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Full-Text Articles in Engineering
De-Risking Pretreatment Of Microalgae To Produce Fuels And Chemical Co-Products, Jacob S. Kruger, Skylar Schutter, Eric P. Knoshaug, Bonnie Panczak, Hannah Alt, Alicia Sowell, Stafanie Van Wychen, Matthew Fowler, Kyoko Hirayama, Anuj Thakkar, Sandeep Kumar
De-Risking Pretreatment Of Microalgae To Produce Fuels And Chemical Co-Products, Jacob S. Kruger, Skylar Schutter, Eric P. Knoshaug, Bonnie Panczak, Hannah Alt, Alicia Sowell, Stafanie Van Wychen, Matthew Fowler, Kyoko Hirayama, Anuj Thakkar, Sandeep Kumar
Civil & Environmental Engineering Faculty Publications
Conversion of microalgae to renewable fuels and chemical co-products by pretreating and fractionation holds promise as an algal biorefinery concept, but a better understanding of the pretreatment performance as a function of algae strain and composition is necessary to de-risk algae conversion operations. Similarly, there are few examples of algae pretreatment at scales larger than the bench scale. This work aims to de-risk algal biorefinery operations by evaluating the pretreatment performance across nine different microalgae samples and five different pretreatment methods at small (5 mL) scale and further de-risk the operation by scaling pretreatment for one species to the 80 …
Modeling The Production Of Microalgal Biomass In Large Water Resource Recovery Facilities And Its Processing Into Various Commodity Bioproducts, James Pierson, Gopi Raju Makkena, Sandeep Kumar, Vinod Kumar, Vivekanand Vivekanand, Hasan Husain, Muhammad Ayser, Venkatesh Balan
Modeling The Production Of Microalgal Biomass In Large Water Resource Recovery Facilities And Its Processing Into Various Commodity Bioproducts, James Pierson, Gopi Raju Makkena, Sandeep Kumar, Vinod Kumar, Vivekanand Vivekanand, Hasan Husain, Muhammad Ayser, Venkatesh Balan
Civil & Environmental Engineering Faculty Publications
Algae are capable of sequestering nutrients such as nitrates and phosphates from wastewater in the presence of sunlight and carbon dioxide (CO2) to build up their body mass and help combat climate change. In the current study, we carried out different case studies to estimate the volume of algal biomass that could be produced annually using the rotating algal biofilm (RAB) method in three large-scale water resource recovery facilities (WRRFs) in Texas: Fort Worth, Dallas, and Houston. We calculated the total amount of lipids, carbohydrates, and proteins that could be fractionated from the algal biomass while using the …
Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar
Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar
Chemistry & Biochemistry Faculty Publications
Selective electrochemical hydrogenation (ECH) of biomass-derived unsaturated organic molecules has enormous potential for sustainable chemical production. However, an efficient catalyst is essential to perform an ECH reaction consisting of superior product selectivity and a higher conversion rate. Here, we examined the ECH performance of reduced metal nanostructures i.e., reduced Ag (rAg) and reduced copper (rCu) prepared via electrochemical or thermal oxidation and electrochemical reduction process, respectively. Surface morphological analysis suggests formation of nanocoral and entangled nanowire structure formation for rAg and rCu catalysts. rCu exhibits slight enhancement in ECH reaction performance in comparison to the pristine Cu. However, the rAg …
Hydrodeoxygenation Of Acetic Acid As A Model Compound For The Aqueous Phase Catalytic Pyrolysis Oils, Hossein Jahromi, Foster Agblevor
Hydrodeoxygenation Of Acetic Acid As A Model Compound For The Aqueous Phase Catalytic Pyrolysis Oils, Hossein Jahromi, Foster Agblevor
Biological Engineering Faculty Publications
Catalytic pyrolysis of biomass generates organic, aqueous, gaseous and solid fractions. The organic fraction can be easily hydrotreated to produce hydrocarbons, but the aqueous phase that contains between 10 to 25% soluble organics can pose challenges in wastewater treatment. The aqueous fraction from the catalytic pyrolysis of Pinyon Juniper wood was characterized for its organic content. The fraction contained about 15 wt% organic compounds determined from Karl Fischer analysis. The organic fractions were further characterized using gas chromatography and mass selective detection (GC/MS). The analysis showed that the dissolved organics were composed of acetic acid, ketones, aldehydes, and phenolic compounds. …
Hydrodeoxygenation Of Pinyon Juniper Catalytic Pyrolysis Oil To Hydrocarbon Fuels, Hossein Jahromi, Foster Agblevor
Hydrodeoxygenation Of Pinyon Juniper Catalytic Pyrolysis Oil To Hydrocarbon Fuels, Hossein Jahromi, Foster Agblevor
Biological Engineering Faculty Publications
As a renewable source, biomass is an essential option for diminishing dependence on conventional fossil fuel energy sources. Pyrolysis is a promising technology for the conversion of biomass into liquid fuels. However, several challenges associated with using pyrolysis oils such as their high acidity and low energy content inhibit their direct use as transportation fuels. We conducted a batch hydrodeoxygenation of pinyon juniper catalytic pyrolysis oil using Ni/SiO2-Al2O3 catalyst to improve the following properties of the oil: heating value, acidity, oxygen content, water content, and viscosity. During the hydrogenation process, the influence of four experimental factors; temperature, catalyst loading, residence …
Bioenergy From Wastewater-Based Biomass, Ronald C. Sims, Sean K. Bedingfield, Reese Thompson, Judith L. Sims
Bioenergy From Wastewater-Based Biomass, Ronald C. Sims, Sean K. Bedingfield, Reese Thompson, Judith L. Sims
Biological Engineering Faculty Publications
