New Peer-Reviewed Research Finds Bioenergy Causes Disproportionate Share of Air Pollution
By Talia Geilen
News Article: https://www.nwf.org/Latest-News/Press-Releases/2023/12-8-23-Bioenergy-Pollution-Study
Research Article: https://www.sciencedirect.com/science/article/pii/S0960148123014519?ssrnid=4312823&dgcid=SSRN_redirect_SD
Background:
Bioenergy uses organic matter that is converted to fuel, heat, or electricity as an energy source [1]. It has been considered a greener source of energy than fossil fuels. Biomass makes up 1.3% of total energy generation in the US [2]. While considered a fossil fuel alternative, the emitted pollutants in biomass combustion pose significant environmental and health concerns. The combustion of different biomass feedstocks (the sources of biomass like post-consumer paper products, mill wastes, forestry residues, food wastes, and municipal solid wastes) the pretreatment of the biomass (processes of leaching, drying, densification, and pelletization), and the combustion of biomass emit harmful ozone-depleting substances and secondary aerosol presursers that contribute to rising global temperatures and greenhouse gases [3]. The Peer-Revied article looks specificaly at wood pellet manufacturing (WPM) and bioenergy generation (BIOE) facilities.
Peer-Reviewed Article:
The paper, ‘Emissions of wood pelletization and bioenergy use in the United States’ by Huy Tran et al. at the University of North Carolina at Chapel Hill, published in the 2023 edition of the Renewable Energy Journal, aims to quantify criteria pollutants from WPM and BIOE facilities to close the knowledge gap in the regulatory emissions inventories for biomass fuel production and combustion sources. Tran et al. explain that in an effort to reduce greenhouse gases and mitigate climate change, biomass as a source of energy gained popularity. They go into the known negative effects of the pollutants on health and the need for more exact emissions data from US bioenergy facilities (emphasizing wood-based biomass) for policymakers to make decarbonization policies.
They compiled the first inventory of the criteria pollutants emitted from not only the combustion of biomass but also the pretreatment of biomass to find the net emissions. A comprehensive list of the BIOE and WPM facility locations and reported emissions was compiled using industrial databases, regulatory reports, air quality permit registries, and the U.S. Energy Information Administration. 126 operational WPM were found, 55 of them were small-scale facilities and were thus excluded from air permit requirements, so the emissions were estimated through comparison of facilities with similar production processes. The rest of the WPM had reported emissions or allowable emissions limits used as primary emissions data. The BIOE facilities and pollutants were found using the Biomass Magazine database, the EPA database, and the Emissions & Generation Resource Integrated Database (eGRID). Spatial analysis and name-matching were used to prevent listing facilities twice. They were able to list 798 operational BIOE facilities and reported emissions data from the eGRID reports. If not explicitly listed in eGRID, through comparison of BIOE processes and feedstock types. The pollutants evaluated were NOx, VOC, CO, NH3, SO2, PM 2.5, and PM 10. They then evaluated the health implications of the WPM and BIOE emissions by evaluating the distance of the facilities to the nearest populated area. Findings were compared to known fossil fuel emissions of similar pollutants from the National Emissions Inventories (NEI) to draw comparisons.
Tran et al. were able to estimate 6617 tpy of NOX, 10,613 tpy of VOC, 851 tpy of SO2, 7178 tpy of PM2.5, and 1249 tpy of HAPs emitted from all WPM facilities and 296,349 tpy of NOX, 134,286 tpy of VOC, 59,129 tpy of PM2.5, 150,980 tpy of SO2, and 13,538 tpy of NH3 emitted from all BIOE facilities. The biomass fuel type that emitted the most was from Municipal solid wastes and liquid wood waste feedstocks from sources like wood and paper mills. They found an inverse relationship between facility size and pollution rate per unit of biomass processed, due to less regulation and required pollution control equipment.
