energy storage 2 - ebc symposium€¦ · energy storage 2.0 advantages of an open system and impact...

Energy storage 2.0

Advantages of an open system and impact

on the water balance of a brewhouse

DR. RUDOLF MICHEL & PETER STERK

EBC SYMPOSIUM:

„MODERN BREWHOUSE TECHNOLOGIES AND WORT PRODUCTION“

WROCLAW, 19 - 20 SEPTEMBER 2016

• Energy transfer from wort boiling to

wort heating of the following brew

Energy storage system – classic version

2 EBC SYMPOSIUM - WROCLAW, 19 - 20 SEPTEMBER 2016

• Energy transfer from wort boiling to wort heating of the following brew

• Balance between total evaporation and energy demand for wort heating required

• The classical energy storage system is a closed loop system (energy storage tank)

• Deviations in total evaporation rate result in

a) energy shortage for wort heating, or

b) energy surplus: energy storage tank is full or additional heat sink required for unloading

• Water balance can’t be influenced – is governed from dimensioning of wort cooler only



Energy in

kettle vapors

Energy demand for

wort heating

Energy losses

of system = +

• the ambient water temperature is too high during summer?

• there is a big seasonal fluctuation of the ambient water temperature?

• there is a need to reduce hot water surplus in the brewhouse?

• the raw material quality requires a low mashing-in temperature?

• an optimized wort boiling process is in place and a total evaporation of 2.5 % is sufficient to reach the

desired wort quality parameters?

• the different yeast strains are demanding an alternating pitching temperature?

• all optimization potentials of the classical energy storage system are already installed?

What to do, if …


Energy storage system 2.0


Energy storage system 2.0 – water management


• Open system with two water tanks

• Both tanks are filled with brewing water

• Dimensioning of the wort cooler to allow a hot water temperature of i.e. 94 °C at the outlet; the higher

temperature spread reduced the amount of hot water

• Cooling of the brewing water from i.e. 94 °C to i.e. 80 °C in wort heater and/or mash vessel

• Integration of mash vessel as additional heat sink

• Potential for water management by using a water mixing unit at the wort cooler or topping up ambient

water via vapor condenser

What is different:



Project example

Brewery close to the equator – no vapor condenser

9

• A brewhouse with a high temperature of ambient water produces generally a hot water surplus.

Example:

• 710 hl cold cast out wort – 14 °P – 2.5 % total evaporation – no vapor condenser

• Ambient water temperature: 30 °C

• Hot water temperature: 79 °C

• Mashing-in temperature: 46 °C

• Pitching temperature: 10 °C

Result “as is”:

• Energy consumption 7.03 / 8.13 kWh/hl (heating surface / boiler house)

• Ambient water consumption 1.53 hl/hl

• Hot water surplus 269 hl per brew

Initial situation


• Additional consumers of hot brewing water in other departments available.

Consumption partly parallel to hot water production in the brewhouse.

Initial situation:

Temperature difference of the wort: (98 °C – 10 °C) = 88 K

Temperature difference of brewing water: (79 °C – 3 °C) = 76 K

Wort-/Brewing water ratio: 88 * 3.95 * 0.97 / 76 * 4.18 = 1.061

After modification of wort cooler:

• Temperature difference of the wort: (98 °C – 10 °C) = 88 K

Temperature difference of brewing water: (94 °C – 3 °C) = 91 K

Wort-/Brewing water ratio: 88 * 3.95 * 0.97 / 91 * 4.18 = 0.886

• 2nd step: Cooling of the hot brewing water from i.e. 94 °C to i.e. 79 °C in the wort heater

Modification of wort cooler and new wort heater installed


Plant design without vapor condenser


Result


Initial situation:


• Spec. water consumption 1.53 hl/hl

• Brewing water-hot surplus 269 hl per brew

Energy and water consumption after modification:


• Spec. water consumption 1.34 hl/hl

• Brewing water-hot surplus 134 hl per brew

Conclusion: 50 % less hot water surplus

23 % less primary energy consumption at steam boiler

Project study

Brewery in Europe – with vapor condenser

Mix of bottom fermented and top fermented beer

14

Process parameter at the wort cooler


• Process parameter at the wort cooler:

Wort temperature IN 98 °C

Wort temperature OUT 22 °C (wheat beer)

Wort temperature OUT 9 °C (lager)

Ice Water IN 4 °C

Brewing water-hot OUT 82 °C

• Thermal efficiency of wort cooler 98 %

• Energy balance at wort cooler

𝑄 = 𝑚 𝑊𝐸𝑆 ∙ 𝑐𝑝𝑊𝐸𝑆 ∙ ∆𝜗𝑊𝐸𝑆 = 𝑚 𝑊ü ∙ 𝑐𝑝𝑊ü ∙ ∆𝜗𝑊ü ∙ η

• Water balance at wort cooler 𝑚 𝑊𝐸𝑆

𝑚 𝑊ü =

𝑐𝑝𝑊ü ∙ ∆𝜗𝑊ü

𝑐𝑝𝑊𝐸𝑆 ∙ ∆𝜗𝑊𝐸𝑆 ∙ η

Increased to 95.5 °C

Study Wheat beer (22 °C pitching temperature)


Classic

Energy storage system

Mashing

50 – 75 °C 2.131 kWh/hl

Wort heating

93 – 100 °C 0.846 kWh/hl

Evaporation

4.4 % 2.859 kWh/hl

TOTAL 5.837 kWh/hl

Brewing water-hot

surplus 60 hl p.b.

