Ruminal degradation characteristics of bagasse with different fermentation treatments in the rumen of beef cattle

This experiment aimed to study the degradation characteristics of bagasse after three fermentation treatments in beef cattle. Bagasse 1 was treated with 0.3% lactic acid bacteria (w/w). Bagasse 2 was treated with 0.3% mixed strains (Saccharomyces cerevisiae, Aspergillus niger, Aspergillus oryzae, and lactic acid bacteria at 2:1:1:1). Bagasse 3 was treated with 0.1% cellulase and 0.1% xylanase in addition to 0.3% mixed strains of bagasse 2. The dry matter (DM), crude ash (ASH), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) in the bagasses were determined. Compared to the control bagasse (without the strain and enzyme treatments), three fermented bagasses showed higher DM after 4 h fermentation. The CP and ASH contents in fermented bagasse 3 were the highest, while the contents of NDF and ADF in fermented bagasse 3 were the lowest among all the groups. The effective degradability of DM, CP, NDF, and ADF was highest in fermented bagasse 3 among the evaluated bagasse feed, followed by fermented bagasse 2 > fermented bagasse 1 > bagasse. Overall, fermented bagasse 3 was better than the control and other treated bagasses, thus fermented bagasse 3 is a hopeful source for ruminant diet of beef cattle.

Poly-Lactic Acid-Bagasse Based Bio-Composite for Additive Manufacturing

Beer bagasse is a residue waste produced in great amounts; nevertheless, it is still underestimated in the industry. The aim of this paper is to develop an innovative and efficient methodology to recycle the beer bagasse by producing Poly-lactic acid(PLA)-based bio-composites, in the forms of pellets and filaments, to be used in additive manufacturing processes. To assess the suitability of beer bagasse for extrusion-based 3D printing techniques, it was, firstly, physically and chemically characterized. Then, it was added in combination with different kinds of plasticizers to PLA to make bio-composites, analyzing their thermal and physical properties. The results prove the great potential of bagasse, evidencing its printability. Both composites' pellets and filaments were used in two different 3D printing machines and the mechanical properties of the 3D-printed models were evaluated as a function of the composition and the kind of technology used. All the used plasticizers improved processability and the polymer-bagasse interface. Compared to neat PLA, no changes in thermal properties were detected, but a lowering of the mechanical properties of the 3D-printed composites compared to the neat polymers was observed. Finally, a comparison between the efficiency of the two 3D printing techniques to be used with the bio-based composites was performed.

Stabilization and Valorization of Beer Bagasse to Obtain Bioplastics

Beer bagasse is a residue produced in large quantities, though it is undervalued in the industry. Its high protein and polysaccharide content make it attractive for use in sectors such as the manufacture of bioplastics. However, its high water content makes it necessary to stabilize it before being considered as a raw material. The main objective of this work was to evaluate the stabilization of beer bagasse and the production of bioplastics from it. In this sense, different drying methods (freeze-drying and heat treatment at 45 and 105 °C) were studied. The bagasse was also characterized physicochemically to evaluate its potential. In addition, bagasse was used in combination with glycerol (plasticizer) to make bioplastics by injection molding, analyzing their mechanical properties, water absorption capacity and biodegradability. The results showed the great potential of bagasse, presenting a high content of proteins (18-20%) and polysaccharides (60-67%) after its stabilization, with freeze-drying being the most suitable method to avoid its denaturation. Bioplastics present appropriate properties for use in applications such as horticulture and agriculture.

Recovery of Mixtures of Construction Waste, PET and Sugarcane Bagasse for the Manufacture of Partition Blocks

The building industry generates millions of tons of construction and demolition waste annually (12 million tons/year are generated in Mexico, of which only 4% is reused or recycled). Concomitantly, the demand for goods and services by the building industry causes significant environmental impacts. On the other hand, plastic waste is also difficult to assimilate into the environment in the short term, and its recovery is of special interest. Therefore, this research focuses on the feasibility of the manufacture of Partition Blocks (essential building element) through the combination of construction and demolition waste (CDW), polyethylene terephthalate (PET) plastic flakes, dust from tire shredding, and residue from the sugar industry (bagasse). The results of this study show that the Partition Blocks made with CDW and PET reach an average compressive strength of 115.003 kgf/cm² (11.278 MPa) (suitable for structural use according to Mexican regulations); the use of lime enhances the consistency of the mixture of CDW and PET (increases its cohesion and homogeneity); and finally, these Partition Blocks have a cost comparable to the current conventional Partition Blocks made with virgin material, thus, conferring them validity as a feasible recycling option for these residues.

Manufacturing of Fluff Pulp Using Different Pulp Sources and Bentonite on an Industrial Scale for Absorbent Hygienic Products

In this study, for the first time, a composite fluff pulp was produced based on the combination of softwood (i.e., long-length fiber), hardwood (i.e., short-length fiber), non-wooden pulps (i.e., bagasse) and bentonite, with specific amounts to be used in hygienic pads (e.g., baby diapers and sanitary napkins). After the defibration process, the manufactured fluff pulp was placed as an absorbent mass in diapers and sanitary napkins. Therefore, tests related to the fluff pulp, such as grammage, thickness, density, ash content, humidity percentage, pH and brightness, tests related to the manufactured baby diapers, such as absorption capacity, retention rate, retention capacity, absorption time and rewet, and tests related to the sanitary napkin, such as absorption capacity and rewet, were performed according to the related standards. The results demonstrated that increasing the amount of bagasse pulp led to increasing the ash content, pH and density of fluff pulp and decreasing the brightness. The addition of bentonite as a filler also increased ash content and pH of fluff pulp. The results also demonstrated that increasing of bagasse pulp up to 30% in combination with softwood pulp led to increasing absorption capacity, retention rate, retention capacity, absorption time and rewet of baby diapers and of sanitary napkins.

Chemical and Structural Elucidation of Lignin and Cellulose Isolated Using DES from Bagasse Based on Alkaline and Hydrothermal Pretreatment

The separation of cellulose, hemicellulose, and lignin components using deep eutectic solvent, which is a green solvent, to obtain corresponding chemicals can realize the effective separation and high-value utilization of these components at low cost. In this study, we used waste biomass sugarcane bagasse as the raw material, choline chloride as the hydrogen bond acceptor, and lactic acid as the hydrogen bond donor to synthesize a deep eutectic solvent of choline chloride/lactic acid (L-DES) and treated sugarcane bagasse pretreated by alkali or hydrothermal methods to separate cellulose, hemicellulose, and lignin. In addition, we comparatively studied the effect of different pretreatment methods on lignin removal by DES and found that the lignin removal rate by L-DES after alkaline pretreatment was significantly higher than that after hydrothermal pretreatment, and the mechanism of action causing this difference is discussed.

