--- (A  case study of Brewering  industry gaseous emissions) by Mr Akindele Faleye --  Ex - BrewMaster North Brewery Ltd Kano.  (MD. WUFAS AGR0Net)....wufasagronet@gmail.com,   WWW . Wufasagronet . Com

—-…….@ WUFAS AGRONet, We don’t know more than Food. —-

 BrewHouse emissions found by Brewers to be pleasant are perceived by some neighborhood residents rather as annoying .  

While pursuing the 2030 Sustainable Food Security Agenda, the Environmental Impact Accessment will be incomplete without measuring the hazardous effect of the Food industry wastages hence other areas such as Effluent water treatment which could cause pollution to lager body of waters and Solid waste such as spent grain which could block drainages causing flooding should be cautiously looked into.

Brew house emission from MASH kettle and Wortcopper in particular in mashing,  emissions arise mainly during boiling phases in decoction methods.

High carbonyl compounds such as Acetaldehyde, Propionaldehyde, Isobutaldehyde and Acetone as well as Phenols are driven off.
In Worrt Copper, water vapour volatile organic substances from Wort copper are predominantly the hop oil compounds. In particular Esters, Ketones, Terpenes, Alcohols, Aldehydes, Furan’s and alkenes.
Approval and abatement programmes must be in place before the establishment of such factories as breweries to contain damaging influences on environment and significant nuisance to general public and neighborhood causing degradability, tendency to accumulate toxicity and
intensifying of odour.

EMISSION MEASUREMENTS ON ORGANIC SUBSTANCES
Due to the multiplicity of substances contained in Brewhouse vapours, quantitative determination of Mass flow rate of individual substances is yet unresolved also emissions are not constant during the duration of brew cycle. The maximum emission level of organic substances arise at the beginning of boiling.
In the measurements of substance in the emissions, Account has to be taken of degradabilty, tendency to accumulate toxicity, effect of decomposition, process intensity of odour. (Terpenes are the major odorous substances in wort emissions depending on variety of Hops oil consists of 70% Terpenes. (De – Terpenation ) .
Hourly odorous gases should as a rule be pass through Off-gases cleaning equipment.

PARAMETER TO BE TAKEN INTO CONSIDERATION ARE:
-Volume flow rate of the off-gas
-.Mass flow rate of odour- intensive substances.
-Local propagation condition
-Duration of emissions
-Distance between the plant and the next existing or planned inhabited areas.
Plant with off gas cleaning have to be subjected to an emission limit level which is to take the form of an odour reduction steps which must be OLFACTOMETRICALLY determined. Olfactometer consists of gas flow meters and nose mask. (Dynamic sampling) However, there is (static sampling) it is filled (gas) into suitable container e.g Foil bag and then transfer to the Olfactometer.
POSSIBLE MEASURES FOR EMISSION REDUCTIONS
Possibility for diminishing emissions of organic and odour- intensive substances from Brewhouse basically involve: Condensation of vapour (Copper vapour Condenser) Process with close loops wort boiling (Vapour Recompression, high temperature wort boiling) Gas Scrubbers, Bio washer. Bio flitter, Activated Carbon Filters (ACF). Combustion pro cess and measures in the area of brewing technology

GAS SCRUBBERS
The gas which cannot be condensed are fed into gas scrubber end must be cooled down to a minimum of 40degree centigrade so that the scrubbing solution. (Polyethylene Fatty acid ester Tween20) is fully effective.
— BIO WASHERS
In Bio Wash her, the organic substance to be broken are taking up in the washing liquid in counterflow. There after the biological breakdown takes place aerobically by micro organisms in an activated sludge tank.
— BIO FILTERS
Both the biowasher and the biofilters operate on the principles of absorption and breakdown by micro organisms the disadvantage of bio filter is that they require a lot of space and prone to break down.
— ACTIVATED CARBON Filter
Odourous substances can also be absorbed by solids. ACF are commonly used. The ( Absorption, Oxidation ) is a technical variation
The odour containing air is clear with Activated Carbon filter . After exhaustion of the filters, thermal desorption and reactivation with Inert gas mixture (Nitrogen, Carbon dioxide) steam takes place. at 550 degree centigrade. Absorption by solids is generally suitable for relatively low volume flow rate only. A pre- separation of solid and water droplets is required
Absorption plants are in use in tobacco processing Chemical cleaning and sewage plants.
— COPPER VAPOUR CONDENSER
The Copper vapour condenser is the usual equipment used to recover the heat of vaporisation of water evaporated during wort boiling. It can be combined with a condensate cooler to increase the level of heat recovery. By condensing the vapour emission of organic and odour intensive substances is considerably reduced also because of heat recovery copper vapour condenser is also economically utilised in small and medium sized. Breweries. also close wort boiling method ( vapour re compression high temperature wort boiling) are the characteristics of this method
—- COMBUSTION OF ODOROUS SUBSTANCES
Odorous substances can also be eliminated by subjecting off gas to atleast 0.3secs to a temperature of 8000c . the disadvantage is high operating cost due to high heat losses in off gas.
— Another way of controlling the off gas ( terpene origin) is the elimination of Hops in the brewery. A research project is presently on by a group of sciencetists in the University of California the aim of which is that
Brewers yeast can be Re engineered to biosynthesized aromatic monoterpene molecule that can impart hoppy flavour to beer by adding recombined DNA derived from yeast mint and basil which produce Linalool and Gereniol to brewers yeast.
The research, if successful will bring about innovation that will completely eliminate the use of Hops .The repercussions of which might be a major Commercial issue to Hops famers.

At WUFAS AGRONET, We are competent and Reliable Food Processing Technologists. Into Human Capital Development Consultancy. Check us out WWW Wufasagronet .com , email us @ : wufasagronet@gmail.com.