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Ewellyn Capanema

Research Assistant Professor

Pulp & Paper Labs NA


Date: 02/03/11 - 7/31/12
Amount: $37,250.00
Funding Agencies: Novozymes

Most methods for lignin analysis require the isolation of lignin from lignocellulosic materials. The main problems in lignin isolation are associated with the complex structure of the cell wall and the interaction of its components. As almost all lignin is linked to polysaccharides, it is not possible to isolate pure lignin without any chemical cleavage. An appropriate isolation procedure should produce a representative lignin preparation and minimize structural changes during isolation. Generally, two approaches are used to isolate lignin from lignocellulosics: acidolysis methods and extraction of lignin after ball milling and/or enzymatic hydrolysis of carbohydrates. Although the acidolytic methods are quite fast and produce lignin preparations of high purity, the acidic conditions employed trigger some changes in lignin structures. Enzymatic hydrolysis cannot be directly applied to lignocellulosic materials, and a preceding efficient milling of the sample is required. During ball milling significant degradation of polysaccharides occurs along with a certain breakdown of the lignin macromolecule. Extraction of the milled wood with 96% dioxane produces milled wood lignin (MWL). Enzymatic hydrolysis of carbohydrates in the milled wood followed by dioxane extraction of the residue produces cellulolytic enzyme lignin (CEL). Isolation of MWL and CEL from softwoods is a rather reliable and robust procedure. However, in case of hardwoods there are two problems. First, the composition of hardwood MWL has been reported to be dependent on the yield of the MWL preparation . S:G ratio increases and phenolic OH content decreases with increasing MWL yield. Even though still there are a lot of questions related to methods of isolation of lignin from wood materials, we at the Department of forest Biomaterials have the proven expertise in this matter. However, the transfer of the already acquired knowledge to non-wood materials still has to be investigated. The two main issues/questions when transferring knowledge on the structure of isolated lignin to lignin in situ are: - how representative of the whole lignin is the obtained preparations, and - how significant lignin degradation is during the milling. Our proposal for the detail structural analysis of corn stover provided by Novozymes is: 1- Mill the extractive free corn stover, in a planetary mill for different extension of time. 2- Analyze the milled material by nitrobenzene oxidation and ozonolysis 3- Isolate lignin from the different milled material by aqueous dioxane and by enzymatic hydrolysis. The main objective is to obtain a lignin preparation with as higher as possible yield with as lower as possible changes in the lignin structure. To obtain this ?ideal? preparation it is necessary to combine the knowledge on the S/V ration, obtained by nitrobenzene oxidation, and E/T ratio, obtained by ozonolysis, which shows the extension of lignin degradation during milling with the yields of isolated lignin. The selected lignin preparation will then be analyzed using a combination of quantitative 13C NMR and HSQC 2D NMR techniques for detail structural characterization .

Date: 05/28/09 - 9/30/11
Amount: $162,438.00
Funding Agencies: State of North Carolina

This project will test the economic impacts on ethanol production of variation in chemical and physical properties of pine wood. We will compare acid, alkaline, and solvent pretreatments on samples of wood with different properties, and determine the yields of fermentable sugars. These yields will be used in economic modeling to project cost-efficiency of ethanol production from pine biomass of different types. The economic model will also include estimates of the capital costs of building an ethanol production facility to utilize pine biomass, and the raw material and process costs of ethanol production from pine biomass. The results will be compared with similar analyses for poplar feedstock, based on existing data, to determine economic feasibility of ethanol production from pine biomass feedstocks. The results of this project will guide investors, researchers, and economic analysts interested in the cost-efficiency of pine biomass feedstocks for ethanol production in North Carolina.

Date: 07/01/08 - 6/30/11
Amount: $20,000.00
Funding Agencies: Forest Biotechnology Industrial Research Consortium (FORBIRC)

Lignin-Carbohydrate Complex (LCC) is believed to have significant effect on lignin removal in kraft pulping. However, direct and detailed evidences are very limited, especially for hardwoods (HW). In this project, variations between kraft pulping of different hardwood species will be correlated with the chemical structures of the hardwood LCCs using a few industrially important hardwood species (E. grandis, E. niten and E. globulus, maple, alder, aspen and acacia). LCC preparations will be isolated from original wood and kraft pulps and comprehensively characterized using high-resolution NMR and wet chemistry methods. Better understanding the mechanism of hardwood pulping will allow optimization of the technical process.

Date: 07/01/09 - 6/30/10
Amount: $20,000.00
Funding Agencies: Forest Biotechnology Industrial Research Consortium (FORBIRC)

Variations between kraft pulping of different hardwood species will be correlated with the morphology of the hardwood using a number of industrially important hardwood species (E. urograndis, E. niten and E. globulus, maple, alder, sweet gum, red oak, aspen, cottonwood and acacia). The kinetics of wood chips delignification will be studied and the reaction rate constants determined. The effect of the wood morphology on pulping performance will be elucidated by comparing the reaction rate of sawdust (only chemistry effect) with the delignification rate of the corresponding chips (the effect of the chemistry and morphology). The microstructure of the hardwood will be studies using FQA method to determine the distribution in the fiber length, width, coarseness, percentage of fines and vessels. The variations in the hardwood microstructure will be correlated with the rate of delignification to evaluate the effect of the wood morphology on the pulping performance.

Date: 05/01/05 - 6/30/08
Amount: $250,000.00
Funding Agencies: NC Biotechnology Center

Fraser fir is important to North Carolina both ecologically and economically. It is a key component of the spruce-fir ecosystem found at the highest elevations of the Appalachian Mountains, including scenic areas along the Blue Ridge Parkway and in Great Smoky Mountains National Park. It is also a major component of the Christmas tree farming industry, which brings over $100 million annually to rural regions of the state. Fraser fir populations in North Carolina have been devastated by an introduced pest, the balsam woolly adelgid (BWA). Death of BWA-infested Fraser fir seems to be due to an over-zealous defense response by the tree, rather than any direct effect of insect feeding. Other fir species from Asia or Europe are either completely resistant to BWA, or tolerant of BWA feeding without the excessive defense response found in Fraser fir. This research will use modern tools of biological research to understand why BWA-infested Fraser firs die, and to look for ways to prevent fir death.

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