Hemicellulose and Nano/Microfibrils Improving the Pliability and Hydrophobic Properties of Cellulose Film by Interstitial Filling and Forming Micro/Nanostructure

In this paper, nano/microfibrils were applied to enhance the mechanical and hydrophobic properties of the sugarcane bagasse fiber films. The successful preparation of nano/microfibrils was confirmed by scanning electron microscope (SEM), X-ray diffraction (XRD), fiber length analyzer (FLA), and ion chromatography (IC). The transparency, morphology, mechanical and hydrophobic properties of the cellulose films were evaluated. The results show that the nanoparticle was formed by the hemicellulose diffusing on the surface of the cellulose and agglomerating in the film-forming process at 40 °C. The elastic modulus of the cellulose film was as high as 4140.60 MPa, and the water contact angle was increased to 113°. The micro/nanostructures were formed due to hemicellulose adsorption on nano/microfilament surfaces. The hydrophobicity of the films was improved. The directional crystallization of nano/microfibrous molecules was found. Cellulose films with a high elastic modulus and high elasticity were obtained. It provides theoretical support for the preparation of high-performance cellulose film.

Nanocellulose Hybrid Lignin Complex Reinforces Cellulose to Form a Strong, Water-Stable Lignin-Cellulose Composite Usable as a Plastic Replacement

The significant challenges in the use of cellulose as a replacement for plastic are its mechanical properties' degradation and uncontrolled deformation during the rewetting process. Herein, inspired by the reinforcement of cellulose by lignin in natural plant tissue, a strong and water-stable lignin-cellulose composite (LCC) was developed. A nanocellulose hybrid lignin complex (CHLC) created from bagasse residue after enzymatic hydrolysis was added into a pulp of bleached fibre extracted from pine to produce a lignin-cellulose sheet. The lignin as a water-stable reinforcing matrix, via the hydrogen bonding of the nanocellulose in the CHLC with the fibre was efficiently introduced onto the fibres and the fibre network voids. Compared with a typical lignin-free cellulose sheet, the dry strength and wet strength of the LCC were 218% and 2233% higher, respectively. The developed LCC is an eco-friendly and biodegradable alternative to plastic.

Antimicrobial and cytotoxic activity to human colon adenocarcinoma cell lines (HT-29) potential of olive oil extraction residue

In the Olive drupe (Olea europaea L.) oil extraction process, 80% of the volume generated is waste (bagasse). Advancing the expansion of the olive oil market, it is necessary to develop alternatives that, in addition to adding value to industrial waste, also reduce possible environmental damage. Our study aimed to understand the antimicrobial and Cytotoxic activity potential of the residues from the extraction of olive oil from the blend of the varieties Arbequina and Arbosana. The extract shows cytotoxic activity, inhibiting about 75% of cancer cells in the human colon at a concentration of 0.15 mg of Gallic Acid equivalent (GAE)/mL. The effectiveness of the extract against microorganisms often associated with foodborne diseases and food decomposition has also been discovered, without compromising the microorganisms responsible for fermentation. Thus, this study provides future perspectives for the use of active ingredients extracted from the residue from the extraction of olive oil.

Thermal Stability, Smoke Density, and Flame Retardance of Ecotype Bio-Based Flame Retardant Agricultural Waste Bagasse/Epoxy Composites

In the study, agricultural waste bagasse was used as a bio-based flame retardant for reducing the flammability of epoxy. Specifically, an interpenetrating network (IPN) was formed through a ring opening reaction between the hydroxyl functional group of bagasse and the epoxy group of triglycidyl isocyanurate (TGIC), forming Bagasse@TGIC. Next, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) was mixed with Bagasse@TGIC, inducing a reaction between the active hydrogen of DOPO and the epoxy group of TGIC, ultimately forming Bagasse@TGIC@DOPO with an IPN structure. Finally, the novel flame retardant was added to epoxy to create a composite. The integral procedural decomposition temperature (IPDT) of pure epoxy is 619 °C; after the introduction of the 30 wt% flame retardant, the IPDT of the resultant composite material increased to 799 °C, greatly increasing the thermal stability by 29%. After the addition of the Bagasse@TGIC@DOPO flame retardant, the limiting oxygen index increased from 21% for the pure epoxy to 29% for the composite, and the UL-94 rating improved from failing rating for the pure epoxy and V-0 rating for the composite. The Raman spectrum indicated that the addition of Bagasse@TGIC@DOPO IPN substantially increased the biochar yield during the burning process, increasing thermal stability. These results confirmed that the epoxy/Bagasse@TGIC@DOPO composite had substantial flame retarding effects.

Productivity and carcass characteristics of lambs fed fibrous agricultural wastes to substitute grass

Background and Aim:

Grass is often scarce for ruminants during the dry season in Indonesia; thus agricultural by-products are widely used as a substitute for grass. This study aimed to determine the effect of replacing Napier grass (NG) with agricultural by-products on the productivity and carcass characteristics of lambs.

Materials and Methods:

Twenty-four 3-month-old male lambs with initial body weights of 13.26±1.29 kg (coefficient of variation=9.73%) were allocated into a completely randomized design with four treatments and six replications. The treatments included: NG=100% NG; corn cobs (CCs)=50% NG and 50% CCs; bagasse (BG)=50% NG and 50% BG; and peanut shells (PSs)=50% NG and 50% PSs. All treatment diets were pelleted and consisted of 40% fibrous feed and 60% concentrate feed, and contained 10.36-11.65% crude protein and 55.47-57.31% total digestible nutrients. Parameters observed included dry matter intake (DMI), dry matter digestibility, body weight gain (BWG), feed conversion ratio (FCR), feed cost per gain (FC/G), and carcass characteristics.

Results:

Lambs fed the PSs diet had the highest (p<0.05) DMI (781 g/d), digestibility, and body weight gain (92.5 g/d; p<0.05). The FCR of the PSs diet (9.13) was similar to NG. The FC/G of the PSs diet (IDR 23,541/kg) was the lowest of all diets. The BG diet had the lowest (p<0.05) digestibility, body weight gain (54.4 g/d), and the highest (13.53) FCR. No significant differences (p>0.05) were found in the carcass or meat characteristics of any diets. The averages of slaughter weight, carcass weight, and carcass percentage were 20.03 kg, 8.02 kg, and 40.0%, respectively. The average meat bone ratio was 3.67.

