1. Summarize

The molasses ethanol waste liquid is a kind of organic substance in high concentration, the COD_Cr up to l2×1O⁴mg/L or more, BOD5 up to 5×1O⁴mg/L or more, the content of SS was about 3×1O⁴mg/L, the waste liquid had a deep color, large colloid and strong corrosivity, and the PH value was about 3~4, It discharged about 6500kg waste liquid with producing 1000L ethanol, it had large discharge value and caused serious pollution. The molasses ethanol waste liquid treatment was always a difficult problem in environment protection, the environmental experts all around the world had tried all sorts of treatment process, which combustion with a concentrated molasses ethanol wastewater, and recovered energy and potassium ash, was recognized as the most thorough treatment program.

2. Process brief description

The ethanol waste liquid from distillation section was pumped to the evaporation and concentration section, after vacuum concentration, the waste liquid was concentrated to 60⁰BX. The vapor condensate was recovered to be used for slurry mixing in ethanol producing, the strong liquid is delivered to the special incinerator for burning, the incinerator could produce the vapor?P: 3.82MPa, T: 450??with no addition of fuel, the steam was delivered for ethanol producing or evaporation after the steam to power a turbine. The ash that produced in boiler combustion and collected by dust catcher contained about 20~22% K₂O, it was the best raw material for compound fertilizer producing.

 

3. Process flow diagram

3.1 Process flow diagram sketch

3.2 Systemdiagram sketch

 

4. Product characteristic

4.1 It solved the difficult technology problem of boiler corrosion, ash blocking and coking for waste liquid consumption, and the boiler could operate continuously 300d/a at least.

4.2 With the application of concentration process, the system could reduce energy consumption.