Production of Polysilicon using a Modified Siemens Process

Graph Analysis
The graphs show each system as a point of interest that can be considered more
thoroughly to determine an optimal setting. For the safety risk factor and the amount of energy
used, it is desirable to be closer to the origin for optimal placement of points. For the production
of polysilicon, it is ideal to be further away from the origin for optimal placement of points.
From the Production vs. Energy Used graph, there is a very distinct and clear trend. As
the amount of energy used increases, so does the amount of polysilicon produced. While the
graph appears to show a very distance and large difference in the amount of energy used in order
to produce more polysilicon, it can be seen that the difference in energy used between system 4
and system 2 is only 8% higher whereas the difference in production is a significant 27%
increase in production. With this, it is clear that from a very distinct trend associated between
energy consumed by the reactor and the production amount that a higher energy consumption
rate is ideal as the production quantity of polysilicon is increased at a much larger quantity.
Next, the safety risk vs production graph is considered. There is no clear trend between
the safety risk of the deposition reactor and the production quantity. In addition, a higher
production rate naturally increases the operating conditions of the deposition reactor resulting in
higher safety risk. In effort to minimize the safety risks of the process while maintaining as large
production as possible, systems 8 and system 2 are reasonable candidates for consideration.
Lastly, the safety risk vs energy graph is considered. Again, there is no clear trend
between the safety risk and the consumption of energy. There is also no direct connection
between an increase in energy consumption and safety risk. Due to many systems having
relatively low safety risks, the ones with the lowest energy use are system 8 and system 9.