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At least 1,135 records · Page 63

2012 ARPA-E Energy Innovation Summit Keynote Presentation (Secretary of Energy Steven Chu)

The third annual ARPA-E Energy Innovation Summit was held in Washington D.C. in February, 2012. The event brought together key players from across the energy ecosystem - researchers, entrepreneurs, investors, corporate executives, and government officials - to share ideas for developing and deploying the next generation of energy technologies. Dr. Steven Chu, Energy Secretary, gave the first keynote presentation of the day. He discusses how President Obama's all-of-the-above approach to energy will help the Unites States solve 21st century global energy challenges and maintain its leadership as an exporter of energy technology. Secretary of Energy Steven Chu highlighted our vulnerability to price fluctuations in the fuel markets, most recently to oil and gasoline, as well as our inability to drill our way out of the problem. Secretary Chu made the case for leveraging energy innovation in order to reduce our exposure to oil price fluctuations and improve the U.S.'s economic competitiveness.

02 PETROLEUM↗

International Voluntary Renewable Energy Markets (Presentation)

This presentation provides an overview of international voluntary renewable energy markets, with a focus on the United States and Europe. The voluntary renewable energy market is the market in which consumers and institutions purchase renewable energy to match their electricity needs on a voluntary basis. In 2010, the U.S. voluntary market was estimated at 35 terawatt-hours (TWh) compared to 300TWh in the European market, though key differences exist. On a customer basis, Australia has historically had the largest number of customers, pricing for voluntary certificates remains low, at less than $1 megawatt-hour, though prices depend on technology.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

The Impact of Energy Efficiency and Demand Response Programs on the U.S. Electricity Market

This study analyzes the impact of the energy efficiency (EE) and demand response (DR) programs on the grid and the consequent level of production. Changes in demand caused by EE and DR programs affect not only the dispatch of existing plants and new generation technologies, the retirements of old plants, and the finances of the market. To find the new equilibrium in the market, we use the Oak Ridge Competitive Electricity Dispatch Model (ORCED) developed to simulate the operations and costs of regional power markets depending on various factors including fuel prices, initial mix of generation capacity, and customer response to electricity prices. In ORCED, over 19,000 plant units in the nation are aggregated into up to 200 plant groups per region. Then, ORCED dispatches the power plant groups in each region to meet the electricity demands for a given year up to 2035. In our analysis, we show various demand, supply, and dispatch patterns affected by EE and DR programs across regions.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Regional Hybrid Energy Systems Technoeconomic Analysis

The National Renewable Energy Laboratory (NREL) has been working with the Idaho National Laboratory (INL) and Argonne National Laboratory (ANL) to analyze the potential that hybridizing Xcel Energy's two nuclear power plants in Minnesota might have. The hybrid nuclear power plants would maximize sales of electricity when its price is high and reduce electricity sales to maximize hydrogen production when the price of electricity is low. This presentation summarizes the project's approach and status and communicates future direction.

ENERGY PLANNING, POLICY, AND ECONOMY,HYDROGEN↗

Drivers of Change in Managed Water Resources: Modeling the Impacts of Climate and Socioeconomic Changes Using the US Midwest as a Case Study

A global integrated assessment model including a water-demand model driven by socio-economics, is coupled in a one-way fashion with a land surface hydrology – routing – water resources management model. The integrated modeling framework is applied to the U.S. Upper Midwest (Missouri, Upper Mississippi, and Ohio) to advance understanding of the regional impacts of climate and socio-economic changes on integrated water resources. Implications for future flow regulation, water supply, and supply deficit are investigated using climate change projections with the B1 and A2 emission scenarios, which affect both natural flow and water demand. Changes in water demand are driven by socio-economic factors, energy and food demands, global markets and prices. The framework identifies the multiple spatial scales of interactions between the drivers of changes (natural flow and water demand) and the managed water resources (regulated flow, supply and supply deficit). The contribution of the different drivers of change are quantified regionally, and also evaluated locally, using covariances. The integrated framework shows that water supply deficit is more predictable over the Missouri than the other regions in the Midwest. The predictability of the supply deficit mostly comes from long term changes in water demand although changes in runoff has a greater contribution, comparable to the contribution of changes in demand, over shorter time periods. The integrated framework also shows that spatially, water demand drives local supply deficit. Using elasticity, the sensitivity of supply deficit to drivers of change is established. The supply deficit is found to be more sensitive to changes in runoff than to changes in demand regionally. It contrasts with the covariance analysis that shows that water demand is the dominant driver of supply deficit over the analysed periods. The elasticity indicates the level of mitigation needed to control the demand in order to reduce the vulnerability of the integrated system in future periods. The elasticity analyses also emphasize the need to address uncertainty with respect to changes in natural flow in integrated assessment.

