FLUIDOS SUPERCRÍTICOS

Transcription

“Electrocatalytic conversion of CO2
into energy compounds”
-Sustainability and waste treatmentJesús García, Susana Tostón, Carlos Jiménez, Fabiola Martínez, Rafael Camarillo,
Isaac Asencio and Jesusa Rincón
Department of Chemical Engineering, University of Castilla-La Mancha
Faculty of Environmental Sciences and Biochemistry
Avda. Carlos III, s/n, 45071, Toledo, Spain
E-mail: [email protected]
Toledo, 22nd of November 2013
Energy and Environment Knowledge Week – E2KW 2013 -
INDEX OF CONTENTS
1. Introduction.
2. Objetive of this work.
3. Metodology.
4. Results.
5. Conclusions.
1. Introduction: Global warming, CO2...
The latest IPCC reports (3rd, 4th y 5th)
In recent decades
Awareness GHG
emissions (especially CO2)
Global warming
-CLIMATE CHANGE-
In the last 40 years, GHG
Technologies that avoid
emissions have been
these emissions
doubled (major
contributor: CO2, 75%)
Renewable
Use fossil fuels
(main source of energy)
Therefore:
Use
fossil fuels
GLOBAL WARMING
energy
Capture and Storage* of CO2
Recycling of CO2
(Complementary technology
to storage)
[CO2]
Earth
temperature
INTERNATIONAL ENERGY AGENCY
In this Century
Fossil fuels will remain the mainstay
of world energy production
1
1. Introduction: Technologies of CO2 recycling.
Objetive: CO2 conversion to fuels and chemicals consumption or can be used
as raw material in the chemical industry.
Main CATALYTIC METHODS
Chemical transformation of CO2
of CO2 conversion:
at ambient conditions requires a
high energy input
1) Photocatalytic reduction of CO2.
2) Electrocatalytic reduction of CO2.
CO2
CHEMICAL
REDUCTION OF CO2
POSSIBLE SOLUTION:
Fuels
Other products
Addressing
CO2 conversion reaction by
CATALYTIC METHODS
CO2
USE FUELS:
-Electricity production
-Industry, etc…
2
Photocatalytic reduction of CO2
Electrocatalytic reduction of CO2
- Involve the use of semiconductors (photocatalysts),
- Involve the use of electrocatalyst, substances that
substances that cause chemical reactions (redox) under
promote chemical reactions (redox) in the presence of
light.
electric power.
- By the time the conversions achieved aren’t very high.
- The conversions achieved are higher than those
obtained in the photocatalytic process.
PhotoElectroCatalytic reduction of CO2
Scheme of a PEC reactor for reducing CO 2 using sunlight
PHOTO-catalysts
sunlight
MAIN LIMITATION: low solubility of CO2 in water
when using aqueous solutions of CO2.
ELECTRO-catalyst
SOLUTIONS:
1) increasing the pressure and the CO2 concentration
in the system, but limit the effectiveness of the process.
2) performing the Photocatalytic or Electrocatalytic
conversion of CO2 in gas phase.
3) PhotoElectroCatalytic conversion of CO2 in gas phase
(alternative and complementary procedure).
RESEARCH
Adapted from (Centi et al., 2007)
3
2. Objetive.
The objective of this work is to develop an
electrocatalytic system that allows, through the use of
electrocatalysts, the conversion of CO2 in gas phase to
hydrocarbons (liquid fuels easy to store and transport)
using electrical current to activate them.
4
3. Metodology.
Connections and operation of
TO ACHIEVE THIS OBJETIVE…
the electrochemical cell
It has been carried out the assembly and
tuning
up
electrochemical
hydrocarbons
of
an
installation
reduction
through
the
of
use
Electrical connection
(WE)
for
CO2
to
of
an
electrochemical cell.
Thermocouple
CO2 +
REACTION
PRODUCTS
OUTLET
H2O
OUTLET
CO2
Heater
cartridge
Electrochemical cell used
Electrical connection
(RE+CE)
INLET
Main component of this cell
H2O
INLET
Membrane Electrode Assembly
(MEA)
ANODIC ZONE
Electrooxidation of
