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Extraction of Maleic Acid and Phthalic Acid by scCO 2 Saturated with Trioctylamine Hassan S. Ghaziaskar and Ahmad Rahmanian Chemistry Department Isfahan University of Technology, Isfahan, Iran. Barcelona, Spain, May 4 – 7, 2008. Outline. History Reactive Exn
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Extraction of Maleic Acid and Phthalic Acid by scCO2 Saturated with Trioctylamine Hassan S. Ghaziaskar and Ahmad Rahmanian Chemistry Department Isfahan University of Technology, Isfahan, Iran Barcelona, Spain,May 4 – 7, 2008
Outline • History • Reactive Exn • Experimental Section • Separation and Determination of Extracted Samples • Parameters Affecting the Exn • Conclusion
Reactive Exns • When the extracting solvents are apolar, their ability to extract the polar compounds such as organic acids, amino acids, and phenols is low. • About 30 years ago extraction with the help of a chemical reaction or strong physical interaction between the extracting solvent and the sample was used to solve the problem in LLE. • In this method usually a small amount of a reactant is added to the extracting solvent to: • 1) Increase solvent polarity • 2) Have specific interactions with analyte • 3) Increase the extraction selectivity
Applications of Reactive Extractions in LLE Systems 1) Separation and purification of heavy metal ions such as platinum, Ga (e.g. selective extraction of Ga from coal), etc using organic ligands or strong Lewis bases 2) Extraction of organic compounds from aqueous solutions have also been extensively studied: a) Separation of amino acids using bis(2-ethylhexyl) phosphoric acids b) Separation of Penicillin using Amberlite LA-2 Amberlite, LA-2 LIX 54-N
RnNH(3 - n)org + H+aq RnNH(4 - n)org+ RnNH+(4 - n) org + A-aq RnNH+ (4 - n)org … A-org R4N+ X-org + HAaq R4N+ A-org + HXaq RnNH+4-n X-org + HAaq RnNH+4-n A-org + HXaq Mechanisms of Reactive Extraction of Organic Acids Using Amines Four major mechanisms for extraction of organic acids with amines has been proposed: 1- Ion exchange mechanism; in an aquous solution of an organic acid or its salt and extractant including an amine 2- Ion-pair formation; when the basic power of the extracting amine is equal or higher than the anion to be extracted. 3- Hydrogen bonding formation 4- Solvation mechanism
Reactive Extraction of Carboxylic Acids in a LLE system Organic extractants already used are divided into 3 major categories: 1- Hydrocarbons and oxygen containing extractants. 2- Solvents containing oxygen and phosphorous. 3- High molecular weight aliphatic amines • higher efficiency • cheaper than organophosphorous solvents • reversible reaction with carboxylic acids • high selectivity • Use of amines in the reactive extraction is limited to tertiary amines with long alkyl chain • primary amines are water soluble • secondary amines are changed into imines when distilled or their pH is changed dramatically for separation of amine from acid
Schematic diagram of SFE system CO2 1st Time Reactive Exn of Carboxylic Acids Using SCF Saturated from TOA
Microsampling Method Used BPR Pump Pump BPR Solvent a b
GC was used for quantitation of the extracted MA & PA • 1. MA decomposes at 135 oC at the GC injection port • 2. TOA-acid ion-pair Boiling point is higher than the injection port temperature • 3. Direct determination of dicarboxylic acids needs very high polar columns. Normal columns leads to broadened and asymmetrical peaks which is not good for quantitative works. Therefore, the acids should be changed to compounds that could be easily separated
Determination of Extracted Samples via Derivatization Methanolic BH3 Benzyl bromide Acetic anhydride TFAA & butanol
Butanoic Acid (Z)/Maleic Acid Dibutyl Ester ROH = Butanol
Phthalic Acid Dibutyl Ester ROH = Butanol
Carrier gas = N2 OV-1, 15 m capillary column Injection port temp. = 240 oC FID temp. = 250 oC Temp. program; 1min at 70 oC with the rate of 10 oC/min to 250 oC for 5 min
Derivatization In 70 μL glass capillary tubes. Three parameters affect the derivatization: 1) The amount of derivatizing agent/g of sample 2) Derivatization temperature 3) Derivatization time These stages were optimized using the GC peak area of the reaction products to the IS (dibenzyl ether)
Effect of the Derivatization Reagent (TFAA) Volume (µL) on the Peak Area of Derivatized Maleic Acid (■), and Phthalic Acid (▲), at 463 K and 20 min Reaction Time
Effect of the Derivatization Reaction Temperature on the Peak Area of Derivatized Maleic Acid (■), and Phthalic Acid (▲), at 423 K.
