PRE FEASIBILITY PROJECT REPORT

PRE FEASIBILITY PROJECT REPORT

for

200 KLPD GRAIN BASED DISTILLERY PLANT AND 10 MW CO-GENERATION POWER PLANT

at

MOUZA : DAKSHIN SIMLA, JL NO: 355, POLICE STATION : KHARAGPUR, DISTRICT: PASCHIM MEDINIPUR, WEST BENGAL

By

SVAKSHA DISTILLERIES LTD.

DLF GALLERIA, UNIT : 709, 7TH FLOOR, PREMISES NO : 02-0124, ACTION AREA 1B, NEW TOWN, KOLKATA-700156, WEST BENGAL

Svaksha Distillery Ltd., Kharagpur (West Bengal)

PREFACE

Svaksha Distillery Ltd. having its office at DLF Galleria, Unit : 709, 7th Floor, Premises No :

02-0124, Action Area 1B, New Town, Kolkata - 700156 are planning to setup a grain based

distillery unit at Mouza - Dakshin Simla, JL No : 355, Police Station - Kharagpur, District -

Paschim Medinipur (Punjab). The industrial unit will have installed production capacity of

200 kL/day of Ethanol/ENA and 10 MW of power co-generation. The specific product mix

will include ENA, industrial alcohol, bottling of country liquor/IMFL and 10.0 MW of power

cogeneration.

The project ensue a capital investment of about Rs. 200 crores on land, land development,

buildings, plant and machinery.

The industry has engaged the services of M/s Ace Engineers and Consultants, Patiala, for;

a) analysing the proposed project from the perspective of pollution generation

b) identifying the sources of pollution, and

c) suggesting pollution control systems.

The present report is intended to identify the pollution being generated by the unit and

suggest appropriate measures to control the pollution. The report comprises of;

a) Description of process of the industrial unit.

b) Identification of the sources and the nature of pollution.

c) Proposed schemes for control of pollution.

d) Basic design and specifications of the proposed pollution control systems.


1.0 THE INDUSTRY

The proposed industrial unit is a grain based distillery with an installed production

capacity of about 200 kL per day of ENA/Ethyl Alcohol. The distillery will use grains

– rotten rice/broken rice, rotten wheat, maize and other grains etc. as basic raw

material.

The product mix will include extra-neutral alcohol (ENA), industrial alcohol, bottled

country liquor and IMFL. The project planning also includes a cogeneration power

plant of 10 MW.

The major raw material and inputs would be grains @~ 2.5 MT/kL of alcohol,

enzymes @400 kg/day, sodium hydroxide @200 kg/day, urea @900 kg/day, anti-

foam agent @100 kg/day, yeast @200 kg/day.

The industry would install two (2) boilers of 35 MT/hour of steam generating capacity

for each of the boiler. The fuel requirement for each of the boiler furnace would

include a maximum of 8 MT/hour of rice husk/coal (in case of non-availability of rice

husk). The total fuel requirements for both the boilers would be around 16 MT/hour

of rice husk/coal.

1.1 Grain based Distillery Process and Operations

The process will have following steps/operations;

a) Grains receiving and storage

b) Grains handling and milling

c) Slurry preparation/liquefaction

d) Yeast activation

e) Saccharification and instantaneous fermentation

f) Multi-pressure distillation

g) Decantation

h) Multi-effect evaporation


i) Spirit storage

Figure 1 shows the manufacturing process and mass balance of distillery.

1.1.1 Grain receiving and storage

Grains such as broken rice/rotten rice, rotten wheat and other edible grains are

procured from various sources, and are stored in gunny bags in covered storage

godowns. Grains may also be stored into silos.

1.1.2 Grain handling and milling

The grain would be lifted in bucket elevators, screened followed by removal of stones

and iron matter. Cleaned grains would then be milled using dry milling process in

hammer mills. The flour would be fed through the bucket elevators and conveyed to

the batch tipping machine through a screw conveyor. The flour addition would be

metered through the batch tipping machine with load cell arrangement, before

transferring the flour to the slurry tank through another screw conveyor (pre-masher)

for slurry preparation process.

1.1.3 Slurry preparation/liquefaction

Grain flour and process water would be fed at controlled rate to slurry tank. Mixed

slurry would be taken to the initial liquefaction tank where additional quantity of

water would be added as per requirement. Viscosity reduction enzyme and stabilizing

chemicals and a portion of liquefying enzyme would also be added at this stage. This

slurry would then be "cooked" in the jet cooker.

The slurry would be continuously pumped to a steam jet cooker where high-pressure

steam at 7.5 bar (g) would rapidly raise the slurry temperature. The mixture of slurry

and steam would then be passed through the retention loop. The retention loop would

have several "U" bends in series with sufficient capacity to provide the desired

retention time at a given flow rate. The cooked mash would be discharged to a flash

tank.

The cooking process, accomplished in the above manner, would convert the slurry

into a hydrated, sterilized suspension and would be therefore susceptible to enzyme

attack for liquefaction.


