Conversion Of Bagasse Research Articles

Lignification in Sugarcane: Biochemical Characterization, Gene Discovery, and Expression Analysis in Two Genotypes Contrasting for Lignin Content

Sugarcane (Saccharum spp.) is currently one of the most efficient crops in the production of first-generation biofuels. However, the bagasse represents an additional abundant lignocellulosic resource that has the potential to increase the ethanol production per plant. To achieve a more efficient conversion of bagasse into ethanol, a better understanding of the main factors affecting biomass recalcitrance is needed. Because several studies have shown a negative effect of lignin on saccharification yield, the characterization of lignin biosynthesis, structure, and deposition in sugarcane is an important goal. Here, we present, to our knowledge, the first systematic study of lignin deposition during sugarcane stem development, using histological, biochemical, and transcriptional data derived from two sugarcane genotypes with contrasting lignin contents. Lignin amount and composition were determined in rind (outer) and pith (inner) tissues throughout stem development. In addition, the phenolic metabolome was analyzed by ultra-high-performance liquid chromatography-mass spectrometry, which allowed the identification of 35 compounds related to the phenylpropanoid pathway and monolignol biosynthesis. Furthermore, the Sugarcane EST Database was extensively surveyed to identify lignin biosynthetic gene homologs, and the expression of all identified genes during stem development was determined by quantitative reverse transcription-polymerase chain reaction. Our data provide, to our knowledge, the first in-depth characterization of lignin biosynthesis in sugarcane and form the baseline for the rational metabolic engineering of sugarcane feedstock for bioenergy purposes.

Selective production of chemicals from biomass pyrolysis over metal chlorides supported on zeolite

Direct biomass conversion into chemicals remains a great challenge because of the complexity of the compounds; hence, this process has attracted less attention than conversion into fuel. In this study, we propose a simple one-step method for converting bagasse into furfural (FF) and acetic acid (AC). In this method, bagasse pyrolysis over ZnCl2/HZSM-5 achieved a high FF and AC yield (58.10%) and a 1.01 FF/AC ratio, but a very low yield of medium-boiling point components. However, bagasse pyrolysis using HZSM-5 alone or ZnCl2 alone still remained large amounts of medium-boiling point components or high-boiling point components. The synergistic effect of HZSM-5 and ZnCl2, which combines pyrolysis, zeolite cracking, and Lewis acid-selective catalysis results in highly efficient bagasse conversion into FF and AC. Therefore, our study provides a novel, simple method for directly converting biomass into high-yield useful chemical.

Sensitivity analysis applied to independent parallel reaction model for pyrolysis of bagasse

The independent parallel reaction model (IPR model) is applied in this work to study the slow dynamic pyrolysis of sugarcane bagasse, based on a thermogravimetric analysis of three ranges of particle diameters. The kinetic parameters and mass fraction of each principal pseudo-component of biomass (hemicellulose, cellulose and lignin) are estimated using the Differential Evolution Algorithm. A comparison of the estimated mass fractions and Arrhenius parameters against experimental values reported in the literature shows good agreement. The influence of various kinetic parameters of the model is also analyzed by means of sensitivity studies using derivative methods based on the DASPK 3.0 code. The results of the relative parametric sensitivity indicate that activation energies affect bagasse conversion more strongly than other parameters, followed by the pre-exponential factors of Arrhenius equation and mass fractions. The sensitivity of the IPR kinetic model to the orders of reaction is very slight.

