تيمار باگاس با استفاده از حلال هاي يوتكتيك اسيد اگزاليك-كولين كلرايد و اسيد لاكتيك-كولين كلرايد

Chemical treatment of Bagasse by oxalic acid-choline chloride and lactic acid-choline chloride deep eutectic solvents

ﮐﺮﺑﻮﻫﯿﺪراتﻫﺎي ﺑﺎﮔﺎس ﮐﻪ ﻋﻤﺪﺗﺎً ﺷﺎﻣﻞ ﺳﻠﻮﻟﺰ و ﻫﻤﯽﺳﻠﻮﻟﺰﻫﺎ ﻫﺴﺘﻨﺪ، ﻣﻮاد اوﻟﯿﻪ ﻣﻬﻤﯽ در ﺻﻨﺎﯾﻊ ﺷﯿﻤﯿﺎﯾﯽ ﻣﯽﺑﺎﺷﻨﺪ؛ ﭼﻮن آﻧﻬﺎ در ﻣﻘﺎدﯾﺮ ﻋﻈﯿﻢ از زﯾﺴﺖﺗﻮده ﻗﺎﺑﻞ ﺗﻬﯿﻪاﻧﺪ و اﯾﻦ ﻣﻮﺿﻮع ﮐﺎرﺑﺮدﺷﺎن را در ﻣﻘﯿﺎسﻫﺎي ﺑﺰرگ ﺗﺴﻬﯿﻞ ﮐﺮده اﺳﺖ. اﺳﺘﺤﺼﺎل و ﺧﺎﻟﺺﺳﺎزي ﺗﺮﮐﯿﺒﺎت ﺷﯿﻤﯿﺎﯾﯽ ﻣﻮﺟﻮد در زﯾﺴﺖﺗﻮدهﻫﺎ ﮐﺎري دﺷﻮار، ﭘﺮﻫﺰﯾﻨﻪ و ﻣﺴﺘﻠﺰم اﺳﺘﻔﺎده از روشﻫﺎي ﭘﯿﭽﯿﺪه و ﻣﻮاد و ﺣﻼلﻫﺎي ﻣﺨﺘﻠﻒ و ﻣﻀﺮ ﺑﺮاي ﻣﺤﯿﻂ زﯾﺴﺖ ﻣﯽﺑﺎﺷﺪ. ﻟﺬا ﭘﮋوﻫﺸﮕﺮان ﺑﻪدﻧﺒﺎل ﯾﺎﻓﺘﻦ ﺗﺮﮐﯿﺒﺎت و ﻓﺮاﯾﻨﺪﻫﺎﯾﯽ ﺳﺎدهﺗﺮ، ﮐﻢ ﻫﺰﯾﻨﻪ و ﮐﻢ ﺧﻄﺮﺗﺮ و اﻟﺒﺘﻪ دوﺳﺖدار ﻣﺤﯿﻂ زﯾﺴﺖ ﻣﯽﺑﺎﺷﻨﺪ. اﺧﯿﺮا اﺳﺘﻔﺎده از ﺣﻼلﻫﺎي ﯾﻮﺗﮑﺘﯿﮏ ﻋﻤﯿﻖ ﺑﻪﻋﻨﻮان ﯾﮑﯽ از اﯾﻦ روشﻫﺎ در ﻓﺮاﯾﻨﺪﭘﺬﯾﺮي زﯾﺴﺖﺗﻮدهﻫﺎ ﮔﺰارش ﺷﺪه اﺳﺖ. اﯾﻦ ﭘﮋوﻫﺶ ﺑﻪ ﺑﺮرﺳﯽ ﺗﺎﺛﯿﺮات اﺳﺘﻔﺎده از ﺣﻼلﻫﺎي ﯾﻮﺗﮑﺘﯿﮏ ﺟﺪﯾﺪ اﺳﯿﺪ اﮔﺰاﻟﯿﮏ-ﮐﻮﻟﯿﻦﮐﻠﺮاﯾﺪ و اﺳﯿﺪ ﻻﮐﺘﯿﮏ-ﮐﻮﻟﯿﻦ ﮐﻠﺮاﯾﺪ در ﺗﯿﻤﺎر ﺑﺎﮔﺎس ﻧﯿﺸﮑﺮ ﭘﺮداﺧﺘﻪ اﺳﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ اﯾﻦ ﺣﻼلﻫﺎي ﻧﻮﯾﻦ در اﻧﺤﻼل و اﺳﺘﺨﺮاج ﮐﺮﺑﻮﻫﯿﺪراتﻫﺎي ﮐﻮﺗﺎه زﻧﺠﯿﺮ و آﻣﻮرف، ﺑﺎﻻﺧﺺ ﻫﻤﯽﺳﻠﻮﻟﺰﻫﺎ ﻣﻮﺛﺮ ﺑﻮده ﺑﻪﻃﻮرﯾﮑﻪ ﺑﺎزده ﻧﻬﺎﯾﯽ ﺑﻪﺗﺮﺗﯿﺐ ﺑﻪ ﺣﺪود 50 و 59% ﮐﺎﻫﺶ ﯾﺎﻓﺘﻪ و ﺑﺨﺶ ﻋﻤﺪه اﯾﻦ اﻓﺖ ﻣﺮﺑﻮط ﺑﻪ ﻫﻤﯽﺳﻠﻮﻟﺰﻫﺎ ﺑﻮد. ﻧﺴﺒﺖ ﺳﻠﻮﻟﺰ ﻣﻮﺟﻮد در ﻫﻮﻟﻮﺳﻠﻮﻟﺰ در ﺗﻤﺎﻣﯽ ﺗﯿﻤﺎرﻫﺎ اﻓﺰاﯾﺶ ﯾﺎﻓﺘﻪ و ﺑﻪ ﺣﺪود 90% رﺳﯿﺪه اﺳﺖ. ﺣﻼل اﺳﯿﺪ ﻻﮐﺘﯿﮏ-ﮐﻮﻟﯿﻦ ﮐﻠﺮاﯾﺪ در اﻧﺤﻼل ﻟﯿﮕﻨﯿﻦ ﻣﻮﺛﺮﺗﺮ ﺑﻮده ﺑﻪﻃﻮريﮐﻪ ﻣﯿﺰان ﻟﯿﮕﻨﯿﻦ ﺑﻪ 6/2% ﮐﺎﻫﺶ ﯾﺎﻓﺖ، اﻣﺎ ﺣﻼل اﺳﯿﺪ اﮔﺰاﻟﯿﮏ-ﮐﻮﻟﯿﻦﮐﻠﺮاﯾﺪ در ﺣﺬف ﻟﯿﮕﻨﯿﻦ ﻋﻤﻠﮑﺮد ﺧﻮﺑﯽ ﻧﺪاﺷﺖ و ﺣﺪاﻗﻞ ﻣﯿﺰان ﻟﯿﮕﻨﯿﻦ در ﻣﺎده ﺗﯿﻤﺎرﺷﺪه در ﺣﺪود 11% ﺑﻮد. ﻫﻤﭽﻨﯿﻦ اﻓﺖ ﮔﺮاﻧﺮوي ﺧﻤﯿﺮﮐﺎﻏﺬ ﺳﻠﻮﻟﺰي ﺣﺎﺻﻞ از ﺗﯿﻤﺎر اﺳﯿﺪ ﻻﮐﺘﯿﮏ-ﮐﻮﻟﯿﻦ ﮐﻠﺮاﯾﺪ ﻧﺴﺒﺖ ﺑﻪ اﺳﯿﺪ اﮔﺰاﻟﯿﮏ-ﮐﻮﻟﯿﻦﮐﻠﺮاﯾﺪ ﺧﯿﻠﯽ ﮐﻤﺘﺮ ﺑﻮد، ﺑﻪﻃﻮريﮐﻪ ﮔﺮاﻧﺮوي ﺧﻤﯿﺮﮐﺎﻏﺬ ﺳﻠﻮﻟﺰي ﺣﺎﺻﻞ از اﯾﻦ دو ﺗﯿﻤﺎر ﺑﻪﺗﺮﺗﯿﺐ 11/1 و 4/3 ﺳﺎﻧﺘﯽﭘﻮاز ﺑﻮد.

