Liquid distributor system and process of liquid distribution

The disclosure provides a system and a process for injecting and uniformly distributing a liquid into a fermentation broth in a bioreactor for maintaining stable condition within the fermentation broth. The system includes a downcomer section which contains two or more circular pipe conduits extending from a wall of the downcomer to the center vertical axis line of the downcomer. Liquid injection apertures are arranged along the circular pipe conduit and are non-uniformly spaced apart from the center vertical axis of the downcomer to the wall of the downcomer. The apertures further alternate and are offset between the top and bottom surfaces of the circular pipe conduit. The process of the disclosure involves using the system described above for carrying out a fermentation process for converting a C1-substrate to at least one product such as ethanol.