Captura, transporte y almacenamiento de CO2
Tema 4. Captura de CO2 por precombustin Master en Ingeniera Ambiental, curso 2013-2014
Prof. Vicente J. Corts
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
Introduction: Precombustion Technology
CO23-15%
CO240%
CO2>95%
Adapted from EPRI 2007
Introduction: Precombustion Technology
CO23-15%
CO240%
CO2>95%
Adapted from EPRI 2007
Introduction: Precombustion Technology
CO2 Capture and H2 Production
Source: CO2CRC
Introduction: Precombustion Technology
CO2 Capture and H2 Production
Source: CO2CRC
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
Gasification: Basic reaction A partial oxidation process that can convert any hydrocarbon into hydrogen and carbon monoxide (synthesis gas or SYNGAS)
(CH)n + O2
For example:
H2 + CO
2 CH4 Methane
O2 Oxygen
4H2 Hydrogen
2 CO Carbon Monoxide
Process Conditions:
~ 950-1550 C, 25-70 bar
Gasification: Basic approach
Extreme Conditions: 950-1550 C 25-70 bar Corrosive slag and H2S gas Products (syngas) CO (Carbon Monoxide) H2 (Hydrogen) [CO/H2 ratio can be adjusted] By-products H2S (Hydrogen Sulfide) CO2 (Carbon Dioxide) Slag (Mineral matter from Coal) Dust
Gas Clean-Up Before Product Use
Gasification: Syngas uses
Both CO2-free electricity and H2 potentially available if capture is incorporated
Concept Partial oxidation process to produce syngas
Gasification agents Elemental Oxygen (Air) Elemental Oxygen (O2) Combined Oxygen (H2O) Oxygen/Water Mixtures Ideal gasification Carbon Inefficiencies Collateral Reactions Carbon Monoxide Partial CO2 Formation Incomplete Carbon Oxidation Pyrolisis Hydrogenation (C + 2 H2 = CH4) Water syngas (CO + H2) Poor syngas (CO + H2 + N2)
Coal gasification principles Severe thermo-chemical operating conditions
Chlorine Nitrogen H2O Carbon monoxide Hydrogen
Carbon dioxide
Mineral matter
Water
Ash
Ammonia Hydrogen Sulphide, H2S
Carbon Sulphur O2 REACTANTS Hydrogen
Hydrochloric Acid, HCl
PRODUCTS
Devolatilisation + Gasification COAL
HEAT 673 K CH4 + CO + CO2 + Oils + Tars + C (Char)
DEVOLATILISATION
PRIMARY REACTIONS SECONDARY REACTIONS
AIR/OXYGEN STEAM
COKE
+ 973 K MINERAL MATTER
CO H2 CO2 CH4
GASIFICATION
COMBUSTION GASIFICATION
Equilibrium compositions for carbon compounds-oxygen-water systems
KEY
P T
60 40
1 atm H/O=3
H2 CO
20 atm H/O=3
68 atm H/O=3 A 60.0 A 40.0
20 0 COMPOSITION, % VOL. COMPOSITION 60 40 20 0 60 40 A 33.3 20 0 1 atm H/O=1 20 atm H/O=1 68 atm H/O=1 A 66.7 1 atm H/O=2 20 atm H/O=2 68 atm H/O=2 A 50.0
H2O CH4 CO2 H2 CO
600
1200
1800
600
1200
1800
600
1200
1800
TEMPERATURE, C
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
Combustion vs Gasification
Gasification Zone
Complete Combustion
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
Gasifiers types and characteristics Gasifiers Moving bed Fluidized bed Entrained flow
Differentiating characteristics Reactants and products flow directions Size of coal feed Residence time for coal particles Operating temperature Operating pressure
The three technologies
C%
Residence P (bar) time
T (C)
Coal feed size
Oxidant demand
Ash conditions
Moving Bed
99
1-1/2 h
30
425-600
>10 mm
Low
Dry ash or slagging
Fluidized Bed
70
3/4 h
900-1050 0-10 mm
Moderate
Dry ash or agglomerating
Entrained Flow
88-98
seconds
12501600
<100m
High
Slagging
Technology Overview: Gasifiers
Moving Bed Gasifiers
Dry carbon fuel fed through the top Slowly drops through the vessel Reacts with steam and oxygen Flow in opposite in directions over the bed Fuel completely spent leaving behind low temperature syngas and dry ash Trace contaminants are later scrubbed from the syngas Lurgi
Source: EPRI
Technology Overview: Gasifiers
Fluidized Bed Gasifiers
Steam and oxygen flow upwards through the reactor tower Fuel injected into, and remains suspended in this stream Gasification takes place. Moderate temperature syngas exits Dry (unmelted) ash is evacuated at the bottom KBR, Southern
Source: EPRI
Technology Overview: Gasifiers
Entrained Flow Gasifiers Fuel fed dry or wet (mixed with water) Reactants (steam and oxygen) flow uni-directionally through the gasifier Stages of gasification take place High temperature syngas exits the reactor Molten slag drops out at the bottom GE, Siemens, Shell, ConocoPhillips
Source: EPRI
The five major commercial gasification technologies In order of decreasing installed capacity
Sasol-Lurgi: dry ash, non-slagging, moving bed
Developed by Lurgi, improved by Sasol. Extensive commercial experience in South-Africa
GE: slagging, entrained flow, slurry feed, single stage.