Conclusion:

It was concluded that agricultural wastes could be used as an alternative to NG at the level of 50% in the diet of lambs without a negative effect on production performance and carcass traits.

Sugarcane biomass colonized by Pleurotus ostreatus for red 4B dye removal: a sustainable alternative

Biosorption of the red 4B dye was evaluated using non-colonized sugarcane bagasse and colonized by Pleurotus ostreatus. The fungal colonization caused an increase in the acid and phenolic groups, making the biosorbent surface more positive, with lower thermal stability due to decomposition of lignocellulosic compounds, lower pHpcz, and smaller pores. The biosorbents showed better adsorption at pH 2.0 and required 260 min to reach equilibrium. The kinetic data fit the pseudo-second order mathematical model, which predicts strong chemical interaction between adsorbent and adsorbate. The mathematical models that best fit the isothermal data were the combination of Langmuir for low dye concentrations and Freundlich for high dye concentrations in the solution for the non-colonized biosorbent, which predict that adsorption occurs in monolayer and multilayer, respectively. For the colonized biosorbent, the model that best fits the isothermal data (25°C and 40°C) was the Freundlich model, showing that the adsorption for this case occurs in multilayers. Thermodynamic studies (25°C, 40°C and 50°C) show that increasing temperature decreases the biosorption capacity (exothermic process for both biosorbents), and the system shows low spontaneity with increasing concentration. Also, the entropy for non-colonized sugarcane bagasse increases at low concentrations, however after fungal colonization, it decreases for both. In industrial effluent, the non-colonized biosorbent presented a higher biosorption capacity, but fungal colonization demonstrates greater sustainability by initially allowing the production of mushrooms.

Azul Bagasse by Acid Hydrolysis

A multilevel factorial design of 23 with 12 experiments was developed for the preparation of cellulose nanocrystals (CNC) from Agave tequilana Weber var. Azul bagasse, an agro-industrial waste from tequila production. The studied parameters were acid type (H2SO4 and HCl), acid concentration (60 and 65 wt% for H2SO4, 2 and 8N for HCl) temperature (40 and 60 °C for H2SO4, 50 and 90 °C for HCl), and hydrolysis time (40, 55 and 70 min for H2SO4; and 30, 115 and 200 min for HCl). The obtained CNC were physical and chemically characterized using dynamic light scattering (DLS), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XDR) techniques. The maximum CNC yield was 90 and 96% for HCL and H2SO4, respectively, and the crystallinity values ranged from 88-91%. The size and morphology of A. tequilana CNC strongly depends on the acid type and hydrolysis time. The shortest CNC obtained with H2SO4 (65 wt%, 40 °C, and 70 min) had a length of 137 ± 68 nm, width 33 ± 7 nm, and height 9.1 nm, whereas the shortest CNC obtained with HCl (2 N, 50 °C and 30 min) had a length of 216 ± 73 nm, width 69 ± 17 nm, and height 8.9 nm. In general, the obtained CNC had an ellipsoidal shape, whereas CNC prepared from H2SO4 were shorter and thinner than those obtained with HCl. The total sulfate group content of CNC obtained with H2SO4 increased with time, temperature, and acid concentration, exhibiting an exponential behavior of CSG=aebt.

Polyhydroxyalkanoate Synthesis by Burkholderia glumae into a Sustainable Sugarcane Biorefinery Concept

Polyhydroxyalkanoate (PHA) bioplastic was synthesized by Burkholderia glumae MA13 from carbon sources and industrial byproducts related to sugarcane biorefineries: sucrose, xylose, molasses, vinasse, bagasse hydrolysate, yeast extract, yeast autolysate, and inactivated dry yeast besides different inorganic nitrogen sources. Sugarcane molasses free of pre-treatment was the best carbon source, even compared to pure sucrose, with intracellular polymer accumulation values of 41.1–46.6% cell dry weight. Whereas, xylose and bagasse hydrolysate were poor inducers of microbial growth and polymer synthesis, the addition of 25% (v/v) sugarcane vinasse to the culture media containing molasses was not deleterious and resulted in a statistically similar maximum polymer content of 44.8% and a maximum PHA yield of 0.18 g/g, at 34°C and initial pH of 6.5, which is economic and ecologically interesting to save water required for the industrial processes and especially to offer a fermentative recycling for this final byproduct from bioethanol industry, as an alternative to its inappropriate disposal in water bodies and soil contamination. Ammonium sulfate was better even than tested organic nitrogen sources to trigger the PHA synthesis with polymer content ranging from 29.7 to 44.8%. GC-MS analysis showed a biopolymer constituted mainly of poly(3-hydroxybutyrate) although low fractions of 3-hydroxyvalerate monomer were achieved, which were not higher than 1.5 mol% free of copolymer precursors. B. glumae MA13 has been demonstrated to be adapted to synthesize bioplastics from different sugarcane feedstocks and corroborates to support a biorefinery concept with value-added green chemicals for the sugarcane productive chain with additional ecologic benefits into a sustainable model.

Effects of sewage sludge and other wastes application on the growth and element uptake of Jatropha curcas in abandoned rare-earth mine soil

The wastes such as sewage sludge (SS) can be used to amend soil of abandoned rare-earth mine land (ARL). The energy plant Jatropha curcas could be used as a pioneer tree species in the ARL. In a pot experiment to address the responses of growth and element uptake of J. curcas, three treatments were established: adding SS to the soil of ARL (T₁), adding SS and bagasse to the soil of ARL (T₂), adding SS, bagasse and passivator to the soil of ARL (T₃), with the untreated soil of the ARL as the control (CK). The results showed that compared with CK, T₁ only significantly increased the plant height of J. curcas, T₂ and T₃ significantly increased the plant height, ground diameter and dry biomass of J. curcas, of which the total dry biomass increased by more than 184.7%. All the three treatments significantly increased the contents of N, P, K and Cu in J. curcas. T₁ and T₂ significantly increased the proportion of exchangeable Zn, Cd and Ni in the substrates, while T₃ showed the opposite effects. T₃ significantly decreased the migration factor (M) and mobility factor (MF) of Zn, Cd, Ni in the substrates, and significantly reduced the contents of Zn, Pb, Cd, Ni in J. curcas, with an inhibition rate of over 36.1%. The comprehensive evaluation of the membership function showed that the order of growth promotion effects on J. curcas was T₂>T₃>T₁>CK, while the order of capacity of inhibiting J. curcas to accumulate Cu, Zn, Pb, Cd, Ni was T₃>CK>T₂>T₁. The combined application of SS and bagasse significantly promoted the growth and element accumulation of J. curcas, and the addition of passivator significantly reduced heavy metals uptake without affecting the growth of J. curcas.

