Source: PENNSYLVANIA STATE UNIVERSITY submitted to NRP
BIOFILTERS FOR METHANE MITIGATION FROM LIVESTOCK FACILITIES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1028650
Grant No.
2022-67022-37610
Cumulative Award Amt.
$300,000.00
Proposal No.
2021-10442
Multistate No.
(N/A)
Project Start Date
Jun 15, 2022
Project End Date
Jun 14, 2026
Grant Year
2022
Program Code
[A1531]- Biorefining and Biomanufacturing
Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
408 Old Main
UNIVERSITY PARK,PA 16802-1505
Performing Department
Agricultural & Biological Engi
Non Technical Summary
The goal of this seed project is to study the causes of nitrous oxide formation in biofilters used for methane abatement of enclosed livestock systems. Biofilters are a promising solution for mitigation of methane emissions from agricultural systems, but the potential generation of the potent greenhouse gas nitrous oxide in these biofilters can hinder their applicability. Our objectives are to test the effects of (1) the concentration of ammonia in the inlet air, (2) the moisture content, and (3) the packing media compaction on the biofilter performance and nitrous oxide formation. Our central hypothesis is that these properties have a strong influence on the production of nitrous oxide in biofilters, and that the understanding of these mechanisms can help us control the production of nitrous oxide in the future. The results of this project will allow us to propose methods to regulate nitrous oxide formation in methane biofilters and will provide a strong foundation for future biofilter designs and specifications, which will make us competitive for future funding to develop economically feasible methane biofiltration systems for livestock facilities.Our system uses gas waste from livestock systems in an engineered system, the biofilter, that could be made completely from biobased materials and commercialized in the marketplace. The main product from the biofilters is the methane mitigation, which is an ecosystem service with an incipient, but increasingly recognized market. These biofilters will contribute to the long-term economic and environmental sustainability of livestock production and processing systems.
Animal Health Component
60%
Research Effort Categories
Basic
20%
Applied
60%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1320410202025%
1330410202025%
3070410202025%
1414010107025%
Knowledge Area
133 - Pollution Prevention and Mitigation; 132 - Weather and Climate; 307 - Animal Management Systems; 141 - Air Resource Protection and Management;

Subject Of Investigation
4010 - Bacteria; 0410 - Air;

Field Of Science
2020 - Engineering; 1070 - Ecology;
Goals / Objectives
Our long-term goal is to enable net zero carbon biofiltration systems for low concentration CH4 oxidation and carbon capture. This will require the ability to regulate the generation of N2O in biofilters, for which we first need to understand the underlying causes of its production. Thus, our objective for this seed project is to study the causes of N2O formation in CH4 biofilters for enclosed livestock systems. To achieve this objective, we proposed the following specific aims:Specific Aim 1. Determine the effect of inlet-air ammonia on the formation of nitrous oxide in methane biofilters.Specific Aim 2. Identify the effect of moisture content on the formation of nitrous oxide in methane biofilters.Specific Aim 3. Determine the effect of compaction in the packing media on the formation of nitrous oxide in methane biofilters.
Project Methods
We will perform a series of experiments to evaluate the effect of key process conditions and packing media on the production of N2O in CH4-oxidizing biofilters. We will use a biofilter system developed in the PI's Vasco Bioeco Lab. The system consists of a bank of laboratory scale biofilter columns connected to a gas dilution system to control inflow gas composition and flowrate by mixing CH4, NH3, and air. A humidifier will be used to control moisture content in the inlet gas. The standard biofilter packing media will consist in a 50:50 mix of compost obtained from the Penn State Organic Materials Processing Center (OMPEC) facility mixed and woodchips provided by the Penn State Office of the Physical Plant Grounds Maintenance.To determine the biofilter efficiency, we will monitor CH4 oxidation by measuring its concentration in the inlet and outlet air streams. We will also monitor the concentrations of CO2, NH3, and N2O, and quantify the N2O generation or mitigation. Concentration of gases will be measured by gas chromatography. We will operate the biofilters under baseline conditions until steady state is reached, and then the experimental conditions will be introduced.Specific Aim 1. Determine the effect of inlet-air ammonia on the formation of nitrous oxide in methane biofilters.We will vary the concentration of NH3 in inlet air of the CH4 biofilter, from 0 to 100 ppm, while keeping the CH4 concentration constant at 0.1%. Then, we will repeat the procedure at a constant CH4 concentration of 1%.We will measure the biofilter efficiency, the production of N2O, and the conversion of NH3. We will perform this test in biofilters packed as follows: (1) standard mix media (compost/woodchips, 50:50), (2) 60:40 standard mix media and expanded vermiculite, which has been reported to increase methane oxidation in biofiltersand has potential for ammonium sorption,and (3) 60:40 standard mix media and sawdust biochar, which has shown the capacity to increase CH4 oxidation in biofiltersand to decrease ammonia emissions in composting.Three biological replicates (filters) of each packing media will be evaluated. We will sample the biofilters on at least three different times during the experiment for microbial community analysis, which will be performed via 16S rRNA gene amplicon sequencing following previous studies.We will also measure the properties of the packing media after the biofiltration process, including proximate and ultimate analysis, water holding capacity, bulk density, porosity, and specific surface area.Specific Aim 2. Identify the effect of moisture content on the formation of nitrous oxide in methane biofilters.We will vary the biofilter operating moisture content by controlling the moisture content in the inlet air stream with the humidifier. We will evaluate moisture content from 20% to 75%in biofilters packed with (1) our standard media (compost/woodchips, 50:50), (2) expanded vermiculite and standard media (40:60), and biochar with standard media (40:60). Three biological replicates (filters) with each packing media will be performed. Both expanded vermiculate and biochar have a high water holding capacity,and thus are expected to allow a high moisture in the biofilter, favoring CH4 oxidation while controlling N2O formation. Biochar has shown to reduce the N2O formation in compost.We will evaluate CH4 oxidation, N2O production, microbial community composition at three different times/moisture contents, and packing media properties as described in Aim 1 above.Specific Aim 3. Determine the effect of compaction in the packing media on the formation of nitrous oxide in methane biofilters.To isolate the effect of the packing media compaction, we propose to develop biofilters with identical packing material (standard packing media described above) but packed at different compaction levels, following the packing procedure reported by Nakhli et al. (2021).We will study the effects of packing bed compaction on the CH4 oxidation and N2O production, and microbial community composition, as described above.

