Engineering Commons^™

Conversion Of Pretreated Hardwood To Medium-Chain Fatty Acids For Production Of Biolubricants, Koorosh Kashkooli

Electronic Theses and Dissertations

Medium-chain fatty acids (MCFA, e.g., hexanoic, heptanoic and octanoic acid) are versatile chemical compounds that are suitable precursors for the production of high-carbon-number, value-added chemicals such as bio-based lubricants. Short-chain fatty acids (SCFA, e.g., acetic, propionic, butyric, valeric acid) and methane are the natural fermentation products of anaerobic digestion, however, they have a lower value compared to MCFAs. Our current investigation seeks to integrate the production of MCFAs through chain elongation fermentation of pretreated biomass with catalytic conversion of MCFAs to lubricant molecules. By adding reducing agents such as ethanol and lactic acid to the anaerobic digestion, and inhibiting methanogenesis, …

Influence Of Mechanical Properties Of Paper Coating On The Crack At The Fold Problem, Seyyed Mohammad Hashemi Najafi

Electronic Theses and Dissertations

Paper coating layers are subject to various stresses and deformations in many converting processes such as calendering, printing, slitting, and folding of the paper. In some cases, products may crack during folding to generate a defect called cracking at the fold (CAF). The parameters that influence these defects are not well understood. The overall goal of this thesis is to better understand the CAF behavior as related to material properties of the coating layer.

A method was developed to produce free-standing pigmented coating layers thick enough to be tested in bending as well as tension. The mechanical properties of these …

Parameters That Influence The Performance Of Dispersion Barrier Coatings, Randy Raditya

Electronic Theses and Dissertations

Barrier coating layers are important in many paper grades used in food packaging and have the potential to help reduce our use of plastics in some situations. Barrier layers to produce water proof packaging such as milk or juice cartons or coffee cups are common. Water based dispersion barrier coatings have the potential to be a low-cost alternative to extrusion coated layers. Water borne coatings are reported to be easy to recycle and break down in the environment. However, barrier properties are often less than what is desired and expected for these water borne coatings. The reason for this poor …

Techno-Economic Analysis Of A Seaweed Extraction Process, Zachary Applebee

Honors College

The goal of this thesis was to perform a techno-economic analysis of a seaweed polysaccharide extraction process that could estimate how economically viable it would be to harvest and process seaweed in Maine to produce algal polysaccharides. I pursued two investigations to answer this question:

First, I continued the research I have been doing on an EPSCoR SEANET funded undergraduate research team working on the extraction and fractionation of sugar kelp (Saccharina Latissima) to produce three different separated polysaccharides: alginate, laminarin, and fucoidan. My contributions to this project were primarily to hydrolyze whole pieces of seaweed and extracted …

Coating Component Migration In Paper Coatings, Emilia Purington

Electronic Theses and Dissertations

In many applications such as in paints and coatings, pigments are mixed with polymeric binders to generate the final product. In the coating of paper, properties like strength, durability, and print quality are affected not only by the binder type, but the final location of the binder relative to the pigments and the fibers. During the application and drying of a paper coating, binder is known to migrate. A number of methods are available to measure the migration of latex or starch. However, all of these methods have some limitations, especially when starch, latex and kaolin are components of the …

Formate Assisted Pyrolysis Of Lignin, Mayank S. Patel

Electronic Theses and Dissertations

A significant fraction of global energy demand is met through nonrenewable petroleum feedstock, which increases the risk of energy security. The energy production from nonrenewable petroleum feedstocks is one of the large contributor to greenhouse gas emissions, which can cause climate change impacts. The energy security can be improved, and the greenhouse gas emissions can be reduced by deriving energy from domestically available renewable lignocellulosic feedstocks such as wood. Wood has three major components: cellulose, hemicellulose, and lignin. The cellulose is primarily used to produce pulp and paper. The hemicellulose is often utilized to produce a valueadded chemical like furfural. …

Mechanistic Studies Of Reducible Metal Oxides As Hydrodeoxygenation Catalysts, Akbar Mahdavi Shakib

