/tech/ - Technology

>>10591
steam is a working fluid, and not a fuel (like petrol). steam requires some external non-reusable fuel source like coal in a boiler.

>>10591
You want a fuel that gives off heat from a chemical reaction and you want this chemical reaction to be easily enough to reverse, so that it can be turned back into fuel ? That is possible but you have to pay for the entropy, so reversing the fuel will cost you energy. I doubt you will find a petrol derivative that can do this, does it really have to be a type of petrol ? If you don't need high temperatures and vast amounts of heat, you could just use a supersaturated sodium-acetate solution, that's pretty cheap and easy to get.

>>10591
You are going to blow shit up in your backyard, aren't you?

>>10591
we can make basically 100% efficient nuclear reactors that spend up 100% of the reactive material.

that is many many times more efficient in all the ways than fossil fuels.

as others said, fuel gives off energy because the chemical bonds break. If you want something that can mend chemical bonds after releasing energy, that would require inputing energy first. aka a battery.

>a type of petrol
you mean a mix hydrocarbons? no. you can burn H2 in many petrol engines, releases water vapour only. you have to make the H2 first of course, but that can be done with solar energy, for example high temperature electrolysis

somebody made a car that ran on water and the CIA killed him

>>10592
But doesnt hydrocarbons when burned into a gas naturally diffuse heat(energy) until it returns into its base temperature resulting in it becoming a fluid again? In this context fuel is ignited turning into hydro carbonic gas before releasing its heat into the water turning it into water vapour. That released heat allows the fuel to turn back into liquid with reduced mass

>>10601
no. burning stuff results in a chemical change, not just a phase change
you can turn CO2 + H2O back into hydrocarbons, but it requires an entirely different process. specifically, it requires a reducing environment. if you run CO2 + H2O over hot coals in an oxygen free environment you'll generate syngas which in turn can be turned into hydrocarbons

>>10601
>>10602
CO2 + H2O + 2C + energy -> 3CO + H2 (syngas)
this process requires coal and is endothermic
then apply https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process which mostly requires steam and is exothermic
I'm not sure whether the combined process is endothermic or exothermic. probably endothermic because the coals have to be red hot

>>10602
What about oxygen free fuel tanks where the petrol has nothing to combust with then what?

>>10604
uh.. you typically don't have fire in your fuel tank