Progress 06/15/24 to 06/14/25

Outputs
Target Audience:The target audience reached by our efforts during this reporting period includes academics in agricultural sciences, environmental engineering, and agricultural engineering, interested in technologiesto reduce emissions from livestockfacilities, and industrial and environmental microbiology researchers interested in solid-state biomanufacturing and bioremediation. Changes/Problems:The overall research objectives and structure of the project remain aligned with the original proposal; however, several refinements and additions have been made in response to new findings and operational challenges encountered. Our experimental approach was originally delayed due to the availability of the biofiltration columns, which were originally deemed unsafe to use and required redesign. However, we were finally able to perform the experimental work in the columns, along with bottle experiments that have enhanced our understanding of the complex phenomena in methane biofilters. During this reporting period, one major issue arose during the pilot-scale continuous experiments when we attempted to replicate the high-moisture conditions (65%) that led to elevated N2O emissions in the bottle-scale studies. At this scale, however, the high moisture content resulted in clogged media, severely restricted airflow, and visible mold growth. These conditions rendered the system inoperable and forced us to terminate the experiments. This outcome highlighted an important practical limitation of biofilter operation under high-moisture regimes, which we will incorporate into future design considerations and feasibility assessments. We also encountered limitations in the low air flow rates that we attempted to test in the continuous biofilters. The flow rate of 0.5 lpm was not enough to provide flow through the whole height of the 1-meter biofiltration column, so we had to reduce the column height to half of the original height for this experimental condition. In the modeling component, we continued to build on the mathematical framework introduced last year, which was originally added to compensate for early delays in experimental work. This year, we extended the model by developing a gene-centric integration approach, which focuses on quantifying the abundance and expression of key functional genes--specifically methane monooxygenase (MMO)--from our omics datasets. This approach emerged as a more suitable alternative to pathway-level integration, offering a mechanistic and scalable way to connect microbial community structure with system performance. However, the unexpectedly long times required for the omics microcial community analysis have not allowed us to perform validation of this approach, which is still pending. Additionally, we continued the parallel work on techno-economic analysis and life-cycle assessment, which were incorporated last year in response to stakeholder interest. These tools are proving critical for evaluating the real-world feasibility of methane biofiltration in agricultural applications, and the results have sparked new questions about system optimization and full-scale implementation, some which may be outside the scope of the current project. What opportunities for training and professional development has the project provided?This project continues to provide meaningful training and professional development experiences for students at all levels. Camila Gonzalez Arango, the PhD student funded by this award, is in the final stages of her doctoral work. She has completed her dissertation and defendedon May 9, 2025. Her dissertation was recently approved and she is scheduled to graduate in August.Throughout the project, Camila has developed a strong foundation in experimental design, process modeling, and interdisciplinary collaboration, contributing significantly to both research outcomes and mentorship within the team. Camila isstaying as a postdoctoral scholar after her graduation, to help us finish this project. Johannes Ali, an MS student in Biorenewable Systems, has made substantial progress in his research over the past year. He has completed several bottle-scale experiments and has starteda pilot-scale experiment based on those findings. In addition, Johannes extracted DNA from all samples generated during his bottle experiments and Camila's pilot-scale studies. Part of these samples have been sequencedand he is currently coordinating RNA extractions and additional sequencing efforts. He is expected to finish his degree in December 2025 and continues to play a key role in advancing the experimental and analytical components of the project. Undergraduate students have also remained actively engaged. Last summer, Irene Ochoa, an undergraduate student at California State University, Channel Islands, worked remotely on a sensitivity analysis of the integratedmodel of the biofilters. She returned this summer as a research assistant to further develop that work, gaining additional hands-on experience with experimental approaches of the biofilter and bioinformatics of the sequencing data. Another undergraduate student, Caitlin Grabowski, spent this reporting period completing herHonors Thesis in Biological Engineering, which was officially approved in April 2025. Her thesis research, which tested different materials for methane biofiltration efficiency and nitrous oxide production,was directly connected to the project's objectives and demonstrates the integration of undergraduate research into the broader project framework. Tate Geiger, who was instrumental in designing and building the biofilters, continues to assist in their operation and documentation, currently working on a draft manuscript to publish the equipment design. These diverse training opportunities reflect the project's continued commitment to developing the next generation of researchers and professionals in biorenewable systems. How have the results been disseminated to communities of interest?We have disseminated project outcomes through a range of local, national, and international conferences, reaching multidisciplinary audiencesincluding students, professionals, and academics. These efforts have helped raise awareness of methane emissions in livestock facilities and introduced the engineering solutions under development, supporting workforce development in aligned fields. We have also engaged with professionals from the public and private sectorsworking on projects with the Pennsylvania dairy industry to reduce their emissions. They are considering the biofilter technology as an emerging approach to reduce emissions from manure and digestate management,and enteric fermentation. Our modeling framework, developed using the biofilters in this project, has been shared with academics working on other systems, and we are currently working with different collaborators on extending this framework to other bioprocessing systems driven by complex microbial communities, such as anaerobic digestion of lignocellulosic biomass and wastewater treatment. What do you plan to do during the next reporting period to accomplish the goals?In the next year, weplan to conduct a series of targeted follow-up experiments to test specific hypotheses that have emerged from the analysis of our existing data.These experiments will allow us to validate trends observed in previous trials and refine our understanding of the system's behavior under varying conditions. We will also complete the metagenomicsequencing that is in process andanalyzethese datasets to gain a deeper understanding of the microbial communities involved in the biofiltration process and their functional roles. These biological data will then be integrated into our process model using the systems framework we have developed. This integrative approach will allow us to capture both performance metrics and underlying biological mechanisms, enhancing the predictive capacity of our model. Finally, we will focus on the preparation and submission of manuscripts for peer-reviewed publication. These manuscripts are already in draft stage and are waiting for the final results.They will disseminate the key findings of the project to the broader scientific community and contribute to the knowledge base surrounding biological methane mitigation technologies. In the meantime, we will continue disseminating our work to conferences presentations and other outreach opportunities.

