Conventional IC engines generally use diesel or petrol as a mode of fuel in the combustion chamber for generating power. A major problem with this is that the IC engine emits harmful gases into the atmosphere resulting in adverse effects on living things and environment. Another problem that the IC engines faces is the lack of fuel efficiency.

Caterpillar is a leader in manufacturing heavy duty vehicles and earth movers like bulldozers, articulated trucks, excavators, compactors, harvesters, etc. The firm was recently granted U.S. Patent No. 9127600, titled Method and Apparatus for generating useful work from the vent gas of a dual fuel Internal Combustion Engine. The invention discloses about an IC engine using duel fuel for combustion resulting in high fuel efficiency which can be primarily used in heavy work vehicles.

The patent describes “An IC engine combusting diesel and gaseous fuels comprising a diesel reservoir in communication with an IC engine via a diesel fuel rail, a gaseous reservoir in communication with the same IC engine via a gaseous fuel rail, a pressure control device measuring the pressure differentials between the gaseous and diesel fuel rail, a pump to pump out the liquefied gaseous fuel from the gaseous reservoir to two different heat exchangers and an auxiliary engine”.  Let’s check how this works.

Firstly, the combustion of diesel occurs in the IC engine. In the meanwhile, the pump pumps out the liquefied gaseous fuel from the gaseous reservoir to two different heat exchangers to absorb heat, wherein one of the heat exchanger is coupled to the exhaust stream of the auxiliary engine.  The heated gaseous fuel is sent back to the gaseous fuel rail, which is then utilized for combustion in the IC engine.

Secondly, if the pressure differential exceeds a desired range, the pressure control device vents gaseous fuel from the gaseous fuel rail to an auxiliary engine for conversion of vented gaseous fuel into useful work.

Other advantages of the newly proposed design include:

  • High fuel efficiency.
  • Use of alternate fuels resulting in conserving conventional fuels like petrol and diesel.
  • Reduced emissions.

Authored by Dinesh Kumar

Contributed by Mechanical and Automotive Patent Division of BananaIP in India

For further information on Mechanical and Automotive Patent law in India, write to