St. Gabriel, LA, United States
St. Gabriel, LA, United States

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White J.E.,Audubon Sugar Institute | White J.E.,U.S. Department of Agriculture | Catallo W.J.,Louisiana State University | Legendre B.L.,Audubon Sugar Institute
Journal of Analytical and Applied Pyrolysis | Year: 2011

Biomass pyrolysis is a fundamental thermochemical conversion process that is of both industrial and ecological importance. From designing and operating industrial biomass conversion systems to modeling the spread of wildfires, an understanding of solid state pyrolysis kinetics is imperative. A critical review of kinetic models and mathematical approximations currently employed in solid state thermal analysis is provided. Isoconversional and model-fitting methods for estimating kinetic parameters are comparatively evaluated. The thermal decomposition of biomass proceeds via a very complex set of competitive and concurrent reactions and thus the exact mechanism for biomass pyrolysis remains a mystery. The pernicious persistence of substantial variations in kinetic rate data for solids irrespective of the kinetic model employed has exposed serious divisions within the thermal analysis community and also caused the broader scientific and industrial community to question the relevancy and applicability of all kinetic data obtained from heterogeneous reactions. Many factors can influence the kinetic parameters, including process conditions, heat and mass transfer limitations, physical and chemical heterogeneity of the sample, and systematic errors. An analysis of thermal decomposition data obtained from two agricultural residues, nutshells and sugarcane bagasse, reveals the inherent difficulty and risks involved in modeling heterogeneous reaction systems. © 2011 Published by Elsevier B.V.


Chen C.,Louisiana State University | Chen C.,Audubon Sugar Institute | Boldor D.,Louisiana State University | Aita G.,Audubon Sugar Institute | Walker M.,Audubon Sugar Institute
Bioresource Technology | Year: 2012

The efficiency of a batch microwave-assisted ammonia heating system was investigated as pretreatment for sweet sorghum bagasse and its effect on porosity, chemical composition, particle size, enzymatic hydrolysis and fermentation into ethanol evaluated. Sorghum bagasse, fractionated into three particle size groups (9.5-18, 4-6 and 1-2. mm), was pretreated with ammonium hydroxide (28% v/v solution) and water at a ratio of 1:0.5:8 at 100, 115, 130, 145 and 160. °C for 1. h. Simon's stain method revealed an increase in the porosity of the biomass compared to untreated biomass. The most lignin removal (46%) was observed at 160. °C. About 90% of the cellulose and 73% of the hemicellulose remained within the bagasse. The best glucose yields and ethanol yields (from glucose only) among all different pretreatment conditions averaged 42/100. g dry biomass and 21/100. g dry biomass, respectively with 1-2. mm sorghum bagasse pretreated at 130. °C for 1. h. © 2012.


Lohrey C.,Audubon Sugar Institute | Lohrey C.,Louisiana State University | Kochergin V.,Audubon Sugar Institute | Kochergin V.,Louisiana State University
Bioresource Technology | Year: 2012

Co-location of algae production facilities with cane sugar mills can be a technically advantageous path towards production of biodiesel. Algal biodiesel production was integrated with cane sugar production in the material and energy balance simulation program Sugars™. A model was developed that allowed comparison of production scenarios involving dewatering the algae to 20%ds (dry solids) or 30%ds prior to thermal drying. The net energy ratio, E R (energy produced/energy consumed) of the proposed process was found to be 1.5. A sensitivity analysis showed that this number ranged from 0.9 to 1.7 when the range of values for oil content, CO 2 utilization, oil conversion, and harvest density reported in the literature were evaluated. By utilizing available waste-resources from a 10,000ton/d cane sugar mill, a 530ha algae farm can produce 5.8millionLofbiodiesel/yr and reduce CO 2 emissions of the mill by 15% without the need for fossil fuels. © 2012.


Aita G.A.,Audubon Sugar Institute | Salvi D.A.,Audubon Sugar Institute | Walker M.S.,Audubon Sugar Institute
Bioresource Technology | Year: 2011

This study is the first one ever to report on the use of high fiber sugarcane (a.k.a. energy cane) bagasse as feedstock for the production of cellulosic ethanol. Energy cane bagasse was pretreated with ammonium hydroxide (28% v/v solution), and water at a ratio of 1:0.5:8 at 160 °C for 1. h under 0.9-1.1. MPa. Approximately, 55% lignin, 30% hemicellulose, 9% cellulose, and 6% other (e.g., ash, proteins) were removed during the process. The maximum glucan conversion of dilute ammonia treated energy cane bagasse by cellulases was 87% with an ethanol yield (glucose only) of 23. g ethanol/100. g dry biomass. The enzymatic digestibility was related to the removal of lignin and hemicellulose, perhaps due to increased surface area and porosity resulting in the deformation and swelling of exposed fibers as shown in the SEM pictures. © 2011 Elsevier Ltd.


Kochergin V.,Audubon Sugar Institute | Miller K.,Audubon Sugar Institute
Applied Biochemistry and Biotechnology | Year: 2011

Development of liquid biofuels has entered a new phase of large scale pilot demonstration. A number of plants that are in operation or under construction face the task of addressing the engineering challenges of creating a viable plant design, scaling up and optimizing various unit operations. It is well-known that separation technologies account for 50-70% of both capital and operating cost. Additionally, reduction of environmental impact creates technological challenges that increase project cost without adding to the bottom line. Different technologies vary in terms of selection of unit operations; however, solid-liquid separations are likely to be a major contributor to the overall project cost. Despite the differences in pretreatment approaches, similar challenges arise for solid-liquid separation unit operations. A typical process for ethanol production from biomass includes several solid-liquid separation steps, depending on which particular stream is targeted for downstream processing. The nature of biomass-derived materials makes it either difficult or uneconomical to accomplish complete separation in a single step. Therefore, setting realistic efficiency targets for solid-liquid separations is an important task that influences overall process recovery and economics. Experimental data will be presented showing typical characteristics for pretreated cane bagasse at various stages of processing into cellulosic ethanol. Results of generic material balance calculations will be presented to illustrate the influence of separation target efficiencies on overall process recoveries and characteristics of waste streams. © 2010 Springer Science+Business Media, LLC.


Ehrenhauser F.S.,Audubon Sugar Institute
Polycyclic Aromatic Compounds | Year: 2015

The nomenclature of polycyclic aromatic hydrocarbons (PAH) and their derivatives has undergone substantial changes since the beginning of the 20th century. The International Union of Applied and Pure Chemistry (IUPAC) has issued rules and recommendations on chemical nomenclature including organic compounds like PAH since 1957. This article presents an overview of the latest version of IUPAC nomenclature for PAH and their derivatives, detailing current changes. In addition, an overview of older nomenclature systems and commonly used, PAH specific terms aiding nomenclature is given. © 2015, Copyright © Taylor & Francis Group, LLC.


Qiu Z.,Audubon Sugar Institute | Aita G.M.,Audubon Sugar Institute
Bioresource Technology | Year: 2013

A previous study revealed that energy cane bagasse (ECB) pretreated with ionic liquid (IL), 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]), exhibited significantly higher enzymatic digestibility than untreated or water-treated ECB due to delignification and reduction of cellulose crystallinity. This study evaluated the effect of multiple recycled IL on the pretreatment of ECB for enzymatic hydrolysis. ECB was pretreated with [EMIM][OAc] (5% (w/w)) at 100 °C or 120 °C for 0.5. h upto 4. h followed by hydrolysis with commercially available enzymes. The post-pretreatment IL-containing liquid was evaporated at 100 °C for 12. h to remove water and then reused during pretreatment without any further purification. The enzymatic digestibility decreased as the number of pretreatment recycles increased. Decreasing pretreatment temperatures from 120 °C to 100 °C and extending the residence times from 0.5. h to 2. h brought significant improvement to the pretreatment efficiency of recycled [EMIM][OAc] on ECB. © 2012 Elsevier Ltd.


Cao S.,Audubon Sugar Institute | Aita G.M.,Audubon Sugar Institute
Bioresource Technology | Year: 2013

Tween 80, Tween 20, PEG 4000 or PEG 6000 was used in combination with ammonium hydroxide for the pretreatment of sugarcane bagasse. Pretreatment was carried out by mixing sugarcane bagasse, ammonium hydroxide (28% v/v solution), and water at a ratio of 1:0.5:20, adding 3% (w/w) surfactant based on the weight of dry biomass, and heating the mixture to 160 °C for 1. h. Fibers were hydrolyzed using two concentrations of commercially available enzymes, Spezyme CP and Novozyme 188. The results indicated that PEG 4000 and Tween 80 gave the highest cellulose digestibilities (62%, 66%) and ethanol yields (73%, 69%) as compared to the use of only dilute ammonia (38%, 42%) or water (27%, 26%) as catalysts, respectively. The enhanced digestibilities of non-ionic surfactant-dilute ammonia treated biomass can be attributed to delignification and reduction of cellulose crystallinity as confirmed by FTIR, TGA and XRD analysis. © 2013 Elsevier Ltd.


Kim M.,Audubon Sugar Institute | Day D.F.,Audubon Sugar Institute
Journal of Industrial Microbiology and Biotechnology | Year: 2011

A challenge facing the biofuel industry is to develop an economically viable and sustainable biorefinery. The existing potential biorefineries in Louisiana, raw sugar mills, operate only 3 months of the year. For year-round operation, they must adopt other feedstocks, besides sugar cane, as supplemental feedstocks. Energy cane and sweet sorghum have different harvest times, but can be processed for bio-ethanol using the same equipment. Juice of energy cane contains 9.8% fermentable sugars and that of sweet sorghum, 11.8%. Chemical composition of sugar cane bagasse was determined to be 42% cellulose, 25% hemicellulose, and 20% lignin, and that of energy cane was 43% cellulose, 24% hemicellulose, and 22% lignin. Sweet sorghum was 45% cellulose, 27% hemicellulose, and 21% lignin. Theoretical ethanol yields would be 3,609 kg per ha from sugar cane, 12,938 kg per ha from energy cane, and 5,804 kg per ha from sweet sorghum. © 2010 Society for Industrial Microbiology.


Qiu Z.,Audubon Sugar Institute | Aita G.M.,Audubon Sugar Institute | Walker M.S.,Audubon Sugar Institute
Bioresource Technology | Year: 2012

Ionic liquids (ILs) are promising solvents for the pretreatment of lignocellulose as they are thermally stable, environmentally friendly, recyclable, and have low volatility. This study evaluated the effect of 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) for the pretreatment of energy cane bagasse in terms of biomass composition, structural changes and enzymatic digestibility. Energy cane bagasse was pretreated with [EMIM][OAc] (5% (w/w)) at 120 °C for 30. min followed by hydrolysis with commercially available enzymes, Spezyme CP and Novozyme 188. IL-treated energy cane bagasse resulted in significant lignin removal (32.0%) with slight glucan and xylan losses (8.8% and 14.0%, respectively), and exhibited a much higher enzymatic digestibility (87.0% and 64.3%) than untreated (5.5% and 2.8%) or water-treated (4.0% and 2.1%) energy cane bagasse in terms of both cellulose and hemicellulose digestibilities, respectively. The enhanced digestibilities of IL-treated biomass can be attributed to delignification and reduction of cellulose crystallinity as confirmed by FTIR and XRD analyses. © 2012 Elsevier Ltd.

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