Impacts
What was accomplished under these goals? Methane remains a high-priority target for emissions mitigation in livestock facilities,where the methane is often emitted in low concentrations, making conventional recovery methods impractical. Biofiltration presents a promising alternative by leveraging methanotrophic bacteria to oxidize methane into less harmful byproducts. However, a major challenge remains: the unintended formation of nitrous oxide, an even more potent greenhouse gas. This project focuses on developing efficient biofiltration systems that can decrease the methane emissions while limiting the nitrous oxide emissions for agricultural applications. During this reporting period, we have significantly advanced both the experimental and modeling aspects of the project, deepened our understanding of microbial dynamics within the system, and taken important steps toward integrating biological data into a robust modeling framework that informs system design and scalability. Experimental Approach During this reporting period, we completed a comprehensive set of bottle-scale experiments to evaluate the influence of key operational parameters on methane oxidation and nitrous oxide (N2O) emissions. Specifically, we tested moisture contents of the packing material at 45%, 55%, and 65%; pH levels of 4, 7, and 10; and two alternative packing materials--perlite and vermiculite--each mixed with compost in a 50:50 ratio. These experiments revealed that high moisture levels and extreme pH values (both acidic and alkaline) significantly increased N2O emissions, highlighting the sensitivity of the system to these conditions. In addition, wefound that both the vermiculite- and perlite-containing biofilters were more efficient at oxidizing methane than compost alone, with vermiculite achieving the highest methane oxidationrate while also producinggreater levels of carbon dioxide and nitrous oxide, indicating a tradeoff between methane removal and nitrous oxide production in biofilters. At the conclusion of the bottle experiments to evaluate the effect of moisture and pH, we extracted and sequenced DNA from all samples, and analysis of the resulting microbial community data is currently underway to enhance our understanding of the drivers of these phenomena. In addition to the bottle studies, we conducted a series of continuous pilot-scale experiments evaluating different operational parameters such as methane inlet concentration and flow rate, which were both found to have a significant effect on methane biofiltration efficiency. These systems initially showed a rapid stabilization phase, with methane removal efficiencies reaching as high as 89%. However, performance declined over time and eventually stabilized at a suboptimal removal level of around 13-27%. Notably, these experiments showed little to no production of N2O. When we tried high moisture content (65%) to try to reproduce the conditions from the bottle experiments that produce high N2O, the biofilters were not operational, since this high moisture content did not allow a continuous air flow rate and promptly generated visible mold formation, which led us to interrupt the experiments. We are now trying intermediate levels of moisture to determine the upper moisture limit for operability and N2Oproduction.We have extracted DNA from all samples collected during these continuous experiments andsequenced them to study the microbial community dynamics through these significant changes in methane removal efficiency. The bioinformatics analysis is currently underway. Concurrently, RNA extraction is ongoing for all samples from both the bottle and pilot-scale studies, which will allow us to assess gene expression and gain further insights into the functional activity of the microbial communities involved. However, the protocol for RNA extraction is still pending, since the sample we are obtaining does not yet comply with the required quality standards for sequencing. Modeling Approach When trying to validate our previously developed process model with the experimental data obtained, we realized that the model did not reflect the observed phenomena. Thus,we developed a dynamic, spatially resolved model that explicitly simulates mass transfer, microbial kinetics, and biomass growth over time, and that better adjusts to the observed data. The system is modeled as a one-dimensional plug flow reactor with axial gas transport, and includes a biofilm domain with evolving thickness driven by microbial growth. Gas-biofilm mass transfer is modeled using non-equilibrium fluxes governed by global transfer coefficients, and CH4 oxidation is represented through dual-substrate Monod. This model adjusts much better to the dynamic changes of the biofilters over time. Building upon the modeling framework developed in the previous reporting period, we performed a sensitivity analysis of our integrated model that combines Monod-based kinetics with predictions from Flux Balance Analysis (FBA) to evaluate system performance under varying environmental and biological conditions. This analysis helped identify key parameters influencing methane oxidation rates and potential nitrous oxide formation, offering guidance for experimental design and system optimization. Since developing FBA models that are realistic of our biofilters could be challenging, limiting the application of the first approach for integrating information about microbial communities into the process model, we have also developed a gene-centric modeling approach to integrate microbial community data directly into the biofilter process model. This approach leverages the quantification of key functional genes--specifically methane monooxygenase (MMO), a critical enzyme in methane oxidation--using data obtained from our metagenomic and transcriptomic analyses. By linking gene abundance and expression levels to microbial activity and reaction kinetics, this method provides a more mechanistic and dynamic representation of the biological processes occurring in the biofilter. We developed this model using data omics data reported for compost in literature, and will be validating it with our own omics data that is currently being generated. Together, the sensitivity analysis and the gene-centric integration framework mark important advancements in our modeling capabilities, enabling more accurate predictions of biofilter performance across diverse operational conditions and microbial community structures. These developments will be crucial as we move toward a systems-level understanding of methane mitigation in agricultural applications.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Gonzalez, C., Regan, J. M., Richard, T. L., & Vasco-Correa, J. (April 5, 2025). "Incorporating compositional abundance data into the ADM1 model to simulate anaerobic digestion of switchgrass under varied process conditions," 26th Annual Pennsylvania State Universitys Interdisciplinary Environmental Research Symposium (PIERS), Student Association of Environmental Science and Engineering, University Park, PA. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Vasco-Correa, J., Wu, Y., Restrepo-Florez, J. M., Valderrama, C., & Rahic, E. (October 2, 2024). "Open-source techno-economic models for decision-making in biorefining research and development," Frontiers in Biorefining, St. Simons Island, GA, Invited Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Vasco-Correa, J., Gonzalez, C., Peacock, V., & Ali, J. (September 14, 2024). "Biofiltration design to reduce diffuse methane emissions," IBE Annual Meeting, Atlanta, GA. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Vasco-Correa, J., Wu, Y., Restrepo-Florez, J. M., Gonzalez, C., Valderrama, C., Porcano, H., & Rahic, E. (September 14, 2024). "Open-source process models to accelerate innovation in biorefining," IBE Annual Meeting, Atlanta, GA. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Peacock, V., Gonzalez, C., Kelly, D., Costello, C., Fabian, E. F., & Vasco-Correa, J. (July 31, 2024). "Assessing the economic and environmental feasibility of biofiltration for methane reductions on Pennsylvania dairy farms," ASABE Annual International Meeting, Anaheim, CA. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gonzalez, C., Parham, K., Delgado-Vela, J., & Vasco-Correa, J. (July 31, 2024). "Integration of methanotrophic flux balance analysis into a mechanistic model for methane biofiltration systems," ASABE Annual International Meeting, Anaheim, CA. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gonzalez, C., Parham, K., Delgado Vela, J., & Vasco-Correa, J. (July 15, 2024). "Advancing Mechanistic Models for Methane Biofiltration Systems," Northeast Agricultural and Biological Engineering Conference (NABEC), State College, PA. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Peacock, V., Gonzalez, C., Kelly, D., Costello, C., Fabian, E. F., & Vasco-Correa, J. (July 15, 2024). "Assessing the feasibility of biofiltration for methane reduction on Pennsylvania dairy farms," Northeast Agricultural and Biological Engineering Conference (NABEC), State College, PA. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Ali, J., Gonzalez, C., & Vasco-Correa, J. (April 18, 2025). "Impact of media properties on biofiltration efficiency for reducing greenhouse gas emissions in livestock operations," Biorenewables Symposium, Center for Biorenewables, University Park, PA. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Grabowski, C., Gonzalez, C., Ali, J., & Vasco-Correa, J. (April 5, 2025). "Exploring mixed packing media in methane biofiltration," 26th Annual Pennsylvania State Universitys Interdisciplinary Environmental Research Symposium (PIERS), Student Association of Environmental Science and Engineering, University Park, PA. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Ali, J., Gonzalez, C., & Vasco-Correa, J. (March 28, 2025). "Impact of media properties on biofiltration efficiency for reducing greenhouse gas emissions in livestock operations," Graduate Exhibition, Graduate School, University Park, PA. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Grabowski, C., Gonzalez, C., Ali, J., & Vasco-Correa, J. (March 27, 2025). "Exploring mixed packing media in methane biofiltration," Gamma Sigma Delta Research Symposium, University Park, PA. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Ali, J., Gonzalez, C., & Vasco-Correa, J. (March 27, 2025). "Impact of media properties on biofiltration efficiency for reducing greenhouse gas emissions in livestock operations," Gamma Sigma Delta Research Symposium, University Park, PA. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Ochoa, I., Gonzalez, C., & Vasco-Correa, J. (November 14, 2024). "Exploring the effect of different parameters of a methane biofiltration model using sensitivity analysis," Annual Biomedical Research Conference for Minoritized Scientists (ABRCMS), Pittsburgh, PA. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Ochoa, I., Gonzalez, C., & Vasco-Correa, J. (September 19, 2024). "Exploring the effect of different parameters of a methane biofiltration model using sensitivity analysis," California State University Channel Islands Fall Student Research Showcase, Camarillo, CA. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gonzalez, C., Parham, K., Delgado-Vela, J., & Vasco-Correa, J. (August 8, 2024). "Air biofiltration technology for the mitigation of diluted methane emissions," 2nd Process Systems Engineering (PSE) in Mexico Summer Workshop, Puebla, Mexico. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Ali, J., Gonzalez, C., & Vasco-Correa, J. (July 24, 2024). "Efficient biofiltration systems to reduce greenhouse gas emissions from livestock facilities," S-1075 The Science and Engineering for a Biobased Industry and Economy, Brookings, SD. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gonzalez, C., Parham, K., Delgado-Vela, J., & Vasco-Correa, J. (July 24, 2024). "Integration of methanotrophic flux balance analysis into a mechanistic model for methane biofiltration systems," S-1075 The Science and Engineering for a Biobased Industry and Economy, Brookings, SD. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Ali, J., Gonzalez, C., & Vasco-Correa, J. (July 15, 2024). "Effects of operational parameters of methane biofilters efficiency and nitrous oxide mitigation," Northeast Agricultural and Biological Engineering Conference (NABEC), State College, PA. Poster Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Ochoa, I., Gonzalez, C., & Vasco-Correa, J. (November 23, 2024). "Exploring the effect of different parameters of a methane biofiltration model using sensitivity analysis," Southern California Conference for Undergraduate Research (SCCUR), San Bernardino, CA. Oral and Poster Presentation.
  • Type: Theses/Dissertations Status: Published Year Published: 2025 Citation: Grabowski, C. (2025). Exploring Mixed Packing Media as a Means of Improving Methane Biofiltration. Honors Thesis. Agricultural and Biological Engineering. The Pennsylvania State University.
  • Type: Theses/Dissertations Status: Accepted Year Published: 2025 Citation: Gonzalez Arango C. (2025). Integrated Modeling of Methane Treatment Systems: Linking Process Performance to Microbial Function in Methane Biofilters and Anaerobic Digestion. PhD. Dissertation. Agricultural and Biological Engineering. The Pennsylvania State University.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Gonzalez, C., Regan, J. M., Richard, T. L., & Vasco-Correa, J. (May 7, 2025). "Integrating omics data into dynamic simulations of anaerobic digestion of lignocellulosic biomass," 47th Symposium on Biomaterials, Fuels and Chemicals, Society of Industrial Microbiology and Biotechnology, Milwaukee, WI. Oral Presentation
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Held, T., Ingalls, G., Noble, B., Schultz, G., Chaudhuri, N. R., Dzade, N. Y. , Fronk, B., & Vasco-Correa, J. (May 21, 2025). "Technologies for the Future of Energy," IndustryXchange 2025: Energy, College of Engineering, University Park, PA, Invited Panel.