H2O for generate
H+ and e-
CATHODIC ZONE
Electroreduction
of
CO2 to hydrocarbons
using H+ and egenerated
in
the
electrooxidation
5
3. Metodology.
Flow diagrams of the experimental installation of electrocatalysis
(continuous operation)
POTENCIOSTAT-GALVANOSTAT
to GC-FID-TCD
WE
CE + RE
CO2 +
REACTION
PRODUCTS
OUTLET
Heater
TANK - aquous
solution of KHCO3 -
CO2
FLOWMETER
cartridge
Thermocouple ELECTROCHEMICAL
CELL
TEMPERATURE
CONTROLLER
HUMIDIFIER
PUMP - aquous
solution of KHCO3 CO2 BOTTLE
6
3. Metodology.
Configuration to channel reaction products leaving the cell and to analyze them
by gas chromatography
Solids
filter
CO2 +
Gaseous products released from decane
REACTION
are injected in GC
PRODUCTS
OUTLET
Heater cord temperature
(130 - 140 °C)
in
Liquid products trapped in decane
are preconcentrated and injected in GC
GC-FID-TCD
decane
Cooling bath
(-5 °C)
7
4. Results.
“Configuration to channel reaction products leaving the cell“
with GC-FID-TCD
1) Reaction products trapped
2) Gaseous products released
in liquid absorbent (decane)
from the liquid absorbent
Identification
Identification
(* pA: picoamps; μV: microvolts; min: minutes)
8
4. Results.
Conditions experiment 12:
-CO2 flow= 250cm3 min-1
-KHCO3 concentration= 0.025 mol/l
-Current intensity= 0.54 A (Galvanostatic mode)
-Cell temperature= 60 °C
-Cell pressure= 1 atm
1) Reaction products trapped in
decane
Preconcentrated and injected
in GC-FID-TCD
Comments:
- Methanol and acetone have been identified.
- The peak whose retention time is 26.3 min.
can be isopropanol or methyl acetate.
It’s necessary to study new temperature ramps.
- There are peaks without identification.
It’s necessary to inject other patterns.
(* pA: picoamps; min: minutes)
9
4. Results.
2) Gaseous products released from
liquid absorbent (decane)
(* pA: picoamps; min: minutes)
- Carbon monoxide (CO) has been identified.
Injected in GC-FID-TCD
(* μV: microvolts; min: minutes)
- Hydrogen (H2) has been identified.
- In the 5 minute there are a peak without identification.
It’s necessary to inject other patterns.
10
5. Conclusions.
Through the use of an electrochemical cell similar to PEM fuel cells is possible to
obtain fuel products from CO2 reduction.
The configuration to channel reaction products which consisted in the absorption
of the reactions products in a cold trap, with decane as absorbing liquid, and their
preconcentration and subsequent injection into GC-FID-TCD has allowed to
identify compounds liquid fuels such as methanol and acetone, and gaseous
compounds such as carbon monoxide and hydrogen.
Upcoming work includes:
Identification and quantification of all products attained.
Deposition of metals on carbon nanotubes in supercritical media to create
advanced electrocatalysts.
11
Thanks for your attention!
“Electrocatalytic conversion of CO2
into energy compounds”
Presented by:
Jesús García García
E-mail: [email protected]
Toledo, 22nd of November 2013
1. Introduction: Technologies of CO2 capture and storage.
Objetivo: evitar que las emisiones antropogénicas de CO2 alcancen la atmósfera.
Captura
Almacenamiento
Transporte
Absorción en disoluciones
En formaciones geológicas:
Implica: gasto adicional de
no acuosas de aminas.
- Minas subterráneas.
energía
- Sumideros terrestres
de CO2.
Contracorriente: flujo de
(depósitos agotados de
gas cargado de CO2 y la
carbón, petróleo,…).
disolución no acuosa de
- Océanos.
aminas.
Emisiones
PROBLEMÁTICA CCS:
- Necesario acondicionar los
lugares de almacenamiento
definitivo
- ¿Seguridad a largo plazo?
Actualmente
Reciclaje de CO2
(Tecnologías complementarias a
la de almacenamiento)
1) Grandes cantidades de CO2
puro y a bajo coste.
2) Numerosas emisiones para
las que no es apropiada la
A FAVOR de estas tecnologías:
captura y almacenamiento
(distancia,…).
3) Buena imagen de la
empresa por adoptar política
de reducción de emisiones.
1) Gasto adicional de energía
Emisiones
de CO2
EN CONTRA de estas tecnologías:
Solución: el aporte adicional de energía a de
proceder de una fuente renovable, como es la
solar.
3. Metodology.
Celda
electroquímica
Se ha llevado a cabo el montaje y puesta a
punto de una instalación de reducción
electroquímica de CO2 a hidrocarburos
mediante
el
empleo
de
una
celda
electroquímica.
Montaje final de la celda electroquímica
PLACA
COLECTORA
PLACA DEL
ÁNODO
JUNTA
AISLANTE
SOPORTES CARBONOSOS
PARA LOS ELECTRODOS
PLACA
COLECTORA
Componentes
principales de la
celda electroquímica
*
PLACA DEL
CÁTODO
Proceso preparación EME:
MEMBRANA
PROTÓNICA
JUNTA
AISLANTE
JUNTA
SELLANTE
PLACA
BIPOLAR DEL
ÁNODO
EME
*
JUNTA
SELLANTE
1)
Preparar electrodos.
2)
Ensamblar electrodomembrana-electrodo.
3)
Montaje en celda.
PLACA
BIPOLAR DEL
Adaptado de (Linares, 2009)
CÁTODO
3. Metodology.
Disposición de las conexiones eléctricas en la celda electroquímica
Conexiones y funcionamiento
de la celda electroquímica
Conexión eléctrica
(WE)
Conexión eléctrica
(RE+CE)
1
WE en cátodo
CE-RE en ánodo
2
y viceversa
Termopar
CE-RE
WE
WE en cátodo
CE en ánodo
RE en cable (EME)
CE
RE
WE
SALIDA CO2
+
PRODUCTOS
REACCIÓN
SALIDA
H2O
Cartucho
calefactor
ENTRADA
CO2
ENTRADA
H2O
COMPARTIMENTO
ANÓDICO
Electrooxidación
de H2O para
generar H+ y e-
COMPARTIMENTO
CATÓDICO
Electrorredución de
CO2 a hidrocarburos
empleando los H+ y egenerados en la
electrooxidación
COMPARTIMENTO
ANÓDICO
COMPARTIMENTO
CATÓDICO
Permite controlar el voltaje
de la celda
COMPARTIMENTO
ANÓDICO
COMPARTIMENTO
CATÓDICO
EME
- Permite controlar el voltaje catódico
– Descartada problemas RE-cable EME
3. Metodology.
Flow diagrams experimental installation of electrocatalysis
(continuous operation)
POTENCIOSTAT-GALVANOSTAT
WE
CE + RE
CO2 +
REACTION
PRODUCTS
OUTLET
Cartridge
TANK - aquous
solution of KHCO3 -
CO2
FLOWMETER
heater
Thermocouple ELECTROCHEMICAL
CELL
TEMPERATURE
CONTROLLER
HUMIDIFIER
PUMP - aquous
solution of KHCO3 CO2 BOTTLE
6
3. Metodology.
Configurations for canalize reaction products leaving the cell, and so be able to
perform the same analysis by gas chromatography
7
4. Results.
“Experimentos para el estudio
Método
Voltametría Cíclica Potenciostática
del comportamiento electroquímico
(VCP)
de los electrodos”
Configuración 1
“Experimentos
seleccionar
adecuada
producto”
con
la
para
el
objeto
metodología
de
más
Configuración 2
analizar la corriente
Configuración 3
9
4. Results.
ESTUDIO DEL COMPORTAMIENTO ELECTROQUÍMICO DE LOS
ELECTRODOS
VCP entre +4V y -4V
Voltaje negativo (catódico): picos de reducción.
Voltaje positivo (anódico): picos de oxidación.
4. Results.
“ESTUDIO DEL COMPORTAMIENTO
ELECTROQUÍMICO DE LOS ELECTRODOS”
Conclusiones:
Condiciones experimento 2:
VCP: determinar
barrido de
voltaje para
1) La aplicación del método VCP a una celda electroquímica permite
la existencia
de
-Flujo CO2= 432cm3 min-1
analizar los cambios en la
reacciones redox.
WE en cátodo
-Concentración KHCO3= 0,5 mol/l
-VCP= entre -0,4 V y 0 V
CE en ánodo
intensidad de corriente como
-Tª en celda= 25 °C
RE en cable (EME)
consecuencia de las reacciones
-Presión
en celda=
1 atm de reducción aparecen cuando los voltajes son negativos.
2) Los picos
de las
reacciones
redox que ocurren en la celda.
Voltajes negativos
Reducción de CO2
(catódicos):
Reducción de H2O
Picos reacciones de
reducción
-0,2V
-
Pico de reducción de
CO2 a -0,2V.
-0,38V
Pico de reducción de
H2O a -0,38V.
10
4. Results.
“Experiments with the aim of selecting the most appropriate
methodology to analyze the product stream”
Configuration 1
Configuration 2
Configuration 3
9
4. Results.
“STUDY OF THE MOST APPROPRIATE
METHODOLOGY
TO ANALYZE THE PRODUCT STREAM“
Configuration
1 conclusions:
Configuration 1
1) The probability with which the MSD identifies the acetone in both chromatograms isn’t high
Conditions in experiment 3:
Conditions in experiment 4:
enough for us to say that acetone is formed in the
reaction CO2 3conversion.
-CO flow= 540cm3 min-1
-CO flow= 540cm
min-1
2
2
-KHCO concentration= 0.5 mol/l
-KHCO concentration= 0.5 mol/l
-Voltage= -2.8 V (Potenciostatic mode)
-Cell temperatura= 60 °C
3
3
2) Other
reaction products (overlapped with the peak of absorbing
liquid or its concentration is
below DL).
1-pentanol absorption
Configuración
2 is proposed…
Decane absorption
94%
Decane
8.326 – 12.228
83%
1- pentanol
25%
30%
3.520 – 9.840
Acetone
Acetone
4%
1.690
4%
CO2
1.494
1- pentanol
absorption
(GC-MSD)
CO2
1.320
1.489
Decane
absorption
(GC-MSD)
11
4. Results.
“STUDY OF THE MOST APPROPRIATE METHODOLOGY TO ANALYZE THE PRODUCT STREAM“
Configuration
2 conclusions:
Configuration
2
1) The probability
with
which
the
MSD
identifies
the
products
isn’t
high
enough for us to say
3
-1
3
-1
-CO2 flow= 540cm min
that
are those products which
-KHCO
3 concentration= 0.5 mol/l
-CO2 flow= 540cm min
are formed from the
reaction
of CO2 conversion.
-KHCO
concentration=
0.5 mol/l
3
-Current intensity= 0.54 A (Galvanostatic mode)
2) Obstruction problems occur in the heated pipe.
-Cell pressure= 13atm
Configuration
is proposed…
Ethylene oxide 4%
Acetaldehyde 3%
Formaldehyde
2%
CO2 2%
2,366 – 3,478
2,426 – 3,766
Methanol 1%
Injection
at 2 hours
(GC-MSD)
7,621 – 8,549
Injection
at 45 minutes
(GC-MSD)
12
4. Results.
“STUDY OF THE MOST APPROPRIATE
METHODOLOGY
TO ANALYZE
Conclusiones
Configuración
2: THE PRODUCT STREAM“
Configuración
2
1)La probabilidad con la que el MSD identifica
los productos
no es lo suficientemente alta como
Condiciones experimento 9:
para que podamos
afirmar
que son esos productos los que se forman a partir de la reacción de
3
-1
-Flujo CO2= 250 cm min
conversión
deHCO
. 1 mmol/l
2=
-Concentración
2SO4
-Intensidad de corriente= 0,54
2)Surgen
problemas
de obstrucción en la tubería calefactada.
amperios (Modo
galvanostático)
WE en cátodo
-Tª en celda= 60 °C
Se plantea la Configuración 3
CE-RE en ánodo
-Presión en celda= 1 atm
Uso H2SO4 como electrolito:
1)
evita problemas de obstrucción,
2)
no mejora los resultados respecto al uso
de KHCO3 y
3)
podría afectar negativamente a los
electrocatalizadores
Se retoma el uso de KHCO3 como electrolito
pero en concentraciones inferiores a las
usadas inicialmente.
Óxido de etileno 3%
Acetaldehído 3%
CO2 2%
2,556 – 3,834
Inyección a
las 2 horas
(GC-MSD)
13
4. Results.
CONFIGURACIÓN 1: Disoluciones de 1 y 5 ppm de metanol, etanol, acetona e
isopropanol (enrase decano)… En GC-MSD
1ppm
Decano 97%
7,841 – 16,412
Acetona 86%
4,232
5ppm
Acetona 90%
3,683
“Solvent delay”
Decano 95%
6,523 – 16,430

FLUIDOS SUPERCRÍTICOS

Transcription

Similar documents

Meeting Agenda - Kubiak Research Group

Energy and CO

How fossil fuels are formed

project poster - Joint Institute for Strategic Energy Analysis

Binary Stream Gas Analyser

Presentation - Harvard University

green highway for economic and environmental

The IOGCC Guidelines on Permitting CCS

MineARC® AirGEN CO / CO2 Scrubber

QAFAC CDR project - Qatar Sustainability Expo