Ports are a major transportation hub for goods movement that drives several economic sectors, but also a major source of harmful pollutant emissions from diesel engines and equipment used in goods movement activities including drayage trucking. Since drayage trucks generally have limited daily mileage, return to a home base every night, and spend a large amount of time creeping and idling, they are well suited for electrification. And because drayage trucks spend a significant portion of their operation time on surface streets with a lot of traffic signals, they are also well positioned to take advantage of connected vehicle technologies that allow them to communicate with other vehicles and traffic infrastructure. As drayage truck fleets are expected to be increasingly electrified and connected in the future, it is important to understand how each of these technological advances and their convergence would impact energy consumption and emissions from drayage truck operations at and around seaports.

This project will evaluate the energy and emission benefits of battery electric trucks and plug-in hybrid electric trucks (BETs/PHETs) over conventional diesel trucks and develop a connected vehicle (CV) application for these trucks. Then, the energy and emission benefits of deploying BETs/PHETs and CV Technologies at ports under a variety of technology penetration scenarios will be estimated. The results and findings from this project can be used to inform the planning and policy development related to goods movement at and around ports.

Lead Faculty: Dr. Peng Hao, Dr. Kanok Bariboonsomsin, Dr. Ji Luo, Dr. Alexander Vu, Daniel Sandez, Chao Wang

Sponsors: Office of the Assistant Secretary for Research and Technology, University Transportation Centers Program, Department of Transportation 

Traffic congestion (either recurrent or non-recurrent) exacerbates the ambient air pollution by contributing a large amount of additional fuel consumption and tailpipe emissions. However, the relationship between the traffic condition and local (e.g., near-road) air pollutant concentration is not well quantified in previous literature. For example, there is a knowledge gap in understanding the impacts of traffic congestion on the degradation of local air quality. The primary goal of this study is to quantify the contributions to the ambient air quality degradation due to traffic congestion, based on statistical methods. First, the air quality measurement data at a fine temporal resolution (e.g. 1-minute or 5-minute) will be requested from a near-road air quality monitoring station. Then, the air quality data, traffic activities, and weather parameters will be integrated into a database. We propose to apply a nonparametric regression technique (e.g., Multivariate Adaptive Regression Splines (MARS) model) to the integrated database for further exploring the influential factors of traffic congestion for air pollutant concentration. The project results can further be used to guide the policy and decision making to mitigate the negative effects on air quality by traffic activities and provide a foundation to evaluate the proactive strategies/applications at both the vehicle/power-train level and traffic level.

Lead Faculty: Dr. Ji Luo, Dr. Guoyuan Wu

Sponsors: Office of the Assistant Secretary for Research and Technology, University Transportation Centers Program, Department of Transportation 

The generation of realistic emissions from many combustion sources under controlled, highly repeatable, conditions typically requires chassis dynamometers, which are not generally accessible to large stationary chambers and to most research groups. Characterizing aerosols from GDI vehicles is an important step in understanding air quality in our region. Less attention has been paid to SOA formation from GDI vehicles, although PM and VOC emissions can be high especially during cold-starts, or gasoline vehicles operating on fuels with different composition. The goal of this study is to characterize the primary emissions and the SOA formation from current technology GDI and PFI vehicles when operated under different driving cycles. For this study, UCR will employ a 30 m³ Mobile Atmospheric Chamber (MACh) (2 mil fluorinated ethylene propylene Teflon film reactor) that was developed to study the aged emissions from different combustion systems. In addition to the mobile chamber, we will also utilize an oxidation flow reactor that was developed in Tampere University of Technology, Finland, which is better suited to measure real-time secondary aerosol formation potential of rapidly changing emission sources due to its improved flow conditions and shorter residence time.

Lead Faculty: Dr. Georgios Karavalakis, Dr. David Cocker, Dr. Thomas Durbin 

Sponsors: Office of the Assistant Secretary for Research and Technology, University Transportation Centers Program, Department of Transportation 