Electronic Theses and Dissertations

Hydrodeoxygenation of phenol to benzene using ruthenium supported titania catalysts strongly varies depending on the support crystal structure and preparation conditions. Here, we performed spectroscopic characterization of titania supports to identify the surface impurities common to commercial and synthesized titania samples using a variety of spectroscopic methods. Sulfate impurities were detected for the commercial anatase samples and a procedure for their elimination was proposed so that inactive catalysts gained reactivity. Surface hydroxyls of different TiO2 samples (anatase, rutile, and pyrogenic) were identified using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments performed on vigorously cleaned surfaces and a facet-specific assignment …

The Production, Characterization, And Upgrading Of Biochars Into Activated Carbon, Kasey Johnston

Honors College

There is a growing demand for sustainable alternatives to petroleum based fuels to be used in the transportation sector. To this end, thermochemical pathways have been proposed for the conversion of renewable feedstock such as wood and corn stover to transportation fuels. Although it is recognized that renewable feedstock sources are environmentally superior to the current petroleum based fuels, the commercial production of renewable fuels via thermochemical pathways must also be economically advantageous. Thermochemical conversion of a renewable feedstock results in the production of a significant amount of biochar that has a low economic value. To improve the overall economics …

Use Of Renewable Cellulose Nanofibrils And Water-Barrier Layers In The Production Of Snack Packaging, Thoalfakar Saheb Alsaady

Honors College

From potato chips to chocolate bars, snack packaging requires materials that have excellent water vapor and oxygen barrier properties, good mechanical behavior, and good grease resistance. The most common material used in snack packaging is polypropylene (PP) layer that has been aluminum coated or metalized on one surface. The problem is not only that non-renewable petroleum is used to produce the plastic, but the production of aluminum requires large energy inputs and generates toxic wastes. In addition, this current packaging does not break down in the environment and cannot be recycled. This research is looking at using layers of cellulose …

Spray-Dried Cellulose Nanofibril-Reinforced Polypropylene Composites For Extrusion-Based Additive Manufacturing, Lu Wang

Electronic Theses and Dissertations

Compared to conventional manufacturing process, additive manufacturing (AM) offers free-form design, lighter and more ergonomic products, short lead time and less waste. Extrusion-based AM can be used to print thermoplastics. However, extrusion-based AM has processing challenges in printing semi-crystalline thermoplastics, for instance, polypropylene (PP). Cellulose nanofibrils (CNF) are one type of cellulose nanofibers that are produced from pulp fibers. CNF has extraordinary properties which make it an ideal candidate to reinforce polymers. Spray-dried CNF (SDCNF) is able to be incorporated into thermoplastic matrices without modifying conventional processing procedures.

The mechanical properties of 3D printed plastic parts have been considered significantly …

Production Of Bio-Oil With Different Oxygen Content And Characterization Of Catalytic Upgrading To Transportation Fuel, Mubarak Mohammed Khlewee

Electronic Theses and Dissertations

The world’s increasing population requires an increase in transportation fuel production. The lack of production of transportation fuels due to the shortage of fossil fuel resources combined with concerns about global emissions of carbon dioxide from fossil fuel combustion are the two major issues that have driven researchers to actively pursue alternative sources for oil production. Biomass is being considered as an alternative feedstock to produce fuel and chemicals due to its abundance and renewability. It has many features that make it suitable as a source of transportation fuel production. However, the bio-oil produced by the fast pyrolysis process has …

Operational Limits Of Blade Coating With High Aspect Ratio Pigments, Lisa Weeks

Electronic Theses and Dissertations

During the blade coating of paper, operational issues such as stalagmite formation, scratches or spits can develop at high solids content and high web speeds. For coatings that contain high aspect ratio pigments, these difficulties appear at lower solids concentrations and slower machine speeds than with more spherical shaped pigments. These operational issues are important because plate shaped particles have good properties in publication and barrier grades. A number of possible mechanisms have been described in the literature, but a clear cause has not been established nor have methods to estimate the operational limits been proposed.

