Pyrolysis of Lignocellulosic Biomass from Appalachian

Region

Oluwatosin Oginni and Kaushlendra Singh

School of Natural Resources, West Virginia UniversityFPS 69th International Convention

Atlanta, Georgia, USAJune 10-12, 2015.

BACKGROUND

Energy Independence and Security Act (2007) gave a goal to increase the amount of renewable fuels used in the United States transportation sector from 2012 level of 15 billion gallons to 36 billion gallons by 2022.

Out of the 36 billion gallons of renewable fuel, the goal is to produce 21 billion gallons of advanced biofuels derived mainly from lignocellulosic feedstock. The lignocellulosic feedstock will be from forest resources and dedicated energy crops.

EIA (2014) estimated that U.S. gasoline and diesel fuel consumption for transportation resulted in the emission of 1522 million metric tons of CO2.

This total was equivalent to 83% of total CO2 emissions by the U.S. transportation sector and 28% of total U.S. energy-related CO2 emissions.

Source: www.proprofs.com; carlessinokc.blogspot.com

Why Biomass?

Carbon sources derived from photosynthesis Biomass is the only renewable carbon source that can be converted to transportation fuel Reduce negative environmental impacts of fossil fuel production and use Less dependence on foreign sources of energy Support rural economies

Motivation and Objective With the adverse environmental effect of fossil fuel, there is a reduction

in the use of coal for energy production.

Therefore, West Virginia been one of the largest coal producer in the country will be adversely affected.

However, West Virginia has about 12 million acres of forest lands which can be used for bioenergy production.

Also, intense effort has been made on production of dedicated energy crops on reclaimed mining lands in West Virginia.

Pyrolysis of these biomass feedstocks can be used to produce bio-oil as liquid transportation fuel and biochar which can be used for carbon sequestration and activated carbon production.

Therefore the objective of this work was to characterize the pyrolysis products of miscanthus and switchgrass grown on reclaimed mining lands in West Virginia.

METHODOLOGY Biomass samples (Switchgrass Kanlow, Switchgrass Bomaster,

Miscanthus Private and Miscanthus Public) were chopped into small sizes and oven dried at 103 0C for 24 hours.

Pyrolysis of the biomass samples were carried in a batch pyrolysis reactor at temperature of 500 0C for 30 minutes under constant flow of nitrogen.

Photograph and Schematic Diagram of the Batch Pyrolysis System

Carbon

Properties

Sulfur

Ash contentHydrogen

NitrogenVolatile matter

Fixed carbonOxygen

CHNS/O Analyzer

Proximate Analyzer

Proximate and Ultimate Analysis of Pyrolysis Products

Carbonmonoxide

Gas Composition

Methane

EthaneHydrogen

NitrogenCarbondioxide

EthyleneOxygen

Gas Chromatography

Brookfield Viscometer with

Water Bath

Heating values, carbon yield and energy conversion efficiency of bio-oil and biochar were estimated.

RESULTS

Percent Yield of Bio-oil, Biochar and Gas Heating Values of Biomass, Bio-oil and Biochar

Biochar Yield Biooil Yield Gas Yield0

10

20

30

40

50

60Miscanthus PublicMiscanthus PrivateSwitchgrass BomasterSwitchgrass Kanlow

Per

cen

t Y

ield

Biomass Bio-oil Biochar0

5

10

15

20

25

30

35 Miscanthus Public Miscanthus PrivateSwitchgrass Bomaster Switchgrass Kanlow

Hig

her

Hea

tin

g V

alu

e (M

J/k

g)

About 30% yield were obtained for biochar while bio-oil production was in the range of 45 - 51% and the gas given off was between 19 and 25%.

HHV for biochars was the highest (28-29MJ/kg) while the bio-oil was the range of 28-29 MJ/kg

Energy Conversion Ef-ficiency

Carbon Yield0

10

20

30

40

50

60

70

80 Miscanthus Public Miscanthus Private

Switchgrass Bomaster Switchgrass Kanlow

Per

cen

t Yie

ld

Energy Conversion Ef-ficiency

Carbon Yield0

10

20

30

40

50

60

70

80 Miscanthus Public Miscanthus PrivateSwitchgrass Bowmaster Switchgrass Kanlow

Per

cen

t Yie

ldCarbon Yield and Energy Conversion Efficiency of Biochar

Carbon Yield and Energy Conversion Efficiency of Bio-oil

Carbon yield and the energy conversion efficiency for bio-oil were higher than that of the biochar.

The carbon stored in the biochar also serves the purpose of carbon sequestration.

Volatile Content of Biomass and Biochar

Ash Content of Biomass and Biochar

The volatile content of the biomass samples were about 80% while the ash contents were between 1-2% (db)

The biochars had a low volatile contents and ash content of less than 10% The volatile content of the biomass samples were converted into bio-oil and gaseous products

Miscanthus Public

Miscanthus Private

Switchgrass Bomaster

Switchgrass Kanlow

0

10

20

30

40

50

60

70

80

Carbon Oxygen Hydrogen Nitrogen Sulfur

Per

cen

tage

Miscanthus Public

Miscanthus Private

Switchgrass Bomaster

Switchgrass Kanlow

0

10

20

30

40

50

60

70

80Carbon Oxygen Hydrogen Nitrogen Sulfur

Per

cen

tage

Elemental Composition of Biochar

Elemental Composition of Bio-oil

Elemental Composition of Biochar and Bio-oil

The high oxygen percentage in the bio-oil is the major basis for the physic-chemical drawbacks in the use of bio-oil.

The biochar samples had a high percentage of carbon (~ 80%) which makes it a good precursor for production of activated carbon.

H2 CO2 C2H4 C2H6 O2 N2 CH4 CO C2H20

10

20

30

40

50

60 200 0C

300 0C

400 0C

500 0C

Per

cen

t Gas

Yie

ld (

%)

H2 CO2 C2H4 C2H6 O2 N2 CH4 CO C2H20

10

20

30

40

50

60 200 0C

300 0C

400 0C

500 0C

Per

cen

t Gas

Yie

ld (

%)

Switchgrass Kanlow Switchgrass Bomaster

Chemical Composition of Gaseous Products

CO2, O2, N2 and CO were the predominant components of the gaseous products

Nitrogen has the highest percentage due to the fact that it was the gas used in keeping the pyrolysis reaction in inert condition.

Conclusion

The properties of the bio-oil were similar to those reported in literatures.

The carbon content of the biochars are significantly high and therefore can serve the purpose of carbon sequestration.

Alternatively, the properties of the biochars produced makes it a suitable raw material for production of activated carbons.

Acknowledgment

THANK YOU FOR YOUR TIME.