Effect of p-TsOH pretreatment on separation of bagasse components and preparation of nanocellulose filaments

The efficient separation of bagasse components was achieved by p-toluenesulfonic acid (p-TsOH) pretreatment. The effects of p-TsOH dosage, reaction temperature and reaction time on cellulose, hemicellulose and lignin contents were studied. Eighty-five per cent of lignin was dissolved, whereas the cellulose loss was minimal (less than 8.1%). Cellulose-rich water-insoluble residual solids were obtained. The degree of polymerization of cellulose decreased slightly, but the crystallinity index (CrI) increased from 52.0% to 68.1%. It indicated that the highly efficient delignification of bagasse was achieved by p-TsOH pretreatment. The nanocellulose filaments (CNFs) were produced by the treated samples. The physico-chemical properties of CNFs were characterized by transmission electron microscopy and thermogravimetric analysis. The results show that the CNFs have smaller average size and higher thermal stability. It provides a new method for CNFs.

Preparation and application of bagasse-based adsorbent for highly efficient removal of mercury ions

A high-performance bagasse-based adsorbent was prepared from agricultural waste bagasse by grafting of acrylamide and aminating with diethylenetriamine. Effects of catalyst dosage, acrylamide concentration, reaction temperature, and bath ratio on the grafting yield were investigated. The adsorption performances for mercury ions were evaluated by batch adsorption experiments and kinetic experiments. The results show that the adsorbent has high adsorption capacity for mercury in a wide range of pH values. The adsorption capacity could be as high as 813.0 mg/g, and the removal percentage for mercury ions can reach 99.9%. The kinetic adsorption experiments show it can achieve adsorption equilibrium rapidly, which implies that the adsorbent has a strong ability to capture mercury ions. Besides, the bagasse-based adsorbent showed promising regeneration performance, and its adsorption amount of regenerated adsorbent only slightly decreased after five recycling. PRACTITIONER POINTS: An amino-rich adsorbent was prepared from bagasse. The adsorbent possesses high adsorption capacity and high removal efficiency for mercury. The aminated bagasse adsorbs mercury rapidly. The adsorbent functionalized with amino possesses strong affinity toward mercury.

N/S-Co-Doped Porous Carbon Sheets Derived from Bagasse as High-Performance Anode Materials for Sodium-Ion Batteries

Heteroatom doping is considered to be an efficient strategy to improve the electrochemical performance of carbon-based anode materials for Na-ion batteries (SIBs), due to the introduction of an unbalanced electron atmosphere and increased electrochemical reactive sites of carbon. However, developing green and low-cost approaches to synthesize heteroatom dual-doped carbon with an appropriate porous structure, is still challenging. Here, N/S-co-doped porous carbon sheets, with a main pore size, in the range 1.8–10 nm, has been fabricated through a simple thermal treatment method, using KOH-treated waste bagasse, as a carbon source, and thiourea, as the N and S precursor. The N/S-co-doped carbon sheet electrodes possess significant defects, high specific surface area, enhanced electronic conductivity, improved sodium storage capacity, and long-term cyclability, thereby delivering a high capacity of 223 mA h g⁻¹ at 0.2 A g⁻¹ after 500 cycles and retaining 155 mA h g⁻¹ at 1 A g⁻¹ for 2000 cycles. This work provides a low-cost route to fabricate high-performance dual-doped porous carbonaceous anode materials for SIBs.

Steam-exploded sugarcane bagasse as a potential beef cattle feedstock: effects of different pretreatment conditions1

Sugarcane bagasse, a lignocellulosic biomass produced by sugar production, is rarely utilized directly due to economic concerns. However, pretreatment of this biomass could make it suitable as a feedstock for the beef cattle industry. Accordingly, this study investigated the effects of different steam explosion conditions on bagasse digestibility using in vitro fermentation techniques, scanning electron microscopy, and detailed chemical analyses. In vitro incubation of an untreated sample and samples pretreated at 6 different pressures ranging from 0.6 to 1.6 MPa at intervals of 0.2 MPa for 5 min was conducted out for 96 h. Results showed that increasing the pressure in the steam explosion pretreatment induced degradation of the hemicellulose and increased soluble sugar content, especially for arabinose (L; P < 0.01) and xylose contents (Q; P < 0.01). In vitro incubation showed that compared with untreated bagasse, gas production and degradation rate of the bagasse improved linearly (L; P < 0.01) after all treatments. The lag time disappeared with steam pressure above 1.0 MPa and the maximum gas production was obtained under pretreatment at 1.4 MPa for 5 min. Furthermore, pretreatment of bagasse by steam explosion enhanced (Q: P < 0.01) quadratically estimated energy values and OM digestibility. Thus, the current results demonstrate that sugarcane bagasse may be effectively used as a potential beef cattle feedstock after steam explosion pretreatment.

Lipases obtained from orange wastes: Commercialization potential and biochemical properties of different varieties and fractions

Brazil is the world's leading orange supplier for juice production purposes. However, the production process generates high amount of wastes, which leads to disposal problems. Orange wastes can be used for lipases production, incorporating the biorefinery concept into juice industries. Thus, the aim of the present study was to investigate the wastes of orange production chain as source of lipases based on different varieties (Pera, Hamlin, Valencia, and Natal), as well as on different fractions of wastes. The mass balance of the juice/wastes (2007-2016 crops) was evaluated, and lipases from different varieties and fraction were biochemically characterized. Overall, the wastes corresponded to approximately 43% of the fruit mass. All the fractions of all varieties showed lipase activity in emulsified olive oil and in p-nitrophenyl substrates. The highest lipase activities were obtained by Natal pulp in emulsified olive oil, Natal frit, and Hamlin peel in p-NPB and Hamlin frit in p-NPL and p-NPP. The bagasse, peel, and frit lipases from the different orange varieties showed optimum pH from 6.0 to 8.0 and optimal temperature from 30 °C to 60 °C. Thus, it is possible concluding that the orange processing for juice production purposes generates a large amount of wastes, which can be destined to profitable purposes as lipases production. Lipases produced by different fractions and varieties are biochemically diverse, enabling the application a wide range of processes. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2734, 2019.

