An overview of Beer Fermentation Process !

The word Beer is derived from a Latin term called bibere which means ‘to drink’. It is an alcoholic fermented drink that is derived from malted grains like wheat, barley, etc. Fermentation is an important process that goes into the making of beer. Brewery plants widely use the fermentation process to create different flavors and styles of beer.

Role of Yeast in beer fermentation

Yeasts are micro-living organisms that have been used for preparing bread, brewing beer and more. They are a specific type of unicellular fungus that grows by splitting themselves in two. Yeast is largely used in beer fermentation for converting the glucose of the malted grains into carbon dioxide and ethanol. Brewery fermentation doesn’t require any oxygen.

For best results, it’s crucial for the yeast to thrive and grow. To achieve this objective you have to create the right environment for the yeast, this includes the right temperature and ample of food (glucose) for the yeast to do its work.

Yeast is categorically identified as either an Ale yeast or lager yeast. Depending upon the recipe or the style of beer to be prepared, the brew picker picks the yeast accordingly. Ale yeast is a top-fermenting strain that works at warm temperatures, while Lager yeast, is a bottom-fermenting strain, that performs best at lower temperatures. Due to temperature differences, each yeast strain imparts vastly different flavors and aromas to the final product, thus leading to different beer styles.

Beer fermentation Process

There are different steps involved in the making of beer like malting, mashing, boiling, etc. The first two steps, especially mashing and sparging, are essentially directed towards accumulating ‘food’ for the yeast.

After the boiling process is over, the wort is cooled, strained and filtered.  Yeast is then added to the fermenting vessel. At this point, the brewing stops and fermentation begins. Fermentation is an important part of brewing technology used in brewing plants. The beer is stored for a couple of weeks at desired temperature; at room temperature (in the case of ales) and at cold temperatures (in the case of lagers). During this period yeast consumes all the sugar in the wort and spits out CO2 and alcohol as waste products.

Carbonation of Beer

Once you are done with the fermentation process, you have a non-carbonated alcoholic beer ready. You can add desired carbonation to the bottled beer, either artificially through carbonation techniques or by simply allowing the beer to naturally carbonate by allowing further fermentation of the yeast, resulting in more carbon dioxide. When this bottled drink is allowed to sit for a period ranging from a few weeks to a few months you get to taste the delicious, fizzy drinks!

Know All About Ethanol-The Benefits and the Making

Rapid depletion of natural resources(petroleum, crude oil, gasoline etc,) their rising prices and harmful emissions are the concerns that set the momentum for alternative fuel. Ethanol has emerged as the right solution to the problem. Ethanol is now being viewed as the best substitute for petroleum that is largely used by vehicles across the globe. Hence,  endeavors are being directed towards enhancing ethanol production process in several bio-based industries. Ethanol can be used in its pure form or it can be blended with other gasoline constituents.

Why ethanol is the favored substitute for petroleum?

Ethanol is a highly preferred alternative to traditional gasoline fuels because it is economical and environmental-friendly. It is produced from agricultural waste products that are rich in sugar and starch. Coming from the surplus agricultural waste, ethanol extraction does not interfere with food production. Moreover, ethanol-fueled vehicles are considered to be more eco-friendly as they emit less carbon dioxide. Even the ethanol-blended fuels such as E10 (10% ethanol and 90% gasoline) can lead to reduced emissions of greenhouse gases by up to 3.9%.

Derived primarily as a result of conversion of the sun's energy, ethanol is also a renewable source. Ethanol formation starts with photosynthesis, when crops, like sugar cane, corn etc, grow using sunlight. These feedstocks are then processed into ethanol. When it burns as fuel it emits water and carbon dioxide. This is used in the next cycle of ethanol production.

Other applications of Ethanol

Apart from being used as biofuel, ethanol is also used in the production of beverages. It is the principal component of alcoholic beverages like whiskey, rum, vodka. Ethanol also finds application in the making of paints, varnishes, perfumes, pharmaceuticals, industrial solvent etc.

Ethanol Production

Ethanol is obtained from crops or plants that have large amount of sugar or constituents that can be converted into sugar. Plants like sugarcane, sugar beets and molasses, corn, wheat, grains etc are ideal raw materials for ethanol production.Fermentation process is the most widely used method for producing ethanol. Synthetic ethanol is created from non-renewable sources like coal and gas.

Ethanol from molasses and other feedstock can be obtained by two methods- dry milling process and wet mill process. Approximately 90 percent of the grain ethanol comes from the dry milling process and the remaining 10 percent is produced from wet mills.