Progress 06/15/23 to 06/14/24

Outputs
Target Audience:The target audience reached by our efforts during this reporting period includesacademics in agricultural sciences, environmental engineering, and agricultural engineering interested in climate-smart technologies for livestock facilities, and industrial and environmental microbiology researchers interested in solid-state biomanufacturing and bioremediation. Changes/Problems:Our experimental approach was originally delayed due to the availability of the biofiltration columns. Our previous system had many leaks and was deemed unsafe to operate with methane at the beginning of the grant period. Rather than repairing it, we decided to replace it, since the leaks were substantial. The mechanical and control parts of the new system were working this year; however, the gas detection systems presented many problems. We had to call someone to service it, which delayed our work for months. To solve this problem, we did the following: first, developed a protocol for batch testing in bottles, to continue our experimental evaluation independently of the biofiltration system's availability; and second, we developed an alternative way to measure the gas concentration in the biofiltration system using gas chromatography which allows us to continue the experiments if/when the automatic detection systems fails. Now we are running the experiments smoothly; however, each experimental run takes 2-3 months, so we do nothave all the results to report yet. Due to the original delay, we decided to also include a mathematical model as part of our research approach, which was not included in our original proposal. This has added great benefits to our approach, significantly improving our understanding of the operation of methane biofilters and helping us reach the overall goal of the project. Thus, we have continued with this approach in parallel to the experiments, adding to the modeling framework. This year, we decided to also include a techno-economic analysis and life cycle assessment, which were not included in the initial proposal either. This was due to questions from different stakeholders about the feasibility of our system in real applications. The results from this approach have opened new avenues of research about the biofilter design at full scale, which we expect to keep pursuing. What opportunities for training and professional development has the project provided?This project has offered ample opportunity for training and professional development for a significant group of students. The PhD student funded by the award, Camila Gonzalez Arango, has received mentoring and training from the PD and co-PDs on different aspects of the project, and has been able to present at a wide range of conferences, receiving training and feedback on her work and communication skills. She has also received numerous awards for her research and mentoring of the other students in the team, and has given two invited talks about the project at national conferences. Two MS students have also been involved in the project. One MS studentin Engineering Design (Shakthi Suresh) finished his thesis that focused on thedesign and building of the pilot biofiltration systems. This student graduated in August of 2023.A new MS in Biorenewable Systems (Johannes Ali) joined the team in January of 2024. This student is currently working on advancing the experimental approaches of the project. In addition, several undergraduate students have been involved in different capacities in the project. This includes four Biological Engineering students working on aspects such as the building and maintenance of the bank of biofilters, bottle experimental approaches, and techno-economic analysis and life-cycle assessment of the system. One of these students (Vancie Peacock) completed her honors thesis in April 2024. Two of the undergraduate students, along with the PhD student, participated in the American Society of Agricultural and Biological Engineers 2023 Bioprocessing Startup Competition with the biofilters concepts, where they received the second-place award. This competitionallowed them to develop entrepreneurship and communication skills and provided them with exposure at the national level of the profession. How have the results been disseminated to communities of interest?We have disseminated the results in a wide variety of conferences targeting academics and students in different disciplines, at the local, regional, national, and international levels. Some of these conferences have targeted specific student audiences, enabling us to engage the next generation of scientists, engineers, and agricultural practitioners, raise awareness about the challenges of diffuse methane emissions, and introduce them to potential engineering solutions that we are developing. We have also been invited to present ourwork to communities of scientists working on climate-smart solutions for the dairy industry in Pennsylvania, who are very interested in technologies to reduce greenhouse gas emissions from enteric fermentation. We have provided feedback on technical documents about emerging technologies for this purpose. Finally, we have also been invited to talk to different communities around the nation about our approach to integrate different mathematical models for biobased systems, including the integration of omics data. This novel approach was all developed under this project, and our models are open-source and sharable. What do you plan to do during the next reporting period to accomplish the goals?In the next reporting period, we expect to finish the proposed experiments, which include the study of the different packing materials, the bottle experiments to test different conditions, and the continuous experiments to test different airflow and methane concentrations in the inlet stream. We also expect to sample and sequence the microbial communities on the biofilters, to enhance our understanding of the actual microorganisms involved in the biofiltration process. These data will then be used to incorporate into our mathematical models, using the integration approach recently developed.

