Hello Stovers; The following study specifically measures nanoparticle production from cookstoves and shows how the size of emission particulates decreases from 3-stone to rocket to FD-TLUD stoves.
Just, B; Rogak, S; Kandlikar, M (2013) Characterization of ultrafine particulate matter from traditional and improved biomass cookstoves. Environmental Science & Technology 47: 3506-3512 Doi: 10.1021/Es304351P Abstract: Biomass combustion in cookstoves has a substantial impact on human health, affects CO2 levels in the atmosphere, and black carbon (BC) and organic carbon (OC) affect the earth's radiative balance. Various initiatives propose to replace traditional fires with "improved" (nontraditional) cookstoves to offset negative local and global effects. In this laboratory study, we compared the size, composition, and morphology of ultrafine particulate emissions from a "three-stone" traditional fire to those from two improved stove designs (one "rocket", one "gasifier"). Measurement tools included a scanning mobility particle sizer, PTFE and quartz filter samples, and transmission electron microscopy. In the improved stoves, particulate mass (PM) emissions factors were much lower although median particle size was also lower: 35 and 24 nm for the rocket and gasifier, respectively, vs 61 nm for the three-stone fire. Particles from improved stoves formed clearly defined chain agglomerates and independent spheres with little evidence of volatile matter and had a higher proportion of BC to total PM, although overall BC emissions factors were fairly uniform. The 3-fold increase in quantities of sub-30 nm particles from improved cookstoves warrants further consideration by health scientists, with due consideration to the higher combustion efficiencies of improved cookstoves. As the authors point out, there needs to be more study into nanoparticle production under actual conditions of stove use and with various qualities of fuels. We don't know that much about the chemistry and human toxicology of nanoparticles from cookstoves. It would seem to me that this work is urgent. When it is done, we may find that the health risks associated with nanoparticles from stoves is way less than nanoparticles from gasification of municipal solid waste and other industrial settings. A Youtube lecture on nanoparticles by Dr. Vyvyan Howard can be found here: http://www.youtube.com/watch?v=N2s6pr0N3vg Any health risks associated with nanoparticles will have to be balanced against human welfare and ecological benefits of improved cook stoves. That is something that needs to be explained to people (like me) involved in rural development who have to know that improved cookstoves can be safely recommended as part a development package. Of course, this nanoparticle business really needs sorting out, because it could also have serious implications for any substantive production of biochar around the world. All the best, Julien -- Julien Winter Cobourg, ON, CANADA _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://stoves.bioenergylists.org/
