Team 3
iBrew
Consultant Brief
Alissa Jones
Lota Onwumelu
Nolan Worstell
The Team:
Lota Onwumelu
Nolan Worstell
Alissa Jones
Description of the customer:
Mr. Barry VanDyke of Harmony Brewery in East Grand Rapids contacted Professor
VanderLeest in May 2011, proposing an environmental initiative to compress the CO2 naturally
produced in fermentation and reuse it for other parts of the process, reducing the overall
carbon footprint of Harmony Brewery in a cost effective manner.
Project Description:
The primary goal of this project is design a system whereby CO2 released in the
fermentation tanks can be made available for the bottle sealing stage at the end of the brewing
process. However, there are more design constraints than those implied in simply capturing the
carbon dioxide and compressing it. The additional constraints are that the carbon dioxide is not
pure enough in its current form for use in the final bottling, the space in the building is limited,
and the amount of carbon dioxide that is produced varies with time during the fermentation
process.
The purity of carbon dioxide obtained from the fermentation tank poses a problem as it
may contain traces of impurities that will affect the overall flavor of the beer itself. We
therefore need to test and identify the impurities present with the carbon dioxide generated,
design a purification process to bring the carbon dioxide purity to food grade and compress the
gas to be usable in later stages. The purification process presents an additional challenge that is
specific to the chemical engineering concentration as it involves the possibility of complex
separations. This means that we will be required to use modeling programs, such as Super
Design Pro, and course content from both mass transport/separations and the various
thermodynamics processes.
Beyond the strictly chemical engineering aspects of the project, there are also spatial
aspects. These spatial aspects come to light in the form of space for the carbon dioxide
compression system itself. The current location of the brewery has a limited amount of space in
which to put the compression system. This affects the designs that can be implemented within
the building as the square footage of the brewery is set, with possible room for expansion only
available in the upward direction and any upward expansion would have to be offset by the
savings produced by the implementation of the compression system itself.
A final possible issue is that the carbon dioxide levels vary during the fermentation
process with little carbon dioxide being produced in the early and late parts of the process.
Various methods of retention will be considered to control the flow of carbon dioxide for the
batch process.
Objectives:
Purity and Compression:
1)
Capture and purify CO2 gas to food-grade purity
2)
Functional for at least the 3 regular brews of Harmony Brewing Company
3)
Fits in brewery
Requirements:
Purity/Compression:
1)
Food-grade purity = 99.90 % CO2, 0.09% including hydrocarbons or nitrogen
2)
Compression of purified CO2 to 750 psig at 72F
3)
Cost of operating < Cost of purchasing same amount of CO2
Major Hurdles:
● Accurately determining the concentrations of the off-gases from fermentation
● Meeting health standards
● Achieving compression without changing the fermentation vessel pressure
● Size constraints
● Designing a pilot purification system for analysis
Status:
1 Data collection
a Pitot tube for rate determination has been ordered.
b Collection bags for analytical testing have been obtained.
c Pipe material confirmed for attachment to off-gas hose.
2 Purification unit
a Need analysis of impurities to know which units would be most effective.
b Considering:
i activated carbon
ii membrane filter
iii a water stripper
1 prevents negative pressure on fermentation vessel caused by
compression unit
2 functions as an air lock, preventing oxygen from entering the
anaerobic vessel
3 Compression unit
a Pending on the flow rate measurement results.
b Location of compression unit before or after purification unit depending on
vapor properties.
c We would specify the unit and advise the ordering.