The gelatinized mash from the flash tank would be liquefied in the initial and final

liquefaction tank where liquefying enzyme (alpha-amylase) would be added. The

liquefied mash would be cooled in mash cooler and transferred to saccharification-

cum-fermentation section. This process would initiate the formation of sugar.

1.1.4 Yeast activation

Yeast seed material would be prepared in water-cooled yeast activation vessel by

inoculation sterilized mash with Active Dry Yeast. Optimum temperature would be

maintained by cooling water. The contents of the yeast activation vessel would then

be transferred to fermenter.

1.1.5 Saccharification and instantaneous fermentation

The liquefied starch slurry, comprising of dextrins, would partly be taken for yeast

development in the yeast activation vessel, and majorly would be transferred into the

fermenter. The nutrient enzymes would first be added to saccharify the starch slurry

causing formation of sugars. Immediately, the active yeast would be introduced in the

system for simultaneous fermentation. The process of fermentation is to convert the

fermentable substrate into alcohol.

To prepare the mash for fermentation, it may have to be diluted with water. The pH of

the mash would be adjusted by the addition of acid. Yeast would be available in

sufficient quantity to initiate fermentation rapidly and complete it within the cycle

time.

At the start of the cycle, the fermentor would be charged with mash and contents of

the yeast activation vessel. Significant heat release would take place during

fermentation. This would be removed by passing cooling water through the fermentor

PHE's to maintain an optimum temperature. The recirculating pumps also serve to

empty the fermentors into beer well. After the fermentors are emptied, they would be

cleaned with water and caustic solutions and sterilized for the next batch. The carbon

dioxide evolved during the process would be vented to atmosphere after the recovery

of alcohol in a scrubber.

1.1.6 Multi-pressure distillation

This process would utilize following columns namely the analyser, degassifier, pre-


rectifier column, stripper, rectifier-cum-exhaust, extractive distillation (ED) column,

recovery column and simmering column in ideal heat intergration in order to reduce

the energy consumption.

The analyser and degassifier columns would be operated under vacuum whereas the

extractive distillation, the simmering, the recovery columns would be operated under

atmospheric condition. The pre-rectifier, rectifier-cum-exhaust columns would be

operated under pressure.

The energy requirement for analyser, degassifier columns would be met by rectifier

column top vapours. The rectifier column top vapors would be condensed in a

thermo-siphon reboilers connected to a flash vapors and would be injected into the

analyser column.

The energy requirement of the simmering column would be met by the top vapours of

pre-rectifier column while that of the recovery column would be through direct steam.

The overall technical alcohol/impure spirit cut will be maintained at 7%. The offered

distillation process would allow direct wash to extra neutral alcohol production of

having a provision to draw rectified spirit.

1.1.7 Decantation

Decantation section would comprise of centrifuge decanter for separation of

suspended solids from whole stillage (spent wash) coming out of distillation plant.

Wet cake has 30-35% w/w solids as removed from bottom of decanter. Thin slops

coming out of decanter would be collected in a tank and transferred for further

treatment and recycle.

1.1.8 Multi-effect evaporation

The thin slops from the distillation would be fed to two stage evaporation system. In

stage I, the falling film evaporation systems would concentrate the solids from 3 %

w/w to 7 % w/w. In stage II, circulation type evaporation system would be installed

having four effects which would increase the concentration of solids from 7 % to 35

% w/w. The vapours evolved from the initial and final effects would be condensed

and reused in the process.


1.1.9 Spirit storage

Spirit storage would be divided into two sections. One would be daily spirit receiver

section and the other would be bulk storage section. The spirit coming out of

distillation would be transferred to daily spirit receivers (separated for RS/ENA).

Subsequently, after gauging, the spirit would be transferred to respective bulk storage

tanks.

1.2 Bottling of country liquor/IMFL

The process would involve mixing of ENA with DM water along with liquor essence

blends, caramels, and colours in stainless steel blending tanks. The ratio of spirit to

DM water would be controlled by proof requirements in the end product. For

example, one case (equivalent to 9 litres) of IMFL (75% proof) requires 4 litres of

spirit and 5 litres of DM water. The blend would be subjected to physical filteration.

Subsequently, the blend would be filled in bottles. The bottles would be labeled,

packed, and stored for final dispatch. The industry would produce around 3000000

cases of liquor per annum.

1.3 Power cogeneration

The power plant will be using the combustion technology. The basic steps involve

fuel handling, boiler, turbo generator and power evacuation system.

Proposed 10 MW cogeneration plant would consist of two (2) high pressure water

tube steam boilers and two (2) extraction-cum-condensing steam turbines of 5 MW

capacity each. Fuel in the steam boiler will be burnt with the help of air in the boiler

furnaces. Water will be circulated in the boiler drum and tubes thus getting heated by

the flame burning in the boiler furnaces. Water would come out of the boiler drum

located at the top of the boiler as steam. Flue gases from the boiler furnaces would

come in contact with the steam coming out of boiler drum. Steam after coming in

contact with the flue gases would get heated up further thus getting superheated.

