Can you drink 3 kl of coffee in the morning?

Probably, if you spread it out over a nine-year period.

3 kilolitres would be 3,000 litres, and as a mug of coffee is about 300 mg that would mean 3 mugs a day would equal 1 litre.

3 mugs a day, per day, for a year would be about 330 litres and, at that rate, it would take 9 years to consume 3,000 litres.

Better get a loyalty card and get a few free ones!