Scholarly record
REDUCING THE ENVIRONMENTAL IMPACT OF FIRING AGRICULTURAL RESIDUES THROUGH SI-AL BASED ADDITIVES
Abstract
In light of the gradual transition toward sustainable and green economy, the valorization of various agricultural residues has been drawing more attention. The leftover products from agricultural processing can be easily turned into a CO2-neutral biofuel. The subsequent deployment of nutrient-rich ash as fertilizer helps to keep a closed cycle of minerals and promote circular economy. This practice, however, comes with its drawbacks: excessive particulate matter (PM) emissions being among the most alarming. The present study investigates the possibility of using Si-Al based additives to reduce PM emissions from firing sunflower husks, a commonly used biofuel. The tests have been conducted on a 25kW automatic pellet boiler with a bottom-feed retort burner. The initial results showed that when firing raw sunflower pellets, the PM emissions reached as high as 622 mg/m3. Most of the PM emissions can be attributed to KCl and K2SO4. It was shown before that aluminosilicates form refractory phases with potassium and hence inhibit its release to flue gas. The raw sunflower pellets have thus been enhanced with kaolin at ratios of 2.5%, 5% and 7.5% and a gradual decrease down to 85 mg/m3 was observed. No technical obstacles or secondary emissions were observed for any of the tested ratios. As such, the maximal kaolin addition should only be limited by the requirements of the particular appliance.
Publication Impact Profile
Publication details
References11
Rabbat, Christelle, Audrey Villot, Sary Awad, and Yves Andr�s. 2023. �Gaseous and particulate matter emissions from the combustion of biomass-based insulation materials at end-of-life in a small-scale biomass heating boiler.� Fuel 338. DOI: 10.1016/j.fuel.2022.127182.
Lachman, Jakub, Mark�ta Kalivodova, Jakub Nabelek, Marek Balas, Pavel Divis, and Martin Lis�. 2024. �Particulate matter emission characteristics of spruce, sunflower and maize: A comparison between nominal and reduced output in a small-scale boiler.� Biomass and Bioenergy 182. DOI: 10.1016/j.biombioe.2024.107102.
Kleinhans, Ulrich, Christoph Wieland, Flemming J. Frandsen, and Hartmut Spliethoff. 2018. �Ash formation and deposition in coal and biomass fired combustion systems: Progress and challenges in the field of ash particle sticking and rebound behavior.� Progress in Energy and Combustion Science 68: 65-168. DOI: 10.1016/j.pecs.2018.02.001.
M�guez, Jos� Luis, Jacobo Porteiro, Frank Behrendt, Diana Blanco, David Pati�o, and Alba Dieguez-Alonso. 2021. �Review of the use of additives to mitigate operational problems associated with the combustion of biomass with high content in ash-forming species.� Renewable and Sustainable Energy Reviews 141. DOI: 10.1016/j.rser.2020.110502.
Siegmund, Theresa, Christian Gollmer, Niklas Horstmann, and Martin Kaltschmitt. 2024. �Carbon monoxide (CO) and particulate matter (PM) emissions during the combustion of wood pellets in a small-scale combustion unit � Influence of aluminum-(silicate-)based fuel additivation.� Fuel Processing Technology 262. DOI: 10.1016/j.fuproc.2024.108111.
Gehrig, Matthias, Marius W�hler, Stefan Pelz, Jens Steinbrink, and Harald Thorwarth. 2019. �Kaolin as additive in wood pellet combustion with several mixtures of spruce and short-rotation-coppice willow and its influence on emissions and ashes.� Fuel 235: 610-616. DOI: 10.1016/j.fuel.2018.08.028.
Yang, Wei, Youjian Zhu, Wei Cheng, Huiying Sang, Hanshen Xu, Haiping Yang, and Hanping Chen. 2018. �Effect of minerals and binders on particulate matter emission from biomass pellets combustion.� Applied Energy 215: 106-115. DOI: 10.1016/j.apenergy.2018.01.093.
Cheng, Wei, Youjian Zhu, Jing�ai Shao, Wennan Zhang, Guihao Wu, Hao Jiang, Junhao Hu, Zhen Huang, Haiping Yang, and Hanping Chen. 2021. �Mitigation of ultrafine particulate matter emission from agricultural biomass pellet combustion by the additive of phosphoric acid modified kaolin.� Renewable Energy 172: 177-187. DOI: 10.1016/j.renene.2021.03.041.
H�fer, Isabel, Theresa Huelsmann, and Martin Kaltschmitt. 2021. �Influence of Ca- and Al-additives on the pollutant emissions from blends of wood and straw in small-scale combustion.� Biomass and Bioenergy 150. https://doi.org/ 10.1016/ j.biombioe.2021.106135. DOI: 10.1016/j.biombioe.2021.106135
Gollmer, Christian, Vanessa Weigel, and Martin Kaltschmitt. 2023. �Emission Mitigation by Aluminum-Silicate-Based Fuel Additivation of Wood Chips with Kaolin and Kaolinite.� Energies 16 (7). DOI: 10.3390/en16073095.
Mack, Robert, Claudia Sch�n, Daniel Kuptz, Hans Hartmann, Thomas Brunner, Ingwald Obernberger and Hans Martin Behr. 2024. �Influence of wood species and additives on emission behavior of wood pellets in a residential pellet stove and a boiler.� Biomass Conversion and Biorefinery 14 (17): 20241-20260. https://doi.org/ DOI: 10.1007/s13399-023-04204-x.
View or Download full articleAccess options
SWS access login
Login as SWS Scientific CommitteeLogin as SWS Scientific PartnerLogin as SWS AuthorAuthors and approved SWS contributors will read and export their own linked papers after identity matching by SWS profile, email and SGEM GlobalID.
For librarian assistance: [email protected]
Purchase Instant Access
- Article can be downloaded after successful payment.
- Article may be used according to SWS library access terms.
- Article cannot be redistributed.