Pyrolytic Bio-fuels Produced from Forestryand Agricultural Feedstocks

By

Philip H. Steele

Forest Products DepartmentForest and Wildlife Research Center

Mississippi State University

Bio-oil production:– Bio-oil results from fast pyrolysis of cellulosic

biomass

– Particles are less than or equal to 2 mm

– Absence of oxygen

– Applied temperatures 400 to 550oC

– Rapid cooling

MSU pyrolysis Gen II pyrolysis reactor:

Raw bio-oil yield = 65% on dry wt basis. 1 dry tonbiomass = 1300 lbbio-oil and gives 130 gal/dt

What are bio-oils?– Bio-oils are water emulsive suspensions of the

thermally fractured biomass chemical structure. Each bio-oil typically contains more than 100 chemical compounds.

– Not an oil as it is

immiscible in petroleum

oils

An MSU objective is to license its pyrolysis reactor design:

• Revised auger design will allow an estimated 4-ton/day biomass throughput

• Our two industrial partners are underway with the new design for 10-ton/day reactors

Oxygen in bio-oil: 45-50% by weight– Incorporated in oxygenated compounds

Causes most of the negative properties:– Variable viscosity

– High acidity

– Pungent odor

– Low energy density (50% that of No. 2 fuel oil)

Bio-oil challenges:

Bio-oil chemical composition by group:Bio-oil chemical composition by group:

7

Wt% , Wt% ,

Water 20-30 Phenols 2-5

Lignin compounds 15-30 Furfurals 1-4

Aldehydes 10-20 Alcohols 2-5

Carboxylic acids 10-15 Ketones 1-5

Carbohydrates 5-10

Upgrading bio-oil :

– Hydrodeoxygenation (HDO)

– Lignocellulosic biodiesel (L-B)

Upgrading bio-oil by hydrodeoxygenation (HDO):

HydrogenOxygen

Water + HDO bio-oil

HDO bio-oil captures 72% of raw bio-oil energy value;it is a mix of hydrocarbons ranging from napthalene through diesel weights.

Water

Hydro-carbons

Packed bed reactor production of MSU HDO will begin next week:

Water % = 0Oxygen % = 0Acid value = 0.1HHV = 44.8

Diesel 30%Gasoline 35%Jet fuel 32%Other 3%

0

40

80

120

160

200

400 900 1400 1900 2400 2900 3400 3900

Wavenumber

% T

ran

sim

itta

nce

Raw bio-oil HDO bio-oil Diesel

AlkanesAromatics

FTIR spectrum; diesel vs raw and HDO bio-oils:FTIR spectrum; diesel vs raw and HDO bio-oils:

HDO bio-oil can be: blended with hydrocarbons; refined in current petroleum refineries:

Refined in petroleum refineries

Blended with petroleum hydrocarbons

5% HDO

SERC co-director, Glenn Steele, demostrating HDO bio-oil/gasoline blend informal engine test:

Esterified bio-oil is a mildly upgraded bio-oil to be utilized as a boiler fuel:

PropertyRaw

bio-oilEsterified

bio-oil

Acid value ( mg KOH/g) 89 46

Viscosity (cSt @ 40 oC) 14.53 7.37

HHV (MJ/kg) 17.5 23.8

Distributed bio-oil manufacture will reduce transportation costs:

Bio-oil upgrading

Disaster mobile

pyrolysis reactors

Industrially captive

pyrolysis reactors

Regional pyrolysis

center

Mobile pyrolysis reactors

Hydrocarbon Biofuels Produced via Pyrolysis of Pine Timber and

Harvest ResiduesBy

Philip H. SteeleSanjeev Gajjela

andFei Yu

Forest Products DepartmentForest and Wildlife Research Center

Mississippi State University