Carbohydrate Extraction from the Chorella Vulgaris Microalgae Strain

The cultivation and exploitation of microalgae biomass as a source of renewable fuels and other chemicals has been an active area of research due to microalgae’s high productivity and the relatively high concentrations of valuable intracellular components, like lipids (fatty acid-based oils), proteins, and polysaccharides. Commercialization of this technology will help mitigate global climate change by reducing fossil-derived products by producing analog renewable fuels and chemicals. Traditionally, the main focus of microalgae-based fuels/chemicals research and development has been on the lipids that many strains generate, but current research shows that solely recovering the oils may not be cost competitive with fossil-derived processes. However, if the polysaccharides can also be recovered and ultimately converted into useful chemical intermediates, this may improve the economics for microalgae-based sustainable product technologies. In this study, previously developed methods for carbohydrate extraction by microwave assisted hydrolysis were further investigated to optimize extraction conditions from Chlorella Vulgaris microalgae. The optimized microwave-assisted hydrolysis conditions resulted in the carbohydrate extraction of greater than 30% of dry Chlorella biomass, which is higher than traditional extraction methods by an autoclave. It was concluded that the microwave increased cell wall rupture compared to an autoclave and thus released more of the sugars contained in the cell wall. Using high performance liquid chromatography (HPLC) with a refractive index detector, I was able to identify that 98% of the total carbohydrates in the extracted fluids were a combination of glucose, galactose and mannose which is crucial because they do not require further hydrolysis prior to biofuel production. Course: IRES Programhttps://commons.und.edu/es-showcase/1021/thumbnail.jp

The Production of Vinyl Acetate Monomer as a Co-Product from the Non-Catalytic Cracking of Soybean Oil

Valuable chemical by-products can increase the economic viability of renewable transportation fuel facilities while increasing the sustainability of the chemical and associated industries. A study was performed to demonstrate that commercial quality chemical products could be produced using the non-catalytic cracking of crop oils. Using this decomposition technique generates a significant concentration of C2−C10 fatty acids which can be isolated and purified as saleable co-products along with transportation fuels. A process scheme was developed and replicated in the laboratory to demonstrate this capability. Using this scheme, an acetic acid by-product was isolated and purified then reacted with ethylene derived from renewable ethanol to generate a sample of vinyl acetate monomer. This sample was assessed by a major chemical company and found to be of acceptable quality for commercial production of polyvinyl acetate and other products

Exploring Large Pore Size Alumina and Silica-Alumina Based Catalysts for Decomposition of Lignin

Evaluation of copper doped silica-alumina and γ-alumina catalysts for lignin decomposition was conducted using a suite of chemical analysis protocols that enabled a comprehensive characterization of the reaction product. X-ray diffraction analysis was used to verify the concentration of doped copper on catalyst supports. Then, batch experiments were performed to study the significance of catalyst support type, catalyst dopant concentration, lignin concentration, catalyst-to-lignin ratio, reactor stirring rate and reaction time. Aqueous products were extracted with dichloromethane and analyzed using a detailed gas chromatography-mass spectrophotometry analytical protocol, allowing for quantification of over 20 compounds. Solid residues were analyzed by thermogravimetric analysis and scanning electron microscopy. The highest yield of monomeric products from these screening experiments occurred with 5 wt% Cu on silica-alumina with a 1:1 w/w ratio of catalyst to lignin. A second set of experiments were conducted at these conditions to evaluate the effect of varying the reaction temperature between 300 and 350 ºC. Lower reaction temperatures (300 ºC) resulted in more unreacted lignin while higher temperatures (\u3e350 ºC) led to an increased formation of liquid phase products, but also increased char formation. While the total amount of liquid phase products increased, the combined yield of monomer phenolic products was only 5–7 wt% of the liquid extracted product and statistically independent of temperature and other operational parameters, although the yields of different chemicals varied with temperature. Unlike most pyrolytic processes, the concentration of gas phase products gradually decreased with increasing reaction temperature and became negligible at 400 ºC, while the formation of coke increased with temperature. This seemingly contradictory result is likely due to increased product polymerization occurring at higher temperatures

Comparative scoping study report for the extraction of microalgae oils from two subspecies of Chlorella vulgaris