Impacts
What was accomplished under these goals? Methane is a potent greenhouse gas with a global warming potential significantly higher than carbon dioxide, making its mitigation a critical target in efforts to combat climate change. Methane emissions from livestock facilities are usually present in low concentrations, which makes them impractical for energy recovery. Biofilters offer a promising approach to reducing methane emissions from agricultural systems, since theycan oxidize methane into carbon dioxide and water using methanotrophic bacteria, thereby significantly lowering the climate impact of these emissions.However, a key potential challenge with methane biofilters is the unintended production of nitrous oxide, a greenhouse gas with an even higher global warming potential than methane. Theobjective for this project is to study the causes of nitrous oxide formation in methane biofilters for agricultural systems. In the first year of this project, we developed a multiphysics mathematical model to predict the performance of the biofilter, and we also built a bank of biofilters to perform experimental assessment of different biofiltration conditions. In the second year (corresponding to this reporting period), we have (1) advanced our experimental approach to assess the feasibility of the biofilters, (2) developed a methodology to incorporate biological information about the microbial communities in the biofilters into the multiphysics model, and (3) performed a techno-economic analysis and life-cycle assessment of the application of the biofilters in dairy farms, as detailed below. Experimental approach: We have developed and standardized a process to test different experimental conditions of the biofilters in bottles, using sequential batches. This allows us to test several conditions simultaneously, faster than what we can test in the bank of continuous biofilters. The results from the bottleexperiments can then be confirmed in the continuous biofilters. We have developed an experimental plant to test the effect of packing material moisturecontents (Aim 2) and pH on biofilter performance and nitrous oxide emissions. pH is a new variable that resulted from an extensive literature review as having a potential influence in the production of nitrous oxide, so it was added to our experimental plan. We have started to studythe effect of certain packing materials on the efficiency of methane biofilters and the production of carbon dioxide and nitrous oxide. We have selected two inorganic materials: perlite and vermiculite to be mixed with compost at a 50:50 ratio. Compost provides the methanotropic microbial inoculum, while the added inorganic material is expected to provide surface area to increase mass transfer. We have performed preliminary experiments to standardize the procedure. We have started continuous experiments in the bank of biofilters, testing different air flows and methane concentrations in the inlet air stream. We have been able to find the limits of operability of the biofilters (Aims 2 and 3), since under low airflows and high moisture contents, the process is not feasible, since no airflow occurs. We have also developed a methodology to verify the concentration of gases in the outlet air stream using gas chromatography, since our automatic detection method has shown sporadic failures. Mathematical modeling approach: We used Flux Balance Analysis (FBA) on a microbial community of methanotrophic bacteria through the KBase platform. FBA, a tool for simulating organism growth in various environmental conditions, predicted metabolic flux distributions to achieve specific cellular objectives. The genomes of different methanotrophs were collected and used for FBA of a methanotrophic microbial community, whichidentified 15 activated genes within the community model when CH4 was the sole carbon source, including those associated with enzymes like methane monooxygenase and methane methanol dehydrogenase. The optimal methane uptake flux, combined with Monod-based biodegradation kinetics, was incorporated into our previously developed multiphysics macroscalemathematical model solved using the Finite Difference Method in Python. Integration of FBA output allowed the correlation and qualitative analysis of methane concentration profiles on the biofilter, considering transport processes and microbial biodegradation. Techno-economic analysis and life-cycle assessment: We performed alife cycle and techno-economic analysis of the application of methane biofiltration on dairy farms in Pennsylvania. The baseline dairy farm for this analysis is a 100-cow tie-stall operation in Pennsylvania that utilizes seasonal mechanical tunnel ventilation and an open pit manure storage system. The baseline farm has two open-bed biofilters: one designed to capture enteric emissions from the barn, and another to capture emissions from the open pit manure storage system. These biofilters are composed of a 50:50 v/v woodchip and compost mixture. Our results showed that methane biofiltration may reduce total dairy farm greenhouse gas emissions by 23% if applied to treat enteric and manure-related methane, and the cost of this reduction may range from $56-$123 per metric ton of carbon dioxide equivalent mitigated. With these combined approaches, we were able to advance the scientific understanding of the methane biofiltration systems and the potential undesirable productions of nitrous oxide. The combined experimental and modeling approach showed that these complex systems required a systemic approach for their development and design. The techno-economic analysis and life-cycle assessment revealed the potential for using these systems in small dairy farms that have limited potential for othersolutions to reduce their greenhouse gas emissions.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Vasco-Correa, J. (November 25, 2023). "Process system engineering for biomanufacturing and bioremediation," International Workshop on Data Science for Bioprocessing and Bioprospecting, UNU Biotechnology Programme for Latin America and the Caribbean (UNU-BIOLAC), Santa Marta, Colombia. Invited Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Vasco-Correa, J. (October 25, 2023). "Process system engineering: application of systems thinking in the study of emergent biotechnologies," Colombia Society of Physics Engineering and Applied Physics, Engineering and Innovation Conference, Manizales, Colombia. Invited Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Vasco-Correa, J. (July 12, 2023). "Process (bio)system modeling in a carbon-negative bioeconomy," ASABE Annual International Meeting, Omaha, NE. Invited Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gonzalez, C., Delgado Vela, J., & Vasco-Correa, J. (April 28, 2024). "Multiscale modeling approach to study the role of C1 metabolism of methanotrophs in methane biofilters," 46th Symposium on Biomaterials, Fuels and Chemicals, Society of Industrial Microbiology and Biotechnology, Alexandria, VA. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Gonzalez, C., Delgado Vela, J., & Vasco-Correa, J. (July 31, 2023). "Integrating genomics data into a mechanistic model for methane biofiltration systems," Northeast Agricultural and Biological Engineering Conference (NABEC), Guelph, ON. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Gonzalez, C., Delgado Vela, J., & Vasco-Correa, J. (July 10, 2023). "Towards the integration of genomics data into a macroscale mechanistic model for methane biofiltration systems," ASABE Annual International Meeting, Omaha, NE. Oral Presentation
