膜管分離器結合預反應器於生質柴油製程之模擬與實驗驗證

摘要為了改善傳統生質柴油的製程，使得在連續下獲得較高的FAME質傳通量，並降低蒸餾所需能耗，本研究提出究薄膜反應器於生質柴油系統以改善，但在薄膜分離的過程中需要結合相平衡控制組成使其形成非均相的狀態，才能將未反應的原油給阻擋住，而系統非均相是不利於反應的進行的。系統相變化對於反應及分離有很大的關係，為了了解轉酯化過程中相變化行為，先利用實驗方式取得生質柴油轉酯化的動力學參數，並利用UNIQUAC模式來描述系統呈均相或非均相。使用薄膜分離系統就必須維持非均相，而為了改善因為攪拌不均而轉化率不高的薄膜反應器，提出膜管分離器結合預反應器的概念，將薄膜反應器分為膜管分離器及預反應器。首先建立膜管分離器模式於生質柴油製程，利用模擬探討膜管分離器內部組成變化及滲透端組成變化，發現膜管中反應微量，因此說明膜管功用主要在於分離。為使轉化率提高後再進行分離。在進入膜管分離器之前加入預反應器，此預反應器可為PFR或CSTR，由模擬發現預反應器形式為CSTR時，系統轉化率明顯提升。藉由模擬此模式，針對FAME質傳通量及選擇性進行探討。由模擬結果得知溫度60℃下，催化劑濃度0.05wt.%，預反應形式以CSTR，預反應器與膜管體積比率50，醇油莫耳比24：1，管長0.6 m時，總操作時間70 min，預反應10 min，則可得到良好的FAME質傳通量及選擇性。為了證實此模式能代表真實系統，本研究將利用真實實驗與模擬相互比較。雖然數值上有些差異，其模擬與實驗結果趨勢顯示相同，結果顯示實驗操作至結束後滲透端組成，其系統都維持在非均相區，滲透端沒有發現TG及DG，可是發現微量MG。

關鍵字

生質柴油；膜管分離器

並列摘要

Abstract To improve the traditional process of biodiesel and continuously obtain biodiesel of high purity, a membrane reactor for the biodiesel system is studied. In membrane separation, the status of compositions in the two liquid phases should be considered to screen out most of the unreacted oil and get the FAME product of high purity.The phases change affects reaction and separation greatly. We used experiment and UNIQUAC model to study that the phases change for transesterification. We proposed a concept of integrated pre-reactors and tubular membrane to improve low conversion ration of membrane reactor caused by uneven stirring. We establish a model of tubular membrane separators for biodiesel and use this model to discuss change of component in feed-side and permeate-side and thus illustrating the role of membrane is mainly in separation. The pre-reactors can be PFR or CSTR. Simulation results shows when CSTR is used as pre-reactor, the conversion ratio is raised significantly. By simulating this system flux and selectivity is investigated. At temperature 60℃,catalytic concentration is 0.05wt.%, CSTR as pre-reactors, pre-reactors and membrane separators volume ratio of 50, operating time of 70 minutes and residence time of 10 minutes, we obtained a good flux and selectively from simulated result. Simulation reveals same trend as experimental result. In the experiment no TG and DG were present in permeate side, but slight amount of MG was found.

並列關鍵字

Biodiesel ； Membrane Separators ； Pre-reactors

參考文獻

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膜管分離器結合預反應器於生質柴油製程之模擬與實驗驗證

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