Water consumption 1.266 hl/hl

NEW:


Mashing

50 – 67 °C 1.449 kWh/hl

Mashing

67 – 75 °C 0.682 kWh/hl

Wort heating

93 – 100 °C 0.846 kWh/hl

Evaporation

4.4 % 2.859 kWh/hl

TOTAL 4.388 kWh/hl

Brewing water-hot

surplus 2 hl p.b.


Study Lager (9 °C pitching temperature)


Classic

Energy storage system

Mashing

52 – 77 °C 2.011 kWh/hl

Wort heating

93 – 100 °C 0.845 kWh/hl

Evaporation

4.4 % 2.862 kWh/hl

TOTAL 5.717 kWh/hl

Brewing water-hot

surplus 197 hl p.b.


NEW:


Mashing

52 – 70 °C 1.448 kWh/hl

Mashing

70 – 77 °C 0.563 kWh/hl

Wort heating

93 – 100 °C 0.845 kWh/hl

Evaporation

4.4 % 2.862 kWh/hl

TOTAL 4.269 kWh/hl

Brewing water-hot

surplus 30 hl p.b.


Project study

Brewery in Asia – with vapor condenser,

big seasonal fluctuation of ambient water temperature

18

Initial situation


100 % malt 40 % adjunct

Percentage of annual production 35 % 45 %

Mashing-in temperature 58 °C 44 °C

Pitching temperature 10.0 °C 10.5 °C

Wort cooling 2-stage 2-stage

Total evaporation 4.2 % 4.2 %

Ambient water temperature Winter Summer Average

10 °C 32 °C 27 °C

Example: classic energy storage system


All Malt Classic ESS

Winter

Classic ESS

Summer

Classic ESS

Average

Hot water temperature ex wort cooler 82 °C 82 °C 82 °C

Hot water temperature brewhouse 82 °C 82 °C 82 °C

Ambient water temperature 10 °C 32 °C 27 °C

Transfer temperature 2nd stage 15 °C 35 °C 31 °C

Load to refrigeration plant (glycol) 5 K 25 K 21 K

Ambient water consumption per brew 85,217 kg 98,059 kg 93,632 kg

Specific water consumption 1.380 hl/hl 1.588 hl/hl 1.516 hl/hl

Brewing water-hot surplus 6,373 kg 19,215 kg 14,788 kg

Brewing water-hot shortage -- -- --

Example: energy storage system 2.0


All Malt ESS 2.0

Winter

ESS 2.0

Summer

ESS 2.0

Average





Brewing water-hot surplus --- 1,265 kg ---

Brewing water-hot shortage -6,039 kg --- -1,407 kg

Energy surplus for mashing 1.065 kWh/hl 1.854 kWh/hl 1.634 kWh/hl

Mash heating from 58 to 72 °C 1.326 kWh/hl 1.326 kWh/hl 1.326 kWh/hl

Example: classic energy storage system


40 % adjunct brew Classic ESS

Winter

Classic ESS

Summer

Classic ESS

Average



Ambient water temperature 10 °C 32 °C 27 °C

Transfer temperature 2nd stage 15 °C 35 °C 31 °C

Load of refrigeration plant (glycol) 5 °C 25 °C 21 °C




Brewing water-hot shortage --- --- ---

Example: energy storage system 2.0


40 % adjunct brew ESS 2.0

Winter

ESS 2.0

Sommer

ESS 2.0

Average






Brewing water-hot shortage --- --- --

Energy surplus for mashing 1.883 kWh/hl 1.955 kWh/hl 1.936 kWh/hl

Heating of malt mash from 44 to 52 °C 0.444 kWh/hl 0.444 kWh/hl 0.444 kWh/hl

Heating of adjunct mash from 44 auf 70 °C 0.980 kWh/hl 0.980 kWh/hl 0.980 kWh/hl

Annual Saving potential


Brand Annual

capacity

Specific

saving Energy savings Energy cost

100 % malt 1,000,000 hl 1.326 kWh/hl 1,326,000 kWh 66,300 €

40 % adjunct 1,285,000 hl 1.936 kWh/hl 2,487,760 kWh 124,388 €

TOTAL 3,813,760 kWh 190,688 €

Assumption: Cost for thermal energy 0.05 €/kWh – Cost for water & waste water 4 €/m³

Brand Brews

per anno

Specific

saving Water savings Water cost

100 % malt 1,297 14,788 kg/Sud 19,177 m³ 76,709 €

40 % adjunct 1,666 15,686 kg/Sud 26,139 m³ 104,557 €

TOTAL 45,316 m³ 181,266 €

• There are different solutions for energy recovery concepts, each having its individual pros & cons.

• The following parameters influence the performance of the energy recovery system regarding its

economic benefit:

Mashing-in temperature

Mashing-in ratio

Mashing program (infusion/decoction)

Total evaporation and brand split

Temperature of ambient water including its seasonal fluctuation

Pitching temperature

Water balance in the brewhouse

Available consumer of brewing water-hot outside the brewhouse

Summary


• Copy & paste is not a suitable idea – all local temperature and process parameters have to be

considered carefully.

• Recipes of each brand and the brand split is required to evaluate the most economic solution.

Pros and Cons have to be worked out and CAPEX must be compared.

• The energy storage system 2.0 is an open system.

It provided an optimized thermal flexibility. The main advantage is the flexibility regarding the water

management in a brewhouse.

Individual solutions required


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