Figure 1. Emissions of NOx and Vox (top), SO2 and PM2.5 (bottom)
The WPM and BIOE facilities are concentrated in the Southeast, Northeast, and Northwest as shown in Figure 1. While Biomass makes up 1.3% of energy generation in the US [2], they found that BIOE accounts for large percentages of the pollutants emitted in energy generation (4% NOx, 17% VOC, 9% CO, 6% NH3, 3% SO2, 9% PM2.5, and 10% PM10). This is an average of 2.8 times the amount of air pollutants per unit of energy generated compared to fossil fuels.
The authors mention that a third of the WPM have violated air quality permits, thus suggesting their data underestimates the true value of pollutants. Another underestimation mentioned in the study is that the researchers do not take into account the transportation and distribution of biomass fuel to and from the facilities. They estimate that 2.3 million people live within 2 km of a biomass facility exposed to biomass fuel pollutants.
They conclude that while biomass as an alternative to fossil fuel increases in demand, it will ultimately harm air quality, and the pollutants will cause known health effects. They urge policymakers to assess the benefits of climate change mitigation strategies when considering ‘greener’ energy sources.
News Article:
The National Wildlife Federation news article by Meshel DeSantis presents the findings of the study and correctly states that biomass and wood pellet production have the potential to be worse for the environment and health than fossil fuels. The article states that the study found that thousands of tons of health-harming pollutants are emitted per year by this energy source. DeSantis quoted the co-author of the study, Edie Juno, highliting the dangers the toxins permeating to nearby towns pose to the people. Juno emphasizes the need for a reexamination of our clean energy investments, especially since the facilities are disproportionatly located in Black low-income comminities. Another co-author, Arunachalam, is quoted stressing the importance of the discovery that more pollutants are emitted per unit of energy than the fossil fuels. DeSantis mentions the study was able to list the 55 different hazardous air pollutants, and estimated 10,000 tons of VOCs and 14,000 tons of particulate matter emitted per year. The author then concludes stating that the estimates could be undervalued by a factor of two, and the violations of the air quality permits at these facilities only increase the health hazards for the communities around the sites.
Analysis:
DeSantis presents the major findings while listing the limitations of the study. The 2 co-authors of the study are quoted, increasing credibility and emphasizing the important findings the researchers want the public to know when it comes to advocating for the right methods of climate change mitigation. The researchers clearly state their desire to have better policies in place to decrease the potential health effects of surrounding communities and DeSantis makes the need for caution when it comes to human health clear, even bringing in the idea that minority communities are disproportionately at risk by these pollutants in surrounding areas. While the methodology of the study was quite technical, DeSantis goes more into the social implications of the findings. I did not think the news article had to present the exact methods as it can get pretty complicated, however, there is little to no information on the way the researchers gathered their data, which can leave the reader on their own to judge the reliability of the study. For this reason, I would rate the article a 9/10.
Sources:
[1] Bioenergy Basics. Energy.gov. (n.d.). https://www.energy.gov/eere/bioenergy/bioenergy-basics
[2] U.S. Energy Information Administration - EIA - independent statistics and analysis. U.S. energy facts explained - consumption and production - U.S. Energy Information Administration (EIA). (n.d.). https://www.eia.gov/energyexplained/us-energy-facts/
[3] Chen, J., Li, C., Ristovski, Z., Milic, A., Gu, Y., Islam, M. S., Wang, S., Hao, J., Zhang, H., He, C., Guo, H., Fu, H., Miljevic, B., Morawska, L., Thai, P., LAM, Y. F., Pereira, G., Ding, A., Huang, X., & Dumka, U. C. (2017). A review of biomass burning: Emissions and impacts on air quality, health and climate in China. Science of The Total Environment, 579, 1000–1034. https://doi.org/10.1016/j.scitotenv.2016.11.025
Nice work, Talia! I agree with your rating for the news article; it was well rounded, had lots of factual information, and spoke on all relevant topics. I agree that they should have included a little more information on the actual findings of the study rather than the social implications, but I understand why they did it -- to make a more comprehensible article for the average reader. The peer reviewed article contained so many abbreviations, numbers, and statistics that were very intimidating and difficult to get through, but the news article was able to simplify everything down so that a non-scientific reader could understand everything. I really liked your choice of article; I wouldn't have thought that National Wildlife Federation would publish anything that goes into detail about chemistry! I think it is incredibly important that the NWF has a "Latest News" section on their website because things are constantly changing and readers should have one spot find reliable information on wildlife and environmental updates.
