An official website of the United States government
Abstract Phase One of the Transportation and Transformation of Ammonia (TRANS2Am) field campaign took place in northeastern Colorado during the summer of 2021. One of the goals of TRANS2Am was to measure ammonia (NH3) emissions from cattle feedlots and dairies. Most of these animal husbandry facilities are co‐located within oil and gas development, an important source of methane (CH4) and ethane (C2H6) in the region. Phase One of TRANS2Am included 12 near‐source research flights. We present estimates of NH3emissions ratios with respect to CH4(NH3EmR), with and without correction of CH4from oil and gas, for 29 feedlots and dairies in the region. The data shows larger emissions ratios than previously reported in the literature with a large range of values (i.e., 0.1–2.6 ppbv ppbv−1). Facilities housing cattle and dairy had a mean (std) of 1.20 (0.63) and 0.29 (0.08) ppbv ppbv−1, respectively. We also found that only 15% of the total ammonia (NHx) is in the particle phase (i.e., ) near major sources during the warm summertime months. We examined the evolution of NH3in one plume that was sampled at different distances and altitudes up to 25 km downwind and estimated the NH3lifetime against deposition and partitioning to the particle phase to be 87–120 min. Finally, we calculated estimates of NH3emission rates from four optimally sampled facilities. These ranged from 4 to 29 g NH3 · h−1 · hd−1.
more »
« less
Route Optimization for Ships Using Ammonia-Based Fuel: A Hybrid Genetic Algorithm–Particle Swarm Optimization Approach
In 2018, the International Maritime Organization adopted a plan to reduce greenhouse gas emissions from ships. As a result, ocean carriers and cruise lines are exploring alternative fuels, such as ammonia, which offers zero CO2emissions. Understanding ammonia-based fuel’s impact on range, speed, and fuel logistics can help companies assess its benefits and limitations. To address this, a mixed-integer non-linear programming model is developed to determine the optimal ships’ routes with the objective of minimizing the total travel time while considering factors such as ship speeds, refueling time, and the non-linear fuel consumption rates. A unique aspect of this study is the consideration of a group of ships with different origins and destinations. To solve the non-linear and NP-hard model, a hybrid genetic algorithm–particle swarm optimization algorithm is developed. The proposed model and meta-heuristics are demonstrated using an actual network consisting of ports around the world. Numerical results from a full factorial design with three factors (number of ships, number of origins, and number of destinations) comparing the travel time differences between using ammonia and conventional fuel indicate that NH3-fueled ships generally experience longer travel times than jet-propulsion fuel 8-fueled ships because of NH3’s lower energy density and more frequent refueling requirements. On average, the increase in total travel time is less than 20%. This study serves as a foundation for decision-makers who must also consider additional factors such as economic feasibility, infrastructure costs, environmental impact, and regulatory requirements when assessing ammonia’s viability as an alternative fuel for fleet-wide adoption.
