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PRE-FEASIBILITY REPORT

FOR

M/S. Godavari Bio refineries Ltd.,

AT

A/P - Sameerwadi,

Tal - Mudhol,

Dist - Bagalkot,

Karnataka State.

Pin No. 587 316

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Prefeasibility Report

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1. EXECUTIVE SUMMARY

Godavari Biorefineries Ltd, is situated at Sameerwadi, Mudhol (Tq), Bagalkot (Dist). It has

an existing distillery to produce Rectrified Spirit of 200 KLPD and downstream product such

as ENA & Ethanol. Spent wash is treated based on Composting principles. It is proposed to

treat spentwash both on Concentration and Incineration and Bio-composting principles.

1. Godavari Biorefineries Ltd., has as existing distillery of 200 KLPD for which the

Environmental Clearance vide letter no. F. No. J-11011/191/2007-IA II (I)

dated 28.03.2008 and amendment vide letter no. J-11011/191/2007-IA II (I) Dated

02.09.2008. The industry proposes to adopt a combination of Concentration and

Incineration technology and bio composting till the available press mud is consumed

on composting principles and shall adopt Concentration and Incineration technology

for the entire spent wash generated from 200 KLPD distillery. The present proposal is

for the amendment of environmental clearance conditions to permit to adopt

Concentration and Incineration as well as bio composting for treatment of spentwash.

2. At present the industry is following Bio-composting technology based on anaerobic

digestion followed by concentration and Bio-composting. It has 26 acres of concreted

compost yard and two mixing machines for mixing of press mud and concentrated

spentwash. There is sufficient availability of pressmud as the industry has attached

sugar factory of 15000 TCD crushing capacity. The amount of press mud generated is

around 80,000 MT/year which is adequate for composting for 250 days of distillery

operation.

3. The industry proposes to adopt concentration. Incineration technology in order to

operate the distillery for 330 days so that the project viability would further improve.

4. The Karnataka State Pollution Control Board vide letter no. KSPCB / RO (BGK)

Lokadalat / Sugar / Pressmud / 2014-2015 / 2078 dated 18.08.2014 directed all the

sugar industries of Karnataka state that the press mud generated from the sugar

industries shall be treaded scientifically before it is disposed off as manure / soil

conditioner, as per directives of the Lokadalat of Karnataka State.

5. In view of the directives of the Lokadalat of the Karnataka State, the industry

proposes to adopt concentration, incineration technology for the spent wash generated

from 150 KLPD distillery and the remaining spent wash generated from the 50 KLPD

distillery shall be treated on bio composting principles for which the existing

infrastructural facilities would be adequate. After the entire press mud is consumed by

the industry the concentration incineration technology would be adapted for the entire

quantity of spent wash from 200 KLPD distillery.

6. The project cost for the concentration incineration technology for 200 KLPD distillery

is around 60 Crores.

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7. The entire spent wash generated shall be burnt in an incinerator boiler and thus, zero

liquid discharge shall be achieved. For air pollution emissions, ESP shall be installed

with a stack height of 80 meters. The vapor condensates from the multiple effect

evaporators and the washing of the equipment shall be treated in condensate polishing

unit and the treated water shall be used as makeup water for cooling towers.

2. INTRODUCTION OF THE PROJECT/ BACKGROUND INFORMATION

A Brief Background on the Godavari Sugar Mills Ltd., Sameerwadi

SOMAIYA GROUP is one of the old and well established Industrial Houses in India with

diversified interests in:

Sugar and its by Products

Alcohol and Bulk Organic Chemicals

Specialty Chemicals

Renewable Energy

Printing and Publishing

A. SUGAR

1. The Godavari Sugar Mills Limited

Sugar Plant

Location:

Sameerwadi, Dist. Bagalkot, State: Karnataka

Capacity : 9,000 TCD

Average Sugar production 1,60,000 M.T p.a.

Co.generation Power plant

Location:

Sameerwadi, Tal Mudhol, Dist. Bagalkot, State: Karnataka

Installed Capacity : 24 MW (1st stage)

2. K.J. Somaiya Institute of Applied Agricultural Research (KIAAR).

Location: Sameerwadi, Dist. Bagalkot, State: Karnataka

Established with the objective of doing basic research in promoting early maturing &

high yielding sugarcane varieties and propagating modern and scientific agricultural

Practices.

B. ORGANIC CHEMICALS

1. Somaiya Organo Chemicals.

(A Unit of The Godavari Sugar Mills Ltd.)

(a) Sakarwadi :

Location:

Sakarwadi, Tal Kopargaon, Dist. Ahmednagar, State: Maharashtra

Distillery:

Capacity: Industrial Alcohol 30,000 KL per annum

Organic Chemical Plant

Capacity:

Acetic Acid : 22,000 MT per annum

Ethyl Acetate : 30,000 MT per annum

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Crotonaldehyde : 5,000 MT per annum

Paraldehyde : 600 MT per annum

Crotonic Acid : 150 MT per annum

Crotonic Anhydride : 50 MT per annum

(b) Sameerwadi :

Location :

Sameerwadi, Tal Mudhol, Dist. Bagalkot, State : Karnataka

Distillery :

Capacity :

Ethyl Alcohol/Rectified Spirit : 20,000 KL per annum

Ethanol (Absolute Alcohol) : 16,500 KL per annum

Extra Neutral Alcohol (ENA) : 12,000 KL per annum

Ethyl Lactate : 500 MT per annum

Bhoomi Labh (An Organic Manur) : 15,000 MT per annum

C. HERABLE & NEUTRACEUTICAL PRODUCTS

1. Genesis Labs Ltd.

It has multipurpose plant for extraction of products such as LYCOPENE,

GLUCOSAMINE, LUTEIN, CALCIUM SENNOSIDES.

D. TWO SUGAR PLANTS IN MAHARASHTRA ON LEASE :

The Company has taken on lease two 2500 TCD Co-operative Sugar Factories in

Maharshtra Viz.:

1.M/s. Indira Gandhi Bharatiya Mahila Vikkas Sahakari Sakhar Karkhana Ltd.,

Tambale, Tal. Bhudargad, Dist. Kolhapur – 416 003.

Phone Kolhapur: (0231) 2668399/2662398 * Fax: 0231-2662398

Phone : Tambale : 02324) 237002-3

2. Pratapgad S.S.K. Ltd.,

Songaon – Karnadoshi. Tal. Jaoli, Dist. Satara – 415 514.

Phone : (02378-235645/235646) * Fax : (02378) 235766

E. ACTIVATED BLEACHING EARTH

(used in refining edible oil)

Lakshmiwadi Mines & Minerals Pvt. Ltd.

Factory :

Survey No. 526, Village : Gundala, Tal. Mundra, Kutch (Gujarat)

Phone : (02838) 226800/226534

Local Off.:

Krishna Bhavan, Sector No.9/43, Shop No.4 Gandhidham, Kutch (Gujarat)

Phone : (02836) 234659/226936 Fax : (02936) 230763

Registered Office :

Yusuf Bldg., 2nd

Fllor, 43, M.G. Road, Fort, Mumbai – 400 001.

Phone : (022) 22048272/22858430

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F. PRINTING & PUBLISHING

1. The Book Centre Ltd.

It has a large, well equipped printing press in Mumbai to cater services of Graphic

Communication under one roof. Being in the industry for last 30 years and with the team

of professionals, it has expertise of executing any assignment of clients

(Multicolour & B/W) of any size with secrecy and of course integrity of product.

2. Somaiya Publications Pvt. Ltd.,

Specialises in publication of nob-fictional and educational books of high standard.

