一氧化碳背景值自動監測系統之架構; Construction of an automated analysis system for background level carbon monoxide

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/6045

Title:	一氧化碳背景值自動監測系統之架構;Construction of an automated analysis system for background level carbon monoxide
Authors:	歐陽長風;Cheng-Feng O-Yang
Contributors:	化學研究所
Keywords:	一氧化碳;CO;carbon monoxide
Date:	2004-07-06
Issue Date:	2009-09-22 10:12:23 (UTC+8)
Publisher:	國立中央大學圖書館
Abstract:	本研究成功開發一套低成本、且適用於一氧化碳和甲烷背景值量測之全自動化層析系統。利用程序控制器對分離管柱直接電阻式升控溫，避免了使用商品化氣相層析儀的必要，不僅大幅縮小了分析系統體積，並使系統建購的成本降低，其加熱方式直接且省電，更新了以往對於氣相層析分析系統構造的傳統觀念，對於偏遠無人測站之使用更為有所助益。實驗中利用鎳觸媒管的催化，將一氧化碳還原為甲烷，使高靈敏的火燄離子偵測器能藉此偵測一氧化碳，本研究中並修正了原本商品化鎳觸媒管的幾何構造，加強其對於分析一氧化碳時的表現。利用加裝於管柱後端的Heart-cut技術，在此具有雙重性功效，其不但能順利達成調理管柱的要求，使分析的狀態維持在最佳，並成功地將不必要的氧氣峰切除，除在層析上簡化了圖譜外，且讓一氧化碳和甲烷的解析能力增強，再者，由於此技術也可以令非分析物之其餘高沸點物質不流經鎳觸媒管，而使鎳觸媒被毒化的可能性降低，延長其壽命，強化了分析系統的長期穩定性。 An automated gas chromatography system was constructed to perform in situ measurement of atmospheric carbon monoxide and methane at background levels. While methane can be detected directly by flame ionization detection (FID), carbon monoxide however needs to be methanized by a nickel catalyst under hydrogen provision in order to be detected by FID with adequate sensitivity. The catalyst bed was prepared by filling approximately 1 g of nickel oxide embedded silica in 1/8” x 10 cm stainless steel tubing and operated at 300 ?C. The design of the system involves several innovated features to save space, cost, and power consumption, pivotal to the deployment in an unattended remote monitoring station. First, the resistive heating directly on the molecular sieve packed column eliminates the need of a commercial gas chromatograph. Second, pressure feedback to the capacitance monometer and the slightly heated sample loop ensure precise air sample loading, which largely control the overall uncertainty of the methane and carbon monoxide measurement. Third, to prevent oxygen and heavy residuals from causing unwanted oxidizing reactions and contamination of the nickel catalyst the post-column heart-cut technique was used to safe-guard and prolong the service time of the nickel catalyst tube.
Appears in Collections:	[Graduate Institute of Chemistry] Electronic Thesis & Dissertation

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