Super-heated steam leaves the boiler in a pipe. Flue gases after super heating the

steam pass through economizer where they pre-heat the boiler feed water before it

enters the boiler drum.

High pressure superheated steam from boiler would be passed through steam turbine


and at the lower pressure goes to the condenser. While passing through the turbine,

the high pressure and temperature steam rotates the turbine rotor and an electric

alternator. This electric power generated is consumed in house, i.e., for running the

distillery plant and utilities like power plant auxiliaries, etc., and surplus power will

be exported to the state grid.

A part of the MP/LP steam is extracted for use in distillery operations. The condensed

steam return to the steam boiler as condensate and is again boiled as steam.

To the possible extent, feed water requirements of the boiler would be met essentially

by the condensate. The steam condensate will be available at 45-50oC and will be

directly used in the feed water circuit, although with certain monitoring for certain

circuits. The make up for the plant operation would be demineralized water and a DM

water treatment plant of adequate capacity would be provided. The power generation

cycle would be provided with a de-aerator serving the dual purpose of de-aerating the

feed water as well as heating the feed water with the extraction steam.

1.4 Sundry utilities

From the standpoint of this report (pollution generation and control), the critical

sections are discussed independently as under;

1.4.1 Steam generator – 2 x 35 MT/hour

The industrial unit plans to setup two boilers of steam generation capacity with a

maximum continuous rating (MCR) of 35 MT/hour, with the outlet steam parameters

at 64 Ata and 480±10°C. The variation on the super-heater outlet temperature shall be

±10°C. The combustion system of the boiler furnaces would be AFBC type.

The boiler will be entirely fueled by rice husk/coal. Coal will be used as alternative

fuel (less than 15% of fuel requirement annually).

Boiler Feed Water

The boiler shall be capable of operating with the following feed water quality*

requirements;

a) pH : 8.8-9.2

b) Oxygen : 0.005 ppm

c) Hardness : 0


d) Total Iron : 0.01 ppm

e) Total Copper : 0.01 ppm

f) Total Silica : 0.02 ppm

g) Hydrazine : 0.01-0.02 ppm

h) Specific electrical conductivity : 0.5 micro ohms/cm

* At 25°C measured after cation exchanger in the H+ form and after CO2 removal

(max.)

Steam Purity

The boiler shall be capable of supplying uninterrupted steam at the MCR rating with

following steam purity levels.

a) Total dissolved solids : 0.1 ppm (max)

b) Silica (max) : 0.02 ppm

1.4.2 Condensate system

To maximize energy conservation, water utilization and plant efficiency, condensate

would be recovered throughout the plant and returned for boiler feed make up.

Allowance has been made for the necessary condensate receivers, pipes work, valves

and traps sets, etc. About 85 % of the steam supply to process is recoverable as

condensate for re-feeding it into the boiler.

1.4.3 Water treatment plant – 1000 m3/day

It is proposed that the water to be used will be received from the ground water. The

water quality will require pre-treatment to satisfy the quality required for boiler feed

water, process requirement, and blending during bottling. Treatment will involve

softening and ion exchange treatment suitable for ultimate quality of water required.

1.4.4 Electrical system

The plant power requirement (including that for power plant auxiliaries) will be about

6.0 MW. Out of total installed power generation capacity of 10 MW, the surplus

power, after meeting in-house requirements, will be exported to state grid.


1.4.4.1 Standby electrical generator

It is proposed to install two 1000 kVA diesel generator set to provide standby power

in case of state power supply failure. They would be complete with synchronization

panel.

1.4.5 Cooling water – 4000 m3/hour

The maximum process and power plant cooling water requirement will be 4000

m3/hour. The cooling tower will be counter/cross flow induced draft cooling tower

with total capacity of about 4000 m3/hr capacity divided into two cells. The cooling

tower shall be designed for a cooling range of 8°C, and an app roach of 5°C while

operating under the atmospheric wet bulb temperature of about 27°C. The cooling

tower shall be carefully sited such that there is no re-entertainment of the vapors into

the cooling tower. Evaporation and drift loss will depend on season and an average

figure will be about 1.60 %. The cooling tower blow-downs will be approximately

0.1%. Whole of the quantity lost will be made-up by adding fresh water/treated

condensate from the process.