climate change, water resources management, socio-↗

Integrated Capture and Conversion of CO 2 to Methanol in a Post‐Combustion Capture Solvent: Heterogeneous Catalysts for Selective CN Bond Cleavage

Abstract An efficient and selective heterogeneous catalyst is identified for the condensed‐phase hydrogenation of captured CO 2 in the presence of an advanced water‐lean post‐combustion capture solvent, ( N ‐(2‐EthoxyEthyl)‐3‐MorpholinoPropan‐1‐Amine), 2‐EEMPA. The catalysts commonly used for gas‐phase CO 2 hydrogenation (e.g., Cu/Zn/Al 2 O 3 ) cause deactivation of amine promoters via N ‐methylation by CO cleavage of formamide intermediates. A heterogeneous catalyst system that suppresses N ‐methylation of amine solvents is identified, demonstrating how Pt, supported by reducible metal oxides CeO 2 or TiO 2 , can be selective for CN cleavage to produce methanol. This is the first known demonstration of integrated low‐temperature thermocatalytic capture and conversion of CO 2 to methanol in an economically viable CO 2 capture solvent. Technoeconomic analyses performed on the state‐of‐technology suggest that methanol can be produced with a minimum selling price of $4.4/gallon ($1,460/metric ton) when using CO 2 captured from a 650 MW natural gas combined cycle plant. Ultimately, a road map of how realistic and achievable improvements to space velocity and methanol selectivity of this integrated process can enable near cost parity to fossil‐derived methanol, with a selling price of ≈$1.4/gal ($470/metric ton), is presented.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Designing Cost‐Effective Carbon Payments to Induce Cellulosic Feedstock Production for Sustainable Aviation Fuel

Perennial bioenergy crops, such as miscanthus and switchgrass, and crop residues have the potential to scale up sustainable aviation fuel (SAF) production and mitigate carbon emissions. However, high establishment costs, delayed returns, and risk–return profiles that diverge from those of conventional crops can hinder incentives to adopt bioenergy crops. We develop an economic model that incorporates spatially varying joint yield and price distributions for the multiple crop choices a farmer faces and apply it to examine the incentives for risk-averse, present-biased, and credit-constrained farmers to produce cellulosic feedstocks under various biomass prices. We link this model to a biogeochemical model to quantify the spatially varying carbon mitigation benefits from these feedstocks in the rainfed region of the United States. We also analyze the cost-effectiveness of two carbon payment policies: annual and upfront. We find that risk-averse, present-biased, or credit-constrained farmers prefer to grow the lower-yielding but less risky switchgrass and harvest corn stover instead of the lower carbon, higher-yielding but riskier feedstock miscanthus, resulting in lower SAF production. Upfront carbon payments incentivize higher quantities of less carbon-intensive SAF production by risk-averse, credit-constrained, and present-biased farmers because they offset a part of the establishment costs of miscanthus. We also find that when farmers are credit-constrained, upfront payments are more cost-effective in terms of carbon mitigation per dollar spent. In contrast, annual payments are more cost-effective when farmers can access credit.

