Transcript APHarvey Moffit Symp 180907

More Efficient Biodiesel
Production
Adam Harvey
Process Intensification Group [PIG]
School of Chemical Engineering & Advanced Materials
Newcastle University
What is Biodiesel??
Methyl ester produced by reacting vegetable oils (triglycerides)
with methanol. This requires a basic catalyst (usually NaOH).
Triglyceride (vegetable oil)
HO
CH2
HO
CH
HO
CH2
Glycerol
COO
CH2
COO
CH
COO
CH2
+ 3 MeOH
Catalyst
+
COOCH3
Biodiesel
(FAME)
x3
Lower Viscosity
Cleaner Burning
Why should/will biodiesel be used?
1.
2.
3.
4.
5.
6.
7.
8.
9.
RENEWABLE
REDUCED LIFECYCLE CARBON DIOXIDE EMISSION
REDUCED POLLUTION:
1. Particulates!!
2. Carbon monoxide
3. Hydrocarbons
4. Sulphur compounds
Immediate effect: distribution network and engines
are already in place
As a use for waste oils
Security of supply
Increased lubricity: increases engine lifetime
Non-toxic
Biodegradable
Project 1: Design of Intensified
Biodiesel Plants
Based on an “intensified” continuous reactor, known as the
oscillatory flow reactor [OFR]
Commercial project: development of a portable biodiesel plant:
• Use in developing countries where supply of transport
fuels can be unreliable:
• Farmers producing their own transport fuel: an example
of “distributed production”
Demonstrator currently being fabricated.
Further development of OFR for biodiesel to start soon.
Intensified, Portable Biodiesel
Plant
Methanol
+ Catalyst
Vegetable
Oil
Portable Unit
REACTOR
SETTLER
DRY
POLISH
glycerol
Flash
Glycerol
Tank
BIODIESEL
TANK
Process Intensification:
The Oscillatory Flow Reactor
15 minutes < 2h
Niche Application of the OFR
Conversion of long residence time batch
processes to continuous processes
• length/diameter ratio much smaller than
equivalent conventional PFR
• plug flow RTD
• effective two phase mixing of liquids
Net flow
Initial
Dispersion
Injection point
Reaction’s Progress
along Reactor
Net Flow In
Net Flow
Out
Commercial Demonstration Plant
Project 2: Solid Catalysts for Biodiesel
1. Reduce capital costs of biodiesel plants
2. Reduced running costs
3. Reduced waste (soap)
4. Reduce glycerol purification costs
waste water,
soap
water
washing,
dry, polish
etc
Oil
Methanol
Catalyst
Reactor
Flash
biodiesel
Neutralisation
glycerol &
methanol
Current Process
Methanol
recycle
salt
glycerol
Biodiesel Process using Solid Catalyst
Oil
Methanol
biodiesel
Reactor
Flash
glycerol
Methanol
recycle
Separation of catalyst from
product via simple - filter
Solid Catalysts (requirements)






Robust (long lifetime)
Active (2h reaction time or less)
Inexpensive
Available in bulk quantities
Easy to manufacture
Stable
Solid Catalysts

Alkaline earth metal oxide substrates, doped with
alkali metals, e.g.:
– LiCaO
– LiMgO
– KCaO
– KMgO
Problem 1
i. Solubility of substrate
ii. Leaching of catalyst
Project 3: Biodiesel Directly from Seed:
“Combined Extraction and Reaction”
Alcohols + Catalyst
Oilseeds
solvent
extraction
+ reaction
• Would facilitate distributed production
• Successful demonstration for rapeseed
Biodiesel
Glycerol
Meal
Conventional Biodiesel Production
1. Farm
Oilseed
Growing
2. Oil Extraction
Meal
Oilseeds
Hexane
Solvent
Extraction
Crushing
Meal
Vegetable Oil
3. Conversion to Biodiesel
Biodiesel
Downstream
Processing
Glycerol
Reactor
Methanol
+ Catalyst
Distributed Biodiesel Production
1. Farm
Oilseed
Growing
Oilseed
Cracking
Methanol
+ Catalyst
Reactor
Downstream
Processing
Biodiesel
Meal
Glycerol
Reactive Extraction

Successfully produced biodiesel directly
from rapeseeds and jatropha nuts
Now optimising the process
 Downstream separation studies have
begun

Other Biodiesel Projects
1.
2.
3.
4.
Biodiesel from Algae: design of
photobioreactors and whole process
Triglyceride cracking to produce biodiesel
Biodiesel from jatropha (reactive
extraction using solid catalysts)
Study of cold flow properties
Acknowledgments
Dr Jonathan Lee, CEAM, Newcastle
 PhD Students
 Research exchange students
 Masters research students

What about the Glycerol?
~15% (volume) of the total output of a
biodiesel reaction is (impure) glycerol.
What should be done with it?
•
•
•
Cosmetics industry?
Energy?
“Renewable chemicals”:
Propylene glycol, methanol, lactic acid,
propane-1,3-diol, epichlorohydrin etc
“Glycerochemistry”
Why not burn the fats/oils directly?
1. Flow
2. Burning characteristics:
1. Trumpet Formation
2. Lacquer Formation
3. Pollution: acrolein formation (a.k.a. 2-propenal)
“Acrolein is such a severe pulmonary irritant and lacrimating agent that
it has been used as a chemical weapon during World War I.” &
“suspected human carcinogen.”