The U.S. Department of Energy (DOE) has stated that biomass is the only renewable resource that can supplant petroleum-based liquid transportation fuels in the near term. Wastewater is beginning to be viewed as a potential resource that can be exploited for biomass production and conversion to bioenergy. We suggest that using wastewater from municipalities and industries as a resource for cultivating biomass and combining wastewater treatment with the production of biomass for bioenergy would provide benefits to both industries. Two waste-based biomass production systems that currently have large nationwide infrastructures include: (1) wastewater treatment systems that can be used to …
The Economics And Logistics Of The Dual Harvest Of Grain And Biomass In A Single-Pass, Matthew T. Wold
The Economics And Logistics Of The Dual Harvest Of Grain And Biomass In A Single-Pass, Matthew T. Wold
Department of Biological Systems Engineering: Dissertations and Theses
Significant interest has developed in using cellulosic resources, especially crop residues, to create biofuels. Collecting these residues in a single-pass of the harvester across the field has the potential to be a low cost option. Two models have been developed; the first characterizes the in-field logistics of single-pass crop residue collection, the second the economics. These models allow the user to easily examine a wide variety of both grain-only and single-pass residue collection harvest cases. A variety of possible residue collection cases have been examined, and their effects both on harvester field capacity and harvest cost compared to grain-only harvest …
Mutant Alcohol Dehydrogenase Leads To Improved Ethanol Tolerance In Clostridium Thermocellum, Steven D. Brown, Adam M. Guss, Tatiana V. Karpinets, Jerry M. Parks
Mutant Alcohol Dehydrogenase Leads To Improved Ethanol Tolerance In Clostridium Thermocellum, Steven D. Brown, Adam M. Guss, Tatiana V. Karpinets, Jerry M. Parks
Dartmouth Scholarship
Clostridium thermocellum is a thermophilic, obligately anaerobic, Gram-positive bacterium that is a candidate microorganism for converting cellulosic biomass into ethanol through consolidated bioprocessing. Ethanol intolerance is an important metric in terms of process economics, and tolerance has often been described as a complex and likely multigenic trait for which complex gene interactions come into play. Here, we resequence the genome of an ethanol-tolerant mutant, show that the tolerant phenotype is primarily due to a mutated bifunctional acetaldehyde-CoA/alcohol dehydrogenase gene (adhE), hypothesize based on structural analysis that cofactor specificity may be affected, and confirm this hypothesis using enzyme assays. …
Simulation Of Corn Stover And Distillers Grains Gasification With Aspen Plus, Ajay Kumar, Hossein Noureddini, Yaşar Demirel, David Jones, Milford Hanna
Simulation Of Corn Stover And Distillers Grains Gasification With Aspen Plus, Ajay Kumar, Hossein Noureddini, Yaşar Demirel, David Jones, Milford Hanna
Yaşar Demirel Publications
A model was developed to simulate the performance of a lab‐scale gasifier and predict the flowrate and composition of product from given biomass composition and gasifier operating conditions using Aspen Plus software. Mass balance, energy balance, and minimization of Gibbs free energy during the gasification were applied to determine the product gas composition. Carbon conversion efficiency and tar content were provided to the model as inputs as these could not be predicted by the model based on minimization of Gibbs free energy. Experiments for validation of the model were performed on a lab‐scale fluidized bed gasifier using corn stover and …
Thermal Degradation Kinetics Of Distillers Grains And Solubles In Nitrogen And Air, Lijun Wang, Ajay Kumar, Milford Hanna, Curtis L. Weller, D. D. Jones
Thermal Degradation Kinetics Of Distillers Grains And Solubles In Nitrogen And Air, Lijun Wang, Ajay Kumar, Milford Hanna, Curtis L. Weller, D. D. Jones
Department of Biological Systems Engineering: Papers and Publications
The pyrolysis and oxidation kinetics of distillers grains and solubles were determined using thermogravimetric analysis. The starting temperature of pyrolysis and oxidation of distillers grains and solubles increased with the increase of heating rate and initial moisture content. The pyrolysis and oxidation of distillers grains and solubles were completed at 650°C and 850°C, respectively, which were independent of the heating rate and the initial moisture content. The residual weights of distillers grains and solubles after pyrolysis and oxidation were 27.15% and 5.49% of the original dry mass of distillers grains and solubles. Thermogravimetrical analysis data was used to determine kinetic …
Co-Production Of Chemical And Energy Products From Distillers Grains Using Supercritical Fluid Extraction And Thermochemical Conversion Technologies, Lijun Wang, Ajay Kumar, Curtis L. Weller, David D. Jones, Milford A. Hanna
Co-Production Of Chemical And Energy Products From Distillers Grains Using Supercritical Fluid Extraction And Thermochemical Conversion Technologies, Lijun Wang, Ajay Kumar, Curtis L. Weller, David D. Jones, Milford A. Hanna
Department of Biological Systems Engineering: Conference Presentations and White Papers
Dry-grind technology has become the dominant method for ethanol production. During drygrind ethanol production, roughly one-third of the dry grain mass resides in the dried distillers grains with solubles (DDGS) as by-products (i.e., ∼0.8 kg/L ethanol). The energy content residing in the 0.8 kg DDGS is about 20 MJ, compared to the consumption of 1 MJ electricity and 10 MJ thermal energy for production of each liter of ethanol. A sequential supercritical fluid process with solvents including carbon dioxide, water and ethanol was used to recover high-value chemicals from DDGS. Thermochemical conversion methods were used to convert the DDGS residue …