Also Publishes books on topics which have bearing on Economics, Philosophy,

Management, Indian Culture and Heritage.

G. EDUCATION & SOCIAL WELFARE

1. Somaiya Vidyavihar

Founded in 1959, Somaiya Vidyavihar has come to encompass the entire educational

spectrum from kindergarten to post graduate education, providing education to around 26,000

students every year, and has a faculty strength of over 1500 Teachers. It comprises of 34

institutes including Jr. & Sr. Colleges in Arts, Science & Commerce, a polytechnic,

Engineering College, Sanskriti peetham, Buddhist Centre, Management Institute and a

“Kendriya Sanskrit Vidyapeeth”, each having well equipped laboratories, libraties and hstel

arrangements.

2. Somaiya Ayurvihar

Somaiya Ayurvihar is committed to offering an integrated package of general and

Specialized health care services. It comprises of a Medical College, a Nursing

School, a 550 bed Hospital with a Blood Bank and an HIV Treatment Centre, a Research

Centre complex and an Institute of Paramedical Studies –a College of Physiotherapy.

3. Shri Girivanavasi Pragati Mandal

In order to bring neglected brethren living in the forest and hilly regions to the mainstream of

our national life, Shri Girivanavasi Pragati Mandal was formed in 1974. The Mandal held 7

(seven) annual Eye-cum-Medical Camps in different States from 1975 to 1981 and treated

1,85,417 people in these Camps held in the interior far away from the rail head or bus stops to

reach out to people living in the remotest part. The Mandal has since established a 40 bed

Eye- cum-General Hospital and a permanent Experimental Farm, a Dairy, an Agricultural

Training Centre, and a free Boarding School at Nareshwadi, near Dahanu, in Thane District,

Maharashtra, about 120 kms away from Mumbai for the welfare of the Tribals right in the

midst of the Tribal Area.

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2.1 Project Proponent

Table No. 1

Sr. No. Name Designation

1 Suhas Uttam Godage General Manager

2.2 Brief description of nature of the project

2.2.1 Climate

The normal temperatures in the region are between 180 C to 43

0 C in summer and 9

0C to 27

0

C in winter. There is no occurrence of frost in area of operation of factory. Hence, climate of

the region is well suited for sugarcane cultivation.

2.2.2 Topography

The topography is slightly undulating. The entire land is medium to heavy Soil. There shall

not be any permanent or temporary change in land use as the entire area is for industrial

purpose.

2.3 Justification of the project for Concentration and incineration and Bio

composting technology

The existing distillery of 200 KLPD is based on Alfa Laval Technology. In this Technology

two options are being explored. If “BH” or “BIH” (i.e. High Grade Molasses) Molasses are

used, the fermentable Sugar Content would vary between 56 to 64% and as such the yield of

R.S. per MT of Molasses shall be around 330 to 380 litres as shown in Table. I and the

effluent quantity shall be around 1.3 to 2.7 litres per liter of R.S. production. The industry

proposes to use (BH, BIH) Molasses whenever the sugar prices are very low as on to-day.

When the Sugar prices are high, the industry proposes to use “C” grade Molasses which have

Fermentable Sugar 42% to 48% at which time the effluent quantity would be brought down

to 4.0 litres per litre of R.S. Production by using Multiple Effect Evaporators. The yield of

Alcohol would be 250 litres Per MT of Molasses. The Spentwash generation at different FS

concentrations are given in Table. II.

Thus the Industry proposes to adopt a flexible operation of the Distillery depending on the

Sugar prices in the market. In the event of using “BH” “BIH” Grade molasses, the quantity of

effluent shall be around 400 Cum/day on an average and the COD Concentration shall be

maximum 1,50,000 mg/l. to 2,20,000 mg/l. In the event of “C” Grade Molasses the quantity

shall be around maximum 800 Cum/day and the COD concentration shall be maximum

3,20,000 mg/l after passing through Multiple Effect Evaporators. The characteristics of

effluent at different Fermentable Sugar concentrations are given in Table. III.

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The industry proposes to adopt this flexible operation as the Sugar production fluctuates

depending on the climatic conditions, Natural forces and the Demand and supply situation in

the Global Market. The variations of Sugar Production in the last twenty years are shown

graphically.

Under the National Ethanal programme there is a mandate to blend 5% ethanol in petrol in

Nine States. This program was started on 1st October 2003. This program took the back seat

in 2004 due to the drought conditions and a disease affected sugarcane crop throughout the

Country and especially in Southern States. Put to the good monsoons in 2004 onwards the

country is set for a reasonably good crop this season. Also the Government of India has set a

deadline for introduction of gasoline and diesel confirming to Euro 3 fuel standards in 11

cities of India. The Euro 3 standard specifies the presence of an oxidant in the fuel, which

minimizes the emissions due to the combustion of these fuels. Ethanol being one of the most

viable additives available, the oil companies have opted to use Ethanol for blending with

petrol. There could be considerable savings in terms of foreign Exchange. The Ethanol

program is expected to be restarted soon, and once this programme is taken to its next step

where the blending would be 10% the demand would be more than doubled.

In 2006-2007 Sugar season, the demand for ethanol at 5% blending in petrol is estimated as

682 million liters and if 10% blending becomes a reality, the requirement for ethanol would

be 1300 million liters.

The additional requirement of Rectified Spirit is estimated as 6100 lakh liters. In fact there

was a shortfall of 1600 lakh liters of R.S. in the year 2005-2006.

To exploit this opportunity the company proposes to expand the Distillery capacity to 200

KLPD.

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3.0 Location: The project site layout map is as below.

Fig 1: Lay out plan

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4.0 MANUFACTURING PROCESS (Distillery)

MOLASSES BASED FERMENTATION TECHNOLOGY

During the last decade, interesting developments have taken place in the field of technology of

fermentation of alcohol, which promise high yield of alcohol, economy in space, economy in steam

consumption and sizable reduction of quality of effluent.

After the Second World War, considerable research and developments in the continuous

process for industrial fermentation have taken place and the processes have been perfected to make

them viable. Continuous processes for alcoholics fermentation are now commercialized. This has

been possible for the outstanding research and development work carried in Russia, Sweden, Austria,

U.S.A. etc. Many processes have been patented.

There are variations in different processes of continuous fermentation. Some use only single

fermenter whereas some use two fermenter or battery of fermentors. For example, US patent,

43,10,629 incorporates use of two fermentors. The first fermenter favors rapid cell growth and second

fermenter favour high rate of fermentation. Yeast is recycled. The alcohol content in first fermenter is

limited to not more than 4-6% v/v and alcohol content in second fermenter attained is 12% v/v

Stillage containing soluble proteins and amino acids provide excellent source of nutrients for yeast

propagation.

The continuous fermentation process involve addition of fresh nutrients medium either

continuously or intermittent withdrawal of portion of nutrient for recovery of fermentation products.

In continuous process fermenter is in constant usage with little shut down and after initial inoculation

of yeast culture, further inoculation is not necessary.

