PRESS CAKE

The cake is not waste - it is an important and valuable part of the business.

There are 2 main choices: fuel or animal feed (though I've heard of it being used as a fertiliser or lawn conditioner). 

If you have animals that you feed then you are already on a winner, rapeseed, linseed or sunflower cake are all good sources of protein and energy. We sell our rape cake for £140 per ton to a farmer up the road who has an intensive beef heard, I've hear of folk getting £190 per ton collected from the press (but that's down south of course!). Sunflower cake is especially valuable since it can be used as a high protein poultry feed.

We have heard of it being sold to power stations where it is mixed with coal to aid combustion and reduce pollution.  If your press makes pellets you could use and/or sell fuel pellets that can be burned in pellet stoves.  

Feed mills will be able to analyse your cake and make up a balanced ration. Your local university or agricultural technical college may be able to formulate a suitable feed from the raw materials you have.

Garden cantres may be interested in rapemeal as a lawn conditioner (especially if you bag it up nicely).

Typical values for rape expeller cake:

Dry Matter: 87%
Raw Protein: 30%
Raw Fat: 15%
Raw Fibre: 10%
Energy (MJ/kg) 13.5
Minerals Ca/P/Na (g/kg): 6.3/10.8/0.1

A more detailed report comparing solvent extracted cake with cold pressedcan be found here 
http://www.eau.ee/~aps/pdf/20052/Leming_i.pdf

Recently a couple of pressing operations have started selling rapemeal briquettes. See this link to one of them:    http://www.greendragonfuel.co.uk/  search around on their site there is also a bit of info about biofuels.