Photoreduction of CO2
to fuels under sunlight
using optical-fiber reactor
學 生 ：周暐祥
報告日期：98/10/16
Introduction
• When sunlight reaches the surface of the Earth,
some of it is absorbed and warms the Earth.
• Some sunlight is utilized by green plants to
produce hydrocarbons that constitute the
world’s fossil fuel reserves, but it takes
millions of years.
Introduction cont.
• For recent year, more and more fossil
energy are consumed.
• When the fossil resource have been used, it
release a lot of the CO2.
• And the fossil resource are not renewable.
Introduction cont.
• As we know, the CO2 is one of the
greenhouse gas.
• For now a day, the temp. of the earth is
going to increase more higher, and the
climate is going to be changed.
• So finding the renewable resource is critical.
Introduction cont.
Reducing the CO2
• Removal of CO2 from Flue Gas
in the Packed Tower by Ammonia Solution
• Production of precipitated calcium
carbonate from calcium silicates and carbon
dioxide
Introduction cont.
• photocatalytic reduction of CO2 into fuels
by using natural
sunlight.
• Using sunlight recycle carbon dioxide and
produce fuels like methanol or gasoline.
Photocatalytic conversion of CO2 into fuels
reaction
• A continuous circular Pyrex glass reactor
(216 cm3) with a quartz window for
conduction of light irradiation.
• Catalyst-coated optical fibers were inserted
in the reactor.
• the light source enter along the fibers to
conduct the photocatalytic reaction on its
surface.
• The incident light is split to two beams
when hitting the internal surface of fiber,
due to the difference of refraction index
between the TiO2 film and the fiber.
• The UVA (320–500 nm) light was obtained
by using an appropriate color filter.
。
• The temp. of the reactor maintain around 75
C.
• The reactor was purged by CO2 gas
bubbling through distilled water for 1 h at
。
75 C before and during the reaction.
• The space velocity of CO2 gas and H2O
vapor was maintained at 0.72 h1 for every
experiment.
Results
• Bandgap energy of Cu (0.5 wt%)–Fe (0.5
wt%)/TiO2–SiO2–acac is substantially
decreased to 1.55 eV, which is promising to
absorb the full range of visible light.
• The largest production rate of ethylene,
0.575 mmol/g-cat h is observed on Cu(0.5
wt%)–Fe(0.5wt%)/TiO2 coated over optical
fiber.
Conclusions
• The idea of recycling carbon dioxide is not
new, but has generally been considered too
difficult and expensive to be worth the
effort.
• But with oil prices exceeding $100 per
barrel and concerns about global warming
mounting, researchers are increasingly
motivated to investigate carbon recycling.
Conclusions cont.
• The advantage of photo-driven reaction is
clearly benefited from the un-limited solar
energy.
• An efficient photoreactor with highphotoactivity catalyst is essential step
toward a commercial-scale application to
produce renewable fuels.
References
• Photoreduction of CO2 to fuels under sunlight
using optical-fiber reactor
The-Vinh Nguyen1, Jeffrey C.S. Wu Department
of Chemical Engineering, National Taiwan
University, Taipei 10617, Taiwan, ROC Received
24 September 2007; received in revised form 10
January 2008; accepted 20 February 2008
Available online 18 April 2008
• Scientists Use Sunlight to Make Fuel From CO2
http://www.redicecreations.com/article.php?id=2611
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