Sounds like a side biz for Starbucks to me.
Almost any form of vegetable oil can be catalytically converted to a cetane based fuel.
Since used coffee grounds can be as high at 15% coffee oil by weight; the extraction should not be difficult. The usual use for extracted coffee oil is simply instant coffee.
As coffee beans are labor intensive and are geographically limited on where they thrive; peanuts which can be grown almost anywhere seem a better source for a plant based fuel.
Henry Ford's first Model-T was built to run on hemp gasoline and the CAR ITSELF WAS CONSTRUCTED FROM HEMP! On his large estate, Ford was photographed among his hemp fields. The car, 'grown from the soil,' had hemp plastic panels whose impact strength was 10 times stronger than steel; Popular Mechanics, 1941.
Rudolf Diesel, the inventor of the diesel engine, designed it to run on vegetable and seed oils like hemp; he actually ran the thing on peanut oil for the 1900 World's Fair. Henry Ford used hemp to not only construct cars but also fuel them.
As an alternative to methanol, hemp has at least one glowing report: the plant produces up to four times more cellulose per acre than trees. And a hemp crop grows a little quicker than a forest.
Hemp has been demonized and prohibited by law because it would bankrupt many industrial companies. There's our risk-averse capitalist again.
It's often forgotten now how many liquid (and occasionally even gaseous or solid) fuels were tried out to run cars before the industry settled on petrol. Hemp, peanut oil, benzene, peroxide, if it burned hotter than ethanol, you can probably find a late edwardian automobile whose engine ran on it.
On the level and looking for a square deal.