Are cat food cans better value and/or better for the planet than pouches?

A friend recently asked the question: "Are cat food cans better value and/or better for the planet than pouches?" Here is (a slightly edited version of) the response I offered:

Inasmuch as a can can (cue Parisian cabaret orchestra) be, and is quite likely to be, recycled, possibly to make a new can, whereas pouches may not be recyclable at all, cans win an easy first point.

The amount of fossil fuel burned to make / recycle a can compared with the petrochemicals that go into making a pouch requires a little bit of calculation.

It takes approximately 4kWh of energy to produce a kilo of recycled aluminium, which means that manufacturing a 15g aluminium can of fizzy pop consumes 60Wh of energy (equivalent to a 60W electric light bulb burning for an hour).

It takes approximately 2kWh of energy to produce a kilo of recycled steel, which means that a 45g steel pet-food can consumes 90Wh of energy. To produce 1 kWh of electricity requires approximately 0.16 litres of crude oil, so to produce a steel pet-food can, 14 ml of crude oil would be required.

It takes 23.6 kWh to produce a kilo of plastic. Assuming that a pet-food pouch weighs 10g, it would take 236Wh of energy to produce the pet food pouch (38 ml of crude oil).

In conclusion, then, to the second point, ideally, one would buy pet-food in aluminium cans, but the manufacture of steel cans is still less energy intensive than the manufacture of plastic pouches.