The influence of particle …

Characterization Of Catalysts For Hydrodeoxygenation Of Bio-Oils Using Phenol As A Model Compound, Abdulazeez Mohammed Khlewee

Electronic Theses and Dissertations

Due to the environmental considerations, depletion of fossil fuel reserves and fluctuating non-renewable fuel price, converting non-edible lignocellulosic biomass into renewable energy resources has gained significant importance. Phenol has been chosen as a model compound for catalytic screening because it is abundant in bio-oil composition and shows a high resistance to oxygen removal during hydrodeoxygenation (HDO) reactions. HDO of phenol produces chemicals that can be used as transportation fuels (Aromatics) or fuel additives. Theoretically, HDO of phenol has two distinct reduction pathways: direct deoxygenation (DDO) and hydrogenation (HYD). The previous results published by our group showed a precedent activity and …

Creating Renewable Tunable Polymers From Hydroxymethylfurfural, Meredith C. Allen

Electronic Theses and Dissertations

The research here deals with the conversion of 5-hydroxymethylfurfural (HMF) into a tunable polymer. HMF is a known derivative that can be acquired from biomass via hydrolysis of cellulose followed by isomerization and finally selective dehydration. The process considered here is being developed to create tunable polymers from HMF and involves several different steps, three of which are covered here. The first step, an etherification, is the reaction of HMF with an alcohol. This step is significant because in this step the R-group from the alcohol is added to HMF and the branching portion formed is carried over to the …

So2-Alcohol-Water Fractionation Of Sugarcane Straw, Asif Sharazi

Electronic Theses and Dissertations

Climate change resulting from fossil fuels combustion is motivating researchers to explore feasible routes to convert renewable biomass into biofuels and biochemicals for a sustainable society. Typically, biofuel is produced from corn or sugarcane but both feedstocks compete with human food supply. Thus, lignocellulosics as renewable feedstock represent a more ethical and ecofriendly approach. Sugarcane straw (SCS) is a cheap and abundantly available feedstock which potentially can be used for biofuels/biochemicals production. It can also help to mitigate environmental and health problems resulting from conventional practice of SCS burning in the fields.

There are different biomass conversion technologies for production …

Characterization Of Paper Dusting, Gregory K. Yum

Electronic Theses and Dissertations

Dusting of paper in various printing and processing operations is a common problem. The dusting tendency of a paper is difficult to characterize with standard laboratory methods; there is currently no standard test available. As the trend to create grades with high filler content continues, the issue of dusting will remain important. The goal of this thesis was to explore various methods to characterize the dusting and linting in a laboratory environment with limited samples and time.

Techniques to cause and collect dust are compared that include a tape pull test, a bending test, and an abrasion test. Methods to …

Liquid Gating Ptfe Membranes To Reduce Fouling, Jonathan C. Overton

Electronic Theses and Dissertations

In the processing industry, fouling due to the accumulation of bioparticles or bacteria on the surface of membranes results in decreased capacity, and subsequently requires filtration membranes to require periodic cleaning, causing increased operating costs. In this work, we evaluate the recently discovered concept of liquid-gated membranes (LGMs) in both filtration characteristics, as well as their ability to facilitate passive cleaning of membranes fouled with whey proteins. Additionally, we show that biofilms formed on the surface of these membranes can be removed through exposure to an air-water interface through a simple dipping step. We further analyze the mechanisms of fouling …

A Study Of Undergraduate Perception And Behavior Toward On-Campus Composting, Sierra Kuun

Honors College

Composting among college students can promote a healthy environment and encourage the appropriate disposal method for generated organic wastes. The purpose of this study was to observe composting behaviors and attitudes among students and foster an increase in knowledge of suitable composting behavior in on-campus apartments.

