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Team:Alberta/HumanPractices/Bioreactor
From 2011.igem.org
Bioreactor Design
At the outset of our project, Team Alberta possessed a vision of communities having the ability to utilize our created fuel for various applications. To make this vision a reality, our team focused much of its efforts on the design of a bioreactor, a self-contained apparatus that would be able to carry out all the processes needed for our fuel’s production. Our bioreactor concept is based on a modular, compact, efficient and safe device, which allows individuals and communities to produce a supply of their own biodiesel using garden wastes, such as grass clippings, as the inputs for production.
The design process allows one to proceed from the abstract to the qualitative; by nature, it is greatly an iterative processes. As alluded to by Suh et al. (2005), at each step in the design process, new information is generated and it is necessary to evaluate the results in terms of the preceding step. Team Alberta applied these insights and carried out several phases of design that progressively allowed us to engineer a functional apparatus.
Process Flow Mapping
In the first stage of design, the processes that are required to be carried out with our bioreactor were determined. Through completing a process-flow map, we were able to determine the required order of various processes, their relation to one another, and the required inputs and resultant outputs of each. This allowed our team to visually see progression of the synthesis of our biodiesel.
We used this map to subsequently determine the components that would be required within our bioreactor to successfully carry out these necessary processes. Efficiency considerations were of most importance throughout this next stage of design. Where possible, we incorporated the reuse of reagents. Moreover, considerations of safe and environmental waste disposal were taken into account. The following is a representative diagram of our initial sketches of the required components of our bioreactor proceeded by descriptions of each part.
| Reactor Part | Description |
|---|---|
| Growth/ Reaction Chamber | This is an all in one chamber in which the N. Crassa is grown, and later reacted with Methanol and HCl to produce our biodesiel. |
| Air Inflow | Allows oxygen to be given to N. Crassa during growth |
| Medium Input | Allows the addition of growth substrates (waste biomass) |
| Drainer with Filter | Removes media from the N. Crassa before esterification. The filter does not have to be small because N. Crassa forms a mat that is easily seperated from liquid media |
| Methanolic HCl Input | Adds methanolic HCl for the esterification Reaction |
| Water Input | After the reaction is finished, adds water to help better separate the non-polar methyl ester product (our biodesiel) |
| Hexane Input | Adds Hexane to solubilise the biodiesel |
| Mixing arms | Mixes the water and hexane for more efficient extraction |
| Liquid-liquid separator | Separates the water layer from the hexane layer |
| Vapour-liquid separator | Vaporizes the hexane (which is recycled) and leaves the raw biodesiel (which can be incorporated as a mixture in conventional desiels, or used on it's own depending on chain length of the methyl ester) |
| Neutralizer/Condenser | Neutralizes the acidic water layer, and allows methanol to be distilled (which is then recycled) |
| Waste Sump | Cleans the water by getting rid of extra organic components from N. Crassa using bacteria (much like a sewage treatment plant) |
Product Design
Team Alberta is currently working with Lisa Brown, a Ph. D. student in the department of engineering, to assist us in transferring our design specifications into an industry-standard blueprint that can be used in the building of our bioreactor. Our team has also been in correspondence with several undergraduate engineering clubs at the University of Alberta, many of which have offered their assistance in building a prototype. Should we be given the opportunity to present our project at the iGEM World Finals at MIT in November, we hope to present a working model of our bioreactor.
To help illustrate what we envision our bioreactor to look like, we enlisted the help of design student, Skye Olsen-Cormack, who kindly was able to provide us with a sketch of how our finished product might appear.