Process for manufacture of alcohol:

Molasses is the chief raw material used for production of alcohol. Molasses contains about 33% total

sugars, of which 30 to 33% are cane sugar and the rest are reducing sugar. During the fermentation,

yeast strains to the species Saccaromyces Cerevisieae, a living microorganism belonging to class

fungi converts sugar present in the molasses such as sucrose of glucose in to alcohol. Chemically this

transformation for sucrose to alcohol can be approximated by the equation:

I) C12H22O11 + H2O 2C6H12O6

Cane Sugar Invertase Glucose + Fructose

II) C6H12O6 2C2H5OH + 2CO2

180 Zymase 2 x 46 + 2 x 44

Glucose / Fructose Ethyl alcohol + Carbon di-oxide

Thus, 180 gm. Of sugars on reaction gives 92 gms of alcohol. Therefore, 1 MT of sugar gives 511.1

kgs of alcohol. The specific gravity of alcohol is 0.7934, therefore, 511.1 kg of alcohol is equivalent

to 511.1 / 0.7934 = 644.19 litres of alcohol. During fermentation other by-products like glycerin,

succinic acids etc. also are formed from sugars. Therefore, actually 94.5% total fermentable sugars are

available for alcohol conversion. Thus, one MT of sugar will give only 644 x 0.945 = 608.6 litres of

alcohol, under ideal condition theoretically.

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Normally only 80 to 82% efficiencies are realized in batch type plant. One MT of molasses containing

45% fermentable sugars gave an alcoholic yield of 230 litres per MT.

For bringing out above biochemical reaction, we require proper and careful handling of yeast,

optimum parameters like pH, temperature control and substrate concentration, which results into

effective conversion of sugars to alcohol. For yeast propagation & multiplication separate equipment

is required. Initially, yeast is developed in the laboratory form the single cell yeast culture. In the

laboratory, yeast is propagated in a test tube on 10 ml. Then it is transferred to bigger flask of 500 ml.

flask are transferred to 5 liter flask containing the sterilized molasses media solution. It is necessary to

adjust the pH of the molasses solution in the range of 4.5 to 5.0. add necessary nutrients such as

ammonium sulfate or urea, di-ammonium phosphate etc. Each stage of development of yeast from 10

ml to 500 ml and 500 ml to 5 litres requires 24 hours in the laboratory. On the plant side, there are

again 3 stages of propagation namely 100 litres,500 litres and 5000 litres. All these equipments are

designed so as to facilitate boiling molasses solution in order to sterilize it and also cooling to bring it

to the proper temperature of 33oC and letting in culture and taking out culture. Boiling, cooling,

introducing culture etc. are done in aseptic manner, i. e. Keeping the fermentation medium free from

any kind of infection. Further stages of yeast propagation are done in open tanks. i.e. pre-fermenter

requires about 8 hours in order to build up necessary concentration of yeast in them. Finally pre-

fermenter is emptied in an empty fermenter, which is previously cleaned and kept ready. Dilute

molasses solution is allowed to flow in this fermenter so as to fill it to its working capacity say about

one lakh litres.

Now a day, readymade compressed yeast is used directly in the pre-fermenters. Good quality

of yeast is available for use in distillery. The yeast is manufactured under strict controlled conditions.

This yeast is useful to obtain a good yield of alcohol by fermentation of molasses. Te stages of yeast

propagation as described above for producing yeast from laboratory scale to pre-fermenter stage may

be totally eliminated. The fermentation of molasses in fermentors take about 24 to 30 hours for

completely exhausting the sugars in molasses.

The average efficiency of conversion of sugars from molasses to alcohol is 80 to 85% of theoretical

value in batch type distilleries. All the sugars are not converted to alcohol during the process or

fermentation because chemicals like glycerin, succinic acid etc are also produced by yeast during their

metabolic process. Therefore, it is not possible to have 100% efficiency of conversion of sugars to

alcohol. The average yield of alcohol from molasses is about 230 litres from 1 MT molasses in batch

type distilleries.

Recently attractive developments have taken place in the field of fermentation and distilleries

whereby one can get high yield of 280 to 300 litres per MT of molasses.

Different technologies are classified as:

1. High brix fermentation

2. Multistage continuous fermentation

3. Immobilized enzyme fermentation

4. Continuous fermentation without yeast separators.

Joint venture of M/s. John Brown Engineers and Allied Breweries, U.K. has developed a

process of continuous stirred fermentation. A continuous stirred fermenter is connected to a gravity

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settler where yeast flocculates and settles out from broth. This process is tested on cane sugar

molasses. High yield of 265 litres of alcohol per MT of molasses is obtained.

In another process developed by Georgia Institute of Technilogy ethyl alcohol is continuously drawn

off a fermenter and contacted with solvent in counter current liquid – liquid extraction column. M/s.

Dynes Holding Co. Atlanta licenses this technology of continuous fermentation followed by solvent

extraction. It is claimed that this process is more energy efficient and alcohol is produced at lower

cost than any other process. This process is also not available to the industry as it is in development

stage.

In Finland, M/s. Dy Alko have developed a continuous process, which involves molasses dilution to

10oBx and fermentation by yeast during fermentation process, a portion of this wash under

fermentation is taken to subsidizer where the yeast is allowed to settle down and the same is re-

circulated for increasing the fermentation efficiency. The yield of alcohol is 270 – 280 litres/ MT of

molasses.

Technology for continuous fermentation process:

The continuous fermentation proposed is the latest and proven technology as compared to the

old batch fermentation technology. It has many advantages like continuity of operation to the batch

fermentation technology. It has 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.

1) “K-SUPER” continuous fermentation with immobilized yeast (KBK):

K-Super proposed to adopt the efficient continuous fermentation in the distillery. The

fermentation process employs a special yeast culture, which can withstand variations in the molasses

equality, temperature and other shock loads. Fermentation plant consists of five to six numbers

fermenter tanks connected in series with all the accessories like plate heat exchangers for cooling, air

& CO2 sparger, 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 bed fermentation (CMB) and which is the latest technology available in the industry at present.

Molasses after weighing is diluted and also pre-treated to an appropriate sugar concentration while

pumping through molasses broth mixer into the fermenter. The partial pre-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 pre-treatment. The fermenters are then inoculated with culture

developed in the culture vessels. This culturing with suitable yeast is carried out only during the start

up in the plant. The culture thus developed maintains itself in fermentors on a 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 fermenters 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 in proper mixing of fermented wash. The retention time for the reaction

is about 24 to 32 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 setting

clarifier. In Wash Settling Clarifier, settable solids settle down. The supernatant goes to Buffer Wash

Tank (BWT) and sludge from bottom goes to sludge tank.

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The CO2 which is liberated in fermentation is scrubbed in water with the help of CO2

scrubber. This CO2 contains ethanol, which is recovered by colleting CO2 scrubber water fed into

sludge trough. The diluted sludge is pumped into sludge settling clarifier. The traces of ethanol

present in diluted 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.

A closed loop cooling tower system with an induced draft-cooling tower with

circulation pupms is also provided to ensure higher cooling efficiency and to minimize water wastage.

2) Cascade (HIFERM-GR) Continuous Process with yeast recycling (PRAJ)

M/s. Praj Industries Ltd., Pune supply complete plants for the fermentation industry. The

process is for continuous production of alcohol from sugar containing raw materials. The process

developed by them for continuous fermentation is adopted for production of alcohol from raw

molasses successfully in several countries like Yugoslavia, Austria, Ghana, Kenya, USA etc.

A set of four /two fermentors is required for this process. This wort enters the first fermenter

and is allowed to overflow to the second fermenter and the wash from 2nd

fermenter goes to 3rd

to 4th

fermenter. The wash coming from the 4th fermenter, it contains 8 – 9.5% alcohol. Process water is also

added to first one or two fermentrs. Water ring blowers sparged fermentation air into first and second

fermenter, carbon dioxide generated into the first and second fermenter is collected and fed into third

fermenter for proper mixing of the fermented wash, while part of the carbon dioxide generated into te

last fermenter is scrubbed in water with the help of CO2 scrubber. This CO2 contains ethanol which is

recovered by collecting CO2 scrubber water fed into sludge trough.

