Storing environmentally friendly generated electricity in reactive chemicals would solve lots of problems (storage; reuse of existing energy industry infrastructure; energy-dense fuel for cars, trucks, and planes; lowering CO2; etc.) However, ammonia is quite corrosive.
Because the steel pipes transporting natural gas throughout the US are under pressure, they are subject to a peculiar form of degradation, stress corrosion. Normally, steel can rust or corrode when exposed outdoors. Simple coatings of paint, tars, polymers, etc. can protect steel, and natural gas transport pipes are coated on the outside to protect them from moisture, air, and the natural PH variations found in different environments. These pipelines and their coatings are examined periodically to prevent catastrophic failures. The pipes are perhaps one-half to two meters in diameter and have a wall thickness of one to three centimeters if I recall.
Stress corrosion is not like normal rust on the surface of steel. It happens inside the steel, along the inter-granular crystalline boundaries within the steel itself. Somehow, the stress inside the steel produces higher rates of corrosion (there is a large literature on this subject, google "stress corrosion"). This type of corrosion can be dangerous because pipes can burst without visible warning of their condition. Detection of stress corrosion requires inspection systems that are much slower (ultrasound, electromagnetic induction measurements, etc.) and less practical than simply looking for corrosion on the outside of the pipes.
Unfortunately, ammonia is corrosive to steel and the insides of existing pipelines and the valves and other fittings would not be prepared to handle ammonia. So ammonia wouldn't be able to utilize the existing natural gas pipeline infrastructure.
I'm not a metallurgist nor even someone that remembers much of my university chemistry classes so I welcome comments from a more informed HN reader.
So ammonia wouldn't be able to utilize the existing natural gas pipeline infrastructure.
That's not what I'm advocating. I was talking about the precedent of companies that know how to run pipelines, do transactions with storage pools, and scheduling. Of course the physical pipes and other equipment would have to be different. But all of the commercial contractual, financial, and legal frameworks are all pretty much worked out.
Because the steel pipes transporting natural gas throughout the US are under pressure, they are subject to a peculiar form of degradation, stress corrosion. Normally, steel can rust or corrode when exposed outdoors. Simple coatings of paint, tars, polymers, etc. can protect steel, and natural gas transport pipes are coated on the outside to protect them from moisture, air, and the natural PH variations found in different environments. These pipelines and their coatings are examined periodically to prevent catastrophic failures. The pipes are perhaps one-half to two meters in diameter and have a wall thickness of one to three centimeters if I recall.
Stress corrosion is not like normal rust on the surface of steel. It happens inside the steel, along the inter-granular crystalline boundaries within the steel itself. Somehow, the stress inside the steel produces higher rates of corrosion (there is a large literature on this subject, google "stress corrosion"). This type of corrosion can be dangerous because pipes can burst without visible warning of their condition. Detection of stress corrosion requires inspection systems that are much slower (ultrasound, electromagnetic induction measurements, etc.) and less practical than simply looking for corrosion on the outside of the pipes.
Unfortunately, ammonia is corrosive to steel and the insides of existing pipelines and the valves and other fittings would not be prepared to handle ammonia. So ammonia wouldn't be able to utilize the existing natural gas pipeline infrastructure.
I'm not a metallurgist nor even someone that remembers much of my university chemistry classes so I welcome comments from a more informed HN reader.