二氧化碳甲烷化技術是一種高效利用二氧化碳排放的途徑，不僅有助於減少溫室氣體排放，也是減緩全球暖化的重要方法之一。該技術利用氫氣與二氧化碳反應，在催化劑的輔助下間歇性地生成可再生能源甲烷。考慮到二氧化碳可以從多種途徑獲得，而這些來源的二氧化碳通常含有其他微量氣體，目前對於這些雜質在二氧化碳甲烷化過程中的影響理解仍然不足。因此，本研究使用自製的Ni/Al2O3催化劑，在300℃、1 bar壓力、氣體空速（GHSV）為4000 h⁻¹及氫氣與二氧化碳比例為4.5的反應條件下，進行了實驗。研究了添加微量氣體（如一氧化碳、氧氣和氮氣等）對二氧化碳轉化率的影響。實驗結果顯示，在含有3%一氧化碳和3%氧氣的條件下，CO₂轉化率分別從90.3%下降至73.87%和68.49%，證實二氧化碳和一氧化碳或氧氣共存時，二氧化碳甲烷化反應受到抑制；而微量的氮氣對反應較沒顯著影響。為了進一步評估催化劑的穩定性，使用熱重分析儀（TGA）對未使用、使用後及再生後的催化劑進行測試和討論。同時，本研究還比較了不同尺寸反應器對反應效果的影響，以全面了解其在實驗中的表現。最後，結合實驗室的碳捕捉系統進行實驗，進一步評估該技術的可行性和局限性。

CO2 methanation is an efficient method for utilizing CO₂ emissions, contributing not only to the reduction of greenhouse gas emissions but also serving as an important approach for mitigating global warming. This technology facilitates the reaction between hydrogen and carbon dioxide, intermittently producing renewable energy methane with the aid of a catalyst.To evaluate the feasibility of this technology on an industrial scale, this study use a homemade Ni/Al₂O₃ catalyst under reaction conditions of 250 to 400°C, 1 to 4 bar pressure, gas hourly space velocity (GHSV) of 4000 h⁻¹, and H2 to CO2 ratio 4.5. The focus of the study was to investigate the impact of introducing trace amounts of other gases (such as carbon monoxide, oxygen, and nitrogen) on CO₂ conversion and CH4 selectivity.Experimental results indicated that the addition of 5% carbon monoxide reduced the CO₂ conversion rate from 90.21% to 59.33%, while the addition of 5% oxygen decreased the CO₂ conversion rate from 90.30% to 45.57%. These findings confirm that the methanation of CO₂ is inhibited in the presence of carbon monoxide or oxygen. Conversely, the addition of 5% nitrogen had no significant impact on the reaction.To further evaluate the stability of the catalyst, thermogravimetric analysis (TGA) was conducted on the unused, post-reaction, and regenerated catalysts, with detailed discussions provided. Additionally, the study compared the effects of different reactor sizes on the reaction performance to gain a comprehensive understanding of their experimental behavior.Finally, the feasibility and limitations of this technology were further evaluated by integrating the laboratory carbon capture system into the experiments.

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