The used box will be transferred to a bioreactor, where the gases will be extracted and fed to genetically modified algae through chemical reactions. The algae will be crushed to form bio-oil using already existing procedures, and converted into biodiesel, which is almost an exact replica of traditional diesel.

This diesel can be used as fuel, without any extra cost of production. Methane gas and fertilizers are bi-products of the process and can be extracted separately.

Some of the concerns in the use of the greenbox include the placement of the greenbox under the car, and whether it would be easy and effortless to replace them. In inclement weather, the swapping of the greenbox may become an irritant.

The question of who would bear the cost of the greenboxes is also a moot point, because it would not reduce the consumption of gasoline or increase engine efficiency, and so is not immediately attractive to the consumer.

Greenbox technology would require a lot of engineering before it becomes applicable for automobiles. The use of genetic modification on the algae and the possibilities of it leaking into the outer world, also raise concerns in some sectors.

The concept has still to be worked out at a practical level, and the trio of inventors is in touch of various governmental and industrial agencies in order to support further research for health and safety tests. They have also had offers from various car companies for their invention.

The size of the greenbox is right now too big to be affordable and practical and will need engineering efforts to make it workable, but the inventors are confident that the greenbox can be adapted to a variety of vehicles from cars and jeeps to trucks and buses.