Waste management issues are quickly becoming a key societal concern. As a result, there has been extensive literature surrounding the benefits of, and factors leading to, pro-environmental behaviors. What specific factors lead an individual, institution, or community to begin composting? In analyzing research on related topics, we can investigate drivers that are transferable to …

The Design And Fabrication Of An Atomic Layer Deposition Reactor For Coating Powders, Natalie Altvater

Honors College

Atomic layer deposition (ALD) is a self-limiting synthesis technique for the growth of conformal ultrathin films on solid state materials. The high conformality of the ALD method is ideal for coating porous, high surface area materials. A fluidized bed reactor (FBR) was designed and built for functionalizing a powder using ALD. The particle bed was fluidized using an inert argon gas. Aluminum oxide (Al2O3) was deposited on a high surface area powder substrate, γ-phase aluminum oxide, via ALD using trimethylaluminum (TMA) and water (H2O) as gas phase precursors. Depositions were done under low pressure conditions. A BET analysis was done …

Catalytic Hydrogenation Of Amino Acids Using Polymer-Derived Microenvironments, Rachel Karno

Honors College

Amino acids are organic compounds that can be found all around us in the world in the building blocks of proteins and peptides. One class of compounds which can be synthesized from amino acids are amino alcohols, another critical compound in society. Amino alcohols are key components in agricultural products and pharmaceutical products. Therefore, developing an efficient and cost-effective method for performing this transformation is an important area of research. The currently used industrial process is to reduce petroleum-derived amino acids with NaBH₄. However, this process is time-consuming and costly because of the need for an intermediate stage …

Production Of Acetic Acid In Kraft Pulp Mill Biorefinery Using Bi-Polar Membrane Electrodialysis, Ravikant Amogisidha Patil

Electronic Theses and Dissertations

The objective of this dissertation was to develop a process for the production of acetic acid in kraft mills. Acetyl groups in hardwood can be hydrolyzed using alkali at 50 °C. The product from this process contains about 15 g/L of sodium acetate and was determined to be suitable for the production of acetic acid.

Experiments performed using aqueous sodium acetate to evaluate the ability of electrodialysis (ED) to separate and concentrate sodium acetate showed that sodium acetate can be concentrated up to 275 g/L starting with an initial concentration of 17 g/L. The transport of water with sodium and …

Selective Hydrogenation Of Furfural To Furfuyl Alcohol Over Copper Magnesium Oxide, Andrew Estrup

Honors College

Furfural is a byproduct of biomass hydrolysis and novel means of utilizing this platform chemical are at the forefront of biofuel research. This project investigated many of the various and viable means of catalytic upgrading of furfural to other value-added chemicals, before ultimately exploring the conversion of furfural to furfuryl alcohol over a copper catalyst on a magnesium oxide support. Reasonable reaction conditions, mechanisms, and catalysts for the conversion of furfural to various products and platform chemicals exist, but no circumstance represents an obviously preferred method. The objective of this research project was to design and conduct experiments that characterize …

Cellulose Nanofibers Use In Coated Paper, Finley Richmond

Electronic Theses and Dissertations

Cellulose Nanofibers (CNF) are materials that can be obtained by the mechanical breakdown of natural fibers. CNF have the potential to be produced at low cost in a paper mill and may provide novel properties to paper, paper coatings, paints, or other products. However, suspensions have a complex rheology even at low solid contents. To be able to coat, pump, or mix CNF at moderate solids, it is critical to understand the rheology of these suspensions and how they flow in process equipment; current papers only report the rheology up to 6% solids. Few publications are available that describe the …

Avoiding Aggregation During Drying And Rehydration Of Nanocellulose, Evelyn Fairman

Honors College

Nanocellulose has attracted attention from academic researchers and industrial corporations worldwide. It is a sustainable raw material with remarkable strength and rheological properties. The industrial production of nanocellulose is an aqueous process; however, many of its valuableproperties are lost upon water removal. Indeed, once dried, nanocellulose irreversibly assembles into a plastic-like material. Currently it can betoo expensive to transport the aqueous suspensions. In order to mitigate high transportation costs, a methodmust be developed to dry and rehydrate nanocellulose whilst maintaining its nano-morphology. The current work demonstrates that the introduction of a cationic surfactant into the aqueous nanocellulose suspensionyields a chemical …