The production of microalgae as a fatty acid oil resource for use in biofuels production is a widespread research topic at the lab scale. Microalgae contain a higher lipid content on a dry-weight basis compared to oilseeds such as soybeans. Additionally, the growth and cultivation cycle of microalgae is 15 days, in comparison to soybeans, for which the cycle occurs once or twice annually. However, to date, it has been uneconomical to produce microalgae oils in a world-scale facility due to limitations in cultivating microalgae at commercial scales. Recent developments suggest that the use of heterotrophic microalgae may be economically feasible for large-scale oil production. To assess this feasibility, a comparative scoping study was performed analysing the feasibility of an industrial-scale process plant for the growth and extraction of oil from microalgae. Processes were developed at the preliminary design level using heterotrophic subspecies and autotrophic subspecies of Chlorella vulgaris. AACE Class 4 cost estimates and economic analyses were performed. This study concludes that processes based on heterotrophic microalgae are more likely to reach economic feasibility than processes using autotrophic microalgae. However, a few barriers still remain to achieving free-market economic viability

Optimizing the Production of Renewable Aromatics via Crop Oil Catalytic Cracking

While HZSM-5 catalytic cracking of crop oil toward aromatics have been well documented, this work adds to this body of knowledge with a full acid byproduct analysis that provides improved mass balance closure along with a design of experiment optimization of reaction conditions. Fatty acids are an inevitable byproduct when converting any triglyceride oil, but are most often overlooked; despite the impact fatty acids have on downstream processing. Acid analysis verified that only short chain fatty acids, mainly acetic acid, were present in low quantities when all feed oil was reacted. When relatively high fatty acid amounts were present, these were mainly uncracked C16 and C18 fatty acids. Optimization is a balance of aromatics formation vs.unwanted gas products, coke and residual fatty acids. A design of experiments approach was used to provide insight into where the optimal reaction conditions reside for HZSM-5 facilitated reactions. These conditions can then form the basis for further development into a commercially viable process for the production of renewable aromatics and other byproducts

An Initial Study of the Catalytic Reforming of Crop Oil‐Derived 1‐Alkenes with HZSM‐5 to Aromatic Hydrocarbons

This study explored the production of aromatic hydrocarbons from the longer‐chain alkenes produced by the pyrolysis/cracking of crop oils. 1‐Tetradecene, serving as a model compound for these alkenes, was reformed in a batch reactor with a HZSM‐5 catalyst to produce a liquid hydrocarbon mixture with a high‐aromatic content. These reactions resulted in a \u3e99% conversion of the 1‐tetradecene feedstock with a yield of up to 22 wt% of aromatic hydrocarbons. Surprisingly, isomers of C3‐substituted benzenes along with xylenes and diaromatics (lower homologs of alkyl‐substituted indanes and naphthalenes) were the main aromatic products rather than their lower‐molecular‐weight (MW) homologs, benzene, toluene, ethylbenzene and xylenes, which are commonly formed with high selectivity during zeolite‐catalyzed reforming. The recovery of higher‐MW aromatics, and particularly bicyclic naphthalenes and indanes, provides mechanistic insights for zeolite‐catalyzed alkene reforming reactions suggesting that these higher‐MW aromatics are likely formed near the catalyst surface at pore openings. Furthermore, the production of acyclic diene intermediates in the size range of C7–C10 provides insight into the overall reaction pathway. The results suggest that this reaction pathway may be a commercially viable option for the production of renewable C3‐substituted aromatic chemicals/chemical intermediates as coproducts to complement the kerosene and diesel fuel blendstocks that are the primary products from crop oil cracking

Fine Partical and Toxic Metal Emissions From the Combustion of Sewage Sludge/Coal Mixtures: A Systematic Assessment

