SYSTEM AND METHOD FOR TREATMENT OF MOLASSES BASED
DISTILLERIES
FIELD OF INVENTION:
[0001] The invention relates to a system and method for treatment of molasses based distilleries and in particular relates to a system and method for obtaining a zero effluent discharge treatment to the molasses based distilleries.
BACKGROUND OF THE INVENTION
[0002] Waste water (effluent) generated in a distillery can typically be classified into process wastewater and non-process wastewater. The non-process wastewater is comparatively pure and as such can be recycled. The process wastewater of a distillery, on the other hand, consists of fermenter sludge, spent lees, and spent wash of which spent less is usually recycled. Fermenter Sludge has a higher Biochemical Oxygen Demand (BOD) and a lower volume as compared to spent wash and therefore it is advisable to dewater fermenter sludge and dispose it off without mixing it with spent wash as it increases the BOD of the receiving stream. [0003] Generally, a molasses based distillery plant discharges huge quantity of untreated water with high biological oxygen demand (B.O.D) level and chemical oxygen demand (C.O.D) level. The amount of effluent (wastewater) generated in a distillery typically depends on the extent of process water used and the technology adopted for manufacturing alcohol. Currently, most distilleries are of conventional batch type in which about 15 KL of spent wash is produced per KL of alcohol. In the modern continuous type distillery, however, spent wash generation is of the order of 10 to 12 KL/KL of alcohol (5 to 6 KL/KL of alcohol if a reboiler is used).
[0004] Some traditional distilleries, for lowering the BOD and COD levels use Biomethination of spent wash. Although, the Biomethination process provides energy generation and results in lesser B.O.D and C.O.D level in the discharged water, this method does not eliminate pollution problems. Moreover, the system used for this process increases the volume of effluent a few fold. Further, some traditional systems use a secondary treatment process in distillery plant to get rid of the pollution problem. This process however is highly power intensive and the end effluent is colored and also in most cases not dischargeable as per pollution control rules. [0005] Conventional bio-compositing method is also used quite often to mix the effluents with press mud available from sugar factory. The process further converts the mix into Bio-fertilizer. In this practice, the disadvantage is that with the quantity of effluent being 12-14 times of the quantity of alcohol produced and the ratio of press mud effluent being 1:3:5, it is difficult to use the entire effluent for Bio Compositing. It is also causes air pollution.
[0006] Distilleries also use an evaporator to concentrate the spent wash to 15-20% and further use the concentrate to mix with press mud for use as a Bio fertilizer. But, the main problems faced by use of such evaporators include frequent chocking of tubes in evaporator and froth formation leading to contamination of condensate water from the evaporator. Moreover, the press mud availability is also limited to six months a year and during monsoon time it becomes difficult to process bio-fertilizer due to flooding of the lagoons.
[0007] Therefore, there is a need for a system and method to overcome the above mentioned problems faced in the conventional molasses based distilleries techniques known in the art.
OBJECTS OF THE INVENTION
[0008] It is an object of the present invention to provide a pollution free
system for Molasses based distilleries.
[0009] It is another object of the invention to recycle the reclaimed water in
the process.
[00010] It is yet another object of the invention to provide an effluent
free system for Molasses based distilleries.
[00011] It is another object of the invention to use boiler ash as
fertilizer.
[00012] It is an object of the present invention to use dried solid fuel
as a fuel.
[00013] It is yet another object of the invention to generate energy out
of the effluent.
SUMMARY OF THE INVENTION
[00014] The described system and method relates to effective treatment of molasses based distilleries. The method of the present disclosure comprises of concentrating post Bio- methanated effluent by means of an energy efficient multi stage evaporator. The method further includes mixing the concentrated Bio- methanated effluent with Baggase/Rice husk in a fixed ratio and drying the resultant mix in a rotary dryer. The method further includes burning the resultant dried fuel in a boiler to generate energy out of the effluent used to run the evaporator and/or the rotary dryer. Further, the method can also use other processes including reuse of the condensate water generated in the evaporator and a process to feed the boiler generated energy to the evaporator, rotary dryer and also used for power generation in high pressure turbines.
BRIEF DESCRIPTION OF THE DRAWINGS
[00015] The detailed description is set forth with reference to the
accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
[00016] Fig. 1 illustrates an exemplary method for treating molasses based distilleries using pollution free and emission free techniques.
DETAILED DESCRIPTION
[00017] This disclosure is directed to a system and method for an effective treatment of effluents of molasses based distilleries. More particularly, the method involves obtaining pollution free and providing effluent free discharge treatment to molasses based distilleries [00018] Multiple and varied implementations and embodiments are described below. In the following section, an exemplary system and method that is suitable for practicing various implementations is described. [00019] Fig.l illustrates an exemplary method for treating molasses based distilleries using pollution free and emission free techniques. [00020] In an embodiment, the process 100 for effluent treatment of molasses based distilleries comprises a means for receiving post bio-methanated effluent in step 102 and concentrating the received post bio-methanated effluent in step 104 by means of an energy efficient multi stage evaporator. In an implementation, the post bio-methanated distillery effluent (2 % - 4% solid) is fed to a five effect evaporator at an ambient temperature. In another implementation, the evaporation process takes place in the evaporator and the effluent is passed through various stages of the evaporator. For instance, the effluent can be passed through different
pre-heaters and subsequently through calandrias. Steam and a part of the generated vapors can act as a healing medium in the calendria jacket. In an implementation, after the evaporation process is complete, the evaporator ejects the concentrated effluent (about 40% solid).
