Motion Inc.: https://www.garrettmotion.com/turbocharger-technology/gasoline-turbochargers/variable-geometry-turbo-for-gas-engines/
[31] Wang, J., Tan, S., & Ng, H. K. (2022). Graphene oxide nanofluid for engine carbon removal. Nanoscale Advances, 4(3), 頁 789-798.