Influence of the crystalline structure of cellulose on the production of ethanol from lignocellulose biomass

Abstract

A b s t r a c t. In recent years, much attention has been devoted to the possibility of using lignocellulosic biomass for energy. Bioethanol is a promising substitute for conventional fossil fuels and can be produced from straw and wood biomass. Therefore, the aim of this paper was to investigate the effect of 1-ethyl-3-methylimidazolium pretreatment on the structure of cellulose and the acquisition of reducing sugars and bioethanol from cellulosic materials. Material used in the study was rye straw and microcrystalline cellulose subjected to ionic liquid 1-ethyl-3-methylimidazolium pretreatment. The morphology of cellulose fibres in rye straw and microcrystalline cellulose was imaged prior to and after ionic liquid pretreatment. Solutions of ionic liquid-treated and untreated cellulosic materials were subjected to enzymatic hydrolysis in order to obtain reducing sugars, which constituted a substrate for alcoholic fermentation. An influence of the ionic liquid on the cellulose structure, accumulation of reducing sugars in the process of hydrolysis of this material, and an increase in ethanol amount after fermentation was observed. The ionic liquid did not affect cellulolytic enzymes negatively and did not inhibit yeast activity. The amount of reducing sugars and ethyl alcohol was higher in samples purified with 1-ethyl-3-methylimidazolium acetate. A change in the supramolecular structure of cellulose induced by the ionic liquid was also observed.

Chemical changes within solids during liquid hot water pretreatment of wood

“…This results in the formation of various ordered crystalline arrangements. The ratio between the crystalline and the amorphous fractions has a significant impact on the physicochemical properties of the fibre (Smuga-Kogut et al 2016), and on the accessibility of cellulose to reactions (Chen 2014).…”

“…The samples were hydrolysed in a two-stage process for quantitative analyses of saccharides (Sluiter et al 2011). The analyses of saccharides were carried out by highperformance liquid chromatography (Agilent 1200, Santa Clara, CA, USA), equipped with a refractive index detector and an Aminex HPX-87P column (Bio-Rad Laboratories, Hercules, CA, USA), at a temperature of 80 °C.…”

Use of Buckwheat Straw to Produce Ethyl Alcohol Using Ionic Liquids

“…The objective of pretreatment with ionic liquids is to disrupt the bonds between the cellulose, hemicellulose, and lignin fibers, and to increase the content of so-called free cellulose, which can be hydrolyzed with the help of enzymes. Certain ionic liquids may cause the removal of lignin, which often constitutes a barrier for enzymes and yeast in the production of ethanol [9]. Therefore, in this study, we examined the applicability of four ionic liquids to process buckwheat straw and demonstrated the effect of ionic liquids on the transformation of the content of cellulose, hemicellulose, and lignin.…”

“…Thus, future studies with respect to the use of ionic liquids with lignocellulosic raw materials should place special emphasis on the search for solvents that will mainly result in the depolymerization of cellulose, and that will not, as demonstrated by the currently available literature, lead to the delignification of the material [9,21,22]. Removal of lignin in the process of bioethanol production from biomass may be significant primarily from the economic standpoint, as lignin itself is a valuable waste that is utilized in numerous industrial applications such as the energy, textile, paper, and other industries [23,24].…”

A comparative study of the structures, crystallinities, Miller indices, crystal parameters, and particle sizes of microwave- and saline water-treated cassava starch

“…Methodologies involving microwave reactors and ionic liquids are sometimes called green technologies in biomass pre-treatment (Piasecka et al 2014;Smuga-Kogut et al 2016). Microwaves have been used in many applications, because they allow faster heating and faster chemical reactions as compared with the conventional methods (Zhu et al 2006;Nomanbhay et al 2013).…”