[00021] In an embodiment, the evaporator releases a pre-determined
amount of condensate water at regular intervals. The condensate water that comes out of the evaporator has negligible B.O.D level and therefore can be reused as process water within the distillery plant. In an embodiment, the steam consumption in the evaporator is as low as 0.12 kg/kg. [00022] In another embodiment, the evaporator can be designed to avoid froth formation and scale formation in its tubes and can be continuously used with CIP cleaning at defined intervals. [00023] In yet another embodiment, the resultant concentrated effluent can be mixed with Baggase/Rice Husk in step 106 of Fig. 1 and fed to a rotary dryer. Typically, the drying process takes place inside the rotary dryer in step 108 of Fig. 1 and the inlet temperature of air is maintained between 350°C to 360°C and outlet temperature is kept around 100°C . In a preferred embodiment, water evaporation takes place inside the rotary dryer and due to this the concentrated effluent and the Baggase/Rice Husk mix up very well to get converted into a solid fuel. In an embodiment, the calorific value of the solid fuel is in the range of 2800 Kcal - 3200 Kcal/Kg. [00024] In an embodiment, the solid fuel so obtained from the rotary dryer can be burnt in a boiler in step 110 of Fig. 1 to generate steam at high pressure. Step 110 of Fig. 1 illustrates a process by which the generated steam can subsequently be used to generate power through a turbine. In an implementation, the generated bleed steam and/or power from the turbine can be used for running the evaporator. In an implementation, the solid fuel
can also be burned in an air heater to generate the energy required for
running the rotary dryer.
[00025] In yet another embodiment of the proposed method, the boiler
configured to generate the steam can also generate ash as a residue in step
112 of Fig. 1. In one embodiment, the generated ash is rich in potash and
can be used as a fertilizer.
[00026] Table 1 demonstrates analysis of the ash generated by the
boiler as a residue.

(Table Removed)
TABLE 1
[00027] It can be noted that since the proposed process generates energy out of the effluent, the disclosed treatment system does not require additional power or other form of energy. It is also to be noted that the present invention also treats and is well applicable to distilleries and sugar mills where baggase is available including standalone distilleries where Rice huslo^baggase/wood chips are available.
[00028] The foregoing illustrated and described embodiments of the invention are susceptible to various modifications and alternative forms, and it should be understood that the invention generally, as well as the specific embodiments described herein, are not limited to the particular forms or embodiments disclosed, but cover all modifications, equivalents and alternatives falling within the scope of the appended claims. By way of
non- limiting example, it will be appreciated by those skilled in the art that particular features or characteristics in one embodiment may be combined as suitable with features or characteristics described in another embodiment. Moreover, the system and method for of the present invention can be a system used along with an automated or even with a manual system.
ADVANTAGES OF THE INVENTION
[00029] The present invention provides a pollution free system for
treatment of Molasses based distilleries.
[00030] The present invention recycles the reclaimed water in the
process.
[00031] The present invention provides an effluent free system for
treatment of Molasses based distilleries.
[00032] The present invention uses boiler generated ash as fertilizer.
[00033] The present invention uses dried solid fuel that can be used as
a fuel.
[00034] The present invention generates energy out of the effluent.

WE CLAIM;
1. A process of treating distillery effluent, said process comprising:
concentrating said effluent in a multiple stage evaporator;
mixing said concentrated effluent with baggase or rice husk in a fixed ratio to obtain a solid fuel; and
burning said solid fuel in a boiler to generate steam at high pressure, wherein said steam is used to run said multiple stage evaporator.
2. The process as claimed in claim 1, wherein said mixing further comprises drying mixture of said concentrated effluent and said baggase or rice husk in a rotary dryer to obtain said solid fuel.
3. The process as claimed in claim 2, wherein in said rotary dryer, inlet temperature of air is maintained between 350°C to 360°C and outlet temperature is maintained around 100°C.
4. The process as claimed in claim 2, wherein said steam is used for power generation in turbines, further wherein said power is used to run said multiple stage evaporator and said rotary dryer.
5. The process as claimed in claim 1, wherein calorific value of said solid fuel is in the range of 2800 kcal - 3200 kcal / kg.
6. The process as claimed in claim 1, wherein said distillery is a molasses based distillery.
7. The process as claimed in claim 1, wherein said effluent is a post biomethanated effluent.
8. The process as claimed in claim 1, wherein said concentrated effluent can be mixed wood chips for obtaining said solid fuel.
9. The process as claimed in claim 1, wherein condensate water generated in said multiple stage evaporator is fed back as process water.
10. The process as claimed in claim 1, wherein said boiler generates ash as residue, further wherein said ash is used as a fertilizer.
11. The process as claimed in claim 1, wherein said process enables pollution free treatment of distillery effluent.
12. The process as claimed in claim 1, wherein said multiple stage evaporator is a five / seven stage evaporator.
13. A system for treating distillery effluent, said system comprising:
a multiple stage evaporator for concentrating said effluent; a mixer to mix said concentrated effluent with baggase or rice husk in a fixed ratio;
a rotary dryer for drying said mix to obtain a solid fuel; and a boiler to burn said solid fuel in a boiler to generate steam at high pressure, wherein said steam is used to run said multiple stage evaporator.
14. The system as claimed in claim 13, wherein said steam is used for power generation in turbines, further wherein said power is used to run said multiple stage evaporator and said rotary dryer.
15. The system as claimed in claim 13, wherein condensate water generated in said multiple stage evaporator is fed back as process water.
16. The system as claimed in claim 13, wherein said boiler generates ash as residue, further wherein said ash is used as a fertilizer.