ReplyDeleteThank you, Mira! Exactly, the peer-reviewed article was pretty dense and number-heavy and the news article focused on accessibility for the reader and the implications of the findings. While that means they left out technical details, they made the information available for anyone to grasp. The "Latest News" section is a great outlet for people who want to keep up with current science but may not usually read research papers. Bioenergy and its health and environmental implications affect policy decisions and climate advocacy, so having trusted organisations to bridge the research and the public is incredibly important.
DeleteHi Talia! I really enjoyed your post! I grew up in a house heated by a wood pellet stove, so I found the topic of these articles interesting! I have never thought about the environmental impact from the production of wood pellets. The discussion of NOx and VOC production from wood pellet manufacturing (WPM) immediately led me to wonder how these emissions are impacting the NOx and VOC ozone formation regimes. Since most WPMs are located in primarily forested areas, I think they are in a NOx limited regime, but with the emissions of NOx from WPM, could this be shifting the regime of these forested areas to be less NOx limited? How would a shift in regimes impact ozone formation? Would this increase in NOx emissions impact the regime since more VOCs are typically emitted than NOx from WPM? I am also curious about what modifications can be made to WPM to reduce emissions?
ReplyDeleteHello Talia, this is a topic I had no previous knowledge about and it really shocks me the WPM facilities have ended up emitting more pollutants per unit energy than their fossil fuel counterparts. Although the range of their percent contribution (3-17) is decently broad. You mentioned that there was an inversely proportional relation between facility size and pollution rate per unit processed. I was wondering what specific regulations/equipment keep these larger facilities from polluting as much and if it is realistic to enforce it on the smaller facilities as well in order to try and reduce harmful admissions. I wish the article mentioned this or gave possible next steps to take after the findings of this study. It is nice to see an author quoted though. Also why is it that wood-based bio mass facilities make up a majority of the pollutants for bio mass energy production? I think it is also critical to mention in articles or summaries of studies that the reason data is underestimated, as with this paper, and how the problem is likely worse than even reported here and the article did a good job with it although possibly could have been mentioned sooner. I also agree the article could have used some more data to work with but did a fine job as is.
ReplyDeleteThanks for your input Dominic! The inverse relationship between the facility size the the pollution rate per unit of energy generated comes from the fact that they have less regulations put on the facility because they release energy on a small scale compared to other major sources. They no not have the set emissions limits from the air quality permits and the pollution reduction equipment like advanced filters and high efficiency boilers are not used. So while they release less emissions in total, there are more pollutants per unit energy generated. Long term this is incredibly harmful and enforcing this on the smaller facilities is would be a great way to reduce emissions.
DeleteHi Talia, you did a great job summarizing the article and the paper. I also agree with you that the article talking about the impact on minority communities was a good thing. I thought this was a very interesting topic. I have never really thought much about the impact of bioenergy and how it could also contribute to air pollution. I thought the maps showing the locations of the forests and BIOE and WPM facilities were particularly interesting. One thing I am curious about is how different types of biomass fuels compare to one another in how much pollution they generate. What about other kinds besides wood pellets?
ReplyDeleteThank you for your feedback Amy! The maps were indeed interesting. The facilities are concentrated in certain areas in the US especially in the Northwest, Northeast and Southeast which would impact the health and environment in those specific areas especially. The types of biomass fuels that were examined did have different effects on emissions. The two types of biomass fuels that had the greatest effects were municipal solid waste and liquid wood waste from the sources like paper mills. These are Bioenergy fuel sources that are not wood pellets like those used in WPM facilities. It would be interesting to see a more specific study based on the types of feedstocks under the same combustion conditions to determine the least harmful types of fuel on air quality and health.