Figure 1 : Idealized Water Balance

All values are in V/V except grains which are in MT/day

Liquefaction (1550)

Grain (500)

MEE condensate/Lees (420)

Steam (160)

Fermentation (1800)

CO2 (150)

Multi-pressure Distillation (1650)

DM Water (200)

Steam (660)

Steam Condensate (660)

Spent Wash (1200)

Spent Lees (450)

Alcohol (200)

Multi Effect Evap. (1025)

Thick Syrup (125)

Steam Condensate (100) Steam (100)

Condensate (900)

Milling Section

Fiber/Husk (20)

Dirt/Dust (10)

Fresh Water (250)

Dryer ( Wet Cake & Thick syrup 300)

Steam (200) DDGS (100 MT)

Decanter

Wet Cake (175)

Multi Effect Evap. (1025)

Fresh Water (500)


Cooling Tower Balance

Water Balance for Misc. use

Water Balance for Treatment

Cooling Tower (1500)

MEE condensate/Lees (930)

Fresh Water (570)

Evaporation Losses (1425)

Blow Down to ETP (75)

Bottle Washing (30) Bottle Wash to ETP (30)

Domestic Use (20) Domestic Eff. to ETP (18)

Soft Water for Blending (50) Spillages to ETP (5)

Water for Softening (1000) Rejects to ETP (50)

Ferm./floor washing (20) Wastewater to ETP (20)

ETP (238)

C. T. Blowdown (75)

Domestic Effluent (18) Irrigation purposes (238)

Bottle wash/spillages (35)

D.M. Reject (50)

Ferm./floor washing (20)

Boiler Blow down (40)


2.0 SOURCES AND NATURE OF POLLUTION

2.1 Water pollution

The impending water uses and consequent water pollution may be because of the

following;

a) Process and dilution water

b) Boiler feed water make-up

c) Cooling water make-up

d) Washing (fermentor, bottle, floor, etc.)

e) DM water for bottled liquor blending

f) Water treatment plant maintenance

g) Domestic consumption

2.1.1 Process and dilution water

The fresh water requirements in the process (in fermentation, liquefaction, etc.) would

be about 950 m3/day. Besides this, 160 MT/day of direct steam would be consumed in

the process for liquefaction section. This figure is after adjusting for all recycle and

reuse potential of various streams.

2.1.2 Boiler feed water make-up and boiler blow-down

The maximum boiler feed water requirement will be about 1680 m3/day (expecting

both the boilers to be operating continuously at MCR), out of which around 85%, i.e.,

about 1450 m3/day, will be met through return condensate. Thus about 15 %, of the

steam generated, will be either used (in the industrial processes) or lost as blow-down

(in order to maintain desired TDS concentration in the boiler feed water, continuous

or intermittent blow-down of condensate is employed). Remaining feed water

requirement will be met through D.M. water. The D.M. water required for the purpose

will be about 230 m3/day. The boiler blowdown, contributing to wastewater

generation will be a maximum of 40 m3/day.


2.1.3 Cooling water make-up and blowdown

The cooling water throughput rate will be a maximum of 4000 m3/hour. Around 1.60

% of the total recirculation water is lost in evaporation, drift, and blow-down losses.

A part of the process water generated (930 m3/day of condensates from multi effect

evaporation and spent lees) would be reused for the cooling tower makeup water, after

its treatment. Thus, fresh make-up water requirement will be about 570 m3/day. The

blow-down rate will be less than 75 m3/day.

2.1.4 Washing

The wash water requirement (for washing of fermenter, bottle, and floor) will be

about 50 m3/day. Whole of this water will contribute to wastewater generation.

2.1.5 DM water for bottled liquor blending

The average water requirement for blending during bottling of country liquor/IMFL

will be about 50 m3/day, which will completely be present in final product. There will

be no wastewater generation.

2.1.6 Water treatment plant maintenance

The D M water treatment requirement is about 1000 m3/day (soft water – for boiler,

process, bottling, etc., requirements). Treatment plant maintenance will generate

about 50 m3/day of reject water. Whole of this water will contribute to wastewater.

2.1.7 Domestic consumption

Some of the water will be required for cooking, drinking, sanitation, etc. Average

daily requirement is expected to be about 20 m3/day. Of this, less than 90%, i.e., ~18

m3/day will be obtained as domestic wastewater.


2.1.10 Overall water requirement

Total average fresh water consumption from the project can be summarized as under;

S. No.

Purpose Fresh water requirement

1. Process & dilution water 950 m3/day

2. Boiler feed water 230 m3/day

3. Cooling water 570 m3/day

4. Washing Requirements 50 m3/day

5. Bottling 50 m3/day

6. Water treatment plant 50 m3/day

7. Domestic requirement 20 m3/day

Total 1920 m3/day

2.1.10 Waste Water Generation

The industry would generate 238 m3/day of wastewater from different streams. The

combined wastewater stream (washing and domestic wastewaters) is expected to have

following characteristics;

1. Flow − <250 m3/day

2. pH − 6.5-8

3. BOD − 2500-3000 mg/l

4. COD − 5000-6000 mg/l

5. TSS − 600-700 mg/l

A part of the wastewater would be reused for spraying in fuel storage area and ash

storage and the remaining wastewater will be disposed onto land for irrigation. The

treated wastewater must conform to the following standards;

1. pH – 5.5-9.0

2. BOD5, 20°C – ≤100 mg/l

3. Total suspended solids – ≤100 mg/l


2.2 Air pollution

The air pollution will be due to combustion emissions released by the boiler furnaces.

