Engineering Commons^™

Will Saf Turbocharge The Corn Ethanol Market?, Richard Perrin, Lilyan Fulginiti, Felipe Miranda De Souza Almeida

Cornhusker Economics

The long-run outlook for the corn ethanol industry is questionable, due to a transition to electric and hybrid vehicles. One source of hope for the long run is the potential demand for producing Sustainable Aviation Fuel (SAF). SAF is a key component in the United States Aviation Climate Action Plan, a path to net-zero greenhouse gas (GHG) emissions in the aviation industry by 2050. Demand for ethanol for SAF offers hope to the ethanol industry, but it depends a great deal on policy decisions that are being made now. Here we sketch out this story.

Based on the information available …

Producer Long-Term Marketing Opportunities With Ethanol Plants, Austin Harthoorn, Logan Lloyd, Cory Walters, Kate Brooks

Cornhusker Economics

Commodity marketing operates in a complex decision environment with constant information flow, which can conceal long-run financially profitable marketing opportunities for producers. In the corn marketing space, the competitive role of ethanol plants throughout the state may provide producers with long-run financial gains by strategically approaching marketing decisions. In this article, we characterize whether producers can gain financially from strategically marketing corn to ethanol plants. For example, do ethanol plants provide a better long-run return from pre-harvest hedging, spring sale, or harvest sale?

We investigate three important contracting times--forward contract for harvest delivery (called pre-harvest hereafter), harvest delivery, and spring …

Comparison Effect On Biogas Production From Vegetable And Fruit Waste With Rumen Digesta Through Co-Digestion Process, Anika Tasnim, Muhammad Rashed Al Mamun, Md Anwar Hossen, Md Towfiqur Rahman, Md Janibul Alam Soeb

Biological Systems Engineering: Papers and Publications

Biogas is the best renewable energy as it can be produced from any biomass for example any plant or living organism. The purpose of this research was to produce biomethane from co-digestion of vegetable and fruit waste with rumen digesta through anaerobic digestion process. In this research, two trials of experiment were conducted. Each trial has three different sample with different mixing ratios. Raw materials used in the experiment was rumen digesta of goat and cow, potato, capsicum, cucumbers, onions, radish, cauliflower, carrot, leafy vegetables, apple, banana, and papaya. In each sample, 1200 gram of raw materials were used. Hydraulic …

Sources Of Variability And Uncertainty In Food-Energy-Water Nexus Systems, Heydi Calderon-Ambelis, Deepak R. Keshwani

Biological Systems Engineering: Papers and Publications

A nexus approach contributes to the strategic allocation of resources to secure food, energy, and water for the world population. Integrated models considering the complex interactions across food, energy, and water (FEW) enhance decision-making and strategic planning towards resilience. However, a significant number of the existing integrated models leave unaddressed the inherent variability and uncertainty present in the FEW sectors. Here, we review the importance of characterizing variability over spatial and temporal scales and the importance of decreasing the uncertainty present within a FEW nexus systems. The review also discusses existing modeling tools that address variability and uncertainty on single …

Risk-Based Machine Learning Approaches For Probabilistic Transient Stability, Umair Shahzad

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Power systems are getting more complex than ever and are consequently operating close to their limit of stability. Moreover, with the increasing demand of renewable wind generation, and the requirement to maintain a secure power system, the importance of transient stability cannot be overestimated. Considering its significance in power system security, it is important to propose a different approach for enhancing the transient stability, considering uncertainties. Current deterministic industry practices of transient stability assessment ignore the probabilistic nature of variables (fault type, fault location, fault clearing time, etc.). These approaches typically provide a conservative criterion and can result in expensive …

Biofuels From Crop Residue: Soil Organic Carbon And Climate Impacts In The Us And India, Adam Liska

Adam Liska Papers

The transformation of crop residue to soil organic carbon and CO₂ is a conserved process that occurs globally. Due to the mathematics of carbon intensity calculations found in government regulations, the amount of CO₂ emitted from crop residue per unit of energy in biofuel is largely independent of the amount of residue removed and the location of its removal, as shown by results from the US and India.

Soil organic carbon (SOC) levels are at equilibria determined by carbon inputs from plant material (+I_c) and loss from oxidation to CO₂

Are the US results relevant …

The Irreversible Momentum Of Clean Energy, Barack Obama

US Department of Energy Publications

The release of carbon dioxide (CO₂) and other greenhouse gases (GHGs) due to human activity is increasing global average surface air temperatures, disrupting weather patterns, and acidifying the ocean. Left unchecked, the continued growth of GHG emissions could cause global average temperatures to increase by another 4°C or more by 2100 and by 1.5 to 2 times as much in many midcontinent and far northern locations. Although our understanding of the impacts of climate change is increasingly and disturbingly clear, there is still debate about the proper course for U.S. policy—a debate that is very much on display …

Sugar Versus Lipid For Sustainable Biofuels, Yaşar Demirel

Yaşar Demirel Publications

Introduction

First‐generation biofuels, namely, ethanol and biodiesel, have led to far reaching impact on the peoples’ life world‐wide.[1] However, they inter-fere with the food supply chain and may not be sustainable although some of the biomass are converted to biofuels after those biomasses have met the human needs. Still, the first‐generation–based biofuels have proved that sugar and lipid platforms can be an answer to energy security and global warming concerns without the need for new infrastructure for feedstock delivery as well as for biomass‐to‐biofuel conversion tech-nologies. At the same time, we are discovering and assessing the long‐term environmental im-plications on …

Effects Of Post Eviction Resettlement On Land-Use And Cover Change In Uganda’S Oil Exploration Areas, Joseph Ssekandi, John Mburu, Oliver Wasonga, Laban Macopiyo, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Evaluation of the changes in land use and land cover change (LULCC) in respect to oil exploration across the Albertine region in Uganda has been focused around the exploration areas and protected areas, with no attention to the potential impacts of evictees’ activities on resettled areas. This study used LANDSAT images to analyze the land use and land cover changes (LULCC) among the period before eviction (2002 and 2005) at the climax of eviction and resettlements (2005-2011), and during the post-resettlement period (2011-2015) to quantify the impacts of resettlements on the environment. LANDSAT images were processed using ERDAS IMAGINE software …

Reply To ‘Co2 Emissions From Crop Residue-Derived Biofuels’, Adam Liska, Haishun Yang, Matthew P. Pelton, Andrew E. Suyker

Adam Liska Papers

The soil organic carbon (SOC) model that we used was parameterized with data from arable land under normal farming conditions in North America, Europe, Africa and Asia, but the equation is insensitive to changes in tillage, soil texture and moisture. The model has reasonable accuracy, however, in predicting changes in SOC, residue remaining and CO₂ emissions from initial SOC, carbon inputs from residue, and daily temperature; the shoot-to-root ratio used in the geospatial simulation was 0.29 (that is, root carbon is 29% of total aboveground carbon), which did not underestimate carbon input to soil (Supplementary Figure 2 in Ref. …

The Figure Of Bitu-Man, Paul Royster

UNL Libraries: Faculty Publications

The ominously imposing figure in the above illustration is “the Syncrude bird deterrent device, locally known as ‘Bitu-man’.” He stands (or stood—the original image was from the late 1970s) in the tailings pond of the Syncrude Canada Ltd. oil sands mining operation along the Athabasca River near Fort McMurray in northeastern Alberta. That operation surface mines (i.e., strip mines) bitumen-impregnated sand, processes it with hot water and steam, and discharges the liquid effluent or “tailings” into a pond covering roughly 3000 hectares (11 square miles). (Google Map coordinates: 56.9°N, -111.3° W). Residue bitumen collects on the surface and poses a …

A Geospatial Approach For Prioritizing Wind Farm Development In Northeast Nebraska, Usa, Adam Miller, Ruopu Li

School of Natural Resources: Faculty Publications

Being cleaner and climate friendly, wind energy has been increasingly utilized to meet the ever-growing global energy demands. In the State of Nebraska, USA, a wide gap exists between wind resource and actual energy production, and it is imperative to expand the wind energy development. Because of the formidable costs associated with wind energy development, the locations for new wind turbines need to be carefully selected to provide the greatest benefit for a given investment. Geographic Information Systems (GIS) have been widely used to identify the suitable wind farm locations. In this study, a GIS-based multi-criteria approach was developed to …

Uncertainties In Life Cycle Greenhouse Gas Emissions From U.S. Beef Cattle, Quentin M. Dudley, Adam Liska, Andrea K. Watson, Galen E. Erickson

Adam Liska Papers

Beef cattle feedlots are estimated to contribute 26% of U.S. agricultural greenhouse gas (GHG) emissions, and future climate change policy could target reducing these emissions. Life cycle assessment (LCA) of GHG emissions from U.S. grain-fed beef cattle was conducted based on industry statistics and previous studies to identify the main sources of uncertainty in these estimations. Uncertainty associated with GHG emissions from indirect land use change, pasture soil emissions (e.g. soil carbon sequestration), enteric fermentation from cattle on pasture, and methane emissions from feedlot manure, respectively, contributed the most variability to life cycle GHG emissions from beef production. Feeding of …

Soil Organic Carbon Dynamics In Agriculture: Model Development And Application From Daily To Decadal Timescales, Matthew P. Pelton

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Soil carbon (C) is the largest terrestrial C pool globally, containing more C than the atmosphere and biosphere. Soil organic carbon (SOC) is a source and sink of CO₂ emissions to and from the atmosphere, thus influencing future climate change. Understanding SOC dynamics is also important for maintaining C stocks to sustain and improve crop yields. An existing model to estimate changes in SOC due to respiration was modified to operate in three computational platforms: MS Excel, MS Excel with Visual Basic for Applications, and supercomputing. This model was validated against CO₂ flux data from a 9-year field …