DeleteNice job, Talia! I agree that the news article did a remarkable job simplifying the results from the paper, and concisely explaining the paper in an amount of words that will not bore readers. This research was eye-opening to me because I had no idea creating wood pellets and other biomass fuel could be so damaging. I had a few questions after reading these articles. Is biomass burning still a reasonable way to sustainably create energy, even though it still contributes to climate change? If not, what quick alternatives might we be able to point to in order to stop consuming bioenergy? Or, can we find a way to make bioenergy less harmful to the environment when consumed/produced?
ReplyDeleteThank you Kevin! I agree this study was eye opening for me as well. When a fuel source is labeled as renewable I assumed that the energy is better than fossil fuels. However, when looking into the pollutants that are being emitted from biomass fuels and in the quantity in which they are entering our environment, it made it clear that there is more nuance than that. We should have more caution when trying to create better climate change mitigation strategies. To answer your question: biomass as an energy source is incredibly efficient and renewable so there is not a limit to the fuel we can burn, unlike fossil fuels. However based on this research it is not a reasonable way to create energy when the contributions to climate change are greater than those of fossil fuels. The quickest way to stop the greatest emissions from bioenergy is to stop harvesting fuel from the municipal solid waste and liquid wood waste feedstocks as those have the greatest emissions. The best solution is to get energy from sources such as solar or wind.
DeleteYour analysis was well-written and insightful, and I agree with your overall score. The article did a good job describing that many pollutants arise from burning biomass and wood pellets, and I liked that it mentioned that this topic is under-researched and that these fuel sources are often considered to be more environmentally friendly, which leads to them not being investigated or considered with much scrutiny. I also liked how the article discussed that "Black, low-income, and other frontline communities" are the most affected by these bioenergy facilities. I wish the article had discussed the different pollutants in a little more detail, especially comparing and contrasting the pollutants from common fossil fuels and these forms of bioenergy. They mention that there is much more pollution produced by burning these bioenergy sources, but they didn't discuss the types of pollutants and what sort of impacts this could have as much as I would have liked.
ReplyDeleteHi Talia! I found this analysis very interesting. I had been wondering about biofuels during class discussion. I found it interesting that so many of the wood pellet manufacturing facilities had violated their air quality permits. I wonder about the oversight process or possible fines that could come from that. I agree that the new article covered the main important ideas from the research article.
ReplyDeleteWould it be possible for the biomass burning process to be made cleaner so its emissions are more equal to its energy output?
Hi Ava! Thank you so much for the feedback. It is really disappointing that the air quality emissions limits are constantly violated. It does raise serious questions about oversight and enforcement. While the study did not go into detail about the fines or penalties that are enforced to the biofuel facilities, it seems like they are not compelling enough to stop these companies from violating the limits because a third of them are continuously in violation of the limits. The possible ways to make biomass emissions cleaner are through high efficiency boilers or filters, or by finding a way to pretreat the biomass in a way that would result in less pollutant emissions.
DeleteThis is a very interesting topic, especially since we just had the lecture on all the pollutants in fossil fuels, seeing a potential replacement to fossil fuels being found to be worse for the environment is surprising. I agree that the news article summed up the results well although the article feels a little short and could be helped by the inclusion of more information regarding the emissions, like the treatments of the biomass before burning also being a large factor. One thing I noticed is that the study only focused on two major types of biomass energy facilities, BIOE and WPM, I was wondering if any other kinds were mentioned briefly in the study or if you found anything about more when you were putting this together and finding context?
ReplyDeleteGreat work, Talia — I really enjoyed reading your analysis! I do have one thought to add. Given that Tran et al. (2023) found that biomass energy facilities emit, on average, 2.8 times more air pollutants per unit of energy than fossil fuels, and the National Wildlife Federation article points out that many of these facilities are located in low-income and minority communities, how do you think policymakers should balance the goals of climate change mitigation with environmental justice and public health when considering bioenergy as part of a “clean energy” strategy?
ReplyDelete