The boiler furnaces, AFBC type, will use chiefly rice husk as fuel, with a maximum

consumption of about 8 MT/hour for each of the boiler.

The critical SPM concentration in the flue gas will be less than 30.0 g/Nm3. Majority

of the particulates (about 60-70%) will have sizes in the range of 2-10 µm. The

emissions are expected to have temperature in the range of 140-150°C.

As per the statutory norms (as applicable to the industry), the flue gas emission shall

not have SPM levels (in the stack) exceeding 100 mg/Nm3. Additionally, the stack

height requirements for discharge of emissions will need to be complied with.

2.2.1 DG set

The industrial unit is planning to have two DG sets, each of 1000 kVA as backup to

state power supply.

As per the applicable norms, the DG sets will be housed in an acoustic chamber.

The combustion emission outlet, of the DG set, will be provided with a muffler along

with a minimum stack height of 6.5 m above the height of nearest building.

2.3 Solid wastes

• The grain based fermentation will result in high protein solids @ 100 MT/day. It

has potential to be used for cattle feed making.

• The boiler furnace will result in ash generation @ 60 MT/day.

2.4 Hazardous waste

The plant facility will result in generation of about 1 kL/year of spent oils (lubricants

and transformer oil), which will be stored on site and sold to authorised recyclers.


3.0 THE POLLUTION CONTROL SYSTEM

While proposing the pollution control system, following considerations will be taken

into account;

a) efficiency of operation to satisfy desired norms

b) initial (capital) cost and recurring (operational) costs

c) ease of operation and management

d) maintenance requirements

3.1 Wastewater treatment system

The project will result in generation of following types of effluents from the process

operations;

a) Spent Wash from Distillation Process : The project would result in generation of

spent wash from the distillation process. Spent wash @ 1200 m3/day would be

generated during the production of alcohol @ 200 KL/day. The spent wash would

be sent to the decanter where wet cake @ 175 MT/day would be separated. The

remaining liquid i.e. thin slops @ 1025 m3/day would be treated in multi-effect

evaporation system.

b) Condensates from Process and MEE : The project would result in generation of

process condensates (spent lees) from the distillation process and multiple effect

evaporation condensates. Spent lees @ 450 m3/day would be generated and MEE

condensate @ 900 m3/day would be generated. Whole of the condensates after

treatment would be used for makeup water of cooling towers.

c) Effluent from other processes : Besides the above mentioned streams, effluent

would be generated from misc. other streams such as – floor/fermentor washing

effluent @ 20 m3/day, cooling towers blow down @ 75 m3/day, domestic effluent

@ 18 m3/day, D.M. plant reject @ 50 m3/day, bottle washing and spillages @ 35

m3/day and boiler blowdown @ 40 m3/day . This effluent would be moderately

polluted and after treatment would be used on land for irrigation purposes.


3.2 Air pollution control system

The air pollution control system will comprise of;

a) ducting arrangement to transport emissions to the APCD,

b) an APCD – electro-static precipitator

c) an ID fan, and

d) a stack to discharge the cleaned flue gas at adequate height.

The furnace emissions, from both the furnaces, will be combined and conveyed into

the APCD, the electro-static precipitator (ESP), where it will get cleaned (SPM

removal) before being discharged into the atmosphere, through a stack of adequate

height. If efficiently operated, the SPM removal efficiency for the system is expected

to be more than 99.8%.

3.2.1 Electro-static precipitator (ESP)

The ESP charge particulates which migrate to the grounded collection plate, loose

there charge and get captured. The particles collect on the plate, creating a dust layer.

The accumulated dust layer is removed, at regular intervals, by rapping the collection

plate or by spraying it with a liquid.

A typical ESP has thin wires, called discharge electrodes, which are evenly spaced

between large plates, called collection electrodes, which are grounded. A negative,

high-voltage, pulsating, direct current is applied to the discharge electrode, creating a

negative electric field around. The applied voltage is increased until it produces a

corona discharge. The free electrons, created by the corona, are rapidly fleeing and

ionise the gas molecules near the discharge electrode, resulting in avalanche

multiplication.

The ionised gas cause particulates to get negatively charged, which experiences strong

electrostatic attraction towards collection electrode plates. The particles encounter the

plate and stick because of adhesive and cohesive forces.

The ESP contain essential components – discharge electrodes, collection electrodes,

high voltage electrical systems, rappers, hoppers, and shell.

3.3 Ash management

The air pollution control system, for the new boiler furnace, will comprise of;


a) Ash vessels

b) Conveying pipes

c) Ash silo

d) Ash storage

e) Ash disposal

This ash handling will be totally enclosed system. The ash handling system shall be

designed to take care of 100% fuel burning. Ash collected from the bottom of furnace

(bottom ash) and the ash collected in the air heater hoppers and ESP (air pollution

control system) hoppers will be taken to an ash silo through a pneumatic conveying

system. Ash silo will have the capacity of storage for 1 day of ash. The ash from the

silo will be unloaded through the ash conditioner and stored on land. This ash will be

finally used for the making of flyash bricks within the premises.


