Entries by Kim Still

Health and Emission Rates of PM2.5

Several articles have pointed out that using biomass-heating stoves can result in health problems in densely populated areas. We are working with friends at the EPA to think about how we might define PM2.5 emission rates for residential biomass heating stoves that would protect health in densely populated cities.  When the population density goes up (more […]

Exploring Horizontal Gasifiers

What happens if a bunch of sticks are bundled together, lit at the tips, and inserted into a well-insulated horizontal enclosure that enters a Rocket stove providing draft? Well, it’s hard to get everything to work well. As Dr. Winiarsky pointed out “Gasifiers are finicky.” But, when all of the tips of the bundle of […]

Shipping and Climate Change

I recently read a Time article that pointed out that shipping accounts for 2.2% of annual global greenhouse gas emissions. To put it in perspective the writer, Aryn Baker, suggests that if shipping was a country, it would be the sixth largest CO2 emitter in the world, on par with Germany. In her reporting from […]

Natural Gas, Methane and Nitrogen Oxides

I didn’t realize that natural gas is mostly methane which is about 84 times worse for climate change compared to CO2. As reported in the recently published study “Methane and NOx Emissions from Natural Gas Stoves, Cooktops, and Ovens in Residential Homes,” methane leaks are bad news for both environmental and personal health. (Lebel, et al, […]

Climate Change: Replacing Natural Gas and Coal Burning in the USA

Could biomass energy reduce the increased demand on electricity for home heating? Could the clean burning of biomass make a greater percentage of electricity partially replacing coal and natural gas, powerful climate forcers? As seen above, renewable energy now makes 20% of the electricity generated in the USA. Residential and commercial energy use makes up […]

Tuning A Stove With Real Time Data

When enough data is available in real time, it is not hard to make progress improving a stove. The LEMS emission hood provides real time, holistic feedback as the experimenter makes changes. Watching all of the measures simultaneously makes it possible to tune a stove like a car. The goal is to burn biomass at […]

Dr. Kirk Smith and The Breathing Space Project

ARC worked closely with Dr. Kirk Smith (1947-2020) when we helped to include emissions in the Water Boiling Test, used to evaluate biomass cookstove performance, for the Shell Foundation. We included the first “Tiers of Performance” with a simple approach that divided stoves into two categories: improved and unimproved. It was great to know Kirk […]

Post Combustion Reduction of PM2.5

Both automobiles and the biomass industry rely on improving combustion efficiency and post combustion reduction of PM2.5 to achieve “clean burning.” It’s really hard to rely on the combustion chamber to burn up enough of the harmful smoke to protect health, especially in large scale applications. Of course, all efforts should be made to be […]

Mass, Insulation and Thermal Efficiency

It is more likely that close to 50% thermal efficiency will be achieved with a biomass burning stove when: Small sticks are burned that produce tall, hot flames while using the least amount of wood. A 30cm in diameter aluminum pot is used with a 14cm high pot skirt that creates a 6mm channel gap. […]