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Peacock, V., Gonzalez, C., Kelly, D., Costello, C., Fabian, E. F., & Vasco-Correa, J. (May 14, 2024). "Assessing the environmental and economic feasibility of biofiltration for methane reduction on Pennsylvania dairy farms," Climate Solutions Symposium, Institute of Energy and the Environment (IEE), University Park, PA. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Vasco-Correa, J. (May 14, 2024). "Bioeconomy solutions for a changing climate: rethinking bioenergy," Climate Solutions Symposium, Institute of Energy and the Environment (IEE), University Park, PA. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gonzalez, C., Peacock, V., Geiger, T., & Vasco-Correa, J. (May 6, 2024). "Air biofiltration technology for the mitigation of diluted methane emissions," Colombian Diaspora Symposium, Penn State Colombian Graduate Student Association, University Park, PA. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Vasco-Correa, J. (May 6, 2024). "Bioeconomy solutions for a changing climate: rethinking bioenergy," Colombian Diaspora Symposium, Penn State Colombian Graduate Student Association, University Park, PA. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gonzalez, C., Delgado Vela, J., & Vasco-Correa, J. (April 28, 2024). "Multiscale modeling approach to study the role of C1 metabolism of methanotrophs in methane biofilters," 46th Symposium on Biomaterials, Fuels and Chemicals, Society of Industrial Microbiology and Biotechnology, Alexandria, VA. Oral presentation and poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gonzalez, C., Delgado Vela, J., & Vasco-Correa, J. (April 19, 2024). "Multiscale modeling approach to study the role of C1 metabolism of methanotrophs in methane biofilters," Biorenewables Symposium, Penn State Center for Biorenewables, University Park, PA. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Peacock, V., Gonzalez, C., Kelly, D., Costello, C., Fabian, E. F., & Vasco-Correa, J. (April 17, 2024). "Assessing the environmental and economic feasibility of biofiltration for methane reduction on Pennsylvania dairy farms," Undergraduate Exhibition, University Park, PA. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Peacock, V., Gonzalez, C., Kelly, D., Costello, C., Fabian, E. F., & Vasco-Correa, J. (March 27, 2024). "Assessing the environmental and economic feasibility of biofiltration for methane reduction on Pennsylvania dairy farms," Gamma Sigma Delta Research Symposium, University Park, PA. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Geiger, T., Gonzalez, C., & Vasco-Correa, J. (March 27, 2024). "Methane biofiltration design for lab scale experimental work," Gamma Sigma Delta Research Symposium, University Park, PA. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Vasco-Correa, J. (February 29, 2024). "Bioeconomy solutions for a changing climate: rethinking bioenergy," Connections to Sustain Science in Latin America Symposium, National Academy of Sciences, Engineering and Medicine (NASEM), Barranquilla, Colombia. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Peacock, V., Gonzalez, C., & Vasco-Correa, J. (July 31, 2023). "Analysis of microbial efficiency in oxidizing low-concentration methane through biofiltration," Northeast Agricultural and Biological Engineering Conference (NABEC), Guelph, ON. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Gonzalez, C., Geiger, T., & Vasco-Correa, J. (July 11, 2023). "Assessment of a bank of biofiltration system for dilute methane emissions abatement," ASABE Annual International Meeting, Omaha, NE. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Peacock, V., Gonzalez, C., & Vasco-Correa, J. (July 9, 2023). "Analysis of microbial efficiency in oxidizing low concentration methane," Circular Bioeconomy Symposium, American Society of Agricultural and Biological Engineers (ASABE), Omaha, NE. Poster.
  • Type: Theses/Dissertations Status: Published Year Published: 2023 Citation: Suresh, S., MS Thesis. (2023) User-centered design and construction of a modular biofilter system for reduction of greenhouse gas emissions. (Engineering Design, School of Engineering Design and Innovation).
  • Type: Theses/Dissertations Status: Published Year Published: 2023 Citation: Peacock, V., Undergraduate Honors Thesis. Assessing the feasibility of biofiltration for methane reduction on Pennsylvania dairy farms: a life cycle and techno-economic analysis. (Biological Engineering).


Progress 06/15/22 to 06/14/23

Outputs
Target Audience:The target audience reached by our efforts during this reporting period is academics in agricultural sciences, environmental engineering, and agricultural engineering interested in climate-smart technologies for livestock facilities. Changes/Problems:Our experimental approach was delayed due to the availability of the biofiltration columns. Our previous system had many leaks and was deemed unsafe to operate with methane at the beginning of the grant period. Rather than repairing it, we decided to replace it, since the leaks were substantial. This took a significant part of the year, but now we have working biofilters that have been tested for leaks and have been approved for the work. This has delayed our experimental work, but we expect to perform most of it in the upcoming year. Due to this delay, we decided to also include a mathematical model as part of our research approach, which was not included in our original proposal. Weexpect that this will be a great added benefit that will improve our understanding of the operation of methane biofilters and help us reach the overall goal of the project. What opportunities for training and professional development has the project provided?One PhD student funded by the award, Camila Gonzalez Arango, hasreceived mentoring and training from the PD and co-PDs on different aspects of the project, and has been able to present in a wide range of conferences, receiving training and feedback on her work and on her communication skills. This project is the core of her doctoral dissertation. One MS in Engineering Design and one undergraduate student in Engineering Science and Mechanics have collaborated in the design and building of the pilot biofiltration systems, providing them with the opportunity to enhance their engineering design skills. This will constitute the core of the MS student thesis. Two undergraduate students in Biological Engineering have been involved in the project as undergraduate researchers, developing skills in experimental approaches and research planning. Two of the undergraduate students are being mentored by the PhD Camila Gonzalez Arango, providing them all with a near-mentoring opportunity that allows Camila to develop her mentoring skills. These students have also formed a group to participate in the American Society of Agricultural and Biological Engineers 2023 Bioprocessing Startup Competition with the biofilters concepts, allowing them to develop entrepreneurship skills. How have the results been disseminated to communities of interest?We have disseminated the results in a wide variety of conferences targeting academics and students in different disciplines. Some of these conferences have been aimed at specific student audiences which allows us to reach the next generation and make them aware of the problem with diffuse methane and the potential engineering solutions. We have also represented the project at students' clubs with the aim of recruiting students for the project. What do you plan to do during the next reporting period to accomplish the goals?Next year, we plan to execute the proposed experiments in the continuous biofilters to accomplish Aims 1 to 3, i.e. to test the effect on inlet-air ammonia, moisture, and compaction of the methane oxidation and formation of nitrous oxide in the biofilters. We also plan to use some of the experimental data to calibrate the computation model.

