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PhD Thesis - Energy Systems Research Unit - University of Strathclyde

PhD Thesis - Energy Systems Research Unit - University of Strathclyde

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production and energy use pr<strong>of</strong>iles includes the time for one batch (hours), the<br />

maximum and minimum oil input per batch (litres), the alcohol and catalyst<br />

types and amount required at maximum load (litres and kg respectively), and the<br />

biodiesel and glycerine produced at maximum load (litres). Again, the methanol<br />

or ethanol requirement may also be made into a temporal pr<strong>of</strong>ile and taken<br />

through to the matching procedure as a demand. This process is also shown in<br />

Figure 6.6.<br />

The energy requirements for the batch process occur at different times<br />

throughout the process, and may include the following demands.<br />

• Heat to boil <strong>of</strong>f any water in the feedstock oil. This is given in kW for a<br />

specified number <strong>of</strong> minutes from the start <strong>of</strong> the process. This may be<br />

added to the heat demand or a 100% efficient electric heater may be<br />

used.<br />

• Electricity for mixing (kW) for a specified number <strong>of</strong> minutes from the<br />

end <strong>of</strong> the previous boiling process.<br />

• Electricity for biodiesel cleaning (for mixing or for bubbling air through<br />

to clean out any soap formed). This is given in kW for a specified<br />

number <strong>of</strong> minutes before the end <strong>of</strong> the batch.<br />

The number <strong>of</strong> minutes for these energy demands may only be specified in<br />

multiples <strong>of</strong> 30 minutes. These specified times are translated into the equivalent<br />

number <strong>of</strong> timesteps using<br />

Number <strong>of</strong> Timesteps = Time x Timesteps (6.25)<br />

60<br />

Where Time = Specified time (minutes)<br />

Timesteps = Number <strong>of</strong> timesteps per hour<br />

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