Engineering Commons^™

Investigations Of Thermal Treatment Of Softwood Kraft Lignin Under Fractional And Ablative Pyrolytic Conditions, Dideolu J. Daniel

LSU Master's Theses

Lignin is second to cellulose in abundance among polymers in nature. Research studies on the development of new products and material combinations in which lignin degradation/conversion products are involved are still in their infancy, because fundamental knowledge about its structure, reactivity, and material and polymer behavior, is still lacking.

The objective of this research study was to investigate the complex thermal deconstruction and mechanistic behavior of a type of technical lignin, known as Kraft lignin, under depolymerization and to develop operating conditions for parameters influencing resulting product yields and operation of pyrolysis reactors.

Softwood Kraft lignin (s-KL) and methanol-fractionated (ex-KL) …

Oxidative Degradation Of Lignin And Investigation Of Utilization Of Lignin-Derived Materials As Building Blocks For Epoxy Resins, Zhen Fang

Theses and Dissertations--Chemistry

Lignin, the second most abundant biopolymer on earth, is potentially a replaceable source for bulky fuels and chemical feedstocks. There have been numerous reports on methods for the oxidative cleavage of β-O-4 linkages but relatively few reports of how those methods affect other linkages that are present in lignin. We investigated how the β-1 and β-5 linkages respond under oxidative conditions proposed for lignin deconstruction based on their effect on β-O-4 linkages. Mechanochemical treatment of lignin can greatly improve the yield of monomer products and we applied a mechanochemical approach, using powerful ring-and-puck milling to promote lignin degradation. Along with …

Production Of Bio-Based Phenol Formaldehyde Foams, Bing Li

Electronic Thesis and Dissertation Repository

Considering the declining non-renewable fossil resources, there is increasing interest in the development of more environmentally conscious, sustainable and cost-effective substitutes for chemical production. Lignin, a main component in lignocellulosic biomass, has been considered to be a potential substitute for petroleum-based phenol due to its phenolic structure.

This PhD dissertation aimed at producing bio-based phenol formaldehyde (BPF) foams using bio-phenols, including but not limited to, kraft lignin (KL), organosolv lignin (OL), hydrolysis lignin (HL), and bio-crude oil from white birth bark. The challenge of the existing process of producing BPF foams is that a low phenol substitution ratio, generally less …

Production Of Activated Carbons From Pyrolytic Char For Environmental Applications, Anastasia Colomba

Electronic Thesis and Dissertation Repository

Biomass pyrolysis has the potential to become a major component of future biorefineries, since biomass is cracked to produce gases, liquid products (bio-oil) and solid products (bio-char). In order for the process to be economically feasible, it is necessary to obtain the maximum value from each stream, thus no by-product can be regarded as a waste.

Bio-char is normally regarded as a by-product of fast pyrolysis, which is optimized to target bio-oil production. However, there are many potentially attractive applications for it: for example, it can be used for the production of activated carbons, which are the most commonly used …

Hydrotreatment Of Lignin Into Green Fuels And Chemicals, Matthew Tymchyshyn

Electronic Thesis and Dissertation Repository

Concerns about declining non-renewable fossil resources, energy security, climate change and sustainability are increasing worldwide. This has resulted in an increased interest in the development of alternatives to fossil resources not only for energy, but particularly for chemical production on a global level. There are a number of promising alternatives to fossil resources, however, lignocellulosic biomass such as forestry residues and wood waste (limbs, bark, sawdust, etc.) seem to be the most promising. They are widely available, renewable and a non-food resource. Therefore woody biomass holds the promise of being a sustainable resources for both energy and chemical production.

The …

Hydrolytic Depolymerization Of Lignin For The Preparation Of Polyols And Rigid Polyurethane Foams, Nubla Mahmood

Electronic Thesis and Dissertation Repository

This doctoral study was aimed to produce bio-polyols from Kraft lignin (KL) and hydrolysis lignin (HL) via depolymerization and utilize the lignin-derived bio-polyols in the preparation of bio-based rigid polyurethane (BRPU) foams at high percentage of bio-contents (50-70 wt.%). This study demonstrated that depolymerization is a practical and effective approach to unleash the potential of utilization of lignin, of complex structures and low reactivity/functionality, for bioproducts and biomaterials.

Depolymerization of KL was realized in alkaline medium using water alone as a solvent or employing water-ethylene glycol (EG) mixture via a low pressure (psig) proprietary process, both effective for producing low …

Reductive Depolymerization Of Kraft Lignin For Chemicals And Fuels Using Formic Acid As A In-Situ Hydrogen Source, Shanhua Huang

Electronic Thesis and Dissertation Repository

In this thesis work, formic acid (FA) proved to be an effective in-situ hydrogen donor for the reductive de-polymerization of kraft lignin (KL). At the optimum conditions without catalysts, i.e., 300 ^oC, 1 h, 18.6 wt.% substrate concentration, 50/50 (v/v) water-ethanol medium at a FA-to-lignin mass ratio of 0.7, KL (M_w ~10,000 g/mol) was effectively de-polymerized, producing de-polymerized lignin (DL, M_w 1, 270 g/mol) at a yield of ~90 wt.% and wt.% yield of solid residue (SR). The effects of heterogeneous catalysts on KL reductive de-polymerization in 50/50 (v/v) water-ethanol medium were also investigated. At all conditions, …