The wash coming out last fermenter goes to yeast separator (Yeast settling tank). In the yeast

separator yeast cream is separated by gravity settling from the wash and returned back to the first

fermenter by acidic treatment to avoid the contamination, nutrient dosing as well mixing of molasses

by broth mixer with the help of O2 scrubber. This CO2 contains ethanol which is recovered by

collecting CO2 scrubber water fed into sludge trough.

The wash coming out last fermenter goes to yeast separator (Yeast settling tank). In the yeast

separator yeast cream is separated by gravity settiling from the wash and returned back to the first

fermenter by acidic treatment to avoid the contamination, nutrient dosing as well mixing of moasses

by broth mixer with yeast cream and sparging the air in yeast activation tank (YAT), therefore yeast

activity will be increase and it is fed to the fermenter No. 1. The top fermented wash overflow

collected in the wash settling tank (WST).

In wash settling tank sludge is settled at the bottom while top supernatant wash over flow to the wash

charger (wash holding tank), then it is pumped to Mash or Primary column for distillation system to

recover the alcohol.

The sludge drain from the bottom of WST is fed in to sludge trough where it is diluted with

CO2 scrubber water. The diluted sludge is pumped into Sludge settling tank (SST). The traces of

ethanol present in diluted sludge are separated at the supernatant, which is collected into wash charger

through overflow and washed sludge from bottom is drain off.

Fermentation auxiliaries like nutrient preparation, sulfuric acid dilution and antifoam agent dosing are

prepared on the ground floor. Nutrient solution and acid is fed to the first fermenter by metering or

dosing pumps.In this maner by controlling parameters like molasses and water flows, pH, Nutrient

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and temperature, alcohol concentration between 5.5 and 9.5 % v/v maintained in first and last

fermenter respectively. Temperature of the individual fermentors is maintained in the desired range of

30 to 32oC by recirculating the fermenting wash through the individual plate heat exchangers. A

separate cooling tower and pump is used for recirculating the cooling water for fermentation.

All the fermentors are covered and connected to a scrubber in order to recover alcohol from

carbon dioxide. The yield of alcohol is 280 litres/MT of molasses containing 47% total fermentable

sugars. Stillage would be appreciably less as alcohol concentration by 12 – 14 litres per liter of

alcohol production depending on alcohol production in the wash.

Average residence time is in fermentors is 24 – 30 hrs. with alcohol % in fermented wash in

the range 8 – 9% (v/v)

M/s Praj Ind. Ltd., Pune has introduced a system in the year 2001 – 02 in which a granulated

flocculating type yeast strain is being used which has a property to settle by gravity force. This

eliminates the use of yeast separators. The fermentation efficiency is claimed as 89 – 90 %.

3) Mojj Engg. Systems Ltd.,

Molasses after weighing is diluted and also pre-treated to an appropriate sugar concentration

while pumping through molasses broth mixer into the fermenter. The partial pre-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 pre-treatment. The fermenters 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 fermentors on a continuous

basis.

Continuous yeast growth in yeast vessel YV03 by adding pasteurized molasses and recycling

partly, the yeast separated in yeast separator after acidification and activation treatment, which helps

to avoid contamination and maintain consistency in operation.

To help the fermentation sustain, the nitrogen is added in the medium in the form of Urea and

DAP as required. Temperature in the fermentors is maintain to an optimum level as required for

efficiency reaction with the help of plate of plate heat exchanger and recirculation pumping system.

This recirculation time foe the reaction is about 22 to 24 hours. Air blower is provided to supply the

necessary oxygen required for the yeast and also for agitation.

This fermentation technology use genetically marked high osmo tolerant yeast strain. The

system optimized the cooling system to maintain fermented broth temperature to 30oC which results

in improve yeast cell mass activity.

The technology incorporated yeast recycle, which maintain high yeast concentration and

reduced fermentation time result in lower fermenter volume, saving in capital and operating cost.

After completion of reaction of the fermented wash is delivered to yeast separation

centrifugal machine to separate the yeast cream. The technology incorporates yeast acidification and

activation, which ensure the yeast, recycle in continuous propagation vessel & fermenter is bacteria

free and ensures no contamination.

In Wash Settling Clarifier, settable solids settle down. The supernatant goes to clarified wash

tank (CWT) and sludge from bottom goes to sludge tank.

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The fermented wash collected in the clarified wash tank is then pumped to stripping column

for distillation.

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 decantation.

The technology incorporated sludge decantation system, which consists of specially designed

lamella separator as against conventional, designed to settle the sludge. The settled sludge after

dilution from CO2 scrubber water pass through the decanter. This ensures the clarified wash going to

distillation is free from sludge, which results in clean distillation column, re-boiler tubes and

integrated spent wash evaporator tubes, This also helps to maintain consistency in operation and avoid

losses due to stoppages. Alternatively the technology also offer pre-clarification of molasses for high

sludge / VFA content in molasses.

A closed loop cooling tower system with an induced draft-cooling tower with circulation

pumps is also provided to ensure higher cooling efficiency and to minimize water wastages.

The system incorporated mechanical ejector in place of air sparger, which results in increase

the dissolved oxygen level, facilitate better contact between yeast and fermentable sugar avoid

hydraulically dead zones, increase yeast cell mass activity for high efficiency & better yield.

The technology achieved 8 – 9% v/v alcohol percentage in fermentedwash.

Biostill process:

Process developed for Continuous Fermentation is Biostill process patented by Alfa Laval of

Sweden. It has some special features. It is a very comprehensive and compact process aimed at only

high yield of alcohol but also reduction of effluent substantially.

In this process, concentrated substrate of 40 – 45 & of final molasses is fed to the fermenter at

a constant flow rate. The process does not involve pretreatment of pasteurization of molasses. It

envisages recycling of stillage to the extent of 70% of total volume in order to eliminate bacterial

infection. The whole fermentation is carried continuously in two fermentors.

Molasses wort is feeded at such a rate that the sugar percentage remains below 1.8 to 2 %

w/w. Ethanol concentration is controlled at 6 to 7 % w/w. Special kind of yeast known as

Saccharomyces pombe is used in the process. The yeast propagates by splitting and not by budding.

It stands high osmotic pressure. The process requires yeast propagation vessels, nutrient tanks and

pumps, yeast separators, hydrocycloses, carbon dioxide scrubber to recover alcohol and efficient plate

heat exchangers for cooling recycled stillage and for cooling fermented wash.

The distillation system differ from the conventional process as far as wash column is

concerned. Other equipments are same as conventional plant.

The wash column divided into two sections –

i) Vaporizer ii) Stripper.

The wash is de-yeasted and also free from sludge by yeast separators of suitable design, as the wash is

pumped from fermenter to wash feed tank. The wash is preheated by plate heat exchanger and

outgoing stillage. It enters the top plate of vaporizing section of wash column. The wash is boiled by

vapour pipe of the column. The concentration of alcohol in the vapour is approx. 50 % v/v. About

16

70% of weak wash is pumped from the bottom of vaporizer through the regeneration heat exchanger

to return to the fermenter via a trim cooler in the form of heat exchange.

A minor stream of 30% remaining weak wash flows to another section of distillation column

called as stripping column. This column is heated by re-boiler instead of heating by steam sparger

employed in conventional plant. The vapours going out consisting of steam and weak ethanol enters

the bottom of vaporizer and provides heat necessary for boiling the wash. Te spent wash leaving the

column is free from alcohol and is concerned to 25% solids. The duel purpose of this column heated

by re-boiler for evaporation and distillation lead to the highest possible stillage concentration without

increase in steam consumption.

