What kind of gas is emitted by a coal powered steam engine, carbon dioxide, or carbon monoxide (same question for diesel).
Both - but mostly carbon dioxide (CO2) and water vapour (H2O) in both steam and diesel cases.
They both involve burning hydrocarbon fuels in air, so you mainly get the oxides of carbon and hydrogen out of the chemical reaction plus heat energy (the bit you really want [:)] ).
Tony
The coal-burning steam engine emits H2O (water vapor, as exhaust steam and to a lesser extent in the smoke – coal contains some hydrogen) and CO2. Both gases are considered benign, although the CO2 is a concern in terms of emissions from our industrial civilization and potential for climate change, and the steam engine will emit much more CO2 than the Diesel because it is less thermally efficient and goes through more fuel for the same amount of work.
The steam engine may emit some CO – a concern for tunnels and snowsheds – but the big worry is the amount of SO2 (sulfer oxide gas) – implicated in acid rain as well as local air pollution. Then, a lot of what the coal-fired steam engine gives off is not gas but particulates – the smoke and cinders. Some of the smoke is coal ash that is entrained in the draft; other parts of the smoke are unburned coal – sooty, dirty, and carcinogenic. A lot of the traditional steam engine design was concerned less about saving fuel and the environment and more about getting maximum power for acceleration and hill climbs, and a lot of the dramatic photos of steam engines climbing hills show a lot of the fuel going up the stack as the dramatic smoke – they are pulling a lot of draft to burn a lot of coal to raise steam without concern for efficiency.
The Diesel is an oil-burning internal combustion (combustion at high compression pressures) engine. It will emit some NOX (nitrogen oxides with varying amounts of oxygen O depending on the molecule), some CO. Much of the hydrocarbon emission from a Diesel will be in the form of smoke on account of the combustion of oil droplets from the injector. That smoke is sooty, dirty, and carcinogenic (contains carbon in the form of carbon-ring compounds), but there is much less of it than with a steam engine. The Diesel will give off some SO2, depending on the level of sulfer in the fuel, but less than a steam engine.
Diesels are relatively clean in terms o
If I’m not mistaken, there’s a big difference in SO2 output in diesels that burn “Off-road” and “Highway” diesel fuel (I’m not sure if this distinction occurs elsewhere, but it does here in CO). So…the company I work for uses Off-road on our machines that never reach public roads (blades, scrapers, etc.) and Highway Fuel in machines that can be used on the road (backhoes, endloaders, etc.).
Are there any requirements on railroad diesel use? Does the EPA, or whoever dictates such things have requirements of what type of fuel railroads use in their locos?
Thanks in advance for any answers.
The only difference between off /on road diesel fuel is the color. A dye is added to the off road fuel
to determan it’s intended use.
Fuel sold for on highway use is subject to "highway use"taxes.
I don’t believe the EPA has a requirement on type of fuel but they have standards concerning emmissions.