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Full-Text Articles in Engineering
Production Of Bio-Based Phenol Formaldehyde Foams, Bing Li
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
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
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
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
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 (Mw ~10,000 g/mol) was effectively de-polymerized, producing de-polymerized lignin (DL, Mw 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, …