Bagasse carbohydrates, which are mainly consist of cellulose and hemicelluloses, are important raw materials in chemical industries; because they can be easily prepared from biomass in large scale, their application is simplified in large scale. Derivation and purification of biomass chemicals are difficult, costly and require the use of complex methods with environmentally dangerous chemicals and solvents. Therefore, researchers are looking for simpler, cheaper, safer and environmentally friendly compounds and processes. The use of deep eutectic solvents has been reported as one of these methods in biomass processing. In this study, the use of new oxalic acid-choline chloride and lactic acid-choline chloride deep eutectic solvents for bagasse treatment was investigated. Results indicated that these new solvents were effective in the solubilization and extraction of short-chain and amorphous carbohydrates, especially hemicelluloses; as the final processing yields were respectively reduced to about 50 and 59%, and the main part of degradation belonged to the hemicelluloses. Cellulose to holocellulose ratio was increased in all treatments to about 90%. The lactic acid-choline chloride solvent was effective in lignin solvation, as the lignin content was reduced to 6.2%, while oxalic acid-choline chloride solvent did not have an ideal efficiency toward lignin removal, and the least amount of lignin in treated product was about 11%. Also, the viscosity drop of cellulosic pulp in lactic acid-choline chloride solvent-treatment was much less compared to oxalic acid-choline chloride solvent-treatment, as the cellulosic pulp viscosity for these treatments were 11.1 and 4.3 cp., respectively.