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Growing the World’s Fuels May, 2013
Converting algae derived Bio-crude into high quality Diesel
Neil Osterwalder, Dan Sajkowski, Ben Saydah
Overview
• Background
– Algae production
– Bio-crude production
• Bio-crude properties
• Process
• New Diesel properties
Sapphire Confidential 3
1st Step: Cultivation of Algae
Algae grow rapidly and continuously, all year
• Ponds are harvested daily and some of the biomass is
removed for processing
• The remaining algae quickly replicate and replace the
harvested portion
• The result is a consistent biomass density, set for
optimal growth
SAPPHIRE PROPRIETARY 4
2nd Step: Harvesting Sapphire uses a Dissolved Air Flotation (DAF) system to concentrate algae
Solution enters the DAF in
dilute concentration After the DAF, the algae is
concentrated 1. Cluster: chemicals are
applied which make the
algae stick together
2. Float: air bubbles float
algae to the surface
3. Skim: floating algae
harvested with a skimmer
DAF technology adapted for algae
SAPPHIRE PROPRIETARY 5
3rd Step: Bio-crude production
1. HTL Reaction: Algae slurry is
reacted at pressure and
Temperature
2. Extraction: solvents are used
to extract bio-crude
components
SAPPHIRE PROPRIETARY 6
Bio-crude
• 30 – 50 % free fatty acids
• Amides other nitrogen compounds
• Elemental analysis show: high Nitrogen content 4-5wt%
high Oxygen content 8 wt %
Sapphire Confidential 7
74%
11% 5%
1%
9%
Total C,H,N,S content
%C
%H
%N
%S
%Not ID
Nitrogen compounds in bio-crude
Sapphire Confidential 8
74%
11% 5%
1%
9%
Total C,H,N,S content
%C
%H
%N
%S
%Not ID
N-Aromatics
Nitriles, Amides
Amides and nitriles are easily hydrogenated compounds
Nitrogen composition
Upgrading of Bio-crude
• Blending of bio-crude with a refinery stream
• Catalyst selection
• Work-up for diesel range product
Sapphire Confidential 9
Bio-crude/Diesel
blend Hydrotreater Distillation Diesel
Feed composition
• Feed composition
– 86.6 wt% Red Diesel
– 13.2 wt% Bio-crude
• Nitrogen content 6’000 ppm
• Oxygen content 10’000 ppm
• Carbon content form bio-crude 9.7%
Sapphire Confidential 10
Bio-crude/Diesel
blend Hydrotreater Distillation Diesel
Oil before hydrotreating
Sapphire Confidential 11
Hydrotreating conditions
• 2000 SCF/Barrel H2
• 370 °C/698 °F reactor temperature
• 124 bar/1800 psi H2 pressure
• Albemarle Ni/Mo-Catalyst
Sapphire Confidential 12
Bio-crude/Diesel
blend Hydrotreater Distillation Diesel
Before and after
Sapphire Confidential 13
Oil after hydrotreating
Sapphire Confidential 14
Bio-crude/Diesel
blend Hydrotreater Distillation Diesel
Distilling Diesel fraction
63 wt% Diesel from Diesel/algae blend
Sapphire Confidential 15
Cold Trap
IBP -450 F
Diesel
650°F+
Cold Trap IBP -450 F Diesel 650°F+
0%
20%
40%
60%
80%
At least 86 % Carbon from algae in Diesel cut Nitrogen: less than 1 ppm Oxygen: not detected
Carbon 14 analysis: Pure Bio-crude contains 18% C14 Hydro treated Diesel cut 3% C14 (diluted 7.4 times)
Bio-crude/Diesel
blend Hydrotreater Distillation Diesel
After hydrotreating
Sapphire Confidential 16
What happens to free fatty acids and free acid amides?
Sapphire Confidential 17
C14-C18 increase
Sapphire Confidential 18
Arb
itra
riy
un
its
Red Diesel
Final Blend
13%
42%
100%
75%
186%
Diesel properties
• Diesel cut is all in spec except for conductivity and lubricity
• Key properties:
Sapphire Confidential 19
Red Diesel Hydrotreated Algae oil/Red Diesel
D93 Flash Point ° F 136 222
Flash Point °C 58 106
D976 Cetane Index 56.5 59.9
D2500 Cloud Point ° F 12.2 15.44
Could Point ° C -11 -9.2
Bio-crude/Diesel
blend Hydrotreater Distillation Diesel
Co-processing with existing refinery streams
• Issues with high Nitrogen/Oxygen content:
– Very exothermic reaction
– Water production
• Co-processing of bio-crude and diesel in a hydrotreater is an excellent way to upgrade bio-crude to high quality diesel
– Co-feed it in the refinery
Sapphire Confidential 20
Bio-crude feed
Summary
• Bio-crude can be co-processed with e.g. Diesel and close to 90 % of bio-derived carbon is in the Diesel fraction
• Ni/Mo catalyst showed great performance to hydrogenate nitrogen and oxygen to NH3 and H2O
• No coking issues with the catalyst
• Higher cetane number for Diesel product
• Bio-crude can be co-processed in a ULSD hydrotreater
Sapphire Confidential 21
Thanks
Sapphire Confidential 22
Questions
Sapphire Confidential 23