Syngas is awesome

The best thing you can do with your plastic waste is reuse it - especially if plastic is expensive. Stony asteroids and our own Moon run short on hydrogen, so will find plastic expensive. But sometimes it is not feasible to reuse the plastic. A plastic item might tear or, if in oxygen and sunlight for too long, degrade.

Via hbdchick comes a means to accelerate the degradation: microwave. We're all here to retrieve the hydrogen. But looking into all this, I'm not minding the Old And Busted way.

The usual process does this at 1025 K but that is too hot even for Venus' surface; it also gets syngas back, which mixes the hydrogen with carbon-monoxide. Luckily hot syngas at least will not explode outside a zinc-oxide catalyst and 30 MPa which is, what, five times the surface pressure. (Unless you add oxygen, which in free gaseous form isn't natural to... anywhere.) Unluckily it takes a second step to separate the gases.

... if we cared to do that.

The CO, as Robert Zubrin teaches us, grants a wide array of useful chemistry (or is that "chemody"?). Mixed with hydrogen it should reduce our rusty metals better - and syngas is so used in sponge iron production. Syngas also makes alcohols starting with methanol at 575 K with those catalysts. It's good for all sorts of stuff. Waste products are carbon dioxide, which we vent out; and water, which we also love. Might be a bit fizzy.

We're here for Venus; hydrogen might be hard to liberate from all that sulfur, absent caustics. CO's molecular mass is 28 like nitrogen gas. Given that Venus' atmosphere is mostly carbon dioxide, our poison waste is a lifting gas even better than the breathable-air mix which will be some high percent of oxygen gas (at 32). Especially if CO be mixed with hydrogen instead. [UPDATE 9/11/26 Humans will be happiest where 0.5 bar with 40% O₂, but the syngas balloon can float anywhere.]

How do we get 1025 K over Venus' surface? Float a BIG transparent balloon with your plastic trash and a few focusing mirrors in it. Let it break the clouds, above. As mentioned this process will only lighten the load.

AMMONIA 12/15: We can also talk fertiliser from urea.