The recycling of spent wash for dilution of molasses is novel idea in this technique. This is

useful to increase soluble salt concentration for optimum osmotic pressure, which is necessary to limit

the growth of fermentation organism yeast without affecting the rate of fermentation and eliminate

contamination.

Choice of Technology:

It would be seen that through the initial investment for modern process of continuous mode

fermentation appears to be on much higher side, the advantages occurring are spectacular. Volume of

effluent discharged is less than that of total effluent discharged in conventional distillation process.

To adopt continuous process of fermentation is an appropriate step towards the updating

technology of alcohol production for efficient performance.

2.2 MULTUPRESSURE VACUUM DISTILLATION

After fermentation the next stage in the manufacture of alcohol is separate alcohol from fermented

wash and to concentrate it to 95 % alcohol called as rectified spirit. For this purpose, method of

distillation is employed.

The distillation column system consist of number of bubble cap plates where wash is boiled

and alcoholic vapours are separated according to their boiling point and concentrated on each plate

stage by stage.

Atmospheric Distillation;

The fermented wash first enters the beer heater, which is a condensing alcoholic vapours by

using wash as cooing medium. Fermented wash from the beer heater goes to degasifying column,

degasifying column bottom goes to top plate of the wash column. This column consists of 18 plates.

The steam is admitted through the steam sparger situated at the bottom of the column gets heated and

by the time it reaches to bottom plate, it consist practically no alcohol. The wash going out is called

spent wash, which is discharged to the drainpipe. The vapours coming from wash column now

consists approximately 50% alcohol and 50% water with impurities such as higher alcohols,

aldehydes, acids, sulfur dioxide etc. Part of these vapours are led to Pre-rectifier column where low

boiling impurities are separated from spirit which is produced at the rate of total production depending

on the extent of purity required & stored separately. Other portion of the vapours, which is major

quantity, is led to rectifying column. This column consists of 44 plates, which helps the removal of

bad smelling fusel oil, which is a mixture of higher alcohol. As the vapours coming from wash

column rise to top of rectifying column, the concentration of alcohol goes on increasing & finally it

reaches to the concentration of 95.5% alcohol. The alcoholic vapours from rectifying column are

17

condensed in the beer heater, principle condenser using water as a coolant and finally vent condenser.

The condensates of all three condensers go back to the top of the rectifying column & uncondensed

gasses are let out from the vent pipe. Actual product of rectifying spirit is drawn from the 3rd

plate

from the top & cooled in alcohol cooler & taken out asa product.

The fusel oil which is a mixture of higher alcohol is drawn from the 6th to 10

th plate from

bottom of rectifying column as a stream of vapours, it is condensed, cooled & led into a decanter

where it is mixed with water. Fusel oil being immiscible with water collects at the top and decanted

through a funnel and sent to storage. The lower portion contains water and alcohol and is sent back to

wash column for recovery of alcohol. Fusel oil is recovered at the rate of 0.2% of alcohol produced.

The alcohol both pure and impure is first led into separate receivers. The quantity of alcohol

produced is assessed daily in the receivers and it is finally transferred to storage vats in the

warehouse. The spirit to the tankers of the customer depending upon the type of requisition.

Multi-pressure Vacuum Distillation:

Multi-pressure distillation system for production of Rectified Spirit and ENA consists of

distillation columns namely –

For –Rectified Spirit mode

1. Degasifying um analyzer column

2. Rectification Column

3. Fusel Oil Concentration Column

FOR – ENA Mode

1. Degasifying cum analyzer column

2. Pre-rectifier Distillation column

3. Extractive Distillation column

4. Rectification column

5. Refining / simmering column

6. Fusel oil Concentration column

7. Head Concentration column

Benefits of Pressure Vacuum Multi-pressure Distillation:

Following are the advantages of pressure vacuum distillation.

• Since the analyser column operates under vacuum, the formation of by-products such as acetal may

minimize there by improvement in quality of alcohol.

• Pre-rectification column ensure removal of sulfur compounds/mercaptans and also reduces load of

lower boiing volatile compounds passing on to Rectifier cum exhaust column.

18

• The chances of scaling due to invert solubility of certain precipitating inorganic salts are minimized

in vacuum distillation.

• Vacuum distillation requires low steam consumption with reboiler i.e. 2.2 Kg/lit. of Rectified Spirit

around 3.2 Kg/lit. of ENA

Manufacturing process for Anhydrous (Fuel) Alcohol:

Anhydrous alcohol is an important product required by industry. As per IS Specification it is

nearly 100% pure / water free alcohol. Alcohol as manufactured by Indian distilleries is rectified

spirit, which is 94.68% alcohol. It is not possible to remove remaining water from rectified spirit by

straight distillation as ethyl alcohol forms a constant boiling mixture with water at this concentration

and known as azeotrope. Therefore, special process for removal of water is required for manufacture

of anhydrous alcohol.

In order to extract water from alcohol it is necessary to use some dehydrant or entrainer,

which is capable of separating water from alcohol.

Simple dehydrant is unslacked lime, Industrial alcohol is taken in a reactor and quick lime is added to

that and the mixture is left over night for complete reaction. It is then distilled in fractionating column

to get anhydrous alcohol. Water is retained by quick lime. This process is used for small scale

production of anhydrous alcohol by bath process.

The various processes used for dehydration of alcohol are as follows:

I) Azeotropic Distillation

II) Molecular Sieves

III) Pervaporation / Vapour permeation system:

III) Dehydration with Molecular Sieve Process:

Molecular sieves are synthetic adsorbents and are developed for vapour phase ethanol

dehydration is metal aluminosilcates with effective pore size opening 3 angstrom (3 x 10-8

cm).

Molecular sieve of type 3A has chemical formula –

(K2O.Na2O).Al2O3.2SiO2.XH2O

During potassium form of molecular sieve has pore size of 3 angstrom.

The diameter of ethanol molecule is 4.4 angstrom

The water vapour molecules are having strong dipoles and elastic. They are drawn into the pores and

condensed at the wall of the pores.

Ethanol vapour bigger in size passes through the bed without getting into the pores of the

molecular sieves.

Water strongly attracted to molecular sieve of 3- angstrom type that for each kilogram adsorbed, 990

Kcal of heat released. This effect is referred as the heat of adsorption.

19

When we remove that same kilagrom of water during regeneration, we must supply 990 Kcal

of heat. This effect referred as the heat of desorption.

3A type molecular sieves is capable of adsorbing up to 22% of its weight in water.

The salient features of the molecular sieve adsorption process:

1) Steam consumption of 0.5 to 0.6 Kg/lit of Rectified Spirit.

2) It is possible to use exhaust steam – 1.5 Kg/cm2 gm (90%) and medium pressure steam 3 – 3.5

Kg/cm2 gm (10%).

3) Safety equipments such as relief valves, flame arresters etc.

4) Steel structure with prompt access to all equipments.

5) Explosion proof installation, easy and safe operation.

The rectified spirit (94 – 96% v/v) from the rectifier feed tank is pumped to a feed preheater to

evaporation (regeneration) column – in evaporation column liquid phase converted in to vapour phase

by application of steam through reboiler at the bottom of the column. The top vapour of the column

fed to the superheater. The vapours are super heated by applying steam – the vapour temp. app. 140 oC – 150

oC. Superheated rectified spirit vapours from feed super heater is passed to one of the pair of

molecular sieve beds for several minutes while passing through the molecular sieve bed water is

absorbed and absolute alcohol vapour at 99.8 – 99.9 % v/v is removed, which is then condensed and

cooled in sent to respective receivers and storage tank.

