Operating internal combustion engines on pyrolysis products

To increases the overall efficienty of a pyrolysis based power plant, it is proposed to operate an internal combustion engine on a liquid fuel such as pyrolysis oil based fuel (8) and, in addition, pyrolysis gas (9) is added to charge air. This allows using otherwise not lost energy contained in the pyrolysis gas. Specifically, a pyrolysis gas supply unit (120, 220) is proposed that is configured for providing pyrolysis gas (9) into a charge air system (161,261) of the internal combustion engine (162, 262). The pyrolysis gas supply unit (120, 220) comprises inter alia a filtering and compressing unit (122, 222) for removing tar from the received pyrolysis gas (9) and pressurizing the pyrolysis gas (9), a pyrolysis gas regulating unit (124, 224) for regulating a flow of the filtered and compressed pyrolysis gas (9) leaving the pyrolysis gas regulating unit (124, 224), a pyrolysis gas admission valve (140, 240) for controlling the amount of the pyrolysis gas (9) provided to the charge air system (161, 261), and a pyrolysis gas admission unit (142, 242, 342) with a charge air passage (115, 215, 315) that is fluidly connectable to the charge air system (161, 261). The pyrolysis gas admission unit (142, 242, 342) is configured to provide pyrolysis gas (9) into the charge air passage (115, 215, 315).