Impacts
What was accomplished under these goals? In the first year of our work, we have advanced the understanding of the methane biofilters through computational models that describe how these systems work, to help predict their behavior and potentially the potential production of nitrous oxide. We have also built a bank of biofilters in our pilot facility to perform experimental work to test the potential causes of nitrous oxide in biofilters. This will allow us to control the production of this harmful gas and ensure that methane biofilters can be applied safely to livestock facilities. Our long-term goal is to enable net zero carbon biofiltration systems for low concentration methane oxidation and carbon capture. Our objective for this seed project is to study the causes of nitrous oxide formation in methane biofilters for enclosed livestock systems. The two principal accomplishment under the goalconsists of (1) developing a mathematical model in Python based on first principles that describe the mass transfer, transfer phenomena, and main biochemical reactions in the biofilter, which will allow us to make predictions about the methane biodegradation and production of nitrous oxide under different process conditions;and (2) building a pilot scale biofiltration system that consists of a bank of ninebiofilter columns connected to a gas system where air, CH4, and ammonia isprovided. We custom-built the biofiltration columns in-house. For the biofiltration column material, we useda polycarbonate tube with an inner diameter of 0.15 m and a height of 1 m. This will allow us to perform the experiments proposed in the following aims. Specific aim 1. Determine the effect of inlet-air ammonia on the formation of nitrous oxide in methane biofilters. For the experimental approach, aliterature review was performed to understand the typical methane ammonia concentration on the exhaust air of livestock facilities, since that is the output that we would like to test in our biofilters. The concentrations usually depend on the number of animals per facility; therefore, we have found different ranges of concentrations for methane and ammonia in livestock facilities. In the case of methane, concentrations between 15-700 ppm were found. For ammonia, concentrations between 3-40 ppm seem to be typical. To determine the effect of ammonia inlet concentration on nitrous oxide production, an experimental design testing low, medium, and high ammonia levels was developed. For the modeling approach, we used the model to firsttestthe effect of different concentrations of inlet-air methane on the performance of the biofilter. This provided us a platform to later add the biochemical equations about the nitrous oxide formation and degradation and tried to calibrate the model to predict these phenomena. Specific aim 2. Identify the effect of moisture content on the formation of nitrous oxide in methane biofilters. We performed batch methane oxidation experiments in serum bottles varying the moisture content of compost from 52% to 80%. We showed that higher moisture contents significantly increase the rate of methane oxidation (p<0.05) by the methanotrophs in the compost. In these experiments, we were unable to detect nitrous oxide. Thus, we will have to evaluate the moisture content effect in the recently built pilot biofilters. For that, humidification columns were fabricated to guarantee full saturation of the inlet mixture of air, methane, and ammonia for the pilot biofilters. A saturated inlet air stream will guarantee a moist packing material with about 60-70% moisture, which will be set as the baseline experiment. The water column of the humidification columns will be varied to change the moisture content of the packing material and evaluate the formation of nitrous oxide in both dry conditions and excess moisture conditions with respect to the baseline experiment. Specific aim 3. Determine the effect of compaction in the packing media on the formation of nitrous oxide in methane biofilters. We evaluated different packing materials for the biofilters and decided on a baseline packing material for the baseline experiment is 50:50 mixture of compost and wood chips. To evaluate the effect of compaction on the packing material, different compactions levels will be tested by comprising the packing material with different known load cells. Production of nitrous oxide will be monitored, as well as the oxidation of methane. We have secured the use of an FTIR gas analyzer to be able to monitor all gases from the biofilterexhausts and we started working on its calibration.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Vasco-Correa, J., Gonz�lez, C. 2023. Mechanistic modeling of methane biofiltration systems. 2023 Institute of Biological Engineering (IBE) Annual Conference. Iowa State University. April 13-15. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Gonz�lez, C., Vasco-Correa, J. 2022. Mechanistic model for methane-contaminated air biofiltration systems. Northeast Agricultural and Biological Engineering Conference (NABEC). Edgewood, Maryland. July 31- August 03. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Gonz�lez, C., Vasco-Correa, J. 2022. Development of a mathematical model for methane biofiltration systems from a biofilm phenomena approach. ASABE Annual International Meeting. Houston-Texas. July 17-20. Oral Presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Gonz�lez, C., Peacock, V., Geiger, T., Vasco-Correa, J. 2023. Air biofiltration technology for the mitigation of diluted methane emissions. Penn State Climate Solutions Symposium. Penn State Institutes of Energy and Environment. May 22-23. Poster presentation
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Peacock V., Gonz�lez, C., Bruns, M.A., Vasco-Correa, J. 2022. Microbial efficiency in oxidizing low-concentration methane through biofiltration. Air biofiltration technology for the mitigation of diluted methane emissions. Penn State Climate Solutions Symposium. Penn State Institutes of Energy and Environment. May 22-23. Poster presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Gonz�lez, C., Vasco-Correa, J. 2023. Mathematical modeling of air biofiltration technology for the mitigation of methane emissions. Biorenewables Symposium. Center for Biorenewables Penn State University. April 21. Poster presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Peacock V., Gonz�lez, C., Bruns, M.A., Vasco-Correa, J. 2023. Microbial efficiency in oxidizing low-concentration methane through biofiltration. Undergraduate Exhibition, Penn State University. April 12th. Poster presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Peacock V., Gonz�lez, C., Bruns, M.A., Vasco-Correa, J. 2023. Microbial efficiency in oxidizing low-concentration methane through biofiltration. Gamma Sigma Delta 28th Annual Research Exposition, Penn State University. March 30th. Poster presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Ferguson J., Gonz�lez, C., Vasco-Correa, J. 2022. Identification of common microbial communities of methanotrophs in methane biofilters. Annual Biomedical Research Conference for Minoritized Scientists ABRCMS 2022. Anaheim, California. November 9-12. Poster presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Peacock V., Gonz�lez, C., Lopez, R., Greenlee, L., Bruns, M.A., Vasco-Correa, J. 2022. Activated hydrochar for CO2 capture in methane biofilters. Northeast Agricultural and Biological Engineering Conference (NABEC). Edgewood, Maryland. July 31- August 03. Poster presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Gonz�lez, C., Vasco-Correa, J. 2022. Mathematical modeling for air biofiltration technology for the mitigation of methane emissions. Twitter Latin American Conference EnvChemPSE. Twitter. July 21. Poster presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Gonz�lez, C., Vasco-Correa, J. 2022. Mathematical modeling of air biofiltration technology for the mitigation of methane emissions. Symposium on Science and Technology Driving the Bioeconomy S-1075. Houston-Texas. July 15-16. Poster presentation.