During the adsorption cycle of app. 8 – 10 mins. The bed undergo a temp. rise due to heat

adsorption (990 Kcal/kh water adsorbed). When the bed reaches the saturation factor, it is regenerated

by vacuum application on the loaded bed and water plus ethanol mixture at 135O proof boils and

released the heat of adsorption and the bed temperature is reduced again.

A moderate vacuum is applied by vacuum pump operating after condensation of the

evaporation column by recycle pump to the regeneration preheater.

The life of molecular sieve may be around five to seven years. However, the operating cost is

considerably less than azeotropic distillation.

Requirement of Input :

Plant Capacity

(KLPD)

*Cooling

Water(M3/hr)

Cooling Water

Make up (M3/day)

**Steam (R.S. to BS.

Alc.) (Kg/Lit.)

***Power (KwH/hr)

Connected Operating

30 70 – 75 50 - 55 0.6 40 20

* Cooling water recirculation rate 50 M3/hr for Molecular Sieve Plant only @ 300C maximum and 4

Kg/Cm2 (g) pressure at cooling water header, ΔT=6

0C

** Steam requirement will be at full capacity operation @ 5 Kg/Cm2 (g) pressure in steam header.

20

*** Electricity will be 440 V, 3 ph, 50 Hz, AC Electric supply. The power requirement will be for

molecular sieve plant only, which excludes utilities like boiler, cooling tower etc.

Fig. 6

The Fermentation Process:

21

Continuous Fermentation:

Fig. 7

Process Flow Diagram (typical) of Multi Pressure Distillation Plant :

22

MATERIAL BALANCE FOR PROPOSED150 KLPD

CO2 out 4465.8 kg/hr Steam to Rectifier reboiler

(water nil) 13125 Kg/hr.

Molasses 22899.9 kg/hr wash feed to distillation Intigrated product alcohol

fermentation 71632 kg/hr distillation 4938 kg/hr

section (water : 262 kg/hr)

Dilution water 29771 kg/hr section

14495.35 kg/hr Steam condensate to Boiler

13125 kg/hr

Spent wash spent lease

31250 kg/hr (17% solid) 5673 kg/hr

Intigrated (water 100%)

evaporation

system condensate

process conden. polishing unit

12276.79 kg/hr 17949.79 kg/hr

conc. sp wash to MEE

18973.21 kg/hr(28% solid). cooling tower make up

& process

Effluent Treatment:

Introduction: The main effluent generated from molasses based distillery is spentwash. The flow and

characteristics of effluent are as below:

Sr.No. Parameter Units Percentage (%)

1. Flow cum/day 1200

2. pH - 4.0 to 4.5

3. Total solids mg/l 1,50,000 to 1,60,000

4. Total Volatile Solids mg/l 80,000 to 90,000

5. C.O.D mg/l 1,40,000 to 1,50,000

6. B.O.D mg/l 60,000 to 65,000

7. Chlorides mg/l 5,000 to 6,000

8. Sulphates mg/l 5,000 to 6,000

9. Total Nitrogen mg/l 1,000 to 1,200

10. Phosphorous mg/l 600 to 800

11. Potassium mg/l 1200 to 1400

23

Treatment Details:

The Spentwash shall have a temperature of 70 to 80◦C., which shall be passed through a Plate heat exchanger to reduce the temperature to 30◦C. It is then passed The Decanted effluent is taken to a storage tank of 7 days capacity (8,400 cum). The sludge from Centrifuge/Decanter is composted.

Spentwash from storage tank which has 15 to 16% solids shall be concentrated to 60% solids

in Multiple Effect Evaporators (MEE). The condensates from the MEE and spentlees from the

distillation process shall be treated in condensate polishing unit (CPU) and the treated water is

recycled as makeup water in Cooling Towers.

The concentrated solids of Spentwash shall be burnt along with addition of coal in Incinerator

boiler the ratio of Spentwash solids to coal is maintain between 4:1 to 4:1.5 depending on the type of

the technology chosen.

The flue gases emanating from the Incinerator boiler shall be dispersed through a stack

having a height of 65 to 70meters after passing through ESP. The Ash from the Boiler shall have the

following characteristics which can be used as a fertilizer after blending.

5.0 PROCESS DETAILS

1) Assessment of New & Untested technology for the risk of Technological Failure

1) Composting Process:

Traditionally Composting Process is adopted for treatment of Spent wash as one of the proven

technology as zero discharge system. At present the SOC has been practicing Composting technology

preceded by Bio-Methanisation for its 60 KLPD Distillery Unit. The Details of this process is attached.

The present system adopts the solid concentration of 5 to 6% for Composting operations. The

Pressmud to Spentwash ratio is as 1: 3.5 and the cycle of operation is 60 days.

In the expansion of the Distillery project, the solids concentration is estimated as 18% solids.

The pressmud to spentwash ratio is taken as 1:1.5 and the cycle of operation shall be

maintained as 60 days. The Laboratory investigations are also been conducted to confirm

these assumptions, even though the Alfa Laval (India) Ltd. the suppliers of technology have

assured that it is possible to achieve the assumptions made in the composting operations.

The Quality of Compost shall have to be also assessed even though the suppliers of this

technology have again assured that there will be no change in compost characteristics. The

risk involved in this technology could be mainly of two types

a. Whether Press mud to Spent wash ratio of 1:1.5 would be sufficient and also the days

for each cycle required would be 60 days or more.

b. With regard to compost quality whether C/N ratio below 17 can be achieved for

effluents having solids concentration of 18%

The industry has already provided the required compost area of 26 acres and made it seepage

proof /impervious by concreting the entire area. This is over and above the stipulated

conditions by the Central Pollution Control Board for Surface composting. The Industry has

24

also provided garland canal to collect the leachate and also a sump well to pump back the

leachate for recirculation in the compost area/storage pond. These are as per the guidelines of

CPCB.

The industry has provided 30 days storage capacity for spent wash as per the guidelines of

CPCB by laying HDPE sheet and stone soling.

The required machinery such as Compost Mixing Machine (Aerotiller), Excavator cum

Loaders and Sieving machines and Bagging Facilities are being provided as per the

Guidelines. Thus the industry has implemented all the stipulated conditions of CPCB

guidelines for surface composting and therefore it can be conclusively said that there will no

risk involved in the implementation and operation of Compost technology.

2) Concentration and Incineration:

The expert appraisal committee has recommended to adopt Concentration and Incineration

technology for treatment of spent wash within two years from the date of starting of the

Production of Rectified Spirit. The project proponent has studied the technologies that are in

operation both in India and Abroad and have to make the following observations.

Indigenous Technology:

a) The Evaporators and Boilers are required to be cleaned frequently and the

exact number of cleanings required is yet to be established.

b) Even though the Concentration and Incinerations plants are working in one or

two places for the last six months in India, the techno economic viability is not

known and the working of the units is yet not evaluated by any expert

committee.

c) It is learnt that in the Industries where the Concentration and Incineration

technology is adopted the modifications are still being made and the nature of

modifications and the present performance is not clearly known.

d) The suppliers are not prepared to give any guarantee for the material used in

the construction and longevity of the system.

