DUAL FLUIDIZED BED GASIFICATION FOR THE PRODUCTIONOF POWER AND RENEWABLE FUELS

Robert Cattolica, Reinhard Seiser, Hui Liu

Department of Mechanical and Aerospace EngineeringUniversity of California San Diego, La Jolla, CA 92093

Matt Summers and Chang-hsien Liao

West Biofuels, LLC, Woodland, CA 95776

November 22, 2017Australian Bioenergy 2017

Outline

• Biomass Energy in California - Renewable Energy Policy

• Waste Stream Biomass Resources in California

• Dual Fluidized Bed Gasification Technology

• Research and Development: Advanced Engineering Analysis, Power, Renewable Fuels Production

California Renewable Power Policy

Renewables Portfolio Standard - Senate Bill (SB) X1-2SB X1-2 requires that all California electricity retailers adopt the goals of 20 percent of retail sales from renewable energy sources by the end of 2013, 25 percent by the end of 2016, and 33 percent by the end of 2020, (SB350) 50 percent by 2030.

Assembly Bill (AB) 32 (“The Global Warming Solutions Act of 2006”)

AB 32 created a comprehensive program to reduce greenhouse gas (GHG) emissions in California. GHG reduction strategies include a reduction mandate of 1990 levels by 2020 and a cap-and-trade program. Executive Order (4/29/2015) 40 percent of 1990 levels by 2030 and 80 percent by 2050.

SB 1122: Bioenergy Feed-in Tariff

Requires that each of California’s three large investor owned utilities (PG&E, SCE, and SDG&E) must procure a share of the statute’s 250 MW. Auction System Implemented to raise Feed-in-Tariff

(1) For biogas from wastewater treatment, municipal organic waste diversion, food processing, andco-digestion, 110 megawatts. ($127.72/MWh)(II) For dairy and other agricultural bioenergy, 90 megawatts. ($197.72/MWh)

(III) For bioenergy using byproducts of sustainable forest management, 50 megawatts. ($199.72/MWh)

Power Generation in California (TWh)

Year Wind SolarSmall hydro

Geo-thermal

BiomassLarge hydro

Coal NuclearNatural

gasTotal

2002 3.5 0.9 4.4 13.9 7.1 26.9 27.6 34.4 90.9 209.7

2003 3.5 0.8 5.1 13.8 5.6 30.9 27.2 35.6 92.4 214.8

2004 4.3 0.7 4.7 14.0 5.9 29.7 28.6 30.2 105.0 223.1

2005 4.4 0.7 5.4 14.4 6.0 34.5 28.1 36.2 96.1 225.8

2006 4.9 0.6 5.8 13.5 5.7 43.1 17.6 32.0 107.0 230.1

2007 5.7 0.7 3.7 13.0 5.4 23.3 4.2 35.7 118.3 209.9

2008 5.7 0.7 3.7 12.9 5.7 21.0 4.0 32.5 122.2 208.5

2009 6.3 0.9 4.0 12.9 5.9 25.1 3.7 31.5 116.7 207.2

2010 6.2 0.9 5.0 12.7 5.8 29.3 3.4 32.2 109.8 205.4

2011 7.6 1.1 6.1 12.7 5.8 36.6 3.1 36.7 91.2 200.9

2012 9.2 1.8 4.3 12.7 6.0 23.2 1.6 18.5 121.7 199.1

2013 12.7 4.3 3.3 12.5 6.4 20.8 1.0 17.9 120.9 199.8

2014 13.1 10.6 2.7 12.2 6.8 13.7 1.0 17.0 122.0 199.2

2015 12.2 15.0 2.4 12.0 6.4 11.6 0.5 18.5 117.5 196.2

2016 13.5 19.8 4.6 11.6 5.9 24.2 0.3 18.9 98.8 198.2

2016 6.8% 10.0% 2.3% 5.8% 3.0% 12.3% 0.2% 9.6% 49.9%

2016 Renewables = 27.9%2020 Goal = 33%

Biomass Power Decreasing 800 MW(1993) - 660 MW (2016)

Waste Stream Biomass Resources in California

Gross annual biomass production in California and amounts estimated to be available for sustainable use .

Biomass

Category

Biomass

(1000 tons/year)

Energy in Resource

(trillion BTUs/year)

Power Production

(Megawatts)

CO2 Reduction

(million tons/yr)

Total 32,000 512 3200 26.5

Agricultural 8,000 128 800 6.63

Almond Biomass 1,000 16 100 0.828

Cotton Biomass 386 6.23 38 0.287

Forest Waste 14,000 224 1400 11.6

Sawmill Residue 1,000 16 100 0.828

California biomass resources, renewable energy content, potential power production and CO2 reduction.

Dual Fluidized Bed Gasification Technology(Thermochemical Conversion of Biomass)

Gasification - 70% of biomass (volatiles) converted to product gasin reformer.

.Combustion - 30% of biomass (char) burned with air to provide heat

for gasification, steam, and processing units.

Senden, Germany~16 MWfuel

Burgeis, Italy~2 MWfuel

Gussing, Austria~8 MWfuel

CHP CHPCHP

Gothenburg, Sweden~32 MWfuel

RNG

Woodland, CA~1 MWfuel

Ceramic bed material

•Dual Fluidized Bed Gasifier

•Fluidized bed material in Europe Olivine sand

•Fluidized bed material Woodland 400 micron dia. ceramic

•Indirectly heated, air-blown, ambient-pressure design.

•Low nitrogen producer-gas, acceptable tar levels.

•Cold-gas efficiency > 70%

Steam

Gasifier

Regenerator

(Combustor)

Woody Biomass

Air

Filter Scrubber

Gas Cleanup Fuel Synthesis

(Char) (Tar)

(Sulfur)

Filter

(Ash)

Exhaust

CHP…Combined Heat and Power, RNG…Renewable Natural Gas

Research

West Biofuels Gasification Pilot Plant

( 1MWth – 6 tons/day – 250kWe)

Woodland Biomass Research Center Woodland, CA

Gas Composition(mole percent)

(a) West Biofuels Gasifier (b) Güssing, Austria ,Gasifier

Hydrogen 40.23 35.0

Oxygen 0.18 0.1

Nitrogen 2.00 2.0

Methane 7.25 9.0

Carbon Monoxide 28.86 22.0

Carbon Dioxide 18.70 20.0

Ethylene 1.28 2.0

Ethane 0.18 0.5

Ammonia (ppm) 149 500

Comparison of the syngas composition form West Biofuels FICFB pilot plant and the GüssingAustria plant. (a) West Biofuels syngas composition (1MWth, 6 tons/day, 0.25MWe) (b) syngas from Güssing BCHP plant (8 MWth, 50 tons/day, 2 MWe).

Research and Development:

• Advanced Engineering Analysis - Chemical Process ModelingComputational Fluid Mechanics

• Power Production - Environmental Compliance - Emissions

• Renewable Fuels Production – example Mixed Alcohol

Advanced Engineering Analysis

Computational Particle Fluid Dynamics SimulationDual Fluidized Bed Gasification

“Barracuda” Code – CPFD Software, Albuquerque ,NMParticle in Cell (PIC) Method

Hui Liu, Robert J. Cattolica, Reinhard Seiser, Chang-hsien Liao, "Three-dimensional full-loop simulation of a dual fluidized-bed gasifier," Applied Energy, 160, 2015, 489-501.

Hui Liu, Robert J. Cattolica, Reinhard Seiser,” CFD studies on biomass gasification in a pilot-scale dual fluidized-bed system,” International Journal of Hydrogen Energy, 41, 2016, 11974-11989.

Hui Liu, Robert J. Cattolica, Reinhard Seiser, ”Operating Parameter Effects on the Solids Circulation Rate in the CFD Simulation of a Dual Fluidized-Bed Gasification System," Chemical Engineering Science, 169, 2017, 235-245.

Multiphase Particle-in-Cell Method(MP-PIC) simulation of pilot gasifierproblem setup

Multiphase Particle-in-Cell Method (MP-PIC) simulation of pilot gasifier

Temperature and particle volume fraction pilot DFB gasifier

Renewable Fuel Project:Mixed Alcohol Synthesis: Converting Producer Gas to Ethanol (Transportation) and associated chemicals.

California Energy Commission Project ($1M)

Partner Gas source Production Goal

UCSD bottled gas bench scale 0.3 liters/day

VTU (Bioenegy 2020+) gasifier slip stream lab scale 3 liters/day

West Biofuels bottled gas/gasifier pilot scale 30 liters/day

Albermarle MoS catalyst

UCSD bench scale system

A B D E C

Guessing

Composition

Woodland

Composition

Woodland recycle I (25% CO2) Woodland recycle II (30% CO2) Woodland Producer Gas

[vol%] [vol%] [vol%] [vol%] [vol%]

H2 42.31% 39.47% 37.00% 34.53% 33.10%

CO 26.10% 29.00% 27.19% 25.38% 28.02%

CO2 21.20% 20.00% 25.00% 30.00% 16.21%

CH4 8.19% 9.00% 8.44% 7.88% 9.56%

C2H4 1.98% 2.20% 2.06% 1.93% 1.56%

C2H6 0.21% 0.32% 0.30% 0.28% 0.18%

N2 10.69%

H2S 0.0158% 0.0150% 0.0141% 0.0131% 0.0000%

Sum 100.00% 100.00% 100.00% 100.00% 99.33%

H2/CO

ratio 1.62 1.36 1.36 1.36 1.18

Table 1. Synthesized gases (A,B,D,E) and producer gas (C) from Woodland Gasifier. The producer gas (C) contains other hydrocarbons (0.67vol%) that are not listed in the table.

The operational conditions studied to optimize catalyst performance:

• Space Velocity: Gas Hourly Space Velocity (GHGSV) defined as volumetric flow rate of the reactants divided by the catalyst bed volume at standard temperature and pressure.

• Temperature: operating temperature inside the synthesis reactor

• Gas Composition: Producer gas composition, particularly the syngas gas (H2, CO) content.

• Pressure: absolute operating pressure as experienced inside the synthesis reactor.

• Methanol recycle: reported as molar percentage of methanol in the feed stream. Corresponding recycle rates can be calculated with the known compositions of reactant mixture and tail gas.

Example Results: Mixed Alcohol Production as a Function of Reactor Temperature.

• California Government GHG policies are driving technology development.

• Significant Biomass Resources are available in California for renewable power and fuels.

• Advanced Gasification Technology is available.

• Production processes for power, fuels, and chemicals are available.

• Principal limitations are the higher cost of production relative to fossil fuels.

Summary and Conclusions