4.0 DESIGN AND SPECIFICATIONS OF POLLUTION

CONTROL SYSTEM

4.1 MULTIPLE EFFECT EVAPORATION

The suggested treatment scheme Effect working on the principle of falling film &

Force Circulation

Analyzer vapors is fed to the first effect evaporator shell side and steam is fed to

shell side finisher at the given pressure and temperature as the heating medium.

Vapors from last effect are condensed in Surface Condenser. A Shell & tube type

Multi-pass Surface condenser is employed for condensing the shell side vapors.

The product at the desired concentration 35 % is obtained at the outlet of Finisher.

Each effect is provided with recirculation cum transfer pump.

The condensate from surface condensers is collected in a common condensate pot.

The condensate is transferred for further treatment / Recycle by using centrifugal

pump.

The Pure steam condensate are collected in receiving vessels and can be pumped

to desired battery limit

Highly efficient operating pumps have been provided for pumping the required

fluid.

The plant is having high level of automation to get consistent output at required

concentration.

The system operates under vacuum. Water-ring vacuum pumps are used to

maintain a desired vacuum.

4.2 Treatment of Condensates

The spent lees and condensates from stage I and stage II of multiple effect

evaporation (930 m3/day) would be collected in a collection tank. The condensates

would be treated in a condensate polishing unit consisting of aeration, clarification,


sand filteration and activated charcoal filteration before its final reuse in cooling water

makeup. The detailed design consideration of condensate polishing unit are as

follows;

Collection tank

The collection tank will be provided with an HRT of about 6 hours for 930 m3/day of

effluent. So, the collection tank will have a total capacity of around 250 m3. The tank

will have conventional rectangular geometry.

UASBR (Upflow Anaerobic Sludge Blanket Reactor)

Flow Rate − 930 m3/day or 38.75 m3/hour

1. COD inlet loading − 2500 mg/l or 2.5 kg/m3

2. COD outlet loading − 1000 mg/l or 1.0 kg/m3

3. Organic Loading Rate − 3.0 kg COD/m3/day

4. Volume of tank required − 900 m3

5. Sludge layer height considered − 3 m

6. Height of settling area − 1.5 m

7. Surface area of the tank − 90 m2

8. Desired upflow velocity − 0.5 m/hour

9. Flow required − 40 m3/hour

Aeration tank

The tank will have completely mixed flow regime. The specifications of the

tank are as under;

Flow Rate − 930 m3/day

1. BOD loading − 500 mg/l

2. MCRT − 6 days

3. F/M − 0.2

4. MLSS − 3500 mg/l

5. MLVSS/MLSS ratio − 0.8

6. HRT − 24 hours


7. Effective tank volume − 950 m3

8. Air requirement (for diffused aeration) − 5000 m3/hour

9. Nutrient ratio (BOD:N:P) required − 100:7:1

10. Treatment efficiency (BOD3 removal) − > 95%

The tank will be provided with fine-bubble diffused aeration system. The air is

supplied by the twin-lobe roots blowers of desired capacity at 0.5 kg pressure.

Secondary clarifier

The secondary settling unit is meant to separate the solids from the mixed liquor from

the aeration tank. The process is very critical for the efficient operation of the ASP.

The clarifier can be described as under;

a) Design overflow rate = 16 m3/m2.day

b) Peaking factor = 1

c) Design flow (at p.f.) = 40 m3/hour

d) Settling area required = 60 m2

The secondary clarifier will be rectangular in geometry. The separated solids

(underflow) would be either recycled back into the aeration tank or would be wasted

(to adjust for the excess sludge generated) onto sludge filter beds.

Intermediate Storage Tank

An intermediate storage tank of around 2 hours HRT would be provided for feeding

the treated effluent in the pressure sand filter and activated charcoal filter. The tank


Sand Filteration

The pressure sand filter will have following specifications;

a) Working principle – down flow

b) Maximum flow rate – 50 m3/hour

c) Minimum flow rate – 20 m3/hour

d) Maximum working pressure – 3 kg/cm2

e) Minimum working pressure – 1.5 kg/cm2

f) Pressure vessel type – vertical cylindrical

g) Filtration rate – 14 m3/m2.hour


h) Effective diameter – 2500 mm

i) Effective height – 3000 mm

j) Filteration media type – Graded sand with under bed

k) Top layer (anthracite 1-2 mm) – 700

l) Second layer (sand 0.4-0.8 mm) – 600 mm

m) Total bed depth – 1300 mm

n) Backwash velocity required – 0.8-1.2 m3/m2.min

o) Backwash water feed rate – ~1 m3/min

Activated Charcoal Filteration

The activated charcoal filter will have following specifications;

a) Working principle – down flow

b) Maximum flow rate – 50 m3/hour

c) Minimum flow rate – 20 m3/hour

d) Maximum working pressure – 3 kg/cm2

e) Minimum working pressure – 1.5 kg/cm2

f) Pressure vessel type – vertical cylindrical

g) Filtration rate – 16 m3/m2.hour

h) Effective diameter – 2500 mm

i) Effective height – 3000 mm

j) Filteration media type – charcoal with minimum 600 iodine value

k) Total bed depth – 1300 mm

l) Backwash velocity required – 0.8-1.2 m3/m2.min

m) Backwash water feed rate – ~1 m3/min

Final Treated Effluent Storage Tank

The final treated effluent storage tank will be provided with an HRT of about 4 hours.

