I'm just going to add another link here. It relates to Pre-atomisation of fuels i.e. Fuel Water Emulsions and is also relevant to orimulsion, subject to the fuel droplet size being correct (you might need a fuel mill) and the method can be applied to your tars. Some ships engines (MAN B&W) are designed to burn FWE with around 30% or more water. Fule water emulsions are formed on board ship.
I think it is SIT in Germany who supply fuel emulsifiers.
This link dsicusses fuel emulsions: