LL--2424Distillery IndustryDistillery Industry

Industrial Waste Treatment

Introduction

There are two types of industries1.Beverages2. Molasses distilleries 2. Molasses distilleries Which produce alcohol.

WHAT IS MOLASSESOn industrial scale, ethanol can be prepared by the fermentation of molasses. Molasses is the mother liquor left after the crystallization of sugarcane juice.It is a dark coloured viscous liquid.

Molasses contains about 60% fermentable sugar.

METHOD OF PREPARATION1. DILUTION OF MOLASSES:- Molasses is first

diluted with water in 1:10 (molasses : water) ratio by volume.

2. ADDITION OF AMMONIUM SULPHATE:- If nitrogen content of molasses is small, it is now fortified with ammonium sulphate to provide fortified with ammonium sulphate to provide adequate supply of nitrogen to yeast.

3. ADDITION OF SULPHURIC ACID:- Fortified solution of molasses is then acidifies with small quantity of sulphuric acid. Addition of acid favours the growth of yeast but unfavours the growth of useless bacteria.

4. FERMENTATION:- The resulting solution is received in a large tank and yeast is added to it at 30O C and kept for 2 to 3 days.

During this period, enzymes sucrase and zymase which are present in yeast, zymase which are present in yeast, convert sugar into ethyl alcohol.

C12H22O11 + H2O � C6H12O6 + C6H12O6

C6H12O6 � C2H5OH + 2CO2

5. FRACTIONAL DISTILLATION :- Alcohol obtained by the fermentation is called WASH, which is about 7% to 10% pure. By using fractional distillation technique, it is converted into 95% pure alcohol which is known as rectified spirit or commercial alcohol.alcohol.

Ethanol manufacturing

Fermentation tank

Fermentation tank

General characteristics of spent washParameter Value

Flow 15 to 18 lit/lit of alcohol

pH 4 to 4.5

COD 80,000 to 1,00,000

BOD 40,000 to 60,000BOD 40,000 to 60,000

TS 60,000 to 1,50,000

SS @1000

Potash 900 to 1200

Phophorus 500 to 800

Alaklinity 380 to 510

Characteristics of Distillery wasteParameter

Yeast sludge

Combined waste

Spent wash

Spent wash

pH 4.8 3.9-4.3 3.5-3.65 4-4.5

Temp 0C --- --- --- 90-95

COD mg/l 368000 27900- 118000 70000-COD mg/l 368000 27900-73000

118000 70000-151200

BOD mg/l 165000 12230-40000

41380 28000-80000

TS mg/l --- 16640-26000

99000 59100-114500

SS mg/l 73000 4500-12000

350 1000

Parameter Yeast sludge

Combined waste

Spent wash

Spent wash

Total nitrogen mg/l

--- --- 1135 14800-19000

Alkalinity mg/l

--- 380-510 --- ---

Colour Dark brown

Dark brown

Rate of waste flow

0.9-1.0 MLD

0.82 MLD

DO -- -- NIL --

Treatment alternatives1. Disposal for irrigation after dilution: -Waste + Dilution water ���� For irrigation2. Two stage biological treatment:-

Lime Biogas Lime Biogas

Waste �

Effluent

NeutralizationAnaerobic treatment

Aerobic treatment

Anaerobic treatment includesi. Digester or ii. Lagoons• Aerobic treatment includesi. ASPii. Trickling filter and SSTii. Trickling filter and SST

3. Composting:- NutrientsSpentwash

ManurePress mud or Solid waste

Composting

4. Potash recovery

Objective questions1. Molasses is waste generated from

__________ industry, whereas spent wash is generated from ___________ industry.

2. pH of distillery spentwash is ______.3. BOD value of spentwash is 3. BOD value of spentwash is

________________.4.Because of high nutrient content of spentwash,

_________ recovery is possible.5. Spentwash, _____________ and ________

can be used for biocomposting.

Theory QuestionsQ1. Draw a neat flow sheet for molasses based

distillery industry and discuss processes in brief.

Q2. give general characteristics of distillery spent Q2. give general characteristics of distillery spent wash and suggest suitable treatment alternatives