The tank will have conventional rectangular geometry. Treated effluent from this tank

would be transferred to the cooling towers for their makeup requirements.

4.3 Treatment of Other Streams

Effluent generation from other misc. streams as discussed above would be less than

250 m3/day. The mixed effluent would be moderately polluted. The mixed effluent

would be collected in a collection tank. Thereafter it would be treated through

anaerobic biofilteration, aeration and clarification. The treated effluent would be


disposed on land for irrigation purposes. The detailed design consideration of effluent

treatment plant are as follows;

Collection tank

The collection tank will be provided with an HRT of about 8 hours for 250 m3/day of

effluent. So, the collection tank will have a total capacity of around 75 m3. The tank


Primary clarifier

The primary settling unit is meant to separate the solids from the untreated effluent.

The process is very critical for the efficient operation of the ETP. The clarifier can

be described as under;


b) Peaking factor = 2.0



The primary clarifier will be rectangular in geometry. The separated solids

(underflow) would be wasted onto sludge filter beds.

Anaerobic Biofilter

Aeration tank

The tank will have completely mixed flow regime. The specifications of the tank are

as under;

Flow Rate − 250 m3/day

1. BOD loading − 600 mg/l

Average Flow Rate assumed 250 KLPD

Average COD Load 6000 mg/l

Peak daily COD Load 1500 kg/day

COD loading assumed 0.3 kg/m2.day

Surface area required 5000 m2

Surface area available per m3 with media 110

Volume of media required 50

Capacity of tank 200 m3


2. MCRT − 6 days

3. F/M − 0.2

4. MLSS − 3500 mg/l

5. MLVSS/MLSS ratio − 0.8

6. HRT − 24 hours

7. Effective tank volume − 250 m3

8. Air requirement (for diffused aeration) − 1000 m3/hour

9. Nutrient ratio (BOD:N:P) required − 100:7:1

10. Treatment efficiency (BOD3 removal) − > 95%

The tank will be provided with fine-bubble diffused aeration system. The air is

supplied by the twin-lobe roots blowers of desired capacity at 0.5 kg pressure.

Secondary clarifier

The secondary settling unit is meant to separate the solids from the mixed liquor from

the aeration tank. The process is very critical for the efficient operation of the ASP.

The clarifier can be described as under;


b) Peaking factor = 2.5



The secondary clarifier will be rectangular in geometry. The separated solids

(underflow) would be either recycled back into the aeration tank or would be wasted

(to adjust for the excess sludge generated) onto sludge filter beds

Septic tank for domestic treatment

The septic tank will provide and effective HRT of at least 48 hours, for maximum

daily flow, to biologically stabilize, partially, the organic pollution load. A two

compartment septic tank will be used for the purpose. The stabilisation compartment

(first compartment) will have volumetric capacity of 50 m3/day, with aspect ratio

(length:width) of at least 3. Floor slope at 1:5 will be provided for sludge

accumulation. The effective submerged depth of tank will not exceed 2.5 m.


Provision will be made for periodic withdrawal (pumping out) of accumulated sludge.

The actual tank dimensions will be worked out to suit the process and site

requirements.

4.4 Treated wastewater disposal

The distillery unit will generate a maximum of 250 m3/day of wastewater. The mode

of wastewater disposal adopted includes;

Disposal onto land for irrigation – <250 m3/day

For disposal of wastewater onto land for irrigation, land area requirement can be

calculated as under;

a) Recommended treated wastewater hydraulic loading for specified class of soil (as

stipulated in IS:2490 (Part I) -1981) – 120-150 m3/hectare/day

b) During the initial phase, plantations are nascent and bio-drain of treated sewage

applied for irrigation is limited. Beyond first two years, as the plantations grow

towards maturity, average wastewater application rate can be steadily increased.

c) Minimum wastewater application rate (during first three years) – ~100

m3/hectare/day

d) Nominal wastewater application rate (after first three years) – ~150

m3/hectare/day

e) Maximum irrigable area required for complete disposal of the treated

wastewater – ~25000 m2

4.5 Air pollution control system

a) The boiler furnace will use a maximum of 8000 kg/hour of rice husk (when used

singly) as fuel for each boiler furnace.

