Combined ensiling and hydrothermal processing as efficient pretreatment of sugarcane bagasse for 2G bioethanol production

Abstract

BackgroundEnsiling cannot be utilized as a stand-alone pretreatment for sugar-based biorefinery processes but, in combination with hydrothermal processing, it can enhance pretreatment while ensuring a stable long-term storage option for abundant but moist biomass. The effectiveness of combining ensiling with hydrothermal pretreatment depends on biomass nature, pretreatment, and silage conditions.ResultsIn the present study, the efficiency of the combined pretreatment was assessed by enzymatic hydrolysis and ethanol fermentation, and it was demonstrated that ensiling of sugarcane bagasse produces organic acids that can partly degrade biomass structure when in combination with hydrothermal treatment, with the consequent improvement of the enzymatic hydrolysis of cellulose and of the overall 2G bioethanol process efficiency. The optimal pretreatment conditions found in this study were those using ensiling and/or hydrothermal pretreatment at 190 °C for 10 min as this yielded the highest overall glucose recovery yield and ethanol yield from the raw material (0.28–0.30 g/g and 0.14 g/g, respectively).ConclusionEnsiling prior to hydrothermal pretreatment offers a controlled solution for wet storage and long-term preservation for sugarcane bagasse, thus avoiding the need for drying. This preservation method combined with long-term storage practice can be an attractive option for integrated 1G/2G bioethanol plants, as it does not require large capital investments or energy inputs and leads to comparable or higher overall sugar recovery and ethanol yields.

What Has Been the Focus of Sugarcane Research? A Bibliometric Overview

“…One of the main applications of bagasse is the bioconversion process that makes it an adequate fermentation media for microorganism production [43]. Another important research area regarding sugarcane bagasse is related to its use as a solid fuel for energy generation and as raw material for production of liquid fuels and chemicals [44]; therefore, a significant amount of research has been done in order to evaluate different pretreatments to improve its energy production capacity [45], e.g., enzyme addition and solids loading [46]. A third venue of research includes other uses of sugarcane bagasse for other industries, e.g., the textile [47], plastic [48], construction [49,50], pharmaceutical [51], and chemical industries [52], among others.…”

Review on Bioenergy Storage Systems for Preserving and Improving Feedstock Value

“…Limited data on deacetylation pretreatment is available for corn stover, but alkali groups in hemicellulose hydrolyzed during storage should positively impact deacetylation. Additionally, organic acids produced during anaerobic storage may serve as catalyzing agents during pretreatment including during steam explosion (Liu et al, 2013) or hot water extraction (Ambye-Jensen et al, 2018;Essien and Richard, 2018). However, ammonia fiber expansion pretreatment is primarily performed prior to long term storage because it results in a shelf-stable format.…”

Pretreatment of sugarcane bagasse by OX‐B to enhancing the enzymatic hydrolysis for ethanol fermentation

“…The annual sugarcane production was around 1907 million tonnes worldwide in 2018 (FAO, 2020). Brazil, China, India, and Thailand are the main sugarcane producers, all together representing 70% of the total worldwide sugarcane production (Ambye‐Jensen, Balzarotti, Thomsen, Fonseca, & Kádár, 2018). One tonne of harvested sugarcane generates approximately 275 kg of bagasse with 50% moisture content (Ambye‐Jensen et al, 2018).…”

“…Brazil, China, India, and Thailand are the main sugarcane producers, all together representing 70% of the total worldwide sugarcane production (Ambye‐Jensen, Balzarotti, Thomsen, Fonseca, & Kádár, 2018). One tonne of harvested sugarcane generates approximately 275 kg of bagasse with 50% moisture content (Ambye‐Jensen et al, 2018). Sugarcane bagasse represents an enormous amount of waste material which can be used for second‐generation (2G) bioethanol production (Ambye‐Jensen et al, 2018).…”

“…One tonne of harvested sugarcane generates approximately 275 kg of bagasse with 50% moisture content (Ambye‐Jensen et al, 2018). Sugarcane bagasse represents an enormous amount of waste material which can be used for second‐generation (2G) bioethanol production (Ambye‐Jensen et al, 2018).…”