methanol recovery: basics, fine tuning, and energy balance issues

methanol recovery: basics, fine tuning, and energy balance issues

METHANOL RECOVERY:
BASICS, FINE TUNING,
AND ENERGY BALANCE
ISSUES
Dickinson College Biodiesel Shop
Carlisle, PA
What is methanol recovery?
Biodiesel and Glycerin contain surplus methanol
Methanol can be driven off via heating and
captured for reuse
May be done within biodiesel reactor or in standalone units
Uses same procedures as making a batch
Why do methanol recovery?
Removes toxic and flammable methanol from your
biodiesel and glycerin
Compliance with environmental laws
Simplifies safe handling of fuel and byproducts
Saves money and resources
How recovery works: methanol
distillation basics
Adding heat turns liquid
methanol into methanol vapor
(evaporation)
Using water condenser cools
vapors returning methanol to
liquid state (condensation)
Plumber’s Delight condenser
Booster condenser
Methanol recovery: how to do it
Methanol recovery: how to do it
Evaluating the purity of recovered
methanol
Biodiesel or Glycerin contains water in addition to
surplus methanol
Boiling point of water is 212oF (100oC)
During recovery, fuel raised to above 240oF
Water vapors can potentially mix with methanol
vapors
Dilutes methanol during condensing stage
How to test the purity of recovered
methanol
Running methanol recovery at the
Dickinson shop
Methanol recovery road blocks
Methanol recovery on glycerin
Pro: glycerin is 30% methanol and yielded more methanol
during recovery
Con: increased amount of methanol overwhelmed 4’
Plumber’s delight condenser and produced greater amounts
of wet methanol
Alternative methods
Booster condenser
Re-circulated cooling
Reflux column
Alternative methods: Booster Condenser
Alternative methods: re-circulated
cooling
Alternative methods: reflux column
Basic reflux column design
Item
Quantity
Price
Total Price
2" to 3/4" Reducing Coupling
2" x 30" Black Steel Threaded
Pipe
2
8.66
17.32
1
52.86
52.86
Copper Scouring Pad
5
3.99
19.95
3/4" x 3/4" x 1/2" Reducing Tee
1
4.45
4.45
3/4" Nipple
2
1.59
3.18
1/2" MPT Dial Type Temperature
Gauge & Well
1
17
Total
Cost:
17
114.76
Reflux column expectations
Increased methanol purity
Allow for successful methanol recovery with 5%
pre-wash
Reflux column performance:
methanol purity
Reflux column performance:
methanol quantity
Reflux column performance:
methanol content of glycerin
Samples pulled at 240oF, 250oF, and 260oF
Methanol Recovery Safety
Biodiesel
Contains 3-5% methanol
Escapes into wash water
Glycerol
Crude glycerol contains about 25% methanol
Classified as hazardous waste- toxic and ignitable
Excess glycerol in the shop is a health and fire hazard.
Plastic “cubies” of glycerol will leak with time
Avoid stockpiling: have a plan!
What is Energy
Work is a force applied over a distance.
W=FxD
Energy enables work.
Kinetic Energy
Thermal Energy
Potential Energy
Mechanical Energy
Electrical Energy
Watts, Joules, and BTUs
1 Joule / second = 1 Watt
3,600 Joules / Hour = 1 Watt
3,600 Joules = 1 Watt Hour
3,600,000 Joules = 1 Kilowatt Hour (kWh)
1055.056 Joules = 1 British Thermal Unit (BTU)
3412.14 BTUs = 1 kWh
150 Watts
4,893.25 Watts
0.150 Kilowatts
4.893 Kilowatts
511.821 BTUs
16,695.6 BTUs
2 hours = 0.300 kWh
2 hours = 9.79 kWh
Cost = 3 cents!
Cost = 99 cents!
Importance of a Balanced Shop
Fuel Efficiency
Input : Output
Research Opportunities
Cost Analysis
Electrical, Material, Labor
Shop Equipment
Item
VoltAmps
Wattage
Tuthill Pumper
667.00
246.79
1” Clear Water Pump
605.00
344.85
Reactor Heating
Component
4,500.00
4,500.00
Dry Tank Heating
Component
1,200.00
780.00
Bubbler
850.00
467.50
Material Input
Input
Cost
Embedded Energy
Gasoline
$4.00/Gallon
125,000 BTUs
Waste Vegetable Oil
Free (For now)
0 BTUs
New Methanol
$4.10/Gallon
68,433 BTUs
Recovered Methanol
Free
0 BTUs
Sodium Hydroxide (NaOH $2.43/Kilogram
11,247 BTUs
Potassium Hydroxide
(KOH)
458.1 BTUs
$8.44/Kilogram (not
bought in bulk)
Embedded Energy
Efficiency of Electric Energy Systems
Friction/Deformation Energy/Thermal Energy
Energy costs of making chemical components.
Methanol
Sodium Hydroxide
Potassium Hydroxide
Saving on Energy
Solar Energy
∆q = m • ∆t • cp
∆q: Change in energy
∆t: Change in temperature of the solution (°C or K)
m: The mass of the solution (kg)
Cp: Specific Heat Capacity (J/kg*K)
∆q = 2.424kg • 1.6°C • 3342.4J/kg*K
∆q = 12,963J = 12.29BTUs
Saving on Energy
Methanol Recovery
Recovered methanol contains no embedded energy
Production costs decrease for the next batch
Spread Sheet
Microsoft
Excel Worksheet
Back Up Plan!
Processing
Step
Device
VoltAmp
Pf of
Device
Average
Wattage
Time
(hours)
Kilowatt
hours
BTU per
kWh
(energy
used)
Total
energy
(BTU)
Pump Oil into
Storage
Tuthill
667.00
.37
246.79
0.08
0.02
11,383
224.74
(.001) x
time x
wattage
3x
BTU/kWh
BTU x
kWh
Pf x
VoltAmp
ELECTRICAL INPUTS
G.
Kilowa
tt
hours
(E X F
X
0.001)
J. BTU
per
kWh
(energ
y
used)
L. Total
energy
this step
(BTU):
(G x J)
D. Pf
of
Devic
e
E.
Average
Wattage
F. Time
(hours)
667.00
0.37
246.79
0.00
0.00
11,383.30
0.00
80.00
0.65
52.00
0.00
0.00
11,383.30
0.00
605.00
0.57
344.85
0.00
0.00
11,383.30
0.00
4,500.00
1.00
4,500.00
0.00
0.00
11,383.30
0.00
A. Process step
B. Device
C. VoltAmp
Pump Oil into Storage
Pump II
Preheat Oil in Storage
Solar Heating
Pump Oil into Appleseed Reactor
Pump I
Preheat Oil in Reactor
Reactor Heating
Component
Mix Oil while Heating
Pump I
605.00
0.57
344.85
0.00
0.00
11,383.30
0.00
Mix During Reaction
Pump 1
605.00
0.57
344.85
0.00
0.00
11,383.30
0.00
Pump Glycerin out of Appleseed
Reactor
Pump I
605.00
0.57
344.85
0.00
0.00
11,383.30
0.00
Heat Fuel during Methanol
Recovery
Reactor Heating
Component
4,500.00
1.00
4,500.00
0.00
0.00
11,383.30
0.00
Mix Fuel during Methanol Recovery
Pump I
605.00
0.57
344.85
0.00
0.00
11,383.30
0.00
Pump Fuel into Settleing Tank
Pump I
605.00
0.57
344.85
0.00
0.00
11,383.30
0.00
Pump Fuel into Wash Tank
Pump I
605.00
0.57
344.85
0.00
0.00
11,383.30
0.00
Pump Fuel into Dry Tank
Pump I
605.00
0.57
344.85
0.00
0.00
11,383.30
0.00
Bubble Dry
Bubbler
850.00
0.55
467.50
0.00
0.00
11,383.30
0.00
Heat Dry
Dry Tank Heating
Component
1,200.00
0.65
780.00
0.00
0.00
11,383.30
0.00
Mix Fuel while Drying
Pump I
605.00
0.57
344.85
0.00
0.00
11,383.30
0.00
Total Time:
0.00
Total kWh:
0.00
Total BTUs:
0.00
Output:Input Analysis
Material
Input
Electrical Input
Total Output
Output:Input Ratio
Cost
879,394.59
418,559.41
6,415,000.00
4.94
$1.99
#4
879,394.59
702,820.00
6,415,000.00
4.05
$2.10
#5
855,600.11
367,206.96
6,415,000.00
5.25
$2.11
#6
855,572.63
420,901.70
6,415,000.00
5.03
$2.15
#7
855,572.63
213,390.31
0.00
0.00
$219.62
#8
855,636.76
533,665.33
6,415,000.00
4.62
$2.10
#9
882,623.75
450,800.82
6,415,000.00
4.81
$1.94
#1
#2
#3
$2.07 per Gallon
Increase batch sizes
Differentiate between recovered methanol and new
methanol used in batched
Buy materials in bulk
Considerations for the Future
Better Record Keeping!
Embedded Energy of Recovered Methanol
Reflux Column for Methanol Recovery from Glycerin