Co2 System Operation And Maintenance: Fill & Download for Free

Nuclear, solar, wind, and hydro all emit a low enough amount of CO2 (largely from cement production during construction) that their greenhouse impact can be more or less ignored. This is particularly true if the site is re-powered with new mechanicals after the system's operating life is up -- doing so just once will extend the useful life of the cement up to the residence time of CO2 in the atmosphere. 100 years is a reasonable service life for a concrete construction and much longer is possible with good maintenance. At that point you can call it zero-carbon for practical purposes.

There are two reasons:At small mom-and-pop restaurants where presentation isn't key, they don't have enough customers asking for soda to justify operations and maintenance of a fountain machine. Contrary to another answer given, contracts with Coca-Cola and Pepsi aren't a big deal since there isn't a lock-in time or penalties to ending contracts early. Repair services on the fountain machines are free and fast (Coca-Cola gas excellent customer service). You can buy bag-in-a-box syrup anywhere and pick any distributor for CO2. In fact, soda companies give rebates if you buy from their distribution service. Soda from a fountain is way more profitable than from a can. So that tells us that it's more than simply a cost/contract issue.The lesser reason is cultural. A drink from a can is more ideal aesthetically and healthy to Asians than from a fountain. In Asia where water filtration systems are poor, bottled products are better. In order to distribute fountain service, water lines must be constructed and filters must be used (again here, not enough soda sales to go through the set- up of a fountain machine). So culturally, Asians who operate businesses in the U.S. have inherited the idea of serving sodas from cans versus the fountain simply because that's how it's usually done.

Q: How long can a nuclear submarine remain underwater?Until the crew runs out of food. Within reason, facilities on the sub can handle routine maintenance, and the reactor fuel is good for a decade or more.Q: How is the oxygen prepared so the crew members can breathe?Electrolysis. Seawater is filtered and broken down into oxygen and hydrogen. The hydrogen is vented overboard, where it goes into solution at depth. Carbon dioxide scrubbers are used to remove CO2 exhaled by the crew, exactly as on spacecraft. The only difference is that, while some spacecraft (like Apollo and the Space Shuttle) use disposable CO2 scrubber material, nuclear subs use an endlessly reusable system in which CO2 is periodically removed from the material and dumped overboard.As with spacecraft, subs also use activated charcoal and other technologies to remove odors, but these would likely never form a limit to safe operating life under normal conditions.Subs also carry chemical oxygen generators similar to those used on airliners for use in emergencies.If you like science, you might enjoy my free award-winning scifi sampler.