Developed by Texaco. Significant commercial experience
Shell : slagging, entrained flow, dry feed, single stage Siemens: slagging, entrained flow, dry feed, single stage ConocoPhillips E-Gas: slagging, entrained flow, slurry feed, two-stage. Developed by Dow Chemical
Proposed IGCC projects are focusing on entrained-flow, slagging gasifiers
GE Energy Radiant gasifier
The Shell gasifier
The ConocoPhillips E-Gas gasifier
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
IGCC
HRSG : Heat Recovery Steam Generator
IGCC Overview
Stack
Gasifier
HEAT RECOVERY STEAM TURBINE
40%
Fuel
Dedusting De H2S
GAS TURBINE
60%
O2
Bottom Ash Ash S
Air
Combined Cycle
ASU
N2 Air
IGCC simplified power balance
History of IGCC availability for the start-up of coal-based units
Excluding operation on back-up fuel
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
Large Scale IGCC Projects Coal IGCC in Operation
Project Site Buggenum Netherland O2-blown Dry-feed Shell Puertollano Spain O2-blown Dry-feed KruppUhde 2600 Wabash Rv USA O2-blown Slurry-feed E-Gas Tampa USA O2-blown Slurry-feed GE Nakoso* Japan Air-blown Dry-feed MHI
Gasifier Type
Coal Consumption (t/d) Output, MW
2000
2500
2500
1700
250
335
260
250
250
Demonstration test start
Jan 1994
Dec 1997
Oct 1995
Sep 1996
Sep 2010
* gasification with enriched-air
Large Scale IGCC Projects
Nuon- Buggenum, Netherlands 250 MW IGCC
Wabash 260 MW IGCC Repowering
Large Scale IGCC Projects
Tampa Electric Polk 250 MW IGCC
250MWe Air Blown IGCC (Fukushima, Japan)
Large Scale IGCC Projects
300 MWe ELCOGAS IGCC (Puertollano, Spain)
Coal Preparation
Gasifier ASU Turbines: GT&ST
Gas Depuration
IGCC vs Conventional Coal PS Clean-up of fuel prior to power generation Solid waste Less Volume: IGCC produce about half the solid wastes of conventional coal plants Better Form: IGCC solid wastes less likely to leach toxic metals than fly ash from conventional coal plants because IGCC ash melts and is vitrified (encased in a glass-like substance) Water Use Less Water: IGCC units use 20%-50% less water than conventional coal plants and can utilize dry cooling to minimize water use
IGCC vs Conventional Coal PS
Environmental Technology => Greatest potential for future Lowest NOX, SOX, particulate matter and lower hazardous air pollutants Hg and CO2 removal Sulfur and non-leachable slag by-products CO2 under pressure takes less energy to remove than from PC flue gas (Gas volume is <1% of flue gas from same MW size PC)
Proven polygeneration flexibility Power, hydrogen, steam, chemicals, zero-sulfur diesel
Key IGCC Market Barriers
Few units in operation just a few on coal Reluctance of customers to be early adopters, and assume technology application risk Unfamiliar and uncomfortable technology to power industry: chemical plant not combustion boiler Currently higher capital and operating costs relative to supercritical boilers Lower availability than other alternatives , 60-80% for 1st generation, 80 for 2nd generation IGCC is an emerging industry, vs. established boiler industry
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
IGCC with CO2 removal
General Overview of Pre-Combustion Technology
Source: VATTENFALL
General Overview of Pre-Combustion Technology
Source: VATTENFALL
General Overview of Pre-Combustion Technology
Source: VATTENFALL
General Overview of Pre-Combustion Technology
Source: VATTENFALL
General Overview of Pre-Combustion Technology
Source: VATTENFALL
Main equipment for Precombustion CO2 capture
CO conversion Sour-gas shift: sulphur-tolerant catalysts Clean-gas shift: high-temperature shift catalyst works in low sulphur conditions, low- temperature shift catalyst does not Hydrogen-fueled gas turbine NOX formation is an issue Mixtures (50/50 H2/N2) can be used CO2 separation Chemical solvents: lower partial CO2 pressures Regeneration by stripping Amines: MEA and MDEA Regeneration by flashing Cooling of solvent Rectisol (methanol), Selexol (glycol/ether)
Physical solvents: higher partial CO2 pressures
Water-Gas Shift Reactor System
IGCC performance results, GE gasifier
IGCC simplified power balance w/o capture, PRB coal
IGCC simplified power balance with capture, PRB coal
IGCC key points
IGCC HHV efficiency= 38 - 41% (Supercritical PC is 39.1%) IGCC with CO2 Capture Reduces efficiency by 6-9 percentage points IGCC efficiency with CO2 capture is 5-7 % higher than PC with CO2 capture 11-12 % lower than NGCC with CO2 capture R&D can increase competitiveness and reduce costs Reduced ASU cost (membranes) Warm gas cleaning for sulfur removal Improved gasifier performance Carbon conversion, throughput
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
Major Technology Issues
Membranes for H2/CO2 separation
High P
H2 + CO2
Membrane Entrainment flow Low P
CO2
H2
Porous membranes
Pd& Pd/Cu alloy dense membranes
Membrane shift reactor Equilibrium shift to CO2 formation at high T
CO + H2O
CO2 + H2
Gasification
DeH2S Coal
H2O Sulphur
H2 + CO
CO2
Air
O2
Membrane shift reactor
H2
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
CO2 avoidance costs for capture power plants
*Capture only
ZEP
LCOE for Hard Coal Plants w/CO2 Capture (capture-costs only)
ZEP
Presentation Outline Introduction Gasification Technology Overview Combustion versus Gasification Types of Gasifiers IGCC IGCC Overview Large Scale IGCC Projects IGCC with CO2 Capture General Overview Improvement opportunities Economics Experiences
Major IGCC + CCS Projects in Development Worldwide
http://sequestration.mit.edu/tools/projects/index_capture.html