Chinese Technology: Spentwash is concentrated to 65% solids through Multiple Effect Evaporators. The

Concentrated Effluent is burnt in a specially designed Boiler. If Spentwash alone is burnt the

steam requirement can be met to an extent of 30 to 35% of the process requirement after

fulfilling the steam required for concentration. The power requirement for the process as

well as for the concentration and burning shall have to be met from external source. The

capital cost of the project is around 45 Crores for 200 KLD distillery. The main constraints are

as below:

a) If the project is to be made feasible the pressure of the boiler should be above 40

kg/sqcm. At present the boilers are designed for a maximum pressure 25 kgs/sqcm.

However the Chinese firm claims that have the capability of designing the boiler to

the required pressure. This appears to be the major risk factor in this technology.

25

b) Even though the advocators of the technology assures the payback period as 2 to 2.5

years there are no plants erected yet in India to verify the claim.

“CONCENTRATED SPENTWASH

FIRED BOILERS” FOR ZERO LIQUID DISCHARGE &

COGENERATION APPLICATION IN DISTILLERIE

Boiler and Heater Group,

A division of Thermax Ltd.

Thermax Limited

CONCENTRATED SPENTWASH FIRED BOILER

Distilleries across the world are increasingly coming under pressure from government and

society regarding the discharge of the polluting effluents i.e. spent wash from the core

process. Since the pH of the concentrated spentwash from the process effluent is less than 4

to 5 it is highly dangerous to drain this effluent to environment.

Considering the potential threat to the soil damage ‘Zero effluent discharge’ (ZED) norm

for distilleries is already in place in number of countries including India.

Existing disposal methods practiced by Distilleries like Bio-methanisation and Bio-

composting are unable to meet the ZED norms as;

Bio- Methanisation

Does not eliminate water

Regulation is difficult

Bio-composting

Availability of press mud

Operational problem during rainy season

Area required is large

Land pollution leads to leaching

26

Considering the practical problems in meeting the ZED with the conventional methods,

Distilleries are increasingly looking for an alternative solution of concentrating the spentwash

and then firing it in a specially designed Boiler.

This fundamental shift in practice in the distillery sector has been facilitated by Thermax’s

successful efforts to develop a commercial-scale boiler technology for firing concentrated

Spentwash.

The benefits of this technology include;

(1) Ability to dispose effluent discharge of distilleries in a safe and environmentally sound

way (by meeting ZED norm)

(2) Steam generation for meeting the process steam and produce electricity requirements of

the distillery through STG.

27

Boiler Features; The technology offered by Thermax is an AFBC, bottom support, over bed fuel feeding with single

drum and three pass (gas) construction.

Heat transfer sections like Super heater, evaporator and economizer are located in third pass.

Feed water from deaerator is pumped to economizer through drum coil pre heater Drum coil pre

heaters are provided to heat the water to the desired limit prior to enter the economizer, to protect the

economizer from dew point corrosion.

To control the final steam temperature, spray type attemperator is provided in between the primary

and secondary super heater sections.

Combustor is constructed with special refractory material, enclosed by steel casing and structure.

Combustor is divided in to multiple compartments depends on the boiler generation capacity. Each

compartment is provided with bed thermocouples for measuring bed temperature and bed level

measuring probes.

Coal firing system consists of coal bunker with variable speed screw feeders to feed the coal. Coal is

distributed inside the combustor by pneumatic spreading system.

Concentrated (58 to 60%) and pre heated Spentwash from the day storage tank is conveyed to boiler

through variable speed pump. Spentwash is sprayed over the fluidizing bed at first pass through 2 nos.

off spray guns (per compartment), which is located at upper furnace.

28

Combustion air, to wind box is supplied from a variable speed FD Fan through Steam Coil Air Pre

Heater with isolation/control dampers at wind box inlets.

For complete combustion, secondary air is provided in two elevations at upper furnace. Spent wash

Spray Gun is located below the secondary air nozzles. SA Fan is provided to supply the secondary air

and coal spreader air at required pressure and flow.

For on-line cleaning of ash deposits on the pressure parts, mechanical rapping system is provided for

all the heat absorbing sections in third pass i.e. SH 1/2, Evaporators and Economisers with separate

drives. Since the spent wash ash is sticky in nature, mechanical rapping system is preferred and

provided in our design

To drain the bed ash from combustor, 4 nos. of bed drain ports are provided in each compartment with

isolation gate.

Fly ash from second pass and third pass is evacuated to ash handling system through RAV from

individual hoppers.

Challenges in spentwash firing:

Fluctuation of solids content in spent wash, cause combustion in stability and

leads to bed slumping as combustion not self sustainable below 55% solid content

Acidic nature- hence the handling need special material.

Highly viscous at solid concentration (>50%)

High alkali content in ash leading to fouling of heat transfer surfaces. Alkalis in

the ash are ranging up to 50% depending on cane growing area. Source of alkalis

mainly through fertilizer.

Presence of chlorides leading to high temperature corrosion on the super heater

section

Ash Analysis:

Sr. No. Parameter Percentage (%)

1. Silica (SiO2) 20 – 22 %

2. Iron Oxide (FeO3) 1.5 – 2.0 %

3. Calcium Oxide (CaO) 8.0 – 8.5 %

4. Magnesium Oxide (MgO) 7.0 – 6.5 %

5. Sulphates (SO4) 8.0 – 8.5 %

6. Phosphates as P2O5 1.5 – 1.8 %

7. Potassium as K2O 43 – 44 %

8. Sodium Oxides (NaO2) 2.5 – 3.0 %

9. Aluminium Oxide (Al2O3) 0.06 – 0.08 %

10. Titanium Oxide 0.01 – 0.0168 %

11. Chloride (Cl-) 5.5 – 6.5 %

29

1) The Central Pollution Control Board has identified the following alternatives for

Spentwash Treatment.

a) Bio-Methanisation followed by Ferti-irrigation/Controlled land Application/Composting

b) Raw Spentwash Composting after reducing the volume of Spentwash with the help of

Reboiler/Evaporators/Reverse Osmosis

c) Concentration and Incineration

In the present case the option a) is not advisable as the quantity of effluent to

be treated shall be around 2400 cum/day (i.e for Bio-Methanisation the spentwash

quantity generated is taken as 12 liters/liter RS production). To handle such huge

quantity of effluent for Ferti-irrigation/Controlled land Application/Composting requires

large area and also filler material. Therefore this option has been ruled out.

The option b) has been found to be feasible for two reasons:

1) The effluent quantity shall be brought down to 400 cum/day during the

sugarcane crushing season by using heavy grade molasses and to 800 cum/day in the

remaining period by using Multiple effect Evaporators for concentration of effluents.

2) All the existing facilities of Composting can be used for this purpose and no

additional infrastructure facilities are required as per the enclosed report on the adequacy

of the effluent treatment plant facilities and the existing effluent treatment plant facilities

6.0 EXISTING EFFLUENT TREATMENT PLANT FACILITIES

Spentwash Storage Pond: A 30 days capacity storage pond of 24,000 cum is provided. The

pond is lined with HDPE sheet of 250 micron thick and stone soling was carried out to

prevent seepage/percolation.

Compost Yard :

26 acres of compost yard is concreted using HDPE sheet of 250 micron thick over which

RCC of 1:2:4 mixture of 150 mm is used. Curb wall is provided to prevent the seepage of

Spentwash from the compost yard. A garland canal is constructed to collect seepages during

the composting operations. The seepages are collected in a tank which is made seepage proof

as per the specifications mentioned for Spentwash storage pond. The efluent from the sump

well is pumped back either on to the compost yard/ spentwash storage pond.

30

Fig : Concreted Compost yard and Aerotiller.

