Author: Gozde Ustuner

Institution: Stony Brook University, The Advanced Energy Center

Proton exchange membrane fuel cells (PEMFCs) are considered promising power sources as they offer a highly efficient and environmentally friendly solution for energy conversion. The practical applications of the commercial fuel cell have been not achieved due to its high cost and limited durability of the membrane electrode assembly (MEA). One of the main reasons for the high cost of the MEA is the amount of Pt used to catalyze the oxygen reduction reaction (ORR) at the cathode of PEMFC. Pt is the most used element due to its high activity towards ORR however, its low durability, high cost and degradation due to CO brings the need for a new catalyst development with low Pt content. To date, Pt-Co alloy nanoparticles have been exhibited as one of the best alternative catalyst for commercial Pt/C catalyst. Thus, this work focuses on synthesis of PtCoN/KB electrocatalyst as it promises highly stable and active ORR catalyst. More specifically, it presents that the incorporation of lower Pt mass loadings with Co catalyst will enhance the performance of the ORR and mass and specific activity of the catalyst. Electrocatalytic activity was seen to be improved by doping the catalyst with Nitrogen (N) in previous studies therefore, controlled number of nitrogen into alloy nanoparticles are infused to improve the activity. Electrochemical testing will be conducted to analyze electrochemical surface area (ECSA), mass and specific activity. The chemical and physical properties of the catalyst are characterized by using material characterization techniques to analyze the nanoparticle structure.

Author: Rebecca Trojanowski

Institution: Brookhaven National Laboratory

Interest in the direct use of biomass for thermal applications as a renewable technology is increasing as is also focus on air pollutant emissions from these sources and methods to minimize the impact. This work has focused on wood chip-fired residential boilers, and the impact of fuel chip quality. Manufacturers often specify a specific moisture content the user should burn with; however, users may stray from this value and use a “green” or wet chip which may have poor implications on the emission and efficiency performance of the boiler. Two chip boilers were tested—Boiler A was tested at full load with four (4) different wood chips and the other, Boiler B, was tested with two (2) different wood chips at full load and at minimum load (15% of full load) used for United States compliance testing. During the minimum load, the boiler operated steady but was also forced to cycle during the low load period. Boiler A had a nominal output of 35 kW and was fired with three different chips to identify the effect of hot-water extraction (HWE) and flue gas drying on the wood chips fuel properties and their combustion emissions. The chips moisture contents were 8.98%, 7.89%, 4.50%, and 27.5%. Boiler B had a nominal output of 24 kW and was fired with both “dry” and “wet” woodchips with average moisture contents of 30% and 45%, respectively. For both boilers, the particulate matter (PM) was measured both in real-time using a Tapered Element Oscillating Microbalance (TEOM) and the standard integrated filter approach in a dilution tunnel, capturing both the condensable and non-condensable PM. Gaseous emissions (carbon monoxide and hydrocarbons [methane equivalent]) were captured in the hot flue stack. The test results for Boiler A showed the HWE treated chip had a 50% reduction in particulate emission compared to air-dried chip—with a total reduction of 73% relative to baseline wood chips with emission factors ranging from 0.05 to 0.19 lb/MMBtu for the HWE to the baseline chip. Efficiency values for Boiler A ranged from 79.2% to 83.3%, with the baseline chip producing the lowest efficiency. The test results for Boiler B showed that the use of wet chips significantly impacts the boilers performance in a negative manner, increasing particulates and decreasing its efficiency, particularly in low load operation. When chips with a moisture content of 30% were used, the boilers performance would meet EPA’s step one emission limits, but still fall short of step two with a value of 0.24 lb/MMBtu. With the use wet chips, the emissions are increased by roughly five times to 1.36 lb/MMBtu and efficiency is reduced from 65.3% to 57.7%. The test results for Boiler A showed the HWE treated chip had a 50% reduction in particulate emission compared to air-dried chip—with a total reduction of 73% relative to baseline wood chips with emission factors ranging from 0.05 to 0.19 lb/MMBtu for the HWE to the baseline chip. Efficiency values for Boiler A ranged from 79.2% to 83.3%, with the baseline chip producing the lowest efficiency. The test results for Boiler B showed that the use of wet chips significantly impacts the boilers performance in a negative manner, increasing particulates and decreasing its efficiency, particularly in low load operation. When chips with a moisture content of 30% were used, the boilers performance would meet EPA’s step one emission limits, but still fall short of step two with a value of 0.24 lb/MMBtu. With the use wet chips, the emissions are increased by roughly five times to 1.36 lb/MMBtu and efficiency is reduced from 65.3% to 57.7%. The work presented here not only shows the impact fuel has on the performance of an automatic fed boiler but also the value in evaluating units at low loads, which are common practice in the field. This work is meritorious because it directly evaluates, for the first time, the emissions species (PM, CO, CH4) produced by woodchip fired boilers operating with a range of expected fuels—ranging from commonplace to specialty and also evaluating the effects of fuel moisture content. The impact of burning an upgraded fuel, or minimally a fuel at the appropriate moisture content, can yield to more than a 50% reduction in particulate emissions.