b) The air-fuel ratio (combustion air) required for complete combustion is 1:5.8, i.e.,

1 kg of fuel requires about 5.8 kg (~ 4.8 Nm3) of air – assuming 30% excess air.

c) Flue gas generation will be about 6.8 kg/kg of fuel.

d) Maximum rate of emission generation will be about 65000 Nm3/hour.

e) The temperature of the flue gas at the outlet of the furnace will be about 140-

150°C.


f) The critical SPM levels will be less than 30000 mg/Nm3.

g) Sufficient velocity will be maintained in the ducts/conduits in order to ensure that

there is un-clogged flow.

h) All of the bends, in the gas flow ducts, are recommended to have throat radius of 2

times the diameter of the duct. Sharp bends, in the ducts/conduits are to be

completely avoided.

i) The emissions follow ideal gas behaviour. Gas flow is incompressible.

j) Due consideration has been accorded to the changes in gas properties and

behaviour with changes in temperature.

k) All inlets, outlets, and approaches are proper, so that there is no turbulence in the

flow. The inner surfaces of the ducts and the APCD (coming in direct contact of

the gas flow) will be reasonably smooth. There will not be any kind of leakage

from any part of the duct/conduit, APCD, or machinery.

l) The sampling port will be provided in the stack, such that its height is, at least, 8

times the stack diameter, from the inlet to the stack. The emission shall be

discharged into the atmosphere at a height, above the sampling port, at least 2

times the stack diameter.

m) While the specifications and operating parameters, being specified hereunder,

represent theoretically optimised values, there may be some variation in any of

these during actual erection/commissioning (to suit site conditions) and

operational fine-tuning of the system. Every effort will be made to ensure that the

system’s performance does not get affected adversely.

4.5.1 Approach duct

There will be two ducts conveying furnace emissions into the APCD and each will

have a diameter of 1800 mm. All bends in the ducts will have throat radius of at least

3600 mm.

4.5.2 Electro-static precipitator (ESP)

The ESP will have following technical specifications;

1. Design gas flow rate – 65000 m3/hour

2. Temperature – 140-150ºC


3. Maximum inlet dust load – 22 g/Nm3

4. Outlet emission dust load – <100 mg/Nm3

5. Plate area – 2025 m2

6. Specific collection area – 111.69 m2/m3s

7. Velocity through ESP – 0.51 m/s

8. Treatment time – ~21.95 s

9. Migration velocity – ~4.9 cm/s

10. Number of fields – 3

11. Efficiency – > 99.54%

Collection electrode specifications;

1. Height of Panel – 6 meters

2. Material – IS 513/CRCA

3. Total no. of plates – 240

4. Width of panel – 735 mm

5. Thickness – 18 SWG

Emitting (discharge) electrode specifications;

1. Height of panel – 6 meters

2. Total no. of electrodes – 1350

3. Type – Spiral

4. Material – ERW tubes and

carbon steel studs

5. Spacing between emitter &

collector electrode

– 200 mm

6. Spacing between collecting

plates

- 400 mm

Electrical specifications;

1. TR sets – 3 nos.

2. TR control type – Microprocessor controlled

3. Nos. per field – 1

4. TR rating

Output voltage

Output current

–

–

120 kV DC

3 x 300 mA


Rapping system specifications;

1. Type – Microprocessor based

electromagnetic plunger

2. Total no. of rapper per unit – 18

3. Rapper impact force (max.) – 20 ft. lb. (adjustable)

Design pressure

1. Maximum – ± 300 mm WG

2. Maximum pressure drop –

flange to flange

– 20-25 mm WG

Power consumption

• Maximum 120 kW – this includes corona (without losses), rapper, PA system,

insulator heaters, hopper heaters, RAVs.

• Power consumption is at steady state for the rated inlet parameters in the basis

of design.

The flue gas cleaning system will achieve SPM removal efficiency of more than

99.54%, resulting in emission discharge with SPM concentration of less than 50

mg/Nm3.

4.5.3 Stack

The stack shall have adequate height to properly disperse SO2 generated or 30 m,

whichever is more. The stack height is calculated using the equation;

H = 14 (Q)0.3

Where, H is stack height (in m), and

Q is quantity of SO2 generated (in kg/hour).

a) Rate of fuel combustion = 8 MT/hour

b) Rate of combustion of S (maximum) = 8 kg/hour

c) Maximum SO2 in the emissions = 16 kg/hour

d) Stack height (minimum) = 32 m

e) Stack diameter = 1.5 m

f) Height of sampling port above inlet = 12 m (minimum)

A sampling port with platform shall be provided for monitoring purposes. A ladder

arrangement shall be provided to access the sampling port.


4.5.4 Blower (ID fan)

To satisfy the suction requirements, and to compensate for the pressure drops (flow

losses), a centrifugal blower shall be provided. It will have the capacity to produce the

flow rate of 30 Nm3/s and total pressure of 0.25 m of water column.

PRE FEASIBILITY PROJECT REPORT

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