Building with Bioplastics - Part 6

August 7, 2012 – Vol.17 No. 21

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 6.

Man-made systems to capture carbon dioxide for plastics and other chemicals.

by Bruce Mulliken, Green Energy News.

Right now. Today. Immediately, with available technology, it is possible to start removing carbon dioxide from the atmosphere and keep it locked away permanently. Plants can be harvested and through various processes to be made into carbon-storing bioplastics. Even if those bioplastics, usually in the form of pellets, aren’t used to make any end products, those bioplastics, complete with their carbon content from the atmosphere, can remain pelletized for eternity. One company says that for each ton of bioplastics made, 2.5 tons of carbon dioxide is removed from the atmosphere. We’d need to make a heckuva lot of bioplastics start reducing CO2 levels in the atmosphere, but it’s a start. (We also still have to reduce our carbon footprint by using cleaner energy, renewable energy and through overall energy efficiency.

Letting plants do their thing – take carbon dioxide out of the air and through photosynthesis make organic compounds that can be made into bioplastics – is a way to remove carbon dioxide from the atmosphere. The chemical trip from carbon in the air by way of plants might be called man-enhanced natural process. There are also methods under development to take carbon dioxide directly from the source, fossil fuel fired powerplants and use that CO2 to make chemicals or fuel.

An earlier article in this publication discussed a project in Germany where carbon dioxide from a powerplant was being used to a certain type of plastic, which was later used in the cover for a vacuum cleaner. The article, “Think Green Plastics to Store Carbon Dioxide” noted that:

"In cooperation with various project partners, Siemens researchers have developed a new recipe for plastic made primarily of renewable resources and CO2. The new material is an alternative to standard polystyrene-based acrylonitrite-butadiene-styrene (ABS) polymer. The new polymer is much "greener" than ABS even though the physical properties of the two materials are similar. In order to demonstrate how practical the new polymer is, scientists used it to create a vacuum cleaner cover. The new material is the result of a three-year project on research into CO2 as an ingredient for polymers. The project, which was recently completed, was funded by the German Research Ministry."

The project in Germany is not alone.

At Cedar Lane Farms, a commercial greenhouse and nursery in Wooster, Ohio, Touchstone Research Laboratory of Triadelphia, West Virginia has begun its Department of Energy (DOE)-awarded project to produce fuels and other high-value, bio-based products (such as chemicals for bioplastics) from algae that feed on carbon dioxide, sunlight and nutrients.

According to a press release:

“The nursery uses an advanced coal-burning system from a previous DOE effort to heat its greenhouses. For the algae project, carbon dioxide generated by that system is being pumped into the ponds and serves two purposes — it keeps flue gas carbon dioxide from being released into the environment and it provides algae with carbon dioxide needed for growth.

“The project also uses another technology developed by Touchstone exclusively for algae systems — a phase change material that covers a majority of the pond surface to regulate daily temperature, control the infiltration of invasive species, and reduce water evaporation losses. Touchstone is testing its integrated system in two indoor and two outdoor algae-producing ponds at the nursery. For each pair, one pond will be covered by the phase change material while the other pond will have no protection and serve as the control. This four pond system has an annual production capacity of approximately 2,000 gallons of oil to be turned into fuel.”

Touchstone won an initial award from DOE in 2009 when the agency funded projects from the American Recovery and Reinvestment Act (ARRA) to determine the feasibility of capturing carbon dioxide from industrial sources for storage or beneficial use, such as conversion to chemicals, plastics, fuels, and building materials.

On the other side of the planet, in Japan, Panasonic, better known for its electronics, has developed a kind of artificial photosynthesis to directly convert CO2 into organic materials like bioplastics.

According to a detailed Panasonic press release:

"Panasonic has developed an artificial photosynthesis system which converts carbon dioxide (CO2) to organic materials by illuminating with sunlight at a world's top efficiency of 0.2 percent. The efficiency is on a comparable level with real plants used for biomass energy. The key to the system is the application of a nitride semiconductor which makes the system simple and efficient. This development will be a foundation for the realization of a system for capturing and converting wasted carbon dioxide from incinerators, power plants or industrial activities.

"CO2 is one of the substances responsible for greenhouse effect and as such, efforts are being made to reduce the emissions of CO2 worldwide. The problem of CO2 is also directly connected to an issue of the depletion of fossil fuels. Artificial photosynthesis is the direct conversion from CO2 into organic materials, which can solve both of these problems.

"In the previous approaches so far, the systems have had complex structures such as organic complexes or plural photo-electrodes, which makes it difficult to improve their efficiency in response to the light. Panasonic's artificial photosynthesis system has a simple structure with highly efficient CO2 conversion, which can utilize direct sunlight or focused light.

"We found firstly that a nitride semiconductor has the capability to excite the electrons with enough high energy for the CO2 reduction reaction. Nitride semiconductors have attracted attention for their potential applications in highly efficient optical and power devices for energy saving. However, its potential was revealed to extend beyond solid devices; more specifically, it can be used as a photo-electrode for CO2 reduction. Making a deviced structure through the thin film process for semiconductors, the performance as a photo-electrode has highly improved.

"The CO2 reduction takes place on a metal catalyst at the opposite side of nitride semiconductor photo-electrode. The metal catalyst plays an important role in selecting and accelerating the reaction. Here, it is noted that the system comprises of only inorganic materials, which can reduce the CO2 with low energy loss. Because of this, the amount of reaction products is exactly proportional to the light power. This is one of the merits in such an all-inorganic system while some conventional systems cannot follow the light power in general because of their internal or external rate-limiting processes in the complex structures.

"The system with a nitride semiconductor and a metal catalyst generates mainly formic acid from CO2 and water with light at a world's top efficiency of 0.2%. The efficiency is of a comparable level to real plants used in the biomass energy source. The formic acid is an important chemical in industry for dye and fragrances. The reaction rate is completely proportional to the light power due to the low energy loss with simple structure; in other words, the system can respond to focused light. This will make it possible to realize a simple and compact system for capturing and converting wasted carbon dioxide from incinerators and electric generation plants."

So, the man-enhanced natural process is available today to reduce the greenhouse gas in the atmosphere. And, in looks as though processes that grab carbon dioxide at the source are not too far behind.

Links.

Think Green Plastics to Store Carbon Dioxide

Panasonic

Touchstone Research Laboratory

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 2.
Residential bioplastic building materials when managed and recycled could sequester carbon dioxide for centuries.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 3.
Building big things for significant carbon sequestration.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 4.
Renewable energy plays a significant role.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 5.
Which plants for feedstock?

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 6.
Man-made systems to capture carbon dioxide for plastics and other chemicals.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 7.
The need for a regulated industry.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 8.
New technologies to convert plant material into chemicals for bioplastics and series wrap-up.