Author: Kun Tan

Institution: Stony Brook University

Replacing fossil fuels and natural gas with alternative fuels like hydrogen is an important step towards the goal of reaching a carbon neutral economy. As an important intermediate step towards utilizing pure hydrogen, blending hydrogen in an existing natural gas network is a practical choice for reducing carbon emissions in the near future. A computational fluid dynamic (CFD) model is developed to quantify frictional losses and energy efficiency of transport of methane/hydrogen blends across straight pipe sections. The CFD model developed in the present study is first validated by verifying that the results obtained in the present study (for pressure drops, numerical friction number (fN), and energy specific toll (EST) agree well with those obtained in an earlier study when identical boundary conditions and model parameters such as Redlich-Kwong equation of state, k-ε turbulence model and pipe wall roughness, are invoked. Furthermore, additional CFD models are developed to assess the effects of other factors such as 1) hydrogen concentration, 2) pipe surface roughness of common pipe materials, and 3) pipe diameter on the dynamics of blended gas flows. The principal conclusions from the present study are as follows: (i) High hydrogen concentration in the gas blends (i.e., greater than 25% and 50%) require higher energy for transporting the blended gases in the pipelines. (ii) Polyethylene (PE) or PE coated pipes, with smoother walls, are 33-40% more energy efficient in transporting gas blends than uncoated stainless steel pipes, which are 17-31% more energy efficient than the uncoated cast iron pipes. (iii) Due to relatively fewer gas interactions with wall surfaces which result in frictional losses, than in the case of smaller diameter pipes, it requires lesser energy to transport blended gases in larger diameter pipes. The CFD model and the simulation results provide valuable operational guidelines for transitioning natural gas networks to transport greener blends of methane and hydrogen.

Author: Wiam Homir

Institution: Stony Brook University

Natural gas consists mostly of Methane gas (CH4) which mainly comes from the decomposition of organic matter. However, there are other ways to produce natural gas other than extracting it from the ground. Methane can be produced from a variety of renewable and sustainable sources. CH4 is a result of a Methanation reaction essentially defined as the process of conversion of (CO) and (CO2) into (CH4) through hydrogenation. Methanation reactions tend to express carbon oxide buildup. To prevent that, Methanation catalysts are added after several hydrogen-producing steps. Through this poster, we will be exploring research that focuses on synthesizing and optimizing methanation nanocatalysts that produce RNG for P2G* technology.

Author: Leela Sotsky

Institution: Stony Brook University; National Renewable Energy Lab

Using hydrogen as fuel has the potential to minimize carbon emissions but implementing hydrogen into existing gas pipeline networks comes with several challenges. Hydrogen can degrade metal pipelines after exposure, which could create safety concerns. Pipeline operators seeking to blend hydrogen into their gas networks will need guidelines to safely inject hydrogen. The U.S. Department of Energy established the Pipeline Blending CRADA – A HyBlend Project to overcome these challenges. The National Renewable Energy Laboratory’s role in HyBlend is to develop an open-source tool, entitled the Pipeline Preparation Cost Analysis tool (PPCT), that can analyze existing natural gas pipeline networks for conversion into hydrogen-blended pipeline systems. The PPCT will be designed for organizations conducting initial assessments of their networks. It will determine if pipelines need to be replaced and/or modified, then provide an estimate of all associated costs. We have identified key pipeline components and their costs. We have also created and analyzed three models of existing gas networks in Scenario Analysis Interface for Energy Systems (SAInT) software. Hydrogen sensitivity analyses were conducted on the models to determine trends in operation conditions. This data will be integrated into the PPCT to create more accurate estimates of the costs of hydrogen blending.

Author: Geuris German

Institution: Stony Brook University

Water treatment facilities are becoming increasingly needed as the climate change crisis continues to alter ecosystems around the globe. Take the water issues currently persisting in the western coastal region of the United States. California has been experiencing its worst drought in over 1000 years. While many potential solutions have been proposed, we are exploring the possibility of utilizing brewery wastewater for water purification. California has almost double the number of breweries in any country (931). According to a publication by The Equipped Brewer, craft brewers, on average, use three gallons of wastewater per gallon of beer produced. In comparison, large brewery facilities use seven gallons of wastewater per gallon of beer. Brewery effluent typically contains high suspended solids, primarily yeasts, hops, other grains, and sugars. These solids are complex for water treatment plants to break down and can consume too much oxygen, disrupting the delicate balance of bacteria and microorganisms that sewage plants rely on. Our approach utilizes the formation of clathrate propane hydrates by mixing propane at 60 psi with wastewater in a windowed reactor and using a cooling bath to lower the temperature to +1-3℃. The collected clean water is achieved by separating the hydrates and then decomposing these hydrates by warming them to room temperature. The water purity is then tested using Total Suspended Solids (TSS). The formation of propane hydrates reduces the number of suspended solids in brewery wastewater and therefore increases water purity.