Problem Statement
Heavy-duty vehicles represent one of the most important contributions to the emissions inventory for both nitrogen oxides (NOx) and particulate matter (PM) emissions. Heavy-duty engines have been subjected to increasingly more stringent standards over the years. The latest round of standards essentially requiring the use of diesel particulate filters (DPFs) and selective catalytic reduction (SCR) to meet the PM and NOx emissions standards, respectively. While these aftertreatment systems have provided significant reductions in PM and NOx emissions, it is important to verify that these systems are operating optimally under the full range of in-use conditions to ensure that air quality standards can be met. This is particularly true in the South Coast Air Quality Management District (SCAQMD), where it is projected that mobile source NOx emission levels will need to be reduced significantly to meet the 2023 and 2031 ozone standards.
The heavy-duty diesel SCR equipped engine has reduced NOx emissions, by 90%, from previous levels when tested on the certification cycle, but not during in-use operation. Compliant 2010 vehicles were found to have NOx emissions ten times higher than the certification limit on low power test cycles, but meeting the limit on certification like cycles, (Dixit et al, 2017, Misra et al., 2013, Quiros et al., 2017, and Lee et al., 2018). The Air Resource Board is proposing a low-NOx standard of 0.02 g/bhp-hr, a low power test cycle, and revisions to the Not-To-Exceed compliance test to try and close the gap between certification and in-use. A different solution is to measure all the trucks all the time with on board sensing and validate compliance from the in-use fleet under the conditions where they produce emissions. It is suggested, that there will always be a gap between our standards (policy) and the in-use emissions (real exposure) until we focus on in-use measurements for our compliance and certification methods.
Complying with in-use conditions will be a challenge and will require a change from laboratory or portable emissions measurement system (PEMS) testing to an on-board continuous measurement and reporting system. The system proposed here is called Onboard Sensing, Analysis, and Reporting (OSAR). OSAR utilizes sensors technology that is borrowed from the vehicles embedded control system. These control sensors have been studied and are relatively accurate, repeatable, and very durable. Tan et al., (2018) evaluated the in-use NOx emission rates from the on-board diagnostic (OBD) sensors of 72 HDDVs. They found that high NOx emissions were still a common problem in from in-use heavy-duty diesel fleets, primarily due to low SCR conversion efficiencies during low temperature operation and potentially from malfunctioning SCRs. Montes (2018) compared these same OBD sensors with the laboratory and found that the sensors on average were with-in 15% (with a range from -5% to +50%) of the laboratory measurement. One significant concern with OBD NOx sensors is that they are disabled below 200 C to prevent humidity damage to the ceramic sensing element. NGK-sparkplugs, a large manufacturer of OBD NOx sensors, developed prototypes that operate at lower conditions than the OBD sensors and also improved their accuracy. The low temperature conditions are important because this is where the highest NOx emissions are generated for SCR equipped diesel engines. Yang et al. (2018) utilized this prototype sensor and found NOx measurements were within approximately ±10% of those the full 1065 compliance PEMS system over a range of driving conditions and emissions sources.

Research Objectives and Plan
The overall goal of this research is to create an on-board reporting system to guide the industry into a sustainable path of emissions control for their vehicles using the real world as the design platform. UCR is already in the contracting process with the South Coast Air Quality Management District to fund Phase 1 of this work. The goal of Phase 1 of this work will be to develop and demonstrate a low cost NOx and PM sensor-based emissions measurement designed for heavy duty engines.
The OSAR system being developed under Phase 1 will include a NOx and PM sensor, a GPS, a ECM logger, and a cellular connection for real-time data reporting. UCR has already made arrangements with a leading commercial OBD NOx sensor manufacturer, NGK-Sparkplugs (also known as NTK Technical Ceramics), to provide 30 in-kind prototype advanced low temperature capable NOx sensors systems. For PM, UCR has made arrangements with EmiSense, a leader in the real-time OBD PM sensors, who will provide five in-kind PM Track sensors and the project will purchase the other five in-situ PM Track sensors. EPA is also looking to provide 10 – 30 ECM cellular data loggers through their Cooperative Research and Development Agreement (CRADA) with UCR. Also since there are many short on/off trips expected (based on our significant amount of activity data logging experience) we plan to integrate some type of ~30 minute battery buffer to delay shutdown during a key-off/on condition. This will allow the system to be warmed up and ready to capture all cold start emissions (future implementation of our design could include machine-learning to do this automatically).
The phase 1 funding, in conjunction with in-kind funding from CARB, will also be used to validate the sensor system. Bench evaluations in CE-CERT’s sensor laboratory will be conducted to evaluate various aspects of the sensor/system operation prior to deploying. This will include tests to evaluate startup, data logging, sensor checks and robustness. PEMS comparisons will also be conducted for validation emissions testing at the start, middle, and end of the demonstration project. For this exercise, to be supported by CARB and the EPA, the mini-PEMS emissions measurements will be cross compared against measurements made with a 1065 PEMS. This would allow the characterization of the accuracy of the PEMS, as well as issues that might be due to aging or drift issues over a real usage cycle.
Under CARTEEH funding, the goal of the research proposed under this proposal would to expand this research to extend the time for the field demonstration for the mini-PEMS, and to develop a visual aid that would provide for provide a visual characterization of emissions on both a spatial and temporal basis. This would allow the scope of the OSAR research to be broadened considerably in terms of scope and stakeholders. This additional funding would further spur the industry into a solution that includes instrumenting all new heavy-duty trucks with ideas for retrofitting older ones depending on feedback from the Agencies. Also it is believed this proposal will be supported by the industry and fleets owners as it benefits everyone with a fair and practical solution for emissions regulations. Eventually other mobile sources will follow this pattern, including non-road and light duty passenger cars.
The overall approach for the CARTEEH program will be to expand the on-vehicle demonstration to 12 months, develop the visual aid, and analysis and reporting.

Lead faculty: Dr. Kent Johnson, Dr. George Scora, Dr. Thomas Durbin, Dr. Georgios Karavalakis 

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