利用雙塔變壓吸附程序濃縮及回收氣化產氫製程中之二氧化碳與氫氣

Using Dual-Bed PSA Process to Concentrate and Recover H2 and CO2 from Gasification Process for H2 Production

李建佑(Chien-Yu Lee)

指導教授 ： 周正堂

國立中央大學/工學院/化學工程與材料工程學系/碩士(2007年)

摘要

煤炭進行水蒸氣觸媒反應後，進一步將觸媒重組物通過水煤氣轉化反應器（water gas-shift reactor）則可得到大量以氫氣、二氧化碳為主體的混合氣體（syngas）。但經由上述所得典型混合產氣，大部分氣體成分為H2、CO2及N2。因此，氫氣的純化程序為製造高純度氫氣（99%+)不可或缺的步驟。
本研究便以合成氣的組成為目標，以實驗探討使用變壓吸附製程純化合成氣中二氧化碳與氫氣的最佳操作條件。
實驗主要分為二階段，以雙塔四步驟真空變壓吸附（4 steps vacuum swing adsorption）製程，來進行操作變數對製程影響的探討。
第一階段為CO2-VSA （vacuum swing adsorption），主要為回收合成氣中之CO2，吸附劑採用zeolite 13X，進料組成為模擬合成氣，訂為40% H2、50% CO2、10% N2；第二階段為H2-VSA，主要再純化第一階段之弱吸附出氣（塔頂出氣），吸附劑採用activated carbon及zeolite 5A混合填塔，進料組成為第一階段CO2-VSA之塔頂出氣組成，訂為60% H2、23.4% CO2、16.6% N2。
實驗上藉由改變操作變數，如：進料壓力、步驟時間、活性碳長度比（carbon ratio ,c.r.）等，以得到最佳的分離操作條件。
結果，可在第一階段CO2-VSA將CO2濃度達到99%（回收率59%）；第二階段H2-VSA將H2 濃度達到95%（回收率44%）。

關鍵字

變壓吸附 ； 氫氣 ； 二氧化碳 ； 實驗 ； 13X沸石 ； 5A沸石 ； 活性碳 ； 層床

並列摘要

The gas from coal, then passing through the water gas-shift reactor,will get a large mount gas mixture (syngas) with main components H2, CO2 and N2. For this reason, it is necessary to have a purification process to manufacture high purity (99%+) hydrogen.
This study experimental study the use of PSA (pressure swing adsorption) process to purify the CO2 and H2 in syngas.
The process includes two stages,which uses the two bed 4-steps vacuum swing adsorption process,to study the effects of the operating parameter on the system.
Stage 1 is the CO2-VSA (vacuum swing adsorption), mainly separating the CO2 of syngas. The adsorbent is zeolite 13X. Feed gas mixture contains 40% H2, 50% CO2, and 10% N2, which simulats the syngas composition. Stage 2 is the H2-VSA, mainly purifying the weak adsorbed component gas (mainly H2) from the bed top of the stage 1. The adsorbents include activated carbon and zeolite 5A in a layered bed. Feed gas composition is the composition of the bed top gas of the stage 1, which is 60% H2, 23.4% CO2 and 16.6% N2.
The optimal operating conditions is obtained by changing the operating variables,for example,feed gas pressure,step time and carbon ratio in the bed.
For stage 1 CO2-VSA,the CO2 purity can reach 99% with a recovery of 59%； for stage 2 H2-VSA the purity can reach 95% with recovery 44%.

並列關鍵字

layered bed ； activated carbon ； Pressure swing adsorption ； hydrogen ； carbon dioxide ； experiment ； zeolite 13X ； zeolite 5A

參考文獻

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