This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and pulverized coal. The objective was to determine potential tradeoffs between CO{sub 2} mitigation through using a CO{sub 2} neutral fuel, such as municipal sewage sludge, and the emergence of other potential problems such as the emission of toxic fly ash particles. The work led to new insight into mechanisms governing the partitioning of major and trace metals from the combustion of sewage sludge, and mixtures of coal and sewage sludge. The research also showed that the co-combustion of coal and sewage sludge emitted fine particulate matter that might potentially cause greater lung injury than that from the combustion of either coal alone or municipal sewage sludge alone. The reason appeared to be that the toxicity measured required the presence of large amounts of both zinc and sulfur in particles that were inhaled. MSS provided the zinc while coal provided the sulfur. Additional research showed that the toxic effects could most likely be engineered out of the process, through the introduction of kaolinite sorbent downstream of the combustion zone, or removing the sulfur from the fuel. These results are consequences of applying ''Health Effects Engineering'' to this issue. Health Effects Engineering is a new discipline arising out of this work, and is derived from using a collaboration of combustion engineers and toxicologists to mitigate the potentially bad health effects from combustion of this biomass fuel

High Octane Gasoline Using Renewable Aromatic Hydrocarbons

Background: The replacement of leaded high octane aviation gasoline with an unleaded renewable alternative would decrease the emissions of lead and fossil-derived carbon into the atmosphere. Replacement has been limited by the requirement of a very high octane number in many existing general aviation aircraft engines. Method: Two separate process pathways were developed that generate an unleaded octane fuel with a motor octane number \u3e96 from triglyceride oils (TGs), such as crop oils and algae oil. A series of experiments coupled with process simulations was used to verify the feasibility of both pathways and to provide preliminary laboratory scale data that could form the basis for further development towards a commercial technology. In the first pathway, TG oil is catalytically cracked to produce a high concentration of simple aromatic hydrocarbons. These aromatic hydrocarbons are then alkylated using propylene to form a mixture, which after purification acquires fuel properties compliant with those in the ASTM specification for 100 octane low lead aviation gasoline (100LL AvGas). In the second process pathway, the aromatic hydrocarbons are isolated after cracking using a sulfolane solvent extraction process to increase alkylation efficiency and fuel quality. Result: The results demonstrate that it is technically feasible to produce a replacement for 100LL AvGas using either pathway, and thus these strategies may be attractive candidates for commercialization

Mercury Oxidation via Catalytic Barrier Filters Phase II

In 2004, the Department of Energy National Energy Technology Laboratory awarded the University of North Dakota a Phase II University Coal Research grant to explore the feasibility of using barrier filters coated with a catalyst to oxidize elemental mercury in coal combustion flue gas streams. Oxidized mercury is substantially easier to remove than elemental mercury. If successful, this technique has the potential to substantially reduce mercury control costs for those installations that already utilize baghouse barrier filters for particulate removal. Completed in 2004, Phase I of this project successfully met its objectives of screening and assessing the possible feasibility of using catalyst coated barrier filters for the oxidation of vapor phase elemental mercury in coal combustion generated flue gas streams. Completed in September 2007, Phase II of this project successfully met its three objectives. First, an effective coating method for a catalytic barrier filter was found. Second, the effects of a simulated flue gas on the catalysts in a bench-scale reactor were determined. Finally, the performance of the best catalyst was assessed using real flue gas generated by a 19 kW research combustor firing each of three separate coal types

Dynamic Testing of Gasifier Refractory: Final Report

The University of North Dakota (UND) Chemical Engineering Department in conjunction with the UND Energy & Environmental Research Center (EERC) have initiated a program to examine the combined chemical (reaction and phase change) and physical (erosion) effects experienced by refractory materials under slagging coal gasification conditions. The goal of this work is to devise a mechanism of refractory loss under these conditions. The controlled-atmospheric dynamic corrodent application furnace (CADCAF) was utilized to simulate refractory/slag interactions under dynamic conditions that more realistically simulate the environment in a slagging coal gasifier than any of the static tests used previously by refractory manufacturers and researchers. High-alumina and high-chromia refractory bricks were tested using slags obtained from two solid fuel gasifiers. Testing was performed at 1475 C in a reducing atmosphere (2% H{sub 2} in N{sub 2}) The CADCAF tests show that high-chrome refractories have greater corrosion resistance than high-aluminum refractories; coal slag readily diffuses into the refractory through its grain boundaries; the refractory grains are more stable than the matrix in the tests, and the grains are the first line of defense against corrosion; calcium and alkali in the slag are more corrosive than iron; and silicon and calcium penetrate the deepest into the refractory. The results obtained from this study are preliminary and should be combined with result from other research programs. In particular, the refractory corrosion results from this study should be compared with refractories removed from commercial gasifiers