You've stumbled into an interesting contemporary engineering problem, as an overall system combining all costs is it cheaper to compress natgas into CNG or liquify it into LNG? And the answer is "it depends".

In both cases you're probably going to have to burn about 10% to 20% onsite to generate the power to run the compressors.

This also explains why its financially viable to spend $1M/mile on gas pipelines instead of transporting it in tanks on the back of trucks.

In as few words as possible this is more or less why your house furnace probably runs on natgas, but probably not your car. As an overall system its more efficient to burn the vapor in your furnace connected by pipes and the liquid in your mobile car.

And that circulates back to my suggestion that if you have to install 20% of flow capacity in the form of generators to run liquifiers, from an overall system standpoint it makes more sense to scale up five times, get somewhat higher process efficiency, and just pump KWh of electricity into the grid rather than making a complicated plant.

Also capture is assumed to be simpler than catching butterflies. It won't be, it won't be cheap, and it won't be effective.

WRT economic costs shouldn't matter when talking about the environment, its unavoidable. Spending $100M on building and operating a temporary plant will as a factor of blowing $100M result in environmental damage likely far exceeding just dumping the fuel unburnt. The planet has suffered incredible damage in the past from "we have to do something", and probably always will in the future.

Well, if someone were to put together a spot compression or generation system, how many older storage sites / leaks sites exist such that it would be worth the apply the capital to design and assemble a number of units which could be leased on an emergency basis?

It seems like back east there are lot of fairly small fracking wells setup for spot generation. If that's a shorter design distance from what could be used then even better.

I agree about the environmental costs, but mostly phrased it the way I did because it's a lot easier to convince a company to release the funds if it's going to cost them one way or another... worse, as a side issue if government steps in with emergency funding to help citizens, it's an unfortunate encouragement of corporate strategy of 'privatize the profits and socialize the risks'.

"In both cases you're probably going to have to burn about 10% to 20% onsite to generate the power to run the compressors."

Isn't burning it in-place better environmentally than just venting it to the atmosphere?

All oil refineries and drilling operations have a flare system that burns off such gas - if not beneficial, why do that besides that it looks cool from a distance at night?