09 BIOMASS FUELS↗

Environmental Tradeoffs of Stover Removal and Erosion in Indiana

When considering the market for biomass from corn stover resources erosion and soil quality issues are important to consider. Removal of stover can be beneficial in some areas, especially when coordinated with other conservation practices, such as vegetative barrier strips and cover crops. However, benefits are highly dependent on several factors, namely if farmers see costs and benefits associated with erosion and the tradeoffs with the removal of biomass. Although typically considered an internal cost, the implication is important to policy and contracting for biomass. This paper uses results from an integrated RUSLE2/WEPS model to incorporate six different regime choices, covering management, harvest and conservation, into a simple profit maximization model to show these tradeoffs explicitly. The results of this work show how different costs for erosion, biomass and conservation managements will affect behavior. If erosion prices are low and no conservation requirement exists, biomass removal will significantly increase erosion, but only in some areas. Alternatively, when erosion prices are high, farmers will parallel socially optimal levels of erosion and conservation management practices can be incentivized through access to a market for stover.

09 BIOMASS FUELS↗

Comparative techno-economic analysis and process design for indirect liquefaction pathways to distillate-range fuels via biomass-derived oxygenated intermediates upgrading: Liquid Transportation Fuel Production via Biomass-derived Oxygenated Intermediates Upgrading

This paper presents a comparative techno-economic analysis (TEA) of five conversion pathways from biomass to gasoline-, jet-, and diesel-range hydrocarbons via indirect liquefaction with specific focus on pathways utilizing oxygenated intermediates. The four emerging pathways of interest are compared with one conventional pathway (Fischer-Tropsch) for the production of the hydrocarbon blendstocks. The processing steps of the four emerging pathways include: biomass to syngas via indirect gasification, gas cleanup, conversion of syngas to alcohols/oxygenates followed by conversion of alcohols/oxygenates to hydrocarbon blendstocks via dehydration, oligomerization, and hydrogenation. Conversion of biomass-derived syngas to oxygenated intermediates occurs via three different pathways, producing: 1) mixed alcohols over a MoS2 catalyst, 2) mixed oxygenates (a mixture of C2+ oxygenated compounds, predominantly ethanol, acetic acid, acetaldehyde, ethyl acetate) using an Rh-based catalyst, and 3) ethanol from syngas fermentation. This is followed by the conversion of oxygenates/alcohols to fuel-range olefins in two approaches: 1) mixed alcohols/ethanol to 1-butanol rich mixture via Guerbet reaction, followed by alcohol dehydration, oligomerization, and hydrogenation, and 2) mixed oxygenates/ethanol to isobutene rich mixture and followed by oligomerization and hydrogenation. The design features a processing capacity of 2,000 tonnes/day (2,205 short tons) of dry biomass. The minimum fuel selling prices (MFSPs) for the four developing pathways range from $3.40 to $5.04 per gasoline-gallon equivalent (GGE), in 2011 US dollars. Sensitivity studies show that MFSPs can be improved with co-product credits and are comparable to the commercial Fischer-Tropsch benchmark ($3.58/GGE). Overall, this comparative TEA study documents potential economics for the developmental biofuel pathways via mixed oxygenates.

Tan, Eric C. D.↗

Life-cycle greenhouse gas emissions of corn kernel fiber ethanol

Corn kernel fiber ethanol that can be produced concurrently with corn starch ethanol has recently been approved as cellulosic biofuel in the USA, suggesting that fiber ethanol could be eligible for a higher credit price than conventional starch ethanol due to its anticipated lower greenhouse gas (GHG) emissions. A life-cycle analysis was conducted to quantify ethanol's GHG emissions. Here we show that fiber ethanol's life-cycle GHG emissions (36-39 g CO(2)e MJ(-1)) are close to meeting the US cellulosic biofuel's legislative mandate of 60% GHG emissions reduction relative to gasoline (similar to 94 g CO(2)e MJ(-1)), with slightly lower emissions under the nth plant mature fiber technology than under the state of technology (SOT). The co-product, distiller's grain with solubles (DGS), can notably affect fiber ethanol's GHG emissions, and this impact may need to be further examined when evidence of DGS market impacts becomes available. (c) 2018 Society of Chemical Industry and John Wiley & Sons, Ltd

biofuel↗

Techno‐economic and greenhouse gas analyses of lignin valorization to eugenol and phenolic products in integrated ethanol biorefineries

