Quraishi Khurrum Shehzad, Bustam Mohamad Azmi, Krishnan Sooridarsan, Aminuddin Noor Fathanah, Azeezah Noraisyah, Ghani Noraini Abd, Uemura Yoshimitsu, Lévêque Jean Marc
Department of Chemical Engineering, Universiti Teknologi PETRONAS, 32610, Bandar Seri Iskandar, Tronoh, Perak, Malaysia; Centre of Research on Ionic Liquid, Universiti Teknologi PETRONAS, 32610, Bandar Seri Iskandar, Tronoh, Perak, Malaysia.
Department of Chemical Engineering, Universiti Teknologi PETRONAS, 32610, Bandar Seri Iskandar, Tronoh, Perak, Malaysia; Research Centre for CO2 Capture (RCCO2C), Universiti Teknologi PETRONAS, 32610, Bandar Seri Iskandar, Tronoh, Perak, Malaysia.
Chemosphere. 2017 Oct;184:642-651. doi: 10.1016/j.chemosphere.2017.06.037. Epub 2017 Jun 12.
A promising method of Carbon dioxide (CO) valorization is to use green microalgae photosynthesis to process biofuel. Two Phase Partitioning Bioreactors (TPPBR) offer the possibility to use non-aqueous phase liquids (NAPL) to enhance CO solubility; thus making CO available to maximize algae growth. This requires relatively less toxic hydrophobic Ionic Liquids (ILs) that comprise a new class of ionic compounds with remarkable physicochemical properties and thus qualifies them as NAPL candidates. This paper concerns the synthesis of ILs with octyl and butyl chains as well as different cations containing aromatic (imidazolium, pyridinium) and non-aromatic (piperidinum, pyrrolidinium) rings for CO absorption studies. The authors measured their respective toxicity levels on microalgae species, specifically, Scenedesmus quadricauda, Chlorella vulgaris and Botryococcus braunii. Results revealed that octyl-based ILs were more toxic than butyl-based analogues. Such was the case for bmim-PF6 at double saturation with an absorbance of 0.11, compared to Omim-PF6 at 0.17, bmim-NTf2 at 0.02, and Omim-NTf2 at 0.14, respectively. CO uptake results for ILs bearing octyl-based chains compared to the butyl analog were 54% (nCO/nIL) (i.e., moles of CO moles of IL) and 38% (nCO/nIL), respectively. Conclusively, 1-butyl-1-methylpiperidinium absorbed 13% (nCO/nIL) and appeared the least toxic, having an absorbance of 0.25 at 688 nm (double saturation at 7 d) compared to 1-butyl-3-methylimidazolium, which showed the highest toxicity with zero absorbance. Accordingly, these findings suggest that 1-butyl-1-methylpiperidinium is capable of transporting CO to a system containing green microalgae without causing significant harm; thus allowing its use in TPPBR technology.
一种很有前景的二氧化碳（CO）资源化利用方法是利用绿色微藻光合作用来生产生物燃料。双相分配生物反应器（TPPBR）提供了使用非水相液体（NAPL）来提高CO溶解度的可能性；从而使CO能够用于最大化藻类生长。这需要毒性相对较小的疏水性离子液体（ILs），这类新型离子化合物具有显著的物理化学性质，因此使其有资格成为NAPL候选物。本文涉及合成具有辛基和丁基链以及含有芳香环（咪唑鎓、吡啶鎓）和非芳香环（哌啶鎓、吡咯烷鎓）的不同阳离子的离子液体，用于CO吸收研究。作者测量了它们对微藻物种的各自毒性水平，具体来说，是对四尾栅藻（Scenedesmus quadricauda）、普通小球藻（Chlorella vulgaris）和布朗葡萄藻（Botryococcus braunii）的毒性。结果表明，基于辛基的离子液体比基于丁基的类似物毒性更大。双饱和时，1-丁基-3-甲基咪唑鎓六氟磷酸盐（bmim-PF6）的吸光度为0.11，而1-辛基-3-甲基咪唑鎓六氟磷酸盐（Omim-PF6）为0.17，1-丁基-双（三氟甲基磺酰）亚胺（bmim-NTf2）为0.02，1-辛基-双（三氟甲基磺酰）亚胺（Omim-NTf2）为0.14，情况就是如此。与基于丁基的类似物相比，带有辛基链的离子液体的CO吸收结果分别为54%（nCO/nIL）（即CO的摩尔数/离子液体的摩尔数）和38%（nCO/nIL）。最后，1-丁基-1-甲基哌啶鎓吸收了13%（nCO/nIL），并且毒性似乎最小，在688nm处的吸光度为0.25（7天时双饱和），而1-丁基-3-甲基咪唑鎓的毒性最高，吸光度为零。因此，这些发现表明1-丁基-1-甲基哌啶鎓能够将CO输送到含有绿色微藻的系统中而不会造成重大危害；从而使其能够用于TPPBR技术。
