doi: 10.18178/ijesd.2025.16.6.1550
Energy Valorization of Cashew Nut Shells: Characterization of Volatile Organic Compounds and Quantitative Health Risk Assessment in Pyrolysis and Direct Combustion Processes
Anselme Bagoro1,*
,
Marie Sawadogo1 ,
Anthony Benoist2 ,
Sayon dit Sadio Sidibe1 ,
Igor W.K. Ouedraogo1
- 1Renewable Energy and Energy Efficiency Laboratory (LabEREE), International Institute for Water and Environmental Engineering (2iE), Rue de la Science, Ouagadougou P.O. Box 594, Burkina Faso
- 2Biomass Wood Energy and Bioproducts Unit (BioWooEB), CIRAD, F-97743 Saint Denis, Reunion, France
- Manuscript receivedMarch 7, 2025
- revisedJune 9, 2025
- acceptedJune 27, 2025
- publishedNovember 21, 2025
Abstract
This study evaluates the health risks associatedwith exposure to atmospheric emissions from energy recovery ofcashew nut shells through pyrolysis and combustion processes.The analysis focuses on two risk categories: carcinogenic risks,assessed by the Individual Risk Excess (ERI), and noncarcinogenicrisks, estimated by the Hazard Quotient (HQ).Samples were collected at the source (industrial chimney) usingisokinetic sampling on activated carbon tubes and subsequentlyanalyzed by gas chromatography coupled with massspectrometry to identify and quantify Volatile OrganicCompounds (VOCs). These concentrations were then modelledat 500 meters using an atmospheric dispersion model of theScreening Modelling in Air Quality Assessment type. The resultsshow that benzene and 1,3-butadiene are the primarycontributors to carcinogenic risks, with a total ERI exceedingthe acceptable threshold of 10⁵. For benzene, direct combustionposes approximately 1.7 times the risk compared to pyrolysis.Similarly, 1,3-butadiene shows a risk reduction with pyrolysis(about 1.3 times lower). Overall, pyrolysis reduces the totalcarcinogenic risk by 26.9% when compared to directcombustion. Regarding non-carcinogenic risks, the HazardQuotients (HQ) for toluene (4.38×10<sup>−5</sup> for combustion and4.03×10<sup>−5</sup> for pyrolysis) and styrene (5.8×10<sup>-4</sup> for combustionand 1.9×10<sup>-4</sup> for pyrolysis) remain below 1, indicating limitedshort-term health effects. Comparing the two recovery processes,the overall hazard quotients show a slight reduction of 11.1%between direct combustion and pyrolysis of cashew nut shells.The study recommends technological improvements and strictregulatory measures to sustainably manage emissionssustainably, thereby protecting public health and theenvironment.
Keywords
- energy valorization
- cashew nut shells
- Volatile Organic Compounds (VOCs)
- health risks
- modelling in air quality assessment
- pyrolysis and combustion
How to Cite
Anselme Bagoro, Marie Sawadogo, Anthony Benoist, Sayon dit Sadio Sidibe, and Igor W.K. Ouedraogo, "Energy Valorization of Cashew Nut Shells: Characterization of Volatile Organic Compounds and Quantitative Health Risk Assessment in Pyrolysis and Direct Combustion Processes," International Journal of Environmental Science and Development, vol. 16, no. 6, pp. 419-425, 2025. https://doi.org/10.18178/ijesd.2025.16.6.1550
Copyright & License
Copyright © 2025 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).