Effluent Spraying System

A) Under Ground Piping System:

The entire composting yard is provided with under ground piping spraying chambers, valves,

and Nylon breaded hose with nozzles. The effluent is pumped from the spraying lagoon

having 2000 m3 capacity through pump 90 m3 per hour capacity into the spraying system

and Effluent is sprayed manually over windrows through Nylon hoses with nozzles. Around

20 hoses are operating per day for effluent spraying.

Windrow: 3.5 x 1.5 M

Spraying Chamber.

Line Diagram of Windrow & Spraying System

31

B) 2 ES Automatic Dispenser Spraying System Mounted on Mahindra LCV.

Used for Mechanical Spraying of Effluent.

Make : Sartime Horological Pvt Ltd.

Capacity : 20 M3 per Hour.

Fig : 2ES Despensor Spraying machine.

It could spray around 20 m3 /Hr of distillery effluent.

Spraying can be continuous for any length of time.

2 windrows can be sprayed uniformly and simultaneously.

No Dependence of Man power

Work continuously in Hot summer.

Shifting of hose pipes avoided.

Consistent and uniform spraying.

Composting Machinery

A) Aerotiller:

For mixing and accelerating composting reaction.

1 - No.

Make - Alfa – Laval

Engine - 320 kv

Turing capacity - 2500 MT/HR

Drum Speed - 700 RPM

32

A specially designed machine for large scale aerobic composting.

•Performs the duties of agitating, shredding, aerating and temperature control in the

composting mass.

•Effectively reduces BOD by supplying fresh air.

•High-powered engine (320 HP) with high carding drum speed (600 rpm).

Fig : Aerotilling on windrow.

B) L/T FRONT END LOADER CUM EXCAVATOR: 3 NO.

For trimming and reshaping windrows after Aerotilling.

For loading and handling of press mud.

For Loading of compost.

Fig : Trimming of Windrow with L&T Loader

33

C ) TRACTORS – 6 Nos.

For handling press mud & compost.

D) GRASS HOPPER /SIEVER : 3 Nos.:

For sieving compost.

Capacity 15 MT/HR

Sieve size is 4 Mesh.

Tray 1 M width and 10 M length

Fig : Sieving of the Bhumilabh.

MICROBIAL CULTURE: MIXED POPULATION OF FUNGI, BACTERIA & ACTINOMYCETES )

Starter culture specially designed for spent wash-press mud degradation

Help to increase press mud to effluent consumption ratio.

Non-pathogenic, non-hazardous.

Can degrade press mud wax.

Also contains beneficial soil microorganisms.

Can be used with concentrated effluent.

34

Fig : Inoculation of windrow with microbial culture.

Godown, Packing and Weighing Facilities

1 200 kg capacity scale for weighing 50 kg bags.

2 Weigh bridge 30MT capacity for weighing Trucks & Tractors.

3 Stitching machine 2 No. for Stitching HDPE bags.

4 Conveyer 1 NO. for loading of Bags.

5 Sealing machine for sealing of 2 kg plastic pouch.

6 Godown for storing of Packed Material & packing.

Size 15 x 12 m.

35

JUSTIFICATION OF THE EXISTING EFFLUENT TREATMENTPLANT FACILITIES

FOR THE EXPANSION OF DISTILLERY CAPACITY FROM 60 KLPD TO 200 KLPD

BASED ON “COMPOSTING PRINCIPLES”

The Godavari Bio refineries Ltd., which is situated in the campus at Sameerwadi. At present

the crushing capacity of the Sugar Unit on an average is 7,500 TCD and the cane crushing is

around twenty lakh MT per annum and the pressmud produced is around 80,000 per annum.

The industry proposes to expand the Sugar cane crushing Capacity to 15,000 MT/day and

intends to crush around thirty lakh MT of sugar cane per annum at which time the pressmud

availabilities shall be 1,20,000 MT/annum. At present the pressmud availability shall be on

an average 80,000 MT per annum. The industry has 27,000 Cum Capacity seepage proof

Holding Tank for storage of spentwash which shall cater to 30 days storage as per the CREP

Conditions.

The industry has twenty acres of HDPE sheet lined and R.C.C for windrows which would be

sufficient to form windrows as per the CREP conditions. It has high powered Mixing

machine for mixing pressmud and spentwash. The material balance for composting is as

given below.

(1) Area required - 850 MT/acre/cycle.

No. of cycles proposed - 5

Press mud available - 80,000 MT

Area required is 80,000/5x850 = 18.2 acres

Concrete area available is 20 acres and hence adequate.

(2) Spentwash Quantity generation:

Using BH/BIH Grade Molasses, the effluent quantity shall be two litres per litre of R.S.

Production.

Daily quantity of spentwash generation shall be 200x2=400 Cum/day.

Considering 180 days of operation, the spentwash generation shall be

180x400=72,000 Cum.

The pressmud required shall be 72,000/1.5 = 48,000 MT

(Press mud to spentwash ratio is taken as 1:1.5).

36

Taking into consideration that the Distillery can operate only maximum 270 days as per the

CREP conditions based on “Composting” as treatment option, the Distillery can operate for

another 90 days based on “C” grade Molasses.

Effluent quantity generation for 90 days shall be 90x800 = 72,000 Cum.

Therefore pressmud required shall be 72,000/1.5=48,000 MT.

Thus total pressmud required shall be 48,000+48,000 = 96,000 MT

Available pressmud is 80,000 MT

Short fall is 96,000-80,000 = 16,000 MT.

Alternatively 16,000x1.5=24,000 Cum of spentwash is to be treated.

The industry shall have to use 24,000/4 = 6,000 MT of BAGASSE CILLO (Bagasse Cillo to

spentwash ratio is taken as 1:4)

(Note: However when the Sugar Factory expands to 15,000 MT/day, the Press mud available

shall be 1,20,000 MT and thus the entire spentwash can be consumed without using any

Bagasse Cillo).

Summary: (A) The industry shall operate 180 days based on BH/BIH Grade Molasses

generating the effluent quantity of two litres per litre of R.S production. The industry shall

operate90 days based on “C” Grade Molasses using Multiple Effect evaporators to

concentrate spentwash to achieve four litres of spentwash per litre of R.S. Production.

(B) The industry shall use 80,000 MT of pressmud and 6000 MT of Bagasse Cillo of its own

Sugar Unit.

(C ) The industry shall operate only for 270 days as mentioned above limiting the total

effluent generation as 1,44,000 Cum per annum.

(D) The photographs of the existing concrete yard for composting and polythene sheet lined

spentwash Holding tank and windrows are enclosed as Exhibits.

Concentration and Incineration : The Expert Committee of the Environmental Appraisal

has taken a policy decision to suggest that the distilleries having more than 60 KLPD shall

adopt Concentration and Incineration method to achieve zero discharge. As has already been

discussed the Concentration and Incineration method is not yet a proven technology and also

due to high capital cost and doubtful returns the industry is not readily willing to adopt this

method.

As the revised TOR conditions impose the Concentration and Incineration, the SOC has

decided to make trials on this technology using bagassecillo as a filler material to absorb

spentwash and make trials using one of the discarded boiler of its sister concern The

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Godavari Sugar Mills Ltd. The Bagassecillo shall be mixed concentrated spentwash at a ratio

of 1:4 and shall be burnt in the boiler having a capcity of 30 T/hr. There shall not be any

existing modifications to the existing boiler except that Sulphur dioxide scrubber shall be

provided besides the wet scrubber which is already exists to remove SPM.

RISK FACTORS: In the boiler furnace there may be clinker formation which requires

cleaning quite often and also the effect of sulphur dioxide on boiler tubes shall have to be

assessed.