Fabrication and Characterization of Graphene Microcrystal Prepared from Lignin Refined from Sugarcane Bagasse

Graphene microcrystal (GMC) is a type of glassy carbon fabricated from lignin, in which the microcrystals of graphene are chemically bonded by sp³ carbon atoms, forming a glass-like microcrystal structure. The lignin is refined from sugarcane bagasse using an ethanol-based organosolv technique which is used for the fabrication of GMC by two technical schemes: The pyrolysis reaction of lignin in a tubular furnace at atmospheric pressure; and the hydrothermal carbonization (HTC) of lignin at lower temperature, followed by pyrolysis at higher temperature. The existence of graphene nanofragments in GMC is proven by Raman spectra and XRD patterns; the ratio of sp² carbon atoms to sp³ carbon atoms is demonstrated by XPS spectra; and the microcrystal structure is observed in the high-resolution transmission electron microscope (HRTEM) images. Temperature and pressure have an important impact on the quality of GMC samples. With the elevation of temperature, the fraction of carbon increases, while the fraction of oxygen decreases, and the ratio of sp² to sp³ carbon atoms increases. In contrast to the pyrolysis techniques, the HTC technique needs lower temperatures because of the high vapor pressure of water. In general, with the help of biorefinery, the biomass material, lignin, is found to be qualified and sustainable material for the manufacture of GMC. Lignin acts as a renewable substitute for the traditional raw materials of glassy carbon, copolymer resins of phenol formaldehyde, and furfuryl alcohol-phenol.

Structural Changes of Bagasse dusring the Homogeneous Esterification with Maleic Anhydride in Ionic Liquid 1-Allyl-3-methylimidazolium Chloride

The maleation of bagasse could greatly increase the compatibility between bagasse and composite matrixes, and the percentage of substitution (PS) of bagasse maleates could be regulated in the homogeneous system. However, due to the complicated components and the linkages of bagasse, it was difficult to control the reaction behaviors of each component. In this paper, the detailed structural changes of bagasse during the homogeneous maleation in ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) were comparatively investigated with the three main components (cellulose, hemicelluloses, and lignin) from bagasse. The PS of the maleated bagasse was 12.52%, and the PS of the maleated cellulose, hemicelluloses, and lignin were 13.50%, 10.89%, and 14.03%, respectively. Fourier translation infrared (FT-IR) and NMR analyses confirmed that the three main components were all involved in the homogeneous maleation. ¹H-¹³C HSQC analysis indicated that the predominant monoesterification of cellulose, diesterification of hemicelluloses and lignin, and the degradation of the three main components simultaneously occurred. Besides, the quantitative analysis from ¹H-¹³C HSQC revealed the relative PS of reactive sites in each component. ³¹P NMR results showed that the reactivity of lignin aliphatic hydroxyls was higher than that of phenolic ones, and the reactivity of phenolic hydroxyls followed the order of p-hydroxyphenyl hydroxyls > guaiacyl hydroxyls > syringyl hydroxyls.

Microwave-Assisted Oxalic Acid Pretreatment for the Enhancing of Enzyme Hydrolysis in the Production of Xylose and Arabinose from Bagasse

In this study, highly-efficient hydrolysis of bagasse into xylose and arabinose sugars (C5 sugars) was developed by microwave-assisted oxalic acid pretreatment under mild reaction conditions. The effects of acid and hydrolysis conditions on the C5 sugar yields were discussed. The results showed that oxalic acid performed better than hydrochloric acid and maleic acid, and was a promising alternative to sulfuric acid for xylose production at the same acid concentration. The maximum yields of xylose (95.7%) and arabinose (91.5%) were achieved via the microwave-assisted oxalic acid pretreatment (120 °C, 10 min, 0.4 mol/L, solid–liquid ratio of 1:50 g/mL), indicating that almost all xylan-type hemicelluloses were released from the cell wall and hydrolyzed into C5 sugars. After pretreatment, more than 90% of the cellulose in the residual bagasse was converted to glucose (92.2%) by enzymatic hydrolysis. This approach could realize the highly-efficient hydrolysis of xylan from bagasse into C5 sugars, which would enhance the enzyme hydrolysis of treated bagasse into glucose.

Comparison of fermented animal feed and mushroom growth media as two value-added options for waste Cassava pulp management

Cassava is one of the main processed crops in Thailand, but this generates large amounts (7.3 million tons in 2015) of waste cassava pulp (WCP). The solid WCP is sold directly to farmers or pulp-drying companies at a low cost to reduce the burden of on-site waste storage. Using an integrated direct and environmental cost model, fermented animal feed and mushroom growth media were compared as added-value waste management alternatives for WCP to mitigate environmental problems. Primary and secondary data were collected from the literature, field data, and case studies. Data boundaries were restricted to a gate-to-gate scenario with a receiving capacity of 500 t WCP/d, and based on a new production unit being set up at the starch factory. The total production cost of each WCP utilization option was analyzed from the economic and environmental costs. Fermented animal feed was an economically attractive scenario, giving a higher net present value (NPV), lower investment cost and environmental impact, and a shorter payback period for the 10-year operational period. The selling price of mushrooms was the most sensitive parameter regarding the NPV, while the NPV for the price of fermented animal feed had the highest value in the best-case scenario.

Effects of inoculum to substrate ratio and co-digestion with bagasse on biogas production of fish waste

To overcome the biogas inhibition in anaerobic digestion of fish waste (FW), effects of inoculum to substrate ratio (I/S, based on VS) and co-digestion with bagasse on biogas production of FW were studied in batch reactors. I/S value was from 0.95 to 2.55, bagasse content in co-digestion (based on VS) was 25%, 50% and 75%. The highest biogas yield (433.4 mL/gVS) with 73.34% methane content was obtained at an I/S value of 2.19 in mono-digestion of FW; the biogas production was inhibited and the methane content was below 70% when I/S was below 1.5. Co-digestion of FW and bagasse could improve the stability and biogas potential, also reducing the time required to obtain 70% of the total biogas production, although the total biogas yield and methane content decreased with the increase in bagasse content in co-digestion. Biogas yield of 409.5 mL/gVS was obtained in co-digestion of 75% FW and 25% bagasse; simultaneously 78.46% of the total biogas production was achieved after 10 days of digestion.