more »
« less
- Award ID(s):
- 2414554
- PAR ID:
- 10611432
- Publisher / Repository:
- Sage
- Date Published:
- Journal Name:
- Transportation Research Record: Journal of the Transportation Research Board
- ISSN:
- 0361-1981
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
null (Ed.)The recent growth in the California hydrogen fuel cell vehicle (FCV) market offers the opportunity to analyze how refueling stations that drivers use after some experience compare with those they initially intended to use. Online surveys completed by 124 FCV adopters in California in early 2019 were analyzed. Respondents listed stations they initially planned to use, stations that they later used, subjective reasons for using them, and important travel destinations. Network GIS analysis was then used to measure estimated travel times between both available and planned retail hydrogen stations and home, work, and frequently traveled routes, both at the time of adoption and at the time of the survey. Results show that 40% of respondents changed refueling stations over time. Those with stations objectively nearer to home, work, and frequently traveled routes were less likely to change their list. Drivers were more likely to subjectively label stations as near home and less likely to label them as on the way compared with objective measurements of these criteria, though these differences are greater for respondents who changed stations. Regardless of whether the station was available pre-adoption or opened post-adoption, stations that respondents added to their lists were farther from home than those they initially intended to use. For stations available pre-adoption, reliability positively influenced adding them after experience, while stations added by drivers that opened post-adoption tended to require short deviations to reach. These results indicate that a mixture of geographic and station-level characteristics contribute to FCV drivers changing stations over time.more » « less
-
Anthropogenic ammonia (NH3) emissions have significantly increased in recent decades due to enhanced agricultural activities, contributing to global air pollution. While the effects of NH3on surface air quality are well documented, its influence on particle dynamics in the upper troposphere-lower stratosphere (UTLS) and related aerosol impacts remain unquantified. NH3reaches the UTLS through convective transport and can enhance new particle formation (NPF). This modeling study evaluates the global impact of anthropogenic NH3on UTLS particle formation and quantifies its effects on aerosol loading and cloud condensation nuclei (CCN) abundance. We use the EMAC Earth system model, incorporating multicomponent NPF parameterizations from the CERN CLOUD experiment. Our simulations reveal that convective transport increases NH3-driven NPF in the UTLS by one to three orders of magnitude compared to a baseline scenario without anthropogenic NH3, causing a doubling of aerosol numbers over high-emission regions. These aerosol changes induce a 2.5-fold increase in upper tropospheric CCN concentrations. Anthropogenic NH3emissions increase the relative contribution of water-soluble inorganic ions to the UTLS aerosol optical depth (AOD) by 20% and increase total column AOD by up to 80%. In simulations without anthropogenic NH3, UTLS aerosol composition is dominated by sulfate and organic species, with a marked reduction in ammonium nitrate and aerosol water content. This results in a decline of aerosol mass concentration by up to 50%. These findings underscore the profound global influence of anthropogenic NH3emissions on UTLS particle formation, AOD, and CCN production, with important implications for cloud formation and climate.more » « less
-
Geodesign is a participatory planning approach in which stakeholders use geographic information systems to develop and vet alternative design scenarios in a collaborative and iterative process. This study is based on a 2019 geodesign workshop in which 17 participants from industry, government, university, and non-profit sectors worked together to design an initial network of hydrogen refueling stations in the Hartford, Connecticut, metropolitan area. The workshop involved identifying relevant location factors, rapid prototyping of station network designs, and developing consensus on a final design. The geodesign platform, which was designed specifically for facility location problems, enables breakout groups to add or delete stations with a simple point-and-click operation, view and overlay different map layers, compute performance metrics, and compare their designs to those of other groups. By using these sources of information and their own expert local knowledge, participants recommended six locations for hydrogen refueling stations over two distinct phases of station installation. We quantitatively and qualitatively compared workshop recommendations to solutions of three optimal station location models that have been used to recommend station locations, which minimize travel times from stations to population and traffic or maximize trips that can be refueled on origin–destination routes. In a post-workshop survey, participants rated the workshop highly for facilitating mutual understanding and information sharing among stakeholders. To our knowledge, this workshop represents the first application of geodesign for hydrogen refueling station infrastructure planning.more » « less
-
Cost-surface analyses in geographic information systems (GIS) can be a useful tool for approximating the travel of historic sailing ships to fill gaps in the historic record. We present the Global-TRANSIT workflow, a least-cost surface raster analysis that uses wind speed and direction to estimate sailing routes and durations for ports globally. Our workflow, freely available as a Python notebook for ArcGIS Pro, makes three contributions relative to previously published toolkits. First, our workflow estimates sail travel for ports at the global scale while accounting for projection-related challenges. Second, our workflow evaluates origin and destination pairs in a many-origins-to-many-destinations matrix structure (compared to previous one-origin-to-one-destination relationship) which increases the scalability of our toolbox. Third, our workflow replaces the deprecated tools used in the previous work with newer tools that reduce the grid-induced bias. Despite the expected limitations of modeling a complex phenomenon like sailing, we find a high correlation between our modeled estimates and historically observed sail duration and routes. The outputs of Global-TRANSIT provide an approximation of the likely duration and route of sail travel between worldwide ports, serving as a reference for understanding historic sail voyage patterns globally and as a benchmark for measuring the evolution of maritime shipping over time.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1177/03611981251338724
