BREWERIES, WINERIES & DISTILLERIESByAnshumaan DeyM.Tech, Chemical EngineeringGuru Gobind Singh Indraprastha University

INTRODUCTION

The range of products from distilleries include industrial alcohols, rectified spirit, absolute alcohol, beverage alcohol, etc.

All the products are obtained through the biochemical process of fermentation by yeast, using carbohydrates as raw materials.

All the products contain ethyl alcohol in different proportions

ORIGIN AND CHARACTERISTICS OF BREWERIES WASTES

Making of beer essentially consists of 2 stages:1.Preparation of malt from grains like barley.2.Brewing the barley.

The malt from the malt house is then transported to the brewing section, where “wort”, the medium of fermentation is prepared.

Characteristically, the brewery waste contains a large amount organic soluble solids indicated by a high BOD in the order of 400-800 mg/L and low suspended solids concentration.

COMPOSITION OF MALT HOUSE AND COMBINED BREWERY WASTE

Malt House Waste

Brewery Waste

pH 6.9 – 9.5 4.0 – 7.0

COD (permanganate value), mg/L

31 – 175 30 – 1225

BOD, mg/L 20 – 204 70 – 3000

Total Solids, mg/L 428 – 700 272 – 2724

Suspended Solids, mg/L

22 – 39 16 – 516

Total Nitrogen (N), mg/L

14 – 56 7 – 42

ORIGIN AND CHARACTERISTICS OF DISTILLERIES WASTES

The beverage alcohol industries utilize different grains, malted barley and molasses as raw materials.

The preparation of mash consists of:1. Preparation of “green” malt.2. Preparation of cooked slurries of grains.3. Mixing of above two followed by pH

adjustment, and nutrient (ammonium salts and phosphates) supplementation.

In molasses distilleries, the preparation of “mash” consists of:

1. Dilution by water to a sugar content of about 15%.

2. pH adjustment to 4.0 – 4.5 to prohibit bacterial activities.

3. Nutrient addition. The alcohol is stripped in a tower leaving a

“spent wash” which is the major polluting component of the distilleries, and it is reported to be 10 – 15 times the final product in volume.

CHARACTERISTICS OF COMPOSITED COMBINED WASTE, SPENT WASH & YEAST SLUDGE FROM DIFFERENT INDIAN DISTILLERIES

Yeast Sludge

Combined Waste

Spent Wash

Spent Wash

pH 4.8 3.9 – 4.3 3.5 – 3.65 4.0 – 4.5

Temperature, oC

- - - 90 – 95

COD, mg/L 368000 27900 – 73000 118000 70000 – 151200

BOD, mg/L 165000 12230 – 40000 41380 28000 – 80000

Total solids, mg/L

- 16640 – 26000 99000 59100 – 114500

Suspended Solids, mg/L

73000 4500 – 12000 350 1000

Total Nitrogen, mg/L

- - 1135 14800 – 19000

Alkalinity - 380 – 510 - -

Colour - - Dark Brown

Dark Brown

DO - - NIL -

Rate of waste flow

- 0.9 – 1.0 MLD - 0.82 MLD

ORIGIN AND CHARACTERISTICS OF WINERIES WASTES

The wineries utilize the fruit juices as the raw materials.

The first operation in any winery is the pressing of fermenting juice from the fruits like grape, ‘mahua’, etc.

The second stage in any winery consists of fermentation of the juice.

In the third stage, i.e. in the brandy plant, wine of either type or the fermentation residue in the wine making is distilled to obtain brandy.

CHARACTERISTICS OF COMBINED WASTES FROM BREWERY, WINERY AND FOOD PROCESSING UNITS.

Temperature 20 – 29 oC

Colour Brownish Yellow

pH 4.0

COD, mg/L 1800 – 3000

BOD, mg/L 1500 – 2000

Dissolved Solids, mg/L 6800 – 9400

Suspended Solids, mg/L 15 – 17

TREATMENT OF WASTES

Usually, the biological treatment is accomplished by two stage process for 90 – 94% BOD reduction.

The yeast sludge from the distilleries which contains very high suspended solids and BOD and is rich in proteins, carbohydrates, vitamins, may be released separately for by – product recovery.

The raw spent wash with low pH, high dissolved solids, high temperature, high sulphates, and high BOD is not amenable to aerobic biological treatment.

TREATMENT OF BREWERY WASTE

Both closed anaerobic digestion and open anaerobic lagooning has been tried in INDIA as a means of anaerobic treatment.

For a BOD reduction of 90.8% a BOD loading of 2.5 kg/m3/day and a detention time of 15 days is suggested by Subbarao et. al.

A digester with a BOD loading of 3.01 kg/m3/day, and operating in mesophilic range with 10 days detention time was reported to have reduced the initial BOD by 90% by Sen and Bhaskaran.

WASTE TREATMENT IN A LARGE DISTILLERY COMPLEX

Production of H2S impairs the anaerobic digestion, as soluble sulphides are toxic to the micro – organisms.

About 90-95% BOD can be achieved in a two stage anaerobic lagoon system.

BOD reduction of 85.5% with a detention time of 60 days and a loading rate of 0.67 kg of BOD/m3/day in the 1st stage, and BOD reduction of 65.5% with a detention time of 40 days and a loading rate of 0.15 kg of BOD/m3/day in the 2nd stage is reported.

About 90% of BOD removal can be accomplished in aerated lagoons with a detention time of 20-28 days.

The same degree of treatment can be achieved with 1:1 dilution at a detention time of 15-16 days.

The BOD removal rate constant, K, for the anaerobic lagoon effluent is found to vary from 0.01 to 0.05/day; with 1:1 dilution BOD removal rate constant was found to improve to 0.06-0.08/day.

Oxidation ditches with 50-60 hours detention time and MLSS concentration of 4000 mg/L are also claimed to reduce the BOD of the anaerobic treatment effluent by about 90%.

In a laboratory study, about 56.2% reduction of BOD is obtained when the distillery waste is used as the medium for growing an adapted variety if yeast.

REFERENCES

1. Waste water treatment 3rd ed., by M.N. Rao and A.K. Dutta, Oxford and IBH.

2. Environmental Engineering, by Peavy, Rowy and Tchobanogolous, Mc Graw Hills International Edition.

THANK YOU