Jim Frederick

Table Mountain Consulting, LLC

TMC

• Utilize the whole tree

• Produce a variety of forest-derived products – Cellulose fiber

– Synthetic fuels and chemicals (e.g. methanol-to-gasoline, dimethyl DME, Fischer Tropsch diesel,…)

– Lignin-derived products

– Pharmaceuticals, neutraceuticals

– Electrical power

• Utilize forest materials for energy

• Plant economic optimization and market demand for products determine the optimal product mix

• Constraint: steam generated must meet mill steam demands

Kraft pulp mill

Methanol to Gasoline

FT Diesel

DME

Gasification – Biomass => CO, CO2, H2, H2O

– CO + H2 => liquid fuels and chemicals

Pyrolysis – Biomass => organic liquids,

gases, char

– Organic liquids are refined to liquid fuels and chemicals

Gasification – Biomass => CO, CO2, H2,

H2O – CO + H2 => liquid fuels

and chemicals

Pyrolysis – Biomass => organic

liquids, gases, char – Organic liquids are

refined to liquid fuels and chemicals

Choices

– Gasification/pyrolysis feedstock can be biomass OR black liquor (OR both)

– Products can be power OR both liquid fuels and power

– Fuel products can be chosen independently

– Ratio of fuel products to power is determined through process design and management of heat utilization

Constraints

– No change in pulp production rate and pulp quality

– Steam production must meet pulp mill requirements

Black liquor concentration

and combustion

Biomass boiler

Residual biomass

Pulping operations

Pulp

HP steam

From the EU BLGMF (Altener) report, Dec 2001

Import or export power

Fiber Power and steam

Pulp

HP steam

Export power

Liquid fuels

or chemicals

Steam turbine

Biomass boiler

Biomass fuel Pulping

operations

BL gasification and liquids synthesis

plant From the EU BLGMF (Altener) report, Dec 2001

Pulp

1. Produce dimethyl ether (DME) and power

a. Maximize DME from BLG syngas (DMEa)

i. Recycle unconverted syngas

ii. Burn wood residues and unconverted syngas to generate process steam and power

b. Increase power production (DMEb)

i. Recycle unconverted syngas

ii. Gasifiy wood residue to fire gas turbine for power

iii. HRSG downstream of gas turbine generates power and process steam

Based on Larson, Consonni, Katofsky, Iisa, Frederick, A Cost-Benefit Assessment of Gasification-Based Biorefining in the Kraft Pulp and Paper Industry v. 1-4, report to the USDOE and AF&PA, 2006.

1. Produce dimethyl ether (DME) and power

c. Single pass syngas for increased power (DMEc)

i. Single pass for syngas through DME synthesis reactor

ii. Burn wood residues and more unconverted syngas to generate process steam and power

iii. HRSG downstream of gas turbine generates power and process steam

2. Produce Fischer Tropsch diesel and power

a. Maximize DME from BLG syngas (FTa)

i. Syngas from black liquor gasification only

ii. Syngas once-through the FT synthesis reactor

iii. Power island includes a biomass gasifier, syngas cooler, and combined cycle power plant with process steam extraction

iv. Unconverted syngas is burned in power island

b. Maximize power generation (FTb)

i. Similar to FTa but with a larger biomass gasifier and gas turbine for more power generation

2. Produce Fischer Tropsch diesel and power

c. Maximize FT diesel production (FTc)

i. Syngas from both black liquor and biomass gasification

ii. Syngas once-through the FT synthesis reactor

iii. Power island burns only unconverted syngas; otherwise the same as in FTa and FTb ; combined cycle power plant with process steam extraction plus a condensing turbine to utilize excess steam

1. Gasification of both black liquor and biomass to produce syngas for biofuels

2. Power and steam generation using combined unconverted syngas plus syngas from gasified biomass plus heat recovered from exothermic syngas processing steps

Fuel synthesis option

Incremental biomass for fuel & energy, dry t/d

Net incremental biomass to mill, %

Syngas from biomass goes to:

DMEa 700 5.4% None produced

DMEb 1,326 24% Gas turbine

DMEc 678 4.8% Gas turbine

FTa 829 9.2% Gas turbine

FTb 2,246 51% Gas turbine

FTc 2,704 64% Synthesis

Based on 1725 ADt/d unbl. pulp production and 2458 t/d dry BL solids.

