痲瘋樹種子榨油及利用超重力旋轉填充床輔助油渣萃取之研究

Mechanical Compression and Oil Extraction of Jatropha Seeds and Application of High-Gravity Rotating Packed Bed

蘇峻賢(Jun-Xian Su)

指導教授 ： 張慶源

國立臺灣大學/工學院/環境工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.10303

摘要

近年來由於化石燃料的耗盡及環境的議題，開始重視替代能源的發展，而其中，又以生質能源為最大宗，並具可行性，被許多國家列為發展替代能源的重點項目。而「痲瘋樹」由於其易於栽種、不可食用，且種子含油量高的特性而成為了非常受關注的生質柴油料源。
在生質柴油的發展中，生產成本較高一直是其發展受限問題之一，而料源的有效利用與副產物的再利用可以幫助降低生產成本。故本研究嘗試從痲瘋樹種子的榨油及油渣再利用的技術探討，期望能找出有效率且省成本的油料獲得方式。
本研究為求有效率且省成本的油料獲得方式，從痲瘋樹種子的螺旋壓榨式榨油程序開始進行，再將榨油殘渣進行溶劑萃取。所得之油料可供產製生質柴油，而萃取後之殘渣可供再利用。由於生質柴油的製備過程中，需添加醇類進行反應，因此本研究選用甲醇、丁醇等醇類進行溶劑萃取的研究，以期望萃取後的溶液可直接進行酯化或轉酯化。而工業上常用以萃取油料的正己烷則用為參考溶劑，與其他溶劑進行比較。
本研究首先以螺旋壓榨式榨油機進行痲瘋樹種子的榨油，並針對不同的操作變數(如：轉速、溫度、進料量、時間)，來討論其榨油的效果。再以恆溫震盪系統與超重力旋轉填充床系統，進行油渣的再萃取，並討論不同得操作條件的萃取效果，來建立溶劑與榨油殘渣在油份萃取上的關係。
結果顯示，在螺旋壓榨式榨油機榨油程序中，於種子質量為500 g、操作溫度達130 ℃、轉速20 rpm的條件下，榨油效果可達87%。在恆溫震盪萃取方面，丁醇的萃取能力大於甲醇。當未溶劑萃取前榨油殘渣質量(mSE)與溶劑體積(VL)比(mSE/VL)為10/100 g/mL時，丁醇及甲醇的平衡萃取效率分別為94.0%及47.2%；當mSE/VL為90/100 g/mL時則分別為63.4%及10.1%。兩溶劑萃油的等溫脫附平衡曲線以Freundlich方程式描述較為合適。在超重力旋轉填充床系統中，探討的操作變數包括：床體轉速、溶劑進流量、固體量、溶劑量、溶劑種類、填充物量。超重力旋轉填充床的轉速(rRPB)提高、溶劑單位固體質之溶劑量進流量(QL/mSE)維持0.5 L/30g-min、溶劑量(VL)增加、油渣顆粒大小為18 mesh以下時，可得較佳的萃取效果。以脫附動力曲線模擬超重力旋轉填充床萃油系統的結果中顯示，以Elovich rate equation進行模擬可得到較符合實驗之結果。
在恆溫震盪系統與超重力旋轉填充床系統之比較中，超重力旋轉填充床系統可有效得縮短萃取平衡的時間，從2天縮短至約60 min。在較高固液比(如：0.3 g/mL)的萃取時，超重力旋轉填充床萃取系統之萃取速率較快，但於較低固液比(如：0.1 g/mL)萃取時，恆溫震盪萃取系統出其之萃取速率則較超重力旋轉填充床萃取系統快；此係因為恆溫震盪萃取一開始時，固體即與全部溶劑接觸，而超重力旋轉填充床萃取與固體接觸之溶劑僅為滯留在填充床中之少量溶劑。

關鍵字

螺旋壓榨式榨油機 ； 痲瘋樹種子榨油殘渣 ； 超重力旋轉填充床 ； 溶劑萃取 ； 恆溫震盪系統

並列摘要

Recent years due to the depletion of fossil fuels and environmental issues, many studies have started to focus on renewable energies. Among them biomass energy is one of the important alternatives. The manufacturing and use of biodiesel has been very successful. However, the reduction of cost of source oil is a key factor for the production. Among the available inedible and cheap raw oil sources of biodiesel, Jatropha curcas L. seed (JCL seed) is an attractive biodiesel feedstock. An efficient extraction of oil from JCL seed can contribute to the cost reduction.
This study examined the sequential extraction of oil from jatropha seeds via screw-press followed by solvent extraction. For screw-press, the effects of screw pressing speed (rS), temperature (TS), feed loading (mS) and time (tS) on the oil recovery efficiency (RO) were investigated. The equilibrium isotherms of screw-pressed residual seed cake and methanol and butanol were established. The results indicated thata high RO of 87% can be achieved at mS = 500 g, TS = 130 °C and rS = 20 rpm.
A high-gravity rotating packed bed (HGRPB) was employed to facilitate the solvent extraction rate and/or extraction efficiency (ηE). The roles of system parameters were elucidated, including rotating speed (rRPB), solvent flow rate (QL), mass of solid(residual seed cake, mSE), volume of solvent (VL), mass of packing (mPK) and size of residual seed cake (dP). Extraction rate equations were proposed. Butanol has higher oil extraction ability than methanol. The extraction of both solvents can be well described by Freundlich isotherm equation. The equilibrium ηE of butanol and methanol, respectively, at mSE/VL = 10/100 g/mL are 94.0% and 47.2%, while those at SE/VL= 90/100 g/mL are 63.4% and 10.1%. Elovich rate equation is appropriate to illustrate the kinetic behavior of HGRPB extraction. The HGRPB exhibits higher extraction ability than the jar-shaking extraction.

並列關鍵字

Mechanical oil extraction ； screw-press ； jatropha seed oil extraction residue ； high gravity rotating packed bed ； solvent extraction ； Jar-sharking system

參考文獻

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