Yes. Unlike diesel and gasoline AdBlue isn't harmful and can be stored outside the fuel tank.

Almost all diesel cars made after September 2015 have AdBlue tanks so therefore they are euro 6 and exempted from ULEZ.

AdBlue is mostly sold in 5L / 10L gallons.

There are multiple websites showing the locations of stations across the country.

Because of less fuel tax (regular fuel at 52p) and only 5% VAT, red diesel is cheaper to buy.

There are only designated red diesel approved forecourts in the UK and not available on majority of the forecourts in the UK.

It is illegal to sell at forecourts without correct permission from HMRC. Any forecourts that sells red diesel must be approved as a supplier by HMRC and this can be a strict. Check on business premises history etc.

Red diesel is a diesel fuel used with red dye coming from approved suppliers.

There are approved petrol stations that sell red diesel when believed to be for a genuine means of usage.

It changes to a liquid when subjected to modest pressure or cooling which means it can be easily stored in bulk tanks or portable cylinders so providing energy wherever it is needed.

There are multiple web links showing where to find LPG service station locations.

Yes. This needs to be done by professional tank converters and approved mechanics.

From approved suppliers delivered in bulk tanks and stored in larger tanks above ground, safely it is then pumped through to customers' vehicles.

Many large companies do not store them any more. LPG service stations are mostly by motorways or dual carriageways.

Yes. It can be used for multiple energy purposes for example some caravans have LPG tanks stored for cooking.