Why can’t we use food to generate the energy needed to power our cars/electronic devices?

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Our bodies use food for energy so why can’t cars or electronics?

In: Technology

5 Answers

Anonymous 0 Comments

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Anonymous 0 Comments

We could, with some caveats, but it’d be a bad idea. Most food isn’t very energy dense, so for the same volume of fuel (which is the limiting factor for something like a car’s gas tank) you’d get a lot less energy from food than from a more dense fuel like gasoline. We sort of use food in biofuels like bio ethanol and biodiesel, but it’s not really food that you’d eat.

Anonymous 0 Comments

The chemistry to do this is somewhat difficult and the result is far less efficient and convenient than what we have now. It is like trying to heat your home via burning wood vs. burning food. The latter is way more expensive.

We could in concept carry around tiny gasoline generators for our phones and other devices but that is also undesirable.

Edit: A gallon of gasoline has about the energy of 57 Big Macs, so your price per gallon would be around $228, ignoring the costs or losses involved in converting it to a usable form.

Anonymous 0 Comments

They can, but there isn’t much reason to. Food is specialized, and unnecessarily complex and fancy. For instance, why would I bother cooking noodles if I was just going to feed them to a car? And the sheer amount of noodles I’d have to cook to get that car to do anything useful is astonishing. All those noodles would be better fed to people who cannot get by on drinking gasoline like cars can. Alternatively, if we could find a way to safely eat and digest gasoline, it might stop world hunger in its tracks.

Anonymous 0 Comments

Humans eat meat and plants because it contains the things we need to keep going. What keeps us going is stuff like Fats, Carbohydrates, and Protein. These things are what our bodies are made of, and we need them to keep rebuilding our body wherever it gets weak.

Generators work by burning stuff to boil water. That water is forced through a turbine to make electricity. Just like a boiling kettle forces out a huge jet of steam, we use a giant kettle and the forced out cloud of steam to spin a big turbine. The turbine spins magnets inside a copper tube, which makes electricity. You can spin the magnet other ways, like by attaching it to a giant pinwheel, or pouring water over a turbine.

The thing about using food is that it isn’t good at directly boiling water. It’s full of stuff that doesn’t burn well. Bodies have to go through a lot of complicated stuff to get what they do out of food(energy to move, nutrition, some heat), but it also produces a lot of unusable waste(poop). Just burning food wouldn’t work, because it doesn’t get hot enough to do much and leaves a lot behind.

Things like wood and coal burn well because they have a lot of carbon, which burns well. Coal has more pure carbon than wood, wood has more pure carbon than leaves/meat(food). The purer, the better to burn and the hotter things burn. Carbon burns very well. Meat and leaves don’t contain very much carbon at all, mostly protein, fats, and carbohydrates.

Cars are different because they use small explosions to spin their turbines. Gasoline is not carbon, it burns better. In fact, it burns so well that it explodes. Not much aside from gasoline is good at making those specific explosions. Gasoline requires purifying. It starts off as thick, not very good, crude oil that you have to filter into pure gasoline.

The human brain doesn’t make a lot of electricity, about 100 watts. That will barely power an LED bulb. You’d need a lot of food to make the same amount of power an average home in the US uses in a day.

TL;DR It’s really hard and wouldn’t work as well as what we’re doing already.