Abstract This work presents techno‐economic and greenhouse gas (GHG) analyses of an ethanol biorefinery integrating lignin conversion into eugenol and other phenolics. Catalytic hydrogenolysis assisted by isopropanol (IPA) is used to convert the lignin recovered after ionic liquid (IL) pretreatment, saccharification, and fermentation. This process was compared to a biorefinery using lignin for energy generation and simulated in SuperPro Designer. Spatial analysis was performed to determine biorefinery locations and capacities in a Mexican state with potential for lignocellulosic biomass, including corn stover, sorghum stubble, and Jatropha fruit shells. Relative to the base case, diverting 50% of lignin to phenolics decreased the ethanol cost of production significantly due to the high market value of the co‐products. The minimum ethanol selling price (MESP) for this case was $2.02 gal −1 . The resulting cradle‐to‐gate GHG footprint of bioethanol was 21 g CO 2 ‐eq MJ −1 , a 78% reduction with respect to gasoline when system expansion is used for allocation. Using market value‐based allocation resulted in 82% GHG reduction. Analysis of scenarios showed that a biorefinery processing 3000 t day −1 biomass and diverting 80% of lignin to phenolics can potentially yield an MESP lower than $1.5 gal −1 . To achieve this, research should target a reduction in IL input by 30% and IPA input by 40%, together with more energy‐efficient separation processes. The reduction in IL and IPA can be achieved by decreasing their loading rates and increasing recycling. Sensitivity analysis showed that, for biomass prices higher than $45 t −1 , biorefinery capacities must exceed 5000 t d −1 biomass input. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd

Martinez‐Hernandez, Elias↗

Cost and profit impacts of modifying stover harvest operations to improve feedstock quality

Biomass quality attributes, and the potential tractability of those attributes, are key to a successful biomass feedstock supply chain, in addition to quantity and price. Modifying harvest operations is one potential approach to managing biomass feedstock quality for corn stover. For example, eliminating raking from stover harvest operations is proposed as an approach to reduce ash content. However, changes in the stover harvest configuration cause changes in per acre profits, per ton costs, and available supply at specified prices. Here we evaluate sensitivity of profit, cost, and supply to conversion from a three–pass to a two–pass stover harvesting configuration as a means to reduce ash content. For all simulated yields, harvest costs are 2–3 per ton cheaper for three–pass versus two–pass systems wherever residue retention coefficients are less than 0.5, and per ton costs for both systems increase dramatically where residue retention coefficients are greater than 0.7. Per acre net returns are greater under all simulated yields wherever residue sustainability retention coefficients are less than 0.6. Under these conditions, farmers lose between 13 and 49 per acre by harvesting with a two–pass rather than a three–pass system. Where competing with stover markets with less stringent quality specifications, meeting ash targets by harvesting with a two–pass system may require higher grower payments of the order of 9–25 per ton to make up for the per acre lost revenue. Here, when solving for the least–cost supply, agronomic simulations suggest about 2/3 of stover is harvested with a three–pass system.

09 BIOMASS FUELS↗

Environmental and cost benefits of multi‐purpose buffers in an agricultural watershed for biomass production

Abstract The cost‐benefit of riparian buffers to landowners has not been fully understood despite its ecosystem benefits. This study investigates the environmental and economic value of multi‐purpose buffers for biomass production under alternative land‐management scenarios at the watershed scale. The work incorporates the Soil and Water Assessment Tool with a field‐scale tool, the Agriculture Conservation Practice Framework, and cost‐benefit analysis. Our work took place in the agriculturally dominant Raccoon River watershed (RRW) in Iowa. The cost analysis includes implementing and harvesting the switchgrass buffers, the value of nitrogen and phosphorus fertilizer, and the forgone income of cropland to determine the net return under 12 alternative feedstock scenarios. We estimated that 14 603 Mg of nitrogen and 2563 Mg of phosphorus runoffs can be intercepted by riparian buffers in the RRW, representing a nutrient loss reduction of 11% of nitrogen and 26% of phosphorus. These nutrients are valued at $1.31 million (M) for phosphorus and $1.24 M for nitrogen as fertilizers. The trapped nutrients account for 12% of the riparian buffers’ total cost. We found that net economic returns increase with biomass market price, increase with maintenance fertilizer application, and decrease with the cropland areas that are converted to buffers. Under current land management, a biomass market price at $60 per dry ton of biomass would be economically viable at the sub‐basin level when maintenance fertilizers are applied. At $80 per dry ton, all 108 sub‐basins in the RRW would be profitable up to $517 a year. The results highlight the trade‐offs between water quality and profitability. Published 2021. This article is a U.S. Government work and is inthe public domain in the USA. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