Effect of Derivatization Reaction Time on the Peak Area of Derivatized Maleic Acid (■), and Phthalic Acid (▲) at 190 oC
2 1.8 1.6 1.4 1.2 Peak area maleic acid / Is 1 0.8 0.6 0.4 0.2 0 0 0.2 0.4 0.6 0.8 1 1.2 g TOA per 5 mL solute The effect of TOA on the Maleic Acid Derivatization
2 1.8 1.6 1.4 1.2 Peak area phthalic acid / Is 1 0.8 0.6 0.4 0.2 0 0 0.2 0.4 0.6 0.8 1 1.2 g TOA per mL solute 5 The effect of TOA on the Phthalic Acid Derivatization
Phthalic Acid Calibration Curve Maleic Acid Calibration Curve
The Effect of Dispersing Agent • Crushed Glass Increases the repeatability and Exn Yield • Increases the Contact Surface of the Solvent and Sample • Reduces Channeling Crushed Glass/Sample = 70 %; Mesh 40-60, and MA/PA = 1
The Effect of Static Time • The sample is kept in contact with the solvent • The higher the static time the higher the • interaction between scCO2 and the sample • and the higher the exn efficiency Static time of 30 min was chosen
Table 1 Amount of maleic acid and phthalic acid extracted in mole fraction (y), in g acid per L of scCO2 (S) at temperatures of 308 and 318 K and pressure range of (100-350) bar.
Table 2 Amount of maleic acid and phthalic acid extracted in mole fraction (y), in g acid per L of scCO2 (S) at temperatures of 55 oC and pressure range of (100-350) bar.
Effect of Pressure on the Exn of Maleic Acid in the Pressure Range of (100-350) bar and Temperatures (oC) of 35 (▲), 45 (■), 55 (●)
Effect of Pressure on the Exn of Phthalic Acid in the Pressure Range of (100-350) bar and Temperatures (oC) of 35 (▲), 45 (■), 55 (●) phthalic acid
Effect of Temperature on the Exn of Maleic Acid in the Pressure Range of (100-350) bar 1.5 times increase in exn of maleic acid
Effect of Temperature on the Exn of Phthalic Acid in the Pressure Range of (100-350) bar 0.8 times increase in exn of phthalic acid
The Effect of scCO2 Density on the Exn Maleic Acid Phthalic Acid
Exn of Maleic Acid with TOA in Comparison with its Solubility in Neat scCO2
Exn of Phthalic Acid with TOA in Comparison with its Solubility in Neat scCO2
a 1 = y 2 Selectivity of scCO2-TOA System for the Extraction of MA & PA Selectivity = MA / PA solubility y
Variation of the Selectivity with Pressure at Different Temperatures • High selectivity of 9 in high pressures • High acidity of maleic acid led to a stronger interaction with TOA
Conclusions • MA & PA was extracted using scCO2-TOA • Max. extracted acids at 55 oC and 350 bar were 3.2 and 0.5 g/L for MA and PA, respectively. • At 300 bar and 45 oC, 41 times increase in solubility of MA in scCO2-TOA compared to neat scCO2 was observed. For PA this was 7 times . • At 300 bar and 45 oC, the selectivity for MA/PA was 9.
Acknowledgment Isfahan University of Technology • Colleagues: • Mohammad Yalpani • Yukata Ikushima • Lourdes Calvo • MSc Students: • Mohammad Nikravesh • Ahmad Rahmanian • Farkhonde Daneshvar • Masoumeh Amirabadi • Somayeh Kouchaki • PhD Students: • Ali Daneshfar • Marzieh Rezayat • Mohammad Kaboudvand • Ali Sheibani • Habib Eskandari • G. Bagherian
مالئيک اسيد صورت بلورهاي سفيد يا به صورت پودر سفيد رنگ، با بوي تحريک کننده سيستم تنفسي هستند و از خانواده اسيدهاي ديکربوکسيليک آليفاتيک غير اشباع ميباشد مالئيک اسيد در آب کاملاً حل ميشود (حدودg 79در g100آب) در اتانول، استون، متانول، پروپانول، اسيد استيک يخسان، نسبتاً حل مي شود کمي در دياتيل اتر و در کلروفرم حل ميشود در بنزن و تتراکلريدکربن غير قابل حل مي باشد مواد شيميايي کشاورزي رزينها در چسبها و بتونهها پوشش سطوح رنگرزي و پرداختپشم نرم کننده
فتاليک اسيد از خانواده ديکربوکسيليک اسيدهاي آروماتيک ميباشد که به صورت بلورهاي سفيد يا به صورت پودر سفيد رنگ ميباشد فتاليک اسيد در آب کمي حل ميشود (حدودmg700 درg100آب) در اتانول ، متانول و کمي در دياتيل اتر حل ميشود کلروفرم حل نميشود. در سنتز عطرهاي سنتزي فنل فتالئين رنگها، داروها فتالايميد آنترانيليک اسيد
The structure of amine-dicarboxylic acid complex (1 ، 1) ,(1 ، 2) Triethylamine-Acetic acid complex (1,3) Tridecyl amine-acetic acid
در سال 1990 تامادا و کينگ مطالعات اسپکتروسکوپي مفصلي بر روي کمپلکس آمين-اسيد دسته اي از ديکربوکسيليک اسيدها از جمله فوماريک، مالئيک و سوکسينيک اسيد انجام دادند
استفاده از اصلاحگرهاي واکنشي براي بهبود استخراج در سيال فوق بحراني مشکل اساسي دي اکسيد کربن فوق بحراني، محدوديت حلاليت مواد قطبي در آن، حتي در دانسيته هاي بالاي دي اکسيد کربن فوق بحراني ميباشد 1- با ا فزودن اصلاحگر به دي اکسيد کربن فوق بحراني، قطبيت سيال افزايش مي يابد و با افزايش قطبيت سيال، برهمکنشهاي ويژه بين سيال و حل شونده نيز افزايش مييابد. 2- افزودن اصلاحگر به سيال فوق بحراني، دانسيته سيال را افزايش ميدهد. 3- افزايش اصلاحگر باعث غير فعال شدن مکانهاي فعال روي توده ماده ميشود. کمک حلالهايغير قطبي براي اولين بار به عنوان اصلاحگر استفاده شدند اثري بر روي گزينش پذيري نميگذارد استفاده از کمک حلالهاي قطبي نتايج بهتري در بر داشت و حلاليت حل شونده ها را به ميزان بيشتري افزايش ميدادگزينش پذيري نيز در آنها بهتر ميباشد
هيل و همکارانش در سال 1994 از استخراج با سيال فوق بحراني در حضور اصلاحگر متانول و اصلاحگر واکنش دهندهN وO- بيس تري متيل سيليل تري فلئورواستاميد (BSTFA)براي استخراج آروماتيکهاي چند حلقه اي، فنولهاي هالوژن دار، ترکيبات آروماتيک هالوژن دار و دي اکسين از خاکستر زبالههاي سوخته شده شهري در کورههاي مخصوص زباله سوزي، استفاده کردند در اين پروژه از تري اکتيل آمين به عنوان کمک حلال واکنشي در فاز فوق بحراني استفاده شد