Enabling Sum Frequency Spectroscopy And Fluorescence Correlation Spectroscopy Of Model Cellular Membranes, Sarah M. Sterling

Electronic Theses and Dissertations

The majority of proteins secreted from cells contain a signal peptide sequence that is required for secretion mediated by the endoplasmic reticulum and Golgi apparatus. However, many proteins lack the essential signal peptide sequence, yet still undergo secretion. Such proteins are known to regulate cell proliferation, differentiation, and migration. Fibroblast growth factor 1 (FGF-1) is one protein which undergoes non-classical protein transport. The role of its interactions with the cellular membrane during non-classical protein transport is not fully understood, although FGF-1 has shown preferential destabilizing effects on artificial membranes composed of acidic phospholipids. In the present work, physiologically relevant model …

Design Focused Computer Module For Chemical Engineering Outreach, Marc Beauchemin

Honors College

The purpose of this project is to propose the use of a computer simulation to provide middle and high school students with a chemical engineering design experience. Long standing collective efforts between the University of Maine Department of Chemical and Biological Engineering and the Pulp and Paper Foundation have resulted in a variety of outreach programs aimed at students of this age. Recently, both organizations have been increasing efforts in these areas, proposing a senior design project focused on making a portable model demonstrating chemical engineering concepts. This project was examined along with other outreach efforts and teaching modules. The …

Fast Pyrolysis Of Muconic Acid And Formic Acid Salts, Laura Duran

Honors College

Lignocellulosic biomass is emerging as a sustainable resource for the production of alternative liquid fuels. As the need to lessen dependence on petroleum sources grows, lignocellulosic feedstocks are being investigated as a renewable, abundant source of energy. Chemical pulping processes include a high-lignin by-product, black liquor, which is already used for fuel in industry. Black liquor is burned to generate steam and electricity and to recover pulping chemicals. Currently, the thermochemical conversion of black liquor to liquid fuel is being researched at The University of Maine. In this black liquor research, an intermediate lignin-derived acid, muconic acid, and formic acid …

Cleavage Of Acetyl Groups For Acetic Acid Production In Kraft Pulp Mills, Ravikant Amogisidha Patil

Electronic Theses and Dissertations

The objective of this thesis was to determine appropriate conditions for cleavage of acetyl groups from northeast hardwood. Currently, acetyl groups end up in a waste product stream in most wood based pulp mills and thus are underutilized. Recently, a techno‐economic analysis was published that evaluated the suitability of the ‘Near‐Neutral Extraction’ process for recovery of acetic acid and ethanol in Kraft pulp mills. The results showed that the proposed process suffered from high capital investment and a low rate of return on investment. Additionally, the revenues generated by the sale of acetic acid were two times greater than the …

Career: A New Class Of Modified Mesoporous Silica Membranes With Controlled Pore Size And Surface Functionalization Through Unique Synthetic Approaches, William J. Desisto

University of Maine Office of Research Administration: Grant Reports

Artificial membranes made from sand-like materials known as silica are potentially more energy efficient than other separation processes such as distillation (change in phase from liquid to gas) because there is no phase change required to perform the separation. In addition, the opportunity exists for combining reaction and separation within a single unit using membrane reactors, thereby increasing yield on thermodynamically-limited reactions. However, the fabrication of high-quality silica membranes with pore size control and surface chemistry control remains challenging because of the inherent limits of existing synthetic approaches used to fabricate silica membranes. The researchers at the University of Maine …

Chemically Enhanced Water Removal In Papermaking, James John Beaupré

Electronic Theses and Dissertations

This work examines the utilization of chemical means to enhance the amount of water removed in the papermaking process prior to the application of heat. Through wet end application of a cationic surfactant, a significant increase in the amount of water removed in the forming and pressing sections is observed. This results in a reduction in the energy required to thoroughly dry the paper.

A variety of compounds hypothesized to potentially enhance dewatering were examined. A cationic surfactant, cetyltrimethylammonium bromide (CTAB), produced significant enhanced dewatering via addition to a pulp slurry. Extensive bench top testing characterized the extent of reduction …