Materials In Use To Built Closed Loop Reactors

Photobioreactors are of various types and each of these employs a wide variety of materials for photobioreactor construction. The materials for the construction of photobioreactors represent a significant practical issue both from the standpoint of the investment cost and biological performance. This page discusses the features and benefits along with the disadvantages of a few prevalent materials utilized for constructing photobioreactor:

in Algae Fuels

Photobioreactors are of various types and each of these employs a wide variety of materials for photobioreactor construction. The materials for the construction of photobioreactors represent a significant practical issue both from the standpoint of the investment cost and biological performance. This page discusses the features and benefits along with the disadvantages of a few prevalent materials utilized for constructing photobioreactor:

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#PolyVinyl Chloride (PVC)
The basal and helical photostage of a helical photobioreactor are generally made of a transparent polyvinyl chloride (PVC) tube

Features & Benefits

Polyvinyl chloride membranes containing immobilized agents have been widely documented and used to prepare membrane sensors in photobioreactors

The unique UV blocking technology prevents harmful ultraviolet light wavelengths from penetrating the PVC while allowing beneficial light wavelengths to pass through the PVC clear pipe.

The advantages include corrosion resistance, non-conductivity and light weight construction.

Using specialty clear PVC piping is beneficial in the use of photobioreactors since clarity is critical in allowing as much light into the process to allow the algae to grow and feed.

Disadvantages

Flexible PVC tubing has been used, but because of the damaging UV rays the PVC tends to break down and get brittle.

PVC when attacked by UV rays on conventional PVC will discolor the surface of the pipe preventing or limiting the light from getting to the medium.

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High Density polyethylene (HDPE)

High Density Polypropylene is used in bag photobioreactors to overcome the problems in using LDPE for algal cultivation.

Features & Benefits
HDPE is the most promising plastic used for algal cultivation since it is cheap and commercially viable

HDPE would cost approximately only one-third that of the current plastic materials used

The HDPE employed reactors are found to produce algae with oil content 1% higher than that of the reinforced LDPE films.

The opaqueness of HDPE help prevent photooxidative damage or photoinhibition

It is also less prone to biofouling (build-up of layer of algae that blocks some of the sunlight from getting through)

Disadvantages
HDPE is not quite as good as LDPE or the five-layer plastic as it is difficult to weld and hence show less tensile strength

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Photobioreactors are of various types and each of these employs a wide variety of materials for photobioreactor construction. The materials for the construction of photobioreactors represent a significant practical issue both from the standpoint of the investment cost and biological performance. This page discusses the features and benefits along with the disadvantages of a few prevalent materials utilized for constructing photobioreactor:

in Algae Fuels

Photobioreactors are of various types and each of these employs a wide variety of materials for photobioreactor construction. The materials for the construction of photobioreactors represent a significant practical issue both from the standpoint of the investment cost and biological performance. This page discusses the features and benefits along with the disadvantages of a few prevalent materials utilized for constructing photobioreactor:

in Algae Fuels

Low Density Polyethylene Film (LDPE)
Tubular photobioreactors made from polyethylene sleeves have been used commercially for algal cultivation.

Features & Benefits
The variants of basic LDPE plastic film used are single layer LDPE, linear low density polyethylene (LