Bioenergy-bioproducts
Agenda

Fermentation
» Xylitol
Lignin
 Products from glycerin, class discussion
based on the article

 Evidence
of fermentation dates to 6,000 BC
» Egyptians brewed a beer-like substance
 Mid-1800s
Louis Pasteur
 Late 19th - ~1940  Alcohol Fuels
 WWI  Acetone for nitrocellulose
 WWII  Penicillin Production
 1970s Oil Embargo
 Brazil EtOH programs
 Today
 Everything’s from Fermentation

Food & Beverages
» Soy Sauce, Pickles
» Beer & Wine

Fuels
» Ethanol & Butanol
» Methane

Pharmaceuticals
» Insulin, HGH

Enzymes
» Cellulase, Rennet

Organic Acids
» Lactate, Formate, Succinate

Solvents
» Acetone


Vitamins
Amino Acids
 Fast-Growing
 Robust
 Minimal
Product Inhibition
 High Product Tolerance
 Easy to Manipulate
 Safe
 Degrade Lignocellulosic Material
 Ferment ALL Resulting Sugars
» High Rates and Yields
 Ethanol
» Saccharomyces cerevisiae
» Zymomonas mobilis
» Thermoanaerobacter BGL1L1
 Butanol
» Clostridium acetobutylicum
» Escherichia coli
» C. beijerinkii
 Lignocellulose
Digestion
» Clostridium thermocellum
Carbon Sources
Vitamins & Growth Factors
Glucose
Sucrose
Glycerol
Starch
Maltodextrin
Corn Sugar, Starch,
Cellulose, Sugarcane,
Sugar Beet Molasses
Antifoaming
agents
Esters, Fatty Acids,
Silicones, Sulphonates,
PEG
Buffers
Calcium Carbonate,
Phosphates
Lactose
Milk Whey
Growth
Factors
Thiamine, Biotin
Fats
Vegetable Oils
Nitrogen Sources
Inducers
IPTG, Pectin
Protein
Chelators
EDTA, Citric Acid
Antibiotics
Ampicillin, Kanamycin
Inhibitors
Rifamycin, Sodium
Barbital
Trace
Elements
Cu, Fe, Mn, Mo, Co
Ammonia
Nitrate
Soybean Meal,
Cornsteep Liquor,
Distillers’ Solubles
Pure Ammonia,
Ammonia Salts, Urea
Nitrate Salts
http://en.wikipedia.org/wiki/Industrial_fermentation
 Few steps
 Fast/short residence time
 Actual yield = theoretical yield
 High productivity
 Recoverable catalyst (the cells)
 Easily separable culture
 Simple
 Controls
» pH
» Temperature
» Agitation
» Headspace
Composition
» Pressure
» Volume
» Residence
Time
Bioethanol production and
chewing gum?
Problems


Baker’s cannot utilize five carbon sugars to produce
ethanol
Genetically modified microorganisms (E.coli KO11,
Z.mobilis, P.stipitis)
» have diverse nutrient requirements
» not as robust as baker’s yeast
» cannot tolerate/metabolize inhibitors generated during
pretreatment

For biomass to ethanol process to be economically
feasible it has to produce high value co-products
Inhibitors

5 groups of inhibitors
» Released during pretreatment and hydrolysis
– Acetic acid and extractives
» By-products of pretreatment and hydrolysis
– HMFs and furfurals, formic acid
» Lignin degradation products
– Aromatic compounds
» Fermentation products
– Ethanol, acetic acid, glycerol, lactic acid
» Metals released from equipment
Xylitol (1)

Sweetener
» as sweet as sucrose
» 40% less calories (suitable for diabetics, does not
use insulin to be metabolized)

Recommended for oral health
» teeth hardening
» antimicrobial properties (causes bacteria to lose the
ability to adhere to the tooth stunting the cavity
causing process)
Xylitol (2)


Feels and tastes exactly like sugar and leaves
no unpleasant aftertaste
Currently produced via chemical way
» acid hydrolysis
» hydrogenation and purification (expensive)

Uses:
» natural sweetener
» chewing gun
» tooth paste
Xylitol (3)
Imagine eating guilt xylitolsweetened brownies or knowing
that xylitol-sweetened chewing
gum is preventing cavities and
gum disease.
With xylitol, you can now have
your sweet tooth and treat it, too!
Pink yeast



Novel, naturally
occurring, robust yeast
from genus Rhodotorula
selected from poplar
trees
Tolerant of (and capable
of metabolizing) high
concentrations of
fermentation inhibitors
Rapidly and effectively
utilizes both hexose and
pentose sugars
PTD3
5-C & 6-C sugars
Ethanol
Xylitol
How do we do it? Fermentation
Synthetic sugars
or hydrolysate
Flasks
Sugar, ethanol, xylitol
analysis HPLC
Mixed synthetic sugars
Experimental
Yields:
Xylitol: 70%
Ethanol: 84%
6C
5C
EtOH
XOH
PTD3 in steam exploded hardwood
and softwood mixture
Experimental
Yields:
Xylitol: 68%
Ethanol: 100%
5C
EtOH
XOH
6C
Xylitol-conclusions

Yes, Pink yeast is able to efficiently utilize 5 and
6C to produce lots of ethanol and xylitol
»
»
»
»
»
Glucose 85% EOH
Galactose 86% EOH
Mannose 94% EOH
Xylose 64% XOH
Arabionse 29% XOH
Lignin
•
3-dimensional phenolic
polymer
•
Complex structure
•
Composes ~15-40% of
lignocellulosic biomass
•
2nd most abundant
natural polymer
Sakakibara
Lignin: current use
•
•
•
•
In Kraft pulping, lignin is
recovered in black liquor
50 million metric tons
produced annually
worldwide
~95% of this is incinerated
for thermal electrical energy
Burning generates an
average fuel value of 23.4
MJ/kg
Arboform
•
•
•
•
•
A lignin-based thermoplastic
Made from a mixture of lignin, plant fibers, and waxes
Developed by German company Tecnaro in 1998
Appearance and some physical properties similar to wood
Moldable like plastic
Arboform: chemical properties
•
Pelletized mixture of lignin,
fine fibers of wood, hemp or
flax, and wax
–
•
Liquifies at temperatures as
low as 170°C
–
–
–
•
•
Up to 50% lignin
Polypropylene: ~160°C
Polyethylene: 105-120°C
Polystyrene: ~240°C
Thermally stable up to 105°C
Can be injection molded
similar to conventional
plastic
Arboform: physical properties
•
•
Better molding capabilities
than plastic
Irregular fiber orientation
resists warping
–
•
•
Flooring & building material
Good acoustic properties
(speakers & musical
instruments)
Currently 300 metric tons
produced annually
Arboform: pros and cons

•
•
•
•
Advantages:
Completely
biodegradable

Disadvantages:
•
Some forms are not water
resistant
Can be burned after use
Not made from crude oil
At least as strong as
plastic
•
Requires removal of sulfur
Cost: $1.60/lb, compared
with less than $1/lb for
polypropylene
•
An alternative to plastic?
•
•
More than 100 million
metric tons of plastics
originating from crude oil
are produced annually
(worldwide)
The pacific trash vortex is
twice the size of Texas,
reaches 300 feet below sea
level, and 90% of it is
plastic
Lignosulfonates

Lignosulfonates is the name for a product containing
sulfonated lignin and other wood chemicals.
» Mainly from the acid sulfite process.
» A small amount from sulfonated kraft lignin.

Before becoming lignosulfonates (marketable product),
this material (spent sulfite liquor) is “cleaned up”.
» Pulping chemicals are removed.
» Sometimes non lignin compounds (sugars, etc) are removed
chemically, biologically, or through physical methods.
» Often the lignin is chemically modified.
» Product is concentrated to a molasses thickness product or
to a powder.
Lignosulfonates-uses

Dispersant
» Concrete, Dyes, Gypsum wallboard

Binder
» Road dust control, animal feed

Emulsifier (think an oil and vinegar salad dressing).
» Emulsions are finely dispersed drops of oil or wax in water.
» Lignin acts a s stabilizer in the emulsion.

Chelating agent
» Oil Well Drilling Fluids, Micronutrient Fertilizers

Raw material for chemical production
» Vanillin (softwood)
Concrete dispersant



Concrete is made up of 3
ingredients: cement, sand,
and aggregate.
Water is mixed in to make a
workable slurry and to
harden the concrete.
By using a dispersant like
lignosulfonates, less water
can be used to get the same
viscosity slurry. This makes
stronger concrete.
Image borrowed from JimRadfprd.com
Dye dispersant


Dyes used to dye cloth are water insoluble.
In order to dye cloth, dye particles are dispersed in
water. What this means are the dye particles are small
enough that they pretty much act like they are
dissolved. A dispersant keep them apart so they don’t
get big and sink. Sulfonated lignins do this very well.
After dying, the lignin is washed out.
Binding-dust control

Dusty roads are considered a
health hazard by the
government and thus dust
control is mandated

Dust can be controlled with
water, lignosulfonates or
calcium chloride.
Binding-dust control


Lignosulfonates cause
the particles to pack
closer together and also
to adhere.
This process forms a
dust “free” and also
more stable road.
Pellet binder

The natural stickiness of
lignosulfonates help
them function as a
pellet binder; it helps
hold the material
together.
Glycerin and products

Class discussion
Acknowledgements
“Bioenergy Lab” on Alcatraz
At the 31st Symposium on Biotechnology for Fuels and Chemicals