Dry Milling Processes includes the following processes:

● The crops or plants are grinded up for easier processing .

● The sugar present in the ground feedstock is dissolved

● Next the sugar is fermented with yeast to produce ethanol.

● The ethanol is then distilled and dehydrated to attain a higher concentration.

● Gasoline or other additive(denaturant) is then added to the product to make it suitable for further use.

Due to the growing popularity of ethanol applications, researches are being conducted to develop more advanced techniques for ethanol production.  So, in the days to come, we can look forward to more dynamic roles of ethanol.

Understanding Shell and Tube Heat Exchangers

Shell and tube heat exchangers are one of the most effective heat exchangers employed in various industries such as refineries and chemical industries. These process equipment are widely used in applications, which require cooling or heating a large volume of process fluids or gases. Shell and tube heat exchangers comprise a cylindrical shell with a large number of small tubes. The tubes are positioned into the cylinder using a tube bundle or "tube stack" which can either have fixed tube plates. The tubes are constructed using thermally conductive materials, which enable the exchange of heat between the hot fluids flowing outside the tubes and the coolant flowing through the tubes. These heat exchangers offer an optimal cooling solution in different fields such as Industrial, Hydraulic, Marine, Railways, etc.

Components of Shell & Tube Exchangers

The shell-and-tube heat exchanger is named for its two major components – round tubes & cylindrical shell. The shell cylinder can be fabricated from a rolled plate or from piping while the tubes are thin-walled tubing manufactured specifically to facilitate heat exchange.

● Tubes: The tubing may be seamless or welded. Tubing may consist of ‘Finns’ to provide more efficient heat transfer surface. Fins are commonly found on the outside of the tubes but are also available on the inside of the tubes. Tubes with a special surface, called high flux tubes, are used to enhance heat transfer on either or both sides of the tube wall.

● Tubesheets: Tubesheets are plates or forgings drilled to provide holes (triangular or square) for holding and inserting the tubes. Tubes are properly secured to the tube sheet to prevent the fluid on the shell side from mixing with the fluid on the tube side. The distance between the tube holes, measured from their centers, is called the tube pitch. Triangular pitch provides higher heat transfer and compactness while square pitch facilitates mechanical cleaning of the outside of the tubes.

● Baffles: Baffles are used for 3 reasons

○ To support the tubes

○ To maintain spacing between them

○ To direct the flow of fluid through the shell.

A segment, known as the baffle cut, is chipped in a way so as to permit the fluid to flow parallel to the tube axis as it flows from one baffle space to another.  The spacing between segmental baffles, called as the baffle pitch, along with the baffle cut, is used to determine the cross-flow velocity and hence the rate of heat transfer and the pressure drop.

● Tie Rods and Spacers - Tie rods and spacers are used to hold baffle assembly together & maintain the selected baffle spacing. The tie rods are secured at one end to the tube sheet and at the other end, holding the assembly together.

● Front Header: Also referred to as a stationary header, is the section from where the fluid enters the tube end of the exchanger.

● Rear Header: Is a section from where the fluid from the tube end leaves the exchanger or returns to the front header.

Working of Shell and tube heat exchanger

There are two fluids of different temperatures involved in the cooling operation, one - the process and the other - the cooling medium. The process fluid to be cooled is generally run through small diameter tubes that are housed within the shell. The outer shell, on the other hand, circulates the cooling medium. Both process and cooling fluid are kept in continuous circulation for the heat exchanger to function properly.

Applications of Shell and Tube Heat Exchangers

Shell and tube heat exchanger is used in various industrial applications due to their expertise in performing tasks such as:

● Cooling of hydraulic and lube oil

● Cooling of turbine, compressor, and engine

● Condensing process vapor or steam

● Evaporating process liquid or steam

Benefits of using Shell and tube exchangers

Shell & Tube Heat Exchangers are used in a number of industries such as refineries because of their advantages on other types of heat exchangers. Their benefits include

● Increased efficiency of heat transfer

● Easy to dismantle, clean and repair

● Compact in size

● Capacity can be increased simply by adding plates in pairs

● Affordable as compared to plate type coolers

● Can be used in systems with high operating temperatures and pressures

Praj industries - one of the leading Heat Exchanger Suppliers in the country, offers Critical Process Equipment & Systems to various process industries such as Oil & Gas, Refining, Petrochemicals, Fertilizers, Chemicals, Food, Pharma and Biotech. Praj also offers a range of static equipment like pressure vessels, reactors, shell and tube heat exchangers, distillation columns and other proprietary equipment as per the client design.