Abstract
Our project aims to use shrimp shells from kitchen waste as raw materials to efficiently manufacture a biofuel butyl butyrate via biosynthetic process. We engineered C. tyrobutyricum and E. coli to achieve this purpose. To use our product to produce the biofuel butyl butyrate, three steps are required: decomposing shrimp shells, co-culturing our engineered C. tyrobutyricum with the N elements as nutrients in decomposed shells together with our engineered E. coli, extracting and storing butyl butyrate. We designed a crushing and drying machine to efficiently decompose shrimp shells into dry powders and a storage tank to safely store the fuel.
1. Purpose of Hardware
1.1. Crushing and drying machine
Our hardware team designed a crushing and drying machine for cleaning and decomposing shrimp shells for this project. Grinders on the market have no drying effect, which can’t meet the needs of our criteria of raw material substrate. The design of this crushing and drying machine can improve the crushing efficiency of shrimp shells into dried powder suitable for the next step production needs. The dried shell powder can be used as raw material for our engineered bacteria to produce the biofuel butyl butyrate.
Figure 1：A wall breaker juicer (Hurom_juicer2, via Wikimedia Commons)
Figure 2: A grinder (Anna Frodesiak, via Wikimedia Commons)
1.2. Storage tank
We also designed storage tanks for butyl butyrate. Current storage tanks often have rectangular windows with limited viewing angle and do not have a sun visor. We designed a circular viewing window to expand the vision for observation and added a sun visor to effectively avoid deterioration of the liquid behind the window by direct sunlight. In addition, commonly used horizontal storage tanks occupy large space and many factories have limited warehouse. Our storage tanks have an angle adjustment design, so that they can be placed horizontally or vertically. Vertical position can be used when storage space is small.
Figure 3: Storage tanks (Fusion, via Wikimedia Commons)
2. Operation of Hardware
The basic operation mode of the crushing and drying machine:
The basic operation of the storage tank:
To use the storage tank, the user need to open the gate and add in the fuel and close the gate. The state of the fuel can be observed through the observation window. Regarding the buckle design of the storage tank, under normal circumstances, the central axis can allow the rotation of the bottle body, but due to the weight of a large amount of liquid, the storage tank is generally in a vertical static state, and when you want to switch to a fixed horizontal position , you need to turn the handle on the outermost side of the central axis to 90 degrees, and insert the central axis into the bottle body, then the handle can be fixed, and you can pull it out when you need to turn the handle.
3. Structure of Hardware
3.1. Crushing and drying machine
The crushing and drying machine is designed based on the structure of the wall breaker juicer and the in-line dry cleaning units of the integrated washing machine.
The model has a cylinder container, a drying net, two motors and two blades. There is a stirring stick above the spindle, the blades below are driven by the motor, and the net in the barrel is driven by the roulette wheel below, which is connected by the belt to another roulette wheel, driven by another motor alone. The rotation of the blades achieves the effect of crushing. The drying net can use the high rotating speed to centrifuge water.
Figure 4: Model of our crushing and drying machine
3.2. Storage tank
The storage tank is a modification of the traditional storage tanks for fuel. It is specially designed with a circular observation window to expand the view for the fuel stored. A better view for the fuel can give the user more information on the status of the fuel and make adjustment of the storage environment on time. Another new design is a sun visor added to the window to protect the liquid behind the window from direct sunlight. Hence, the fuel is safer from deterioration. The tank also has two rotatable stands on both sides to adjust the position of the tank. In addition to the conventional horizontal position of the tanks, our tanks can be placed vertically when storage space is limited. Buckles on the connection sites of the stands are designed to control the angle adjustment. The angle adjustment function also facilitates the infusion of liquid. The horizontal placement has better stability, while the vertical placement demands less space.
Figure 5: Model of our storage tank
4. Theory
4.1. Crushing and drying machine
Our crushing and drying machine are designed by combining the techniques of the drying function of the in-line dry cleaning units of the integrated washing machine and the crushing function of the wall breaker
The drying function of the in-line dry cleaning units is achieved by the following principle: the air is heated by the heater, heats the wet clothes, and is discharged with evaporated water out of the machine, forming a cycle. In this way, the dryer constantly discharges the moisture of the clothes to achieve the purpose of drying clothes. We used this principle in realizing the drying function of our machine.
For the crushing function, our model also has the same principle as a wall breaker, which uses the rotation of the blade to achieve the crushing effect.
4.2. Storage tank
We used the simplest and most effective form of storage tanks on the market, and added rotatable stands for angle adjustment and a circular observation window with a sun visor for larger viewing angle and better shielding of sunlight into the tank.
5. Limitation
5.1. Crushing and drying machine
If the shrimp shells are too hard, the blade can hit empty, and the motor can be easily burned out, the user needs to equip a spare motor.
5.2. Storage tank
The gas formed by the volatilization of the liquid stored in the storage tank might pollute the environment. (Chang, W.-L, 2010)
6. Biosafety
Butyl butyrate mildly irritates eyes and skin and is an environmental pollutant. If the operator improperly operates the storage tank gate, the volatilization of butyl butyrate will cause great harm to the environment. If the operator adjusts the angle improperly, butyric acid staring at the leakage and volatilizing will also cause great harm to the environment.
7. Future development
As a stand-alone product, our crushing and drying machine can realize the integration of crushing and drying, and improve the efficiency of experimental raw material extraction. If the amount of shrimp shells is large, the bearing capacity of the stirring stick, the blades and the motors may not be enough, modification of the structure and optimization of the materials for these parts might be necessary.
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