Download Slide 1

Biodiesel Production via Continuous Supercritical Catalytic Packed Bed Reactor
Oregon State University ◦ School of Chemical, Biological and Environmental Engineering
Team Members: Staci Van Norman, Mike Knapp, Malachi Bunn
Project Sponsors: Dr. Nick Wannenmacher, Dr. Brian Reed, Kevin Harris M.S., M.B.A.
Chevron, Beaver Biodiesel, Willamette Biodiesel, Encore Fuels, ONAMI, MBI
Gas Chromatography
Data Analysis
 Little or no modification to existing diesel
engines
 In the supercritical state the miscibility (how well
components mix) is greatly increased
 Reduced emissions such as (CO2, CO, etc.),
non-toxic and degrades 4 TIMES faster than
petrodiesel
 Water content in the oil does not effect the conversion
 Glycerol purity (> 96%) can be sold for cosmetic and
and has been shown to assist with the formation of
9
pharmaceutical
uses
esters. Additionally, glycerol is more soluble in water
which makes product separation easier9
 Gas Chromatography (GC)
with a Flame Ionization
Detector (FID), used to detect
electric current (Response) of
eluting compounds, for
determining sample
composition
2
 Oxygen content in biodiesel (BD) improves
combustion efficiency and also has a flash point
of 302°F (150°C) compared to petrodiesel of
147°F (64°C)
 Product quality is more consistent than batch methods
 Free fatty acids (FFA) are converted to esters
Project Objectives
Establish optimal operating conditions for different feedstock oils to obtain the highest
production at the lowest operating cost (low energy input and separation cost)
What is Biodiesel?
 Monoalkyl esters of long chain fatty acids derived from renewable lipid feedstocks3
 Produced from renewable vegetable oils, waste cooking oil, animal fat and non-edible oils
How is Biodiesel Produced?
4
 Two internal standards used
for mass determination
Camelina Oil Chromatogram Overlay
Response [mV]
 Reduces dependency on imported petroleum
Our Production Technology –
Continuous, Supercritical, Catalytic Packed Bed Transesterification
Why Biodiesel?1
 Certified standards used for
ethyl and methyl ester
calibrations
Determine feasibility of unrefined natural oil feedstocks obtained from national and
local suppliers
 Reaction of one large multi-ester molecule with
three alcohols to make three esters and one
glycerol4
Time [min]
Develop kinetic model of transesterification reaction under supercritical
heterogeneous catalytic continuous flow conditions
Operating Parameters
Molar Ester Percent
 Reactor temperature (290°C & 305°C)
Conduct economic comparison to classical batch processes
 Alcohol to oil molar ratio (20:1 & 30:1)
 Molar amount of esters present in product stream ignoring
unreacted feedstock alcohol - this excess alcohol is recycled back
into the alcohol feedstock storage tank
 Residence time within reactor based on standard
flow conditions (4, 6 & 8 minutes)
 Catalyst Material
 Homogeneous (i.e. liquid-liquid phase)
 Heterogeneous (i.e. solid-liquid phase)
Catalyst
Tin catalyst applied to 50-250 μm 304 stainless steel plasma powder (OSU Patented Technologies)
 Pressure of reactor (constant at 2500 psi)
Ester Percent of Reactor Products
Limitations of Current BD Technology
 Homogeneous catalysts require refined oils
 Reaction can take an hour or longer
 Free fatty acid content over 0.5 wt% and water bearing oils cause
soap and froth formation which reduces productivity and makes
separation of products difficult1
 Pretreatment required to prevent soap formation
before combining with liquid catalyst and alcohol
Domestic Biodiesel Production
305°C – 20:1
 4 minute
 6 minute
 8 minute
304 Stainless Powder
Treated 304 Stainless Powder
5
 Analysis completed on classical batch method using
soybean, methanol and base catalysts
$2.15/gal
Kinetic Model
 For a 60 million gallon production facility, when
considering only raw material, utility and fuels costs
from an economic analysis completed at Iowa State
University6
Canola
Feedstock Oils
Castor
 Food Grade Canola
Yellow Grease
 Need for a shift to more efficient, cost effective
reaction methods to meet increasing demand
 Commercial Yellow Grease
 Unrefined Jatropha
 Expeller Pressed (MT) Camelina
 Industrial Castor
 Expeller Pressed (OR) Soybean
Jatropha
Variability of Crude Oil Price
7
 As of June 8th, 2009 crude oil
was $68.7/bbl8
Additional Motivation
for Biofuels
 Decrease dependence on
petroleum based fuels
 Build local economies
Dollar/barrel ($/bbl)
 At the beginning of this project
(March 2009) crude oil was $45/bbl
Camelina
 Expeller Pressed (OR) Camelina
Soy Bean
Second Order Rate at 305˚C
Slope = 2k(1/Xe -1)CA0
Reaction rate kinetics change
from first to second order with
increasing reactor
temperature for canola oil
Soybean oil continues to be
first order with increasing
temperature
Economic Comparison
Experimental Setup
 Analysis completed on raw material costs for ethanol
and soybean oil including transportation costs
$68.7/bbl
 This estimation does not include capital costs which
would decrease with increasing production output
$0.98-$0.99/gal
Conclusions
Minimal variation in % molar ester content using different oils
No significant benefit to increasing temperature or reactant
ratio within the tested operating
conditions
 Reduce distribution costs
High Pressure
Pumps
References available upon request.
Reaction kinetics modeling of
canola and soy bean oil
conversion data
First Order Rate at 290˚C
Slope = k/Xe
Electrical & Control
Housing
Reactor & Preheater
Housing
Cooling Loop & Pressure
Regulation
Initial economic analysis comparison, to classical batch
production, demonstrates about
50% reduction in material
costs per gallon produced using
this technology
 High FFA content changes the reaction kinetics, making
overall ester production faster
 Technology is ready for pilot scale production, including
implementation of separation techniques