| Yes, it can be. By carefully designing the size of the various chambers in a stove, full combustion can be achieved such that the only byproducts are CO2 and H20. This does not happen in a conventional fireplace. Part of the motivating design goals for "rocket stoves" is to achieve this sort of complete combustion. If you're interested in the chemical and physical processes that comprise combustion, I cannot recommend the Faraday Lectures highly enough. Michael Faraday was an experimental physicist, and the data resulting from his experiments were what James Maxwell used to derive Maxwell's Equations for electromagnetic phenomena. Separately, he gave a lecture on candles and combustion, which has been recreated in the original language here: https://www.youtube.com/playlist?list=PL0INsTTU1k2UCpOfRuMDR.... The important intuition is that combustion is a gaseous process. When burning (solid) wood, the heated wood will give off gasses and particulate matter (soot). Those gasses and particulates will combine with gaseous oxygen in an exothermic reaction called combustion. In a conventional fireplace, the oxygen and temperature constraints result in incomplete combustion, leading to particulate pollution as you mention. The search term to learn more about overcoming those hurdles is "rocket stove". In these sorts of stoves, there's a few modifications that result in more-complete combustion. There's separate chambers for the wood and the combustion. In the first chamber, the same processes as in a conventional fireplace occur: the wood burns, creating soot and hydrocarbon gasses. In the second chamber, hot air is added to provide a secondary source of oxygen, and the airflow velocity is reduced (by carefully calculating chamber size using the Bernoulli fluid equation), resulting in complete combustion. By having a right angle between the input from the wood chamber and the chimney, you can achieve a chaotic mixing (in terms of chaos theory) between the wood byproducts and the added oxygen, which also helps ensure complete combustion. So the entire system has the following parts: a chamber to burn the wood; a chamber where hot external air is added and full combustion achieved; a tall chimney to ensure a good draft and airflow; a "bell" to slow air velocity of the hot exhaust and ensure good thermal transfer; a final exhaust port. Here's some resources: https://www.youtube.com/watch?v=IsO9vLn8JHw https://en.wikipedia.org/wiki/Rocket_mass_heater https://paulwheaton.com/efficient-wood-heat/ https://permies.com/f/260/rocket-mass-heaters |