growing the world’s fuels - algae biomass...

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


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


Bio-crude

• 30 – 50 % free fatty acids

• Amides other nitrogen compounds

• Elemental analysis show: high Nitrogen content 4-5wt%

high Oxygen content 8 wt %


74%

11% 5%

1%

9%

Total C,H,N,S content

%C

%H

%N

%S

%Not ID

Nitrogen compounds in bio-crude


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


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%


Bio-crude/Diesel


Oil before hydrotreating


Hydrotreating conditions

• 2000 SCF/Barrel H2

• 370 °C/698 °F reactor temperature

• 124 bar/1800 psi H2 pressure

• Albemarle Ni/Mo-Catalyst


Bio-crude/Diesel


Before and after


Oil after hydrotreating


Bio-crude/Diesel


Distilling Diesel fraction

63 wt% Diesel from Diesel/algae blend


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


After hydrotreating


What happens to free fatty acids and free acid amides?


C14-C18 increase


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:


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


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


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


Thanks


Questions


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