Hello all,
I am building a Bio Diesel production setup and was asking around for a controller for it.
The unit will need to be initialised by a manual bellpress which then tells the Arduino to check sensors, drives and general system health and when all checks out ok then proceed to pump waste oil "from our local fast food suppliers" into a processing hopper, inline prior to the hopper will be a centrifugal filter which will be controlled by the Arduino.
Once the oil has filled the hopper a float switch will tell Arduino to stop filling the hopper and proceed to heat the oil to a specific temperature.
Once this temperature is reached the oil will be sampled for ph and then the appropriate amount of caustic soda and methanol respectively will be added to the hopper over 5 mins, at the same time a temp sensor is maintaining the temp and a propeller is mixing the solution.
Once the solution has been mixed for 30 mins the solution is then left to sit at a maintained temp for 12 hours.
once 12 hours has expired the system opens a valve and releases the glycerine from the bottom of the hopper in to a holding tank and then aerates the methyl ester left in the hopper for a further 6 hours to remove any residual water.
once this has passed the fuel is then pumped into a holding tank ready to be gobbled up by my car.
If this is possible I would accept any help from anyone in regards to setting this system up so it doesn't burn my house down 
I could do this process with timers and contactors but I really want to get into programming as I am a pascal programmer and want to learn new things!
Thanks.
The Arduino could handle this just fine, the code would probably end up being pretty simple, however you would still need alot of other components to enable the Arduino to throw your bigger switches and receive inputs at appropriate voltage levels, etc. Nothing that hasn't been done before though, for example Arduino I/O pin (can handle around 40mA) -> Transistor (around 600mA depending on the type) -> Relay (can be your big switches to turn on heaters, etc.).
Keep us posted on your progress, I actually started designing/building a Biodiesel production system ages ago but it ended up getting shutdown mostly due to my Grandfather not being too keen on me cooking fuel in his barn ;D
Ha ha, thanks for the reply, I understand his concerns ;D
yeah the other "stuff" is what I am concerned about, I have a idea of how the programming would work and I don't doubt the abilities of the arduino, however I do doubt the abilities of other Stuff talking to the unit, this is going to take a bit of research I can tell, by the way a commercial unit that does the same thing is around $3k
Sounds rather cheap for a commercial unit... (I do reckon you'll save plenty of money doing it yourself.. nevermind the coolness factor and the satisfaction of doing it yourself)
I wish you the best of luck in beating 'the man' 
when I say commercial unit I mean that the unit is produced commercially to sell to customers, the unit is only small I think 20L batches at a time.
When you can produce diesel for $AUD0.25 a litre it makes sense to do it however I do not have 3 grand and also want to learn more logic so it will work well