09 BIOMASS FUELS↗

Algae to HEFA : Economics and potential deployment in the United States

Abstract To reach the goals set by the US Department of Energy's Sustainable Aviation Fuel (SAF) Grand Challenge, currently available feedstocks may be insufficient. Giving priority to developing, prototyping and reducing the cost of algal feedstock before investing and lining up locations is important. As the production of algal feedstocks advances, a simplified conversion approach using more mature technologies can help reduce the investment risk for algae‐based fuels. Reducing process complexity to the steps described here [namely, conversion of lipids to HEFA (hydroprocessed esters and fatty acids) fuels and relegating the remainder of the biomass to anaerobic digestion or food/feed production] enables the near‐term production of algal SAF but presents challenging economics depending on achievable cultivation costs and compositional quality. However, these economics can be improved by present‐day policy incentives. With these incentives, the modeled algae‐to‐HEFA pathway could reach a minimum fuel selling price as low as $4.7 per gasoline gallon equivalent depending on the carbon intensity reduction that can be achieved compared with petroleum. Uncertainty about algal feedstock production maturity in the current state of technology and the future will play a large role in determining the economic feasibility of building algae‐to‐HEFA facilities. For example, if immaturity increases the feedstock price by even 10%, SAF production in 2050 is about 58% of the production which could have been achieved with mature feedstock. Additionally, growth in this conversion pathway can be notably boosted through the inclusion of subsidies, and also through higher‐value coproducts or higher lipid yields beyond the scope of the process considered here.

09 BIOMASS FUELS↗

Optimal Strategies for Hybrid Battery‐Storage Systems Design

As stationary hybrid energy‐storage systems (HESS) for power systems applications have recently drawn interest due to their enhanced performance and decreasing cost, developing systematic approaches for HESS design while considering controls is gaining traction. Herein, a method is presented to optimally design hybrid battery storage by proposing a mathematical modeling framework, formulated as a mixed integer linear programming model. The optimization is capable of handling multiple subsystems of batteries, considering their economic and technological performance. Decisions involve sizing of the batteries, optimal temporal and strategic dispatch to end uses, and energy sources for charging each battery. The applicability of the model is tested on four case studies for three battery chemistries representing distinct objectives: high‐power, high‐energy, and second life. Compared to traditionally designed battery storage with a homogeneous battery, optimally designed hybrid systems can save 12%–26% of system costs, depending on the nature of the dispatch profile. Findings point to design preference toward the second life battery supplemented with some high‐power or high‐energy battery capacity, or both. With the utilized electricity price structure, customers can experience approximately 10%–35% reduction in their bills.

Koleva, Mariya↗

Carbon mitigation payments can reduce the riskiness of bioenergy crop production

Abstract Perennial bioenergy crops provide substantial carbon mitigation benefits but have risky returns. We couple economic analysis with a biogeochemical model (DayCent) to examine the effect of carbon mitigation payments on the spatially varying bioenergy crop returns and risk profiles relative to conventional crops across the rainfed United States. These payments increase the likelihood of positive profit in the Midwest for miscanthus and southern states for switchgrass. At low biomass prices, these payments make bioenergy crops appealing to risk‐averse farmers. At moderate biomass prices, these payments make bioenergy crops appealing to all farmers regardless of risk preference.

09 BIOMASS FUELS↗