0

20

40

60

80

100

120

140

Stea

m, k

g/s

Liquid fuels processes

Additional steam from CHP plant

Net steam generated in fuel plant

Steam generated from recovery and power boilers

Pulp mill steam requirement

• Adequate biomass supply

• Separation and recovery of S and Na

– Temperature and pressure effects

– H2S recombined with green liquor => lime required

• Changes in equivalent capacity of some standard pulp mill operations?

• Configure the integrated plant for excellent heat utilization

• On pulping: none

• On brownstock washing: none

• On black liquor evaporation: none

• On recovery boiler throughput: gasification of all black liquor means no demand

for a recovery boiler

Sulfur separates from sodium during gasification (and pyrolysis)

• Recapture of H2S, followed by causticizing:

H2S + Na2CO3 => NaHS + NaHCO3

NaHCO3 + Ca(OH)2

=> NaOH + H2O + CaCO3

• Causticizing of conventional green liquor:

Na2CO3 + Ca(OH)2 => 2NaOH + CaCO3

2 CaO per 2 NaOH

1 CaO per 2 NaOH

Lime consumption and causticizer volume requirement and can be doubled when H2S has to be recaptured

55% release at 950oC, pressurized O2 (30 bar) gasificationa

15% release at 950oC, atmospheric pressure air gasificationa

100% release at 700oC, atmospheric pressure steam gasification

a Lindblom, M. An Overview of the Chemrec Process Concepts (2003).

Oxidant T, C P, bar % of S to H2S

Increase in lime and causticizer volume required

O2 950C 30 bar 55% 55%

Air 950C 1 bar 15% 15%

Steam 700C 1 bar 100% 100%

Biomass FT crude Power t/d t/d MWe (net)

a. burn biomass for 1,659 238 88 steam & power, OR

b. gasify biomass for 4,493 238 230 steam & power, OR

c. gasify biomass 5,374 783 78

for syngas

Based on Larson et al., 2006

Gasify black liquor for syngas AND:

Basis: 1327 ODt pulp/day and 212 MWth process steam produced

Impact (as % increase) Gasification

Biomass required to 225%

Evaporation load none

Rcovery boiler throughput -100%

Recaust operations 0% to +100%

Process steam generationa none

Power generation 100% – 170%

Biofuels production, % input LHV 18% - 42% a steam to pulp mill only

• Biomass:

– Much technology development under way

– Commercial pyrolysis technology is available

• Black liquor:

– no technologies under development

• Mass distribution (nominal, on an ash-free basis): – Pyrolysis gas: 15%

– Pyrolysis oil: 70%

– Pyrolysis char: 15%

• Energy retained in pyrolysis oil: 65-70%

• Integration issues: – Energy to drive pyrolyze

– Utilization of pyrolysis gas and char

Source: K Mäenpää, Metso, 2012

Gases: CO, CO2, H2, H2O(v), methane, other light hydrocarbons

Liquids: CxHyOz liquids from benzene to C20

+

Char: carbon and inorganic matter

60-65% crude oil yield

Biomass Crude pyrolysis oil

Hydrotreated oil

C, wt-% 51.9 33.7 25.2

H, wt-% 6.2 5.2 4.2

O, wt-% 41.8 31.2

Total 100.0 70.0 29.5

Energy content, MJ/kg biomass

19.6 17.5

Fuel value retained, % 58.2

• To Dr. Kristiina Iisa for her guidance on the pyrolysis section of this presentation