The world of today is facing many problems, and it would be an honor to help solve even one of these problems. If I will be give a chance to invent somethinf to make the world a better place, it would be for the environment in general. A so-called "converter" is what I will invent. I will invent a machine that needs no environmental raw materials such as trees to produce papers so that no trees can be cut due to paper demand. Also, machine that can convert other raw materials for something to become reusable and can be alternative to what we use today such as natural gas and fossil fuel so that it won't run out in the future because we have other resources. Lastly, I will invent a machine converter that will converts salt water to fresh or drinking water because our fresh water is less than 5% of the world's water while salt water has a large amount of percentage so why not use it ao that put fresh water will not dry up.
It's certainly hard to imagine a machine that could make paper without any environmental raw materials. Do you mean that it would use something else, like stone or something? I suppose that would also be an environmental raw material.
The salt water converter idea is already a thing. Some countries are already converting tons of salt water to fresh water. This is call desalination. Unfortunately, things like this only seem to be developed when they are absolutely need. We aren't that good at working on prophylactic solutions as a society.