Effect of Reaction Temperature and Type of Catalyst on Hydrogen Production in Supercritical Water Gasification of Biomass

The aim of this study was to investigate the feasibility of hydrogen production from sugarcane bagasse by supercritical water gasification (SCWG) at low temperature and in presence of alkali catalyst. Experiments were carried out in a batch autoclave reactor at 400 °C and 9% solid content. Effect of reaction time and alkali catalyst on gas yield, gas composition, carbon gasification efficiency (CGE) and hydrogen gasification efficiency (HGE) were investigated. Influence of reaction time on gas yield and composition as well as on CGE was found to be insignificant. Extending the reaction time even up to 4 h could not cause an attractive conversion of bagasse. In the presence of catalysts (K CO , KHCO , NaHCO and NaOH), sugarcane

SO3H-functionalized ionic liquid: Efficient catalyst for bagasse liquefaction

Liquefaction is a process for the production of biofuel or value-added biochemicals from non-food biomass. SO3H-, COOH-functionalized and HSO4-paired imidazolium ionic liquids were shown to be efficient catalysts for bagasse liquefaction in hot compressed water. Using SO3H-functionalized ionic liquid, 96.1% of bagasse was liquefied and 50.6% was selectively converted to low-boiling biochemicals at 543K. The degree of liquefaction and selectivity for low-boiling products increased and the average molecular weight of the tetrahydrofuran soluble products decreased with increasing acidic strength of ionic liquids. Analysis of products and comparative characterization of raw materials and residues suggested that both catalytic liquefaction and hydrolysis processes contribute to the high conversion of bagasse. A possible liquefaction mechanism based on the generation of 3-cyclohexyl-1-propanol, one of the main products, is proposed.

Alkali‐based AFEX pretreatment for the conversion of sugarcane bagasse and cane leaf residues to ethanol

Sugarcane is one of the major agricultural crops cultivated in tropical climate regions of the world. Each tonne of raw cane production is associated with the generation of 130 kg dry weight of bagasse after juice extraction and 250 kg dry weight of cane leaf residue postharvest. The annual world production of sugarcane is approximately 1.6 billion tones, generating 279 MMT tones of biomass residues (bagasse and cane leaf matter) that would be available for cellulosic ethanol production. Here, we investigated the production of cellulosic ethanol from sugar cane bagasse and sugar cane leaf residue using an alkaline pretreatment: ammonia fiber expansion (AFEX). The AFEX pretreatment improved the accessibility of cellulose and hemicelluloses to enzymes during hydrolysis by breaking down the ester linkages and other lignin carbohydrate complex (LCC) bonds and the sugar produced by this process is found to be highly fermentable. The maximum glucan conversion of AFEX pretreated bagasse and cane leaf residue by cellulases was approximately 85%. Supplementation with hemicellulases during enzymatic hydrolysis improved the xylan conversion up to 95-98%. Xylanase supplementation also contributed to a marginal improvement in the glucan conversion. AFEX-treated cane leaf residue was found to have a greater enzymatic digestibility compared to AFEX-treated bagasse. Co-fermentation of glucose and xylose, produced from high solid loading (6% glucan) hydrolysis of AFEX-treated bagasse and cane leaf residue, using the recombinant Saccharomyces cerevisiae (424A LNH-ST) produced 34-36 g/L of ethanol with 92% theoretical yield. These results demonstrate that AFEX pretreatment is a viable process for conversion of bagasse and cane leaf residue into cellulosic ethanol.

Optimization of sugarcane bagasse conversion by hydrothermal treatment for the recovery of xylose

This work aims at the valorization of sugarcane bagasse by extracting xylose which is destined to the production of xylitol after purification and hydrogenation. Our approach consists in applying the principle of biorefinery to sugarcane bagasse because of its hemicellulose composition (particularly rich in xylan: (92%)). Optimizing of the thermal treatment was investigated. A treatment at 170 °C for 2 h was found optimal, with higher solubilzation of hemicellulose than that at 150 °C and lower degradation of sugar monomers than 190 °C. Recovery of xylose was high and the purity of xylose solution (78%) allows expecting an easy purification and separation of xylose before hydrogenation. Analysis of thermal hydrolyzates shows the presence of xylan oligomers and polymers with large distribution of DPs. This fraction should be submitted to enzymatic treatment to recover more xylose monomer.