Esterification Mechanism of Bagasse Modified with Glutaric Anhydride in 1-Allyl-3-methylimidazolium Chloride

The esterification of bagasse with glutaric anhydride could increase surface adhesion compatibility and the surface of derived polymers has the potential of immobilizing peptides or proteins for biomedical application. Due to its complicated components, the esterification mechanism of bagasse esterified with glutaric anhydride in ionic liquids has not been studied. In this paper, the homogenous esterification of bagasse with glutaric anhydride was comparatively investigated with the isolated cellulose, hemicelluloses, and lignin in 1-allyl-3-methylimidazolium chloride (AmimCl) to reveal the reaction mechanism. Fourier transform infrared (FT-IR) indicated that the three components (cellulose, hemicelluloses, and lignin) were all involved in the esterification. The percentage of substitution (PS) of bagasse was gradually improved with the increased dosage of glutaric anhydride (10-40 mmol/g), which was primarily attributed to the increased esterification of cellulose and hemicelluloses. However, the PS fluctuation of lignin led to a decrease in the PS of bagasse at high glutaric anhydride dosage (50 mmol/g). The esterification reactivity of bagasse components followed the order of lignin > hemicelluloses > cellulose. The esterification mechanism was proposed as a nucleophilic substitution reaction. Nuclear magnetic resonance (NMR) analysis indicated that lignin aliphatic hydroxyls were prior to be esterified, and primary hydroxyls were more reactive than secondary hydroxyls in cellulose and hemicelluloses.

Low Temperature Soda-Oxygen Pulping of Bagasse

Wood shortages, environmental pollution and high energy consumption remain major obstacles hindering the development of today's pulp and paper industry. Energy-saving and environmental friendly pulping processes are still needed, especially for non-woody materials. In this study, soda-oxygen pulping of bagasse was investigated and a successful soda-oxygen pulping process for bagasse at 100 °C was established. The pulping parameters of choice were under active alkali charge of 23%, maximum cooking temperature 100 °C, time hold at maximum temperature 180 min, initial pressure of oxygen 0.6 MPa, MgSO4 charge 0.5%, and de-pithed bagasse consistency 12%. Properties of the resultant pulp were screened yield 60.9%, Kappa number 14, viscosity 766 dm³/kg, and brightness 63.7% ISO. Similar pulps were also obtained at 110 °C or 105 °C with a cooking time of 90 min. Compared with pulps obtained at higher temperatures (115-125 °C), this pulp had higher screened yield, brightness, and acceptable viscosity, while the delignification degree was moderate. These results indicated that soda-oxygen pulping at 100 °C, the lowest cooking temperature reported so far for soda-oxygen pulping, is a suitable process for making chemical pulp from bagasse. Pulping at lower temperature and using oxygen make it an environmental friendly and energy-saving pulping process.

Polyols from Microwave Liquefied Bagasse and Its Application to Rigid Polyurethane Foam

Bagasse flour (BF) was liquefied using bi-component polyhydric alcohol (PA) as a solvent and phosphoric acid as a catalyst in a microwave reactor. The effect of BF to solvent ratio and reaction temperatures on the liquefaction extent and characteristics of liquefied products were evaluated. The results revealed that almost 75% of the raw bagasse was converted into liquid products within 9 min at 150 °C with a BF to solvent ratio of 1/4. The hydroxyl and acid values of the liquefied bagasse (LB) varied with the liquefied conditions. High reaction temperature combining with low BF to solvent ratio resulted in a low hydroxyl number for the LB. The molecular weight and polydispersity of the LB from reactions of 150 °C was lower compared to that from 125 °C. Rigid polyurethane (PU) foams were prepared from LB and methylene diphenyl diisocyanate (MDI), and the structural, mechanical and thermal properties of the PU foam were evaluated. The PU foams prepared using the LB from high reaction temperature showed better physical and mechanical performance in comparison to those from low reaction temperature. The amount of PA in the LB has the ability of increasing thermal stability of LB-PU foams. The results in this study may provide fundamental information on integrated utilizations of sugarcane bagasse via microwave liquefaction process.

Hydrogen production via supercritical water gasification of bagasse using Ni-Cu/γ-Al2O3 nano-catalysts

Biomass gasification in supercritical water media is a promising method for the production of hydrogen. In this research, Cu-promoted Ni/γ-Al2O3 nano-catalysts were prepared with 2.5-30 wt% Ni and 0.6-7.5 wt% Cu loadings via the microemulsion method. Nano-catalysts were characterized by inductively coupled plasma (ICP), Brunauer Emmett Teller (BET) technique, X-Ray Diffraction (XRD), H2 chemisorption and Transmission Electron Microscopy (TEM) technique, as well as Carbon-Hydrogen-Nitrogen-Sulfur (CHNS) analysis was carried out for elemental analysis of bagasse. Nano-catalysts were assessed in a batch micro-reactor under 400°C and 240 bar. The microemulsion method decreased the catalyst average particle size and increased the percentage dispersion and reduction of the catalysts. The total gas yield increased with an increase in Ni and Cu loadings up to 20 wt% Ni and 5 wt% Cu and then started to decrease. Using the microemulsion technique for the preparation of Ni-Cu/γ-Al2O3 nano-catalyst, increased the hydrogen yield to 11.76 (mmol of H2/g of bagasse), CO yield to 2.67 (mmol of CO/g of bagasse) and light gaseous hydrocarbons to 0.6 (mmol of light gaseous hydrocarbons/g of bagasse). Promotion of Ni/γ-Al2O3 with copper increased the mole fraction of hydrogen in the final gasification products to 58.1 mol%.

Separation of Lignin from Corn Stover Hydrolysate with Quantitative Recovery of Ionic Liquid

Abundant lignocellulosic biomass could become a source of sugars and lignin, potential feedstocks for the now emergent bio-renewable economy. The production and conversion of sugars from biomass have been well-studied, but far less is known about the production of lignin that is amenable to valorization. Here we report the isolation of lignin generated from the hydrolysis of biomass dissolved in the ionic liquid 1-butyl-3-methylimidazolium chloride. We show that lignin can be isolated from the hydrolysate slurry by simple filtration or centrifugation, and that the ionic liquid can be recovered quantitatively by a straightforward wash with water. The isolated lignin is not only free from ionic liquid, but also lacks cellulosic residues and is substantially depolymerized, making it a promising feedstock for valorization by conversion into fuels and chemicals.

