Comparison of bioethanol preparation from triticale straw using the ionic liquid and sulfate methods

Abstract

Triticale straw constitutes a potential raw material for biofuel production found in Poland in considerable quantities. Thus far, production of bioethanol has been based on food raw materials such as cereal seeds, sugar beets or potatoes, and the biofuel production methods developed for these lignocellulose raw materials can threaten the environment and are inefficient. Therefore, this study aimed to compare of methods for pretreatment of triticale straw using 1-ethyl-3-methylimidazolium acetate and the sulfate method in the aspect of ethanol production intended for fuel. Based on the conducted experiments it has been determined that the use of 1-ethyl-3-methylimidazolium acetate for the pretreatment of triticale straw resulted in an increase of reducing sugars after enzymatic hydrolysis and ethyl alcohol after alcoholic fermentation. Furthermore, the study compared the efficiency of enzymatic hydrolysis of triticale straw without pretreatment, after processing with ionic liquid, recycled ionic liquid and using sulfate method, allowing a comparison of these methods. The more favorable method of lignocellulose material purification was the use of ionic liquid, due to the lower amount of toxic byproducts formed during the process, and the efficiency test results of bioethanol production using pretreatment with ionic liquid and sulfate method were similar. Ionic liquid recycling after pretreatment of rye straw using lyophilization allowed us to reuse this solvent to purify rye straw, yet the efficiency of this method remained at a low level. As a result of the conducted study it was determined that the use of ionic liquid-1-ethyl-3-methylimidazolium acetate enhanced the yield of bioethanol from triticale straw from 1.60 g/dm3 after processing without pre-treatment to 10.64 g/dm3 after pre-treatment.