Thermoplasticization of bagasse. II. dimensional stability and mechanical properties of esterified bagasse composite

This research was to investigate the conversion of bagasse into a thermomoldable material through esterification of the fiber matrix. For this purpose, bagasse fiber was esterified in the absence of solvent using succinic anhydride. The dimensional stability and mechanical properties of composites prepared from the esterified fibers were studied. Dimensional stability was found to be dependent on the total ester and monoester/diester content of esterified fibers and increased with increasing total ester and monoester content of the fibers. The mechanical properties (bending strength, tensile strength, and hardness) were enhanced with increasing monoester contents. Scanning electron microscopy was used to prove the occurrence of thermoplasticization of the esterified fibers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 575–586, 2000

Thermoplasticization of bagasse. II. dimensional stability and mechanical properties of esterified bagasse composite

This research was to investigate the conversion of bagasse into a thermo- moldable material through esterification of the fiber matrix. For this purpose, bagasse fiber was esterified in the absence of solvent using succinic anhydride. The dimensional stability and mechanical properties of composites prepared from the esterified fibers were studied. Dimensional stability was found to be dependent on the total ester and monoester/diester content of esterified fibers and increased with increasing total ester and monoester content of the fibers. The mechanical properties (bending strength, tensile strength, and hardness) were enhanced with increasing monoester contents. Scanning electron microscopy was used to prove the occurrence of thermoplasticization of the esterified fibers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 575-586, 2000

Thermoplasticization of bagasse. I. preparation and characterization of esterified bagasse fibers

This research was to investigate the conversion of bagasse into a thermo- formable material through esterification of the fiber matrix. For this purpose, bagasse was esterified in the absence of solvent using succinic anhydride (SA). The reaction parameters of temperature reaction, time, and amount of succinic anhydride added were studied. Ester content, Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical thermal analysis (DMTA) were used to characterize the chemical and thermal proper- ties of the esterified fibers. The results showed that on reacting bagasse with SA in the absence of solvent, ester content up to about 48% could be obtained. Diester formation increased with increasing reaction time and temperature at high levels of ester content. Ester content determination of the esterified fibers and their corresponding holocellu- loses showed that the reaction took place in the lignin and holocellulose components of bagasse. The IR results showed that the crystallinity index of different esterified bagasse samples did not decrease as a result of increasing the ester content. DSC and TGA results showed that esterified-bagasse fibers were less thermally stable than the untreated fibers, DMTA results showed that esterification of the fibers resulted in a decrease in the tan δ peak temperature of the esterified fibers compared to the un- treated fiber. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 561-574, 2000

Application of rumen microorganisms for enhanced anaerobic degradation of bagasse and maize bran

Batch and continuous culture experiments with rumen microorganisms were carried out in order to study the anaerobic conversion of maize bran and bagasse. Within a pH range similar to that of the rumen at 39°C and a substrate concentration of 20 g total solids per litre in batch cultures, maximum degradations of 49 and 52% of the total fibre fractions of maize bran and bagasse, respectively, were obtained after incubating for 168 h. Total production of volatile fatty acids (VFA) and methane per gramme volatile solids (VS) digested in 7 days were 11.85 mmol and 0.077 1 for bagasse and 10.38 mmol and 0.064 1 for maize bran, respectively. At loading rates between 20 and 35 g total solids per litre per day, and solid and hydraulic retention times of 60 and 19 h, respectively, total fibre degradation was in the range 54–69% with around 30% apparent loss of lignin. Average productions of VFA and biogas per gramme VS digested per day varied between 6.45 and 7.75 mmol and 0.06 and 0.191, respectively. The continuous culture system appeared to perform better than batch cultures in converting agro-industrial residues to VFA which are substrates of methanogenic bacteria. It is suggested that the artificial rumen reactor be used in combination with a high-rate methanogenic reactor as means of efficient anaerobic conversion of bagasse and maize bran to methane.