Screening of Xylanolytic Aspergillus fumigatus for Prebiotic Xylooligosaccharide Production Using Bagasse

Sugarcane bagasse is an important lignocellulosic material studied for the production of xylooligosaccharides (XOS). Some XOS are considered soluble dietary fibre, with low caloric value and prebiotic effect, but they are expensive and not easily available. In a screening of 138 fungi, only nine were shortlisted, and just Aspergillus fumigatus M51 (35.6 U/mL) and A. fumigatus U2370 (28.5 U/mL) were selected as the most significant producers of xylanases. These fungi had low β-xylosidase activity, which is desirable for the production of XOS. The xylanases from Trichoderma reesei CCT 2768, A. fumigatus M51 and A. fumigatus U2370 gave a significantly higher XOS yield, 11.9, 14.7 and 7.9% respectively, in a 3-hour reaction with hemicellulose from sugarcane bagasse. These enzymes are relatively thermostable at 40-50 °C and can be used in a wide range of pH values. Furthermore, these xylanases produced more prebiotic XOS (xylobiose and xylotriose) when compared with a commercial xylanase. The xylanases from A. fumigatus M51 reached a high level of XOS production (37.6%) in 48-72 h using hemicellulose extracted from sugarcane bagasse. This yield represents 68.8 kg of prebiotic XOS per metric tonne of cane bagasse. In addition, in a biorefinery, after hemicellulose extraction for XOS production, the residual cellulose could be used for the production of second-generation ethanol.

In vivo detoxification of aflatoxinB1 by magnetic carbon nanostructures prepared from bagasse

BACKGROUND

Aflatoxins are serious hazard to poultry industry and human health. Broiler chickens fed on aflatoxin contaminated feed develop various abnormal signs and behavior including less attraction toward feed, abnormal faeces consistency, growth retardation, dirty and ruffled feather, abnormal organs size and weight and blood serum biochemistry. Therefore the study was aimed to detoxify aflatoxin B1 in poultry feed. In this study a novel adsorbent was prepared from bagasse, characterized in vitro and in vivo it was fed to different groups of poultry birds along with aflatoxin B1. The groups were given arbitrary names A, B, C, D, E and F. Group A was fed with normal decontaminated feed, group B was fed with aflatoxin contaminated (200 μg/kg feed) feed while the groups C, D, E and F were fed with aflatoxin contaminated (200 μg/kg feed) feed plus 0.2, 0.3, 0.4 and 0.5% adsorbent respectively. Clinical signs and behavior of the chicks; blood level of alanine transferase, alkaline phosphatase, serum albumen, serum total proteins and serum globulin; Mortality; Body and organ weights; Hemorrhages in organs etc. were monitored in order to study the efficacy of the adsorbent for binding of aflatoxin B1 in the gastrointestinal tract of chickens. Statistical approach was adopted to analyze the data.

RESULTS

It was found that adsorbent amount 0.3%/kg feed was highly effective to adsorb and detoxify aflatoxin B1 in gastrointestinal tract of broiler chickens and pass safely leaving no harmful effects. However the results of groups E and F fed on 0.4% and 0.5% respectively showed slight variation in tested parameters from group A.

CONCLUSIONS

The prepared adsorbent was efficient for the detoxification of aflatoxin B1 in gastrointestinal tract of chicks and no negative symptoms associated with the use of activated carbon as previously reported were observed for the adsorbent under study.

Bioelectricity versus bioethanol from sugarcane bagasse: is it worth being flexible?

BACKGROUND

Sugarcane is the most efficient crop for production of (1G) ethanol. Additionally, sugarcane bagasse can be used to produce (2G) ethanol. However, the manufacture of 2G ethanol in large scale is not a consolidated process yet. Thus, a detailed economic analysis, based on consistent simulations of the process, is worthwhile. Moreover, both ethanol and electric energy markets have been extremely volatile in Brazil, which suggests that a flexible biorefinery, able to switch between 2G ethanol and electric energy production, could be an option to absorb fluctuations in relative prices. Simulations of three cases were run using the software EMSO: production of 1G ethanol + electric energy, of 1G + 2G ethanol and a flexible biorefinery. Bagasse for 2G ethanol was pretreated with a weak acid solution, followed by enzymatic hydrolysis, while 50% of sugarcane trash (mostly leaves) was used as surplus fuel.

RESULTS

With maximum diversion of bagasse to 2G ethanol (74% of the total), an increase of 25.8% in ethanol production (reaching 115.2 L/tonne of sugarcane) was achieved. An increase of 21.1% in the current ethanol price would be enough to make all three biorefineries economically viable (11.5% for the 1G + 2G dedicated biorefinery). For 2012 prices, the flexible biorefinery presented a lower Internal Rate of Return (IRR) than the 1G + 2G dedicated biorefinery. The impact of electric energy prices (auction and spot market) and of enzyme costs on the IRR was not as significant as it would be expected.

CONCLUSIONS

For current market prices in Brazil, not even production of 1G bioethanol is economically feasible. However, the 1G + 2G dedicated biorefinery is closer to feasibility than the conventional 1G + electric energy industrial plant. Besides, the IRR of the 1G + 2G biorefinery is more sensitive with respect to the price of ethanol, and an increase of 11.5% in this value would be enough to achieve feasibility. The ability of the flexible biorefinery to take advantage of seasonal fluctuations does not make up for its higher investment cost, in the present scenario.

Understanding mild acid pretreatment of sugarcane bagasse through particle scale modeling

Sugarcane bagasse is an abundant and sustainable resource, generated as a by-product of sugarcane milling. The cellulosic material within bagasse can be broken down into glucose molecules and fermented to produce ethanol, making it a promising feedstock for biofuel production. Mild acid pretreatment hydrolyses the hemicellulosic component of biomass, thus allowing enzymes greater access to the cellulosic substrate during saccharification. A particle-scale mathematical model describing the mild acid pretreatment of sugarcane bagasse has been developed, using a volume averaged framework. Discrete population-balance equations are used to characterise the polymer degradation kinetics, and diffusive effects account for mass transport within the cell wall of the bagasse. As the fibrous material hydrolyses over time, variations in the porosity of the cell wall and the downstream effects on the reaction kinetics are accounted for using conservation of volume arguments. Non-dimensionalization of the model equations reduces the number of parameters in the system to a set of four dimensionless ratios that compare the timescales of different reaction and diffusion events. Theoretical yield curves are compared to macroscopic experimental observations from the literature and inferences are made as to constraints on these "unknown" parameters. These results enable connections to be made between experimental data and the underlying thermodynamics of acid pretreatment. Consequently, the results suggest that data-fitting techniques used to obtain kinetic parameters should be carefully applied, with prudent consideration given to the chemical and physiological processes being modeled.

