Continuous Fermentation

The continuous mix bio fermentation is the latest and proven technology as compared to the old batch fermentation technology. It has many advantages like continuity of operation,higher efficiency and ease of operation. Continuous fermentation also results into consistent performance over a long period as compared with batch fermentation. Most modern ethanol production plants adopt this continuous fermentation technology. Considering all the above advantages, we have proposed to adopt the efficient continuous mix bio fermentation in the distillery. The fermentation process employs special yeast culture, which can with stand variations in the molasses quality, temperature and other shock loads.Continuous mix bio Fermentation plant consists of four numbers continuous mixed bio reactors connected in series with all the accessories like plate heat exchangers for cooling, spares, broth mixers and air blowers etc. The yeast is immobilized using special media and it remains in the fermentation plant throughout and hence it gives tremendous advantages in maintaining the yeast population and in combating the bacterial infection. The technology is called continuous mixed bio fermentation (CMB) and which is the latest technology available in the industry at present. Molasses after weighing is diluted and also per-treated to an appropriate sugar concentration while pumping through Contentious Molasses Broth Mixer into the Contentious mixed bio reactors.. The partial per-treatment of molasses is required to reduce scaling of the equipment due to the sludge present in the molasses, which is separated out very easily in this per-treatment. The bio reactors are then inoculated with culture developed in the culture vessels. This culturing with suitable yeast is carried out only during the start-up of the plant. The culture thus developed maintains itself in bio reactors on continuous basis.

To help the fermentation sustain the assailable nitrogen are added in the medium in the form of Urea and DAP as required. Temperature in the bio reactors is maintained to an optimum level as required for efficient reaction with the help of Plate Heat Exchanger and recirculation pumping system. This recirculation also helps improper mixing of fermented wash. The retention time for the reaction is about 24 to 36 hours. Air blower is provided to supply the necessary oxygen required for the yeast and also for agitation. After completion of reaction the fermented wash is delivered to Wash Settling clarifies. In Wash Settling clarifies, settable solids settle down. The supernatant goes to Buffer Wash Tank (BWT) and sludge from bottom goes to Sludge Tank.

The CO2, which is liberated, is scrubbed in water, with the help of CO2 Scrubber. This CO2 contains ethanol,which is recovered by collecting CO2 Scrubber water into Sludge Trough. The diluted sludge is pumped into Sludge Settling clarifies. The traces of ethanol present in diluted sludge are separated at the supernatant, which is collected into BWT through overflow and washed sludge from bottom is drained off.

The fermented mash collected in the Clarified Wash Tank is then pumped to Mash or Primary column for distillation.