Biomass pyrolysis oil vs No.2 heating oil?

cowdog

In 2015, Brookhaven National Laboratory conducted research that proves biomass pyrolysis oil can replace No.2 heating oil, while reducing CO and NOx emissions.

Because No.2 heating oil is essentially diesel, No.2's price is linked with price of transportation diesel, which creates affordability problems when global oil prices are high.

There is a stable domestic supply for biomass, especially in rural areas without natural gas service. Biomass pyrolysis operations can be set up in small scale.

Can biomass pyrolysis oil compete with No.2 heating oil?

How to modify existing equipment for biomass oil?

My reading on this topic:
(1) biomass pyrolysis oil has 50% lower heating value than No.2, so the tank need to be filled twice as frequent.
(2) biomass pyrolysis oil has higher viscosity than No.2, especially when cold. It requires a higher pressure fuel pump.
(3) Biomass pyrolysis oil should be stored as cold as possible to slow down polymerization, but heated to 200-300"F just in time before combustion to reduce viscosity and improve atomization.

Steamhead

Not only would the tank need to be filled twice as often, but the firing rate of the burner would have to be doubled to get the same BTU input. Switching back and forth would not be practical, at least in residential applications.

cowdog

Steamhead said:

Not only would the tank need to be filled twice as often, but the firing rate of the burner would have to be doubled to get the same BTU input. Switching back and forth would not be practical, at least in residential applications.

You mean the amount of fuel injected. Yes, but it could also mean making the "on" cycle 2x longer. Most boilers/furnaces' BTU are constrained not by the burner but by the heat exchanger.

HVACNUT

What about the cost in electric to pre heat? Seems like one step forward, two steps back at this point. 

cowdog

HVACNUT said:

What about the cost in electric to pre heat? Seems like one step forward, two steps back at this point. 

Electric preheat is only necessary during start, after start the preheater can get heat from flame or flue.

Steamhead

cowdog said:

HVACNUT said:

What about the cost in electric to pre heat? Seems like one step forward, two steps back at this point. 

Electric preheat is only necessary during start, after start the preheater can get heat from flame or flue.

A standard oil burner would probably need some sort of preheater added. Beckett and Carlin both make preheaters that go on the nozzle lines but I don't know if they're up to this task.

Steamhead

cowdog said:

Steamhead said:

Not only would the tank need to be filled twice as often, but the firing rate of the burner would have to be doubled to get the same BTU input. Switching back and forth would not be practical, at least in residential applications.

You mean the amount of fuel injected. Yes, but it could also mean making the "on" cycle 2x longer. Most boilers/furnaces' BTU are constrained not by the burner but by the heat exchanger.

Nope. A BTU is a BTU, and if you're only burning half the BTUs, you won't get enough heat. Plus, the stack temperatures would be too low, which could cause condensation in the boiler and chimney.

cowdog

Steamhead said:

cowdog said:

Steamhead said:

Not only would the tank need to be filled twice as often, but the firing rate of the burner would have to be doubled to get the same BTU input. Switching back and forth would not be practical, at least in residential applications.

You mean the amount of fuel injected. Yes, but it could also mean making the "on" cycle 2x longer. Most boilers/furnaces' BTU are constrained not by the burner but by the heat exchanger.

Nope. A BTU is a BTU, and if you're only burning half the BTUs, you won't get enough heat. Plus, the stack temperatures would be too low, which could cause condensation in the boiler and chimney.

Condensation improves efficiency because you don't lose the latent heat of evaporation. Condensing boilers are very energy efficient. Just make sure the condensation are properly drained don't drip back to the stack.

Jamie Hall

@Steamhead is -- no surprise -- right. First place, a BTU is a BTU. To heat a certain structure -- or fire a certain process -- you need to provide a certain number of BTUs per hour. If a fuel has half the BTU content of another fuel, you are going to have to burn twice as much of it. Also, you can't double the "on" cycle as @cowdog suggests unless the burner is firing less than half the time to begin with. Which won't be the case anywhere near design temperature for a residence, or design load for a process. You can't get out of that one.

Physics has this nasty way of derailing dreams...

Now to condensation. First place, in many systems you won't condense -- again, anywhere near load -- unless the flame is badly undersized for the boiler. Second place, flue gas condensate is astonishingly corrosive stuff. Got a little problem there... and third place, if you are looking at a boiler at or near full load and you have adjusted the firing rate and pattern to suit, unless the return water is sufficient in quantity and cool enough, the condensation won't happen in the boiler -- it will happen in the stack. You really don't want that. See corrosion...

Preheating is a colossal bore. Yes, it can be done. But if you are planning to do it "on the fly" you have to cope with the high viscosity while feeding the oil from the tank to the preheater. In marine applications, this is done with big transfer pumps to a day tank, which latter is preheated.

Then... not mentioned, but let's consider just for a moment the overall energy efficiency of running natural gas for the pyrolysis process... really?

I could go on...

cowdog

Jamie Hall said:

@Steamhead is -- no surprise -- right. First place, a BTU is a BTU. To heat a certain structure -- or fire a certain process -- you need to provide a certain number of BTUs per hour. If a fuel has half the BTU content of another fuel, you are going to have to burn twice as much of it. Also, you can't double the "on" cycle as @cowdog suggests unless the burner is firing less than half the time to begin with. Which won't be the case anywhere near design temperature for a residence, or design load for a process. You can't get out of that one.

Physics has this nasty way of derailing dreams...

Now to condensation. First place, in many systems you won't condense -- again, anywhere near load -- unless the flame is badly undersized for the boiler. Second place, flue gas condensate is astonishingly corrosive stuff. Got a little problem there... and third place, if you are looking at a boiler at or near full load and you have adjusted the firing rate and pattern to suit, unless the return water is sufficient in quantity and cool enough, the condensation won't happen in the boiler -- it will happen in the stack. You really don't want that. See corrosion...

Preheating is a colossal bore. Yes, it can be done. But if you are planning to do it "on the fly" you have to cope with the high viscosity while feeding the oil from the tank to the preheater. In marine applications, this is done with big transfer pumps to a day tank, which latter is preheated.

Then... not mentioned, but let's consider just for a moment the overall energy efficiency of running natural gas for the pyrolysis process... really?

I could go on...

Well said, but the pyrolysis process does not have to burn natural gas, the pyrolysis gas is enough to sustain the reaction. If an area has natural gas, pyrolysis oil probably cannot compete with it.

EBEBRATT-Ed

I could see this in a large commercial or industrial burner. We used to burn #4 & #6 oil and preheat it all the time in the old days

On residential this would cause to many issues. Oil heaters carbon up and need frequent cleaning. The firing rate of small residential burners is to low, you would be constantly be plugging nozzles. with bits of carbon not so with large burners

300# oil pumps need more horsepower to drive them.

Maybe @retiredguy will agree.

And of course @Steamhead is right. you would have to fire the burnere at 2x the rate.

The flue gas would have to be tested in a lab stack temperatures and condensation would be an issue, not to mention the increased viscosity would be a problem in cold storage areas

HVACNUT

cowdog said:

Not only would the tank need to be filled twice as often, but the firing rate of the burner would have to be doubled to get the same BTU input. Switching back and forth would not be practical, at least in residential applications.

You mean the amount of fuel injected. Yes, but it could also mean making the "on" cycle 2x longer. Most boilers/furnaces' BTU are constrained not by the burner but by the heat exchanger.

Nope. A BTU is a BTU, and if you're only burning half the BTUs, you won't get enough heat. Plus, the stack temperatures would be too low, which could cause condensation in the boiler and chimney.

Condensation improves efficiency because you don't lose the latent heat of evaporation. Condensing boilers are very energy efficient. Just make sure the condensation are properly drained don't drip back to the stack.

Oil fired condensing boilers aren't very popular in the States. Where is the return on investment? I'm not seeing it.

cowdog

HVACNUT said:

Oil fired condensing boilers aren't very popular in the States. Where is the return on investment? I'm not seeing it.

Yes, gas fired condensing boilers are more popular, I am just saying condensation is good for efficiency, so as long as the water drips off the right tube it's not a problem.

Jamie Hall

I agree -- with your proviso in bold face. Condensing is good for efficiency -- a maximum increase of about 10% as a matter of fact -- provided the boiler is designed and built for it, including using the correct metals, and the rest of the system is running in such a way as to permit condensing. Otherwise, it's a catastrophe waiting to happen.