Mapping the lignin distribution in pretreated sugarcane bagasse by confocal and fluorescence lifetime imaging microscopy

BACKGROUND

Delignification pretreatments of biomass and methods to assess their efficacy are crucial for biomass-to-biofuels research and technology. Here, we applied confocal and fluorescence lifetime imaging microscopy (FLIM) using one- and two-photon excitation to map the lignin distribution within bagasse fibers pretreated with acid and alkali. The evaluated spectra and decay times are correlated with previously calculated lignin fractions. We have also investigated the influence of the pretreatment on the lignin distribution in the cell wall by analyzing the changes in the fluorescence characteristics using two-photon excitation. Eucalyptus fibers were also analyzed for comparison.

RESULTS

Fluorescence spectra and variations of the decay time correlate well with the delignification yield and the lignin distribution. The decay dependences are considered two-exponential, one with a rapid (τ1) and the other with a slow (τ2) decay time. The fastest decay is associated to concentrated lignin in the bagasse and has a low sensitivity to the treatment. The fluorescence decay time became longer with the increase of the alkali concentration used in the treatment, which corresponds to lignin emission in a less concentrated environment. In addition, the two-photon fluorescence spectrum is very sensitive to lignin content and accumulation in the cell wall, broadening with the acid pretreatment and narrowing with the alkali one. Heterogeneity of the pretreated cell wall was observed.

CONCLUSIONS

Our results reveal lignin domains with different concentration levels. The acid pretreatment caused a disorder in the arrangement of lignin and its accumulation in the external border of the cell wall. The alkali pretreatment efficiently removed lignin from the middle of the bagasse fibers, but was less effective in its removal from their surfaces. Our results evidenced a strong correlation between the decay times of the lignin fluorescence and its distribution within the cell wall. A new variety of lignin fluorescence states were accessed by two-photon excitation, which allowed an even broader, but complementary, optical characterization of lignocellulosic materials. These results suggest that the lignin arrangement in untreated bagasse fiber is based on a well-organized nanoenvironment that favors a very low level of interaction between the molecules.

Techno-economic evaluation of 2nd generation bioethanol production from sugar cane bagasse and leaves integrated with the sugar-based ethanol process

BACKGROUND

Bioethanol produced from the lignocellulosic fractions of sugar cane (bagasse and leaves), i.e. second generation (2G) bioethanol, has a promising market potential as an automotive fuel; however, the process is still under investigation on pilot/demonstration scale. From a process perspective, improvements in plant design can lower the production cost, providing better profitability and competitiveness if the conversion of the whole sugar cane is considered. Simulations have been performed with AspenPlus to investigate how process integration can affect the minimum ethanol selling price of this 2G process (MESP-2G), as well as improve the plant energy efficiency. This is achieved by integrating the well-established sucrose-to-bioethanol process with the enzymatic process for lignocellulosic materials. Bagasse and leaves were steam pretreated using H3PO4 as catalyst and separately hydrolysed and fermented.

RESULTS

The addition of a steam dryer, doubling of the enzyme dosage in enzymatic hydrolysis, including leaves as raw material in the 2G process, heat integration and the use of more energy-efficient equipment led to a 37 % reduction in MESP-2G compared to the Base case. Modelling showed that the MESP for 2G ethanol was 0.97 US$/L, while in the future it could be reduced to 0.78 US$/L. In this case the overall production cost of 1G + 2G ethanol would be about 0.40 US$/L with an output of 102 L/ton dry sugar cane including 50 % leaves. Sensitivity analysis of the future scenario showed that a 50 % decrease in the cost of enzymes, electricity or leaves would lower the MESP-2G by about 20%, 10% and 4.5%, respectively.

CONCLUSIONS

According to the simulations, the production of 2G bioethanol from sugar cane bagasse and leaves in Brazil is already competitive (without subsidies) with 1G starch-based bioethanol production in Europe. Moreover 2G bioethanol could be produced at a lower cost if subsidies were used to compensate for the opportunity cost from the sale of excess electricity and if the cost of enzymes continues to fall.

High throughput screening of hydrolytic enzymes from termites using a natural substrate derived from sugarcane bagasse

BACKGROUND

The description of new hydrolytic enzymes is an important step in the development of techniques which use lignocellulosic materials as a starting point for fuel production. Sugarcane bagasse, which is subjected to pre-treatment, hydrolysis and fermentation for the production of ethanol in several test refineries, is the most promising source of raw material for the production of second generation renewable fuels in Brazil. One problem when screening hydrolytic activities is that the activity against commercial substrates, such as carboxymethylcellulose, does not always correspond to the activity against the natural lignocellulosic material. Besides that, the macroscopic characteristics of the raw material, such as insolubility and heterogeneity, hinder its use for high throughput screenings.

RESULTS

In this paper, we present the preparation of a colloidal suspension of particles obtained from sugarcane bagasse, with minimal chemical change in the lignocellulosic material, and demonstrate its use for high throughput assays of hydrolases using Brazilian termites as the screened organisms.

CONCLUSIONS

Important differences between the use of the natural substrate and commercial cellulase substrates, such as carboxymethylcellulose or crystalline cellulose, were observed. This suggests that wood feeding termites, in contrast to litter feeding termites, might not be the best source for enzymes that degrade sugarcane biomass.

Compositional analysis of lignocellulosic feedstocks. 2. Method uncertainties

The most common procedures for characterizing the chemical components of lignocellulosic feedstocks use a two-stage sulfuric acid hydrolysis to fractionate biomass for gravimetric and instrumental analyses. The uncertainty (i.e., dispersion of values from repeated measurement) in the primary data is of general interest to those with technical or financial interests in biomass conversion technology. The composition of a homogenized corn stover feedstock (154 replicate samples in 13 batches, by 7 analysts in 2 laboratories) was measured along with a National Institute of Standards and Technology (NIST) reference sugar cane bagasse, as a control, using this laboratory's suite of laboratory analytical procedures (LAPs). The uncertainty was evaluated by the statistical analysis of these data and is reported as the standard deviation of each component measurement. Censored and uncensored versions of these data sets are reported, as evidence was found for intermittent instrumental and equipment problems. The censored data are believed to represent the "best case" results of these analyses, whereas the uncensored data show how small method changes can strongly affect the uncertainties of these empirical methods. Relative standard deviations (RSD) of 1-3% are reported for glucan, xylan, lignin, extractives, and total component closure with the other minor components showing 4-10% RSD. The standard deviations seen with the corn stover and NIST bagasse materials were similar, which suggests that the uncertainties reported here are due more to the analytical method used than to the specific feedstock type being analyzed.