Natural dyes from lignocellulosic biomass hydrolysates

Wheat straw has been hydrolyzed in two different conditions, namely subcritical water and 100 °C boiled water, and the hydrolysates obtained are used to dye wool yarns. The wool samples are pretreated with three types of mordants before dyeing with wheat straw hydrolysates. Irrespective of the metal types used in pretreatment process, subcritical water hydrolysate always results in same color in dyeing process. However, three colors are obtained for each mordant when 100 °C boiled water is used as a dyeing reagent. The effect of the total phenolic contents of the hydrolysates on color development has also been evaluated. The total phenolic and sugar contents of subcritical water hydrolysate are found higher and the dyeing performance of this hydrolysate is better than the 100 °C boiled water hydrolysate. Light and wash fastness of dyed wools are also assessed. Light and wash fastness tests result in 3-4 and 4-5 rating respectively

Investigation of Organic Solvents’ Effects on Kenaf (Hibiscus cannabinus L.) Biomass Conversion in Subcritical Water

Kenaf biomass was hydrolyzed under subcritical water conditions in the presence of various organic solvents. The solvents tested were tetrahydrofuran (THF), acetone, xylene (mixed isomers) and methanol. The organic compounds released into hydrolysates, total organic contents, water-soluble total phenols, and the molecular weight distributions of the polysaccharides in the hydrolysates, solid residues leftover after hydrolysis and gaseous products formed during the solubilization process were determined. The results showed that organic solvents significantly enhanced the dissolution of kenaf biomass (methanol \u3c (omp)xylene ≤ acetone ~ tetrahydrofuran). The hydrolysis percentage was found to be between 75-82% depending on the type of the solvent. Hydrolysis yield and total organic carbons released into hydrolysates highly differed when the solubilization process was performed under carbon dioxide pressure and this effect considerably varied based on the type of solvent used in hydrolysis process. The main gas product formed during hydrolysis process was carbon dioxide with ~80% composition. Morphological measurements of the solid biomass residues left after hydrolysis showed substantial degradations with increasing number of pores on the biomass surfaces

Comparison of perennial grasses and corn-based biomass materials for high-yielding hydrogen gas production

Both perennial grasses and corn biomass residues are non-edible for humans and have high carbohydrate contents that make them promising raw materials for biofuel production. This study evaluated perennial grasses (miscanthus and switchgrass) and corn-based biomass materials (corn stover, stalk, cob, husk, and bran) for high-yielding hydrogen gas production by aqueous-phase reforming (APR). The biomass materials were dissolved in subcritical water to obtain hydrolysates for use as feed solutions in APR. The dissolution experiments showed that hydrolysis percentages and total organic carbon releases were considerably higher in corn biomass fractions as compared to perennial grasses. The highest (66.7 mL H2) and lowest (27.0 mL H2) hydrogen yields were observed when miscanthus and corn bran biomass hydrolysates, respectively, were used as the feed solution. Hydrogen production yields were found to be in the following descending order: Miscanthus > corn cob > corn stover > switchgrass > corn husk corn stalk >> corn bran. In general, the biomass hydrolysates that had less organic carbon resulted in higher hydrogen production. Hydrolysis and gasification results for corn husks from various types of corn (field corn, sweet corn, seed corn, and popcorn) were different. The findings of this study will be beneficial for selection of the right biomass material for production of a specific value-added product from biomass. This study focused on biofuel hydrogen gas, which has the highest specific energy content of all conventional fuels. © 2017 American Society of Agricultural and Biological Engineers

Comparison of Perennial Grasses and Corn-Based Biomass Materials for High-Yielding Hydrogen Gas Production

Abstract. Both perennial grasses and corn biomass residues are non-edible for humans and have high carbohydrate contents that make them promising raw materials for biofuel production. This study evaluated perennial grasses (miscanthus and switchgrass) and corn-based biomass materials (corn stover, stalk, cob, husk, and bran) for high-yielding hydrogen gas production by aqueous-phase reforming (APR). The biomass materials were dissolved in subcritical water to obtain hydrolysates for use as feed solutions in APR. The dissolution experiments showed that hydrolysis percentages and total organic carbon releases were considerably higher in corn biomass fractions as compared to perennial grasses. The highest (66.7 mL H2) and lowest (27.0 mL H2) hydrogen yields were observed when miscanthus and corn bran biomass hydrolysates, respectively, were used as the feed solution. Hydrogen production yields were found to be in the following descending order: miscanthus &amp;gt; corn cob &amp;gt; corn stover &amp;gt; switchgrass &amp;gt; corn husk = corn stalk &amp;gt;&amp;gt; corn bran. In general, the biomass hydrolysates that had less organic carbon resulted in higher hydrogen production. Hydrolysis and gasification results for corn husks from various types of corn (field corn, sweet corn, seed corn, and popcorn) were different. The findings of this study will be beneficial for selection of the right biomass material for production of a specific value-added product from biomass. This study focused on biofuel hydrogen gas, which has the highest specific energy content of all conventional fuels. Keywords: APR, Corn biomass, Hydrogen, Hydrolysis, Miscanthus, Switchgrass.</jats:p

Investigation of Organic Solvents’ Effects on Kenaf (Hibiscus cannabinus L.) Biomass Conversion in Subcritical Water

Kenaf biomass was hydrolyzed under subcritical water conditions in the presence of various organic solvents. The solvents tested were tetrahydrofuran (THF), acetone, xylene (mixed isomers) and methanol. The organic compounds released into hydrolysates, total organic contents, water-soluble total phenols, and the molecular weight distributions of the polysaccharides in the hydrolysates, solid residues leftover after hydrolysis and gaseous products formed during the solubilization process were determined. The results showed that organic solvents significantly enhanced the dissolution of kenaf biomass (methanol \u3c (omp)xylene ≤ acetone ~ tetrahydrofuran). The hydrolysis percentage was found to be between 75-82% depending on the type of the solvent. Hydrolysis yield and total organic carbons released into hydrolysates highly differed when the solubilization process was performed under carbon dioxide pressure and this effect considerably varied based on the type of solvent used in hydrolysis process. The main gas product formed during hydrolysis process was carbon dioxide with ~80% composition. Morphological measurements of the solid biomass residues left after hydrolysis showed substantial degradations with increasing number of pores on the biomass surfaces

Electrolysis of coal slurries to produce hydrogen gas: Effects of different factors on hydrogen yield

The study was aimed to investigate the effects of different factors (such as acid concentration, cell potential, temperature, coal types, and geometric area of the membrane) on the coal slurry electrolysis and hydrogen evolution. It was observed that all of the above factors affected hydrogen production upon completion of the electrolysis. The results revealed that an increase in the initial acid concentration up to 5.0 M brought about an increase in the current density and hydrogen evolution. However, the higher the acid concentration was taken (&gt;7.0 M) then the lower the current density and hydrogen evolution were, which resulted in significant change due to the agglomeration of coal samples and stuck on the electrode surface. Furthermore, the CO2 evolution (14 ml) was observed only at high temperature (100 °C) and high (2.0 V) cell potential when the H2 amount was 776 ml. The coal type was observed to have influenced the electrolysis. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.MAG 106M306 Çukurova ÜniversitesiFinancial supports from Scientific and Technical Research Council of Turkey (TUBITAK, the project number: MAG 106M306) and Çukurova University Research Fund are gratefully acknowledged

Production of activated carbon materials from kenaf biomass to be used as catalyst support in aqueous-phase reforming process

In the present study, low value-added woody biomass, kenaf (Hibiscus cannabinus L.), was utilized for production of activated carbons (ACs) that can be used as catalyst support for deposition of metal particles such as Pt to produce highly active catalysts for gasification of biomass hydrolysates by aqueous-phase reforming (APR) process. H3PO4 was used as activating agent for production of AC materials. ACs produced from kenaf and non-hydrolyzed fraction of kenaf after dissolution in subcritical water were compared with the commercial one. The activated carbon material from kenaf had highest BET surface area and total pore volume among the materials tested including commercial AC. The catalyst prepared by Pt deposition on this material (kenaf AC-Pt) had also highest BET surface area and total pore volume. This catalyst exhibited very high activity and selectivity for hydrogen production (0.015 mol H2/g catalyst) in APR of biomass hydrolysate. © 2016 Elsevier B.V. All rights reserved

Xylitol production from lignocellulosics: Are corn biomass residues good candidates?

Pentosan-rich fractions of biomass materials have potential for production of value-added product, xylitol. Xylitol is widely used as a sugar substitute in food industry but it is also a building block for a variety of commodity chemicals. Xylitol is one of top 12 high value-added intermediate chemicals that can be produced from biomass. Present study evaluated corn biomass residues (corn stover, husk, and cob) and corn bran as alternative raw materials for xylitol production. The productions were performed by chemical and thermochemical routes that were based on releasing of xylose sugar from the materials and then reduction of the hydrolysates for xylitol formation. The results showed that the use of isolated hemicellulose fraction versus biomass material itself as starting material produced more concentrated xylitol with fewer amounts of byproducts. Corn bran is the best alternative raw material to produce xylitol compared to corn stover, husk and cob. The yield of xylitol was observed to be higher in chemical method in the conditions studied. © 2017 Elsevier LtdUniversity of Nebraska-Lincoln: 1024460Financial support from University of Nebraska-Lincoln is gratefully acknowledged (Foundation fund name and number: Layman 1024460)