Recovery of Formic Acid by Reactive Extraction Using an Environmentally-Friendly Solvent

Abstract

Today many carboxylic acids are recovered from biological production media and industrial wastewaters. Reactive extraction is favored over other separation methods due to its high recovery efficiency, ease of operation, low energy demand and reduced cost. However, use of toxic organic diluents in the organic phases is the main disadvantage of the method. In this study, the appropriateness of an environmentally-friendly solvent, sunflower oil (SFO) to be used as organic phase diluent during the recovery of formic acid (FA) from aqueous solutions by reactive extraction was evaluated. Alamine-336 was used as the extractant and the results obtained with SFO were compared with those obtained using octanol. The separation process reached an equilibrium in 3 hours and the recovery efficiency increased with the increase in extractant percentages. The initial FA concentration positively influenced the recovery when SFO was used as the diluent. In the ranges of the parameters studied, the highest recovery values were 98.6% and 82.6% with octanol and SFO, respectively. This study shows that low molecular weight carboxylic acids, e.g. FA can be recovered from aqueous solutions by reactive extraction using environmentally-friendly solvents such as SFO. Key Words: Formic acid, Reactive extraction, Sunflower oil, Alamine-336, EquilibriumFormik Asidin Çevre Dostu Bir Çözücü Kullanılarak Tepkimeli Özütleme Yöntemi ile Geri Kazanımı ÖZ: Günümüzde pek çok karboksilik asit biyolojik üretim ortamlarından ve endüstriyel atık sulardan geri kazanılmaktadır. Tepkimeli özütleme, yüksek geri kazanım verimi, işlem basitliği, düşük enerji gereksinimi ve maliyeti nedeniyle diğer ayırma yöntemlerine tercih edilmiştir. Fakat organik fazlarda zehirli organik seyrelticilerin kullanımı yöntemin en önemli dezavantajıdır. Bu çalışmada çevre dostu bir çözücünün, ayçiçek yağının formik asidin sulu çözeltilerinden tepkimeli özütleme yöntemi ile geri kazanımı sırasında organik faz seyrelticisi olarak zehirli organik kimyasallar yerine kullanımı değerlendirilmiştir. Özütleyici olarak Alamine-336 kullanılmış ve ayçiçek yağı ile elde edilen sonuçlar oktanol ile elde edilen sonuçlarla karşılaştırılmıştır. Ayırma süreci 3 saatte dengeye ulaşmış ve geri kazanım verimi özütleyici yüzdesi ile birlikte artmıştır. Ayçiçek yağı seyreltici olarak kullanıldığında başlangıç asit derişimi geri kazanımı pozitif yönde etkilemiştir. Çalışılan değişken aralıklarında oktanol ve ayçiçek yağı ile en yüksek geri kazanım verimleri sırasıyla %98,6 ve %82,6'dır. Bu çalışma formik asit gibi düşük molekül ağırlıklı karboksilik asitlerin tepkimeli özütleme ile ayçiçek yağı gibi çevre dostu çözücüler kullanılarak sulu çözeltilerden geri kazanılabileceğini göstermiştir.

Recovery of Fumaric acid from Aqueous Solution Using Laboratory Prepared Nontoxic Diluent

“…Recovery of fumaric acid with the help of modified oils (made from sunflower, rice bran, & Sesame oil) was carried out in the manner as described in the section: experimental setup used and procedure.The modified oils failed to extract fumaric acid from aqueous solution.Marti [13] also reported that sunflower oil could not extract formic acid so above observation is consistent with the results cited in the literature. The TOA was used as extractant to facilitate the process of extraction of fumaric acid from aqueous solution.…”

“…The values of Z decrease with the increase in % TOA and are higher for higher acid concentration. Marti [13] and H Uslu [6] also obtained similar values of Z while using natural diluents.…”

Evaluation of Distribution of Succinic Acid between Binary Phase System with Biodiesel + N,N-Dioctyloctan-1-amine

“…ese results are in agreement with the finding of Marti [34] for formic acid. Also, Marti [34] compared the results of extraction of formic acid using alamine 336 in sunflower oil with alamine octanol system.…”

“…Also, Marti [34] compared the results of extraction of formic acid using alamine 336 in sunflower oil with alamine octanol system. e values of loading ratio (Z) decrease with the increase in alamine concentration, and at higher initial concentration, often the values of Z are greater than 0.5, indicating the formation of alamine-acid aggregates [34].…”

“…Reactive extraction can be made industrially viable with traditional extractants such as amines and phosphorous compounds only when they are blended with cheap and nontoxic vegetable oils. Many researchers have recently explored this new possibility [26][27][28][29][30][31][32][33][34][35]. Recently, biodiesel as extracting solvents was successfully employed to remove aromatic compounds from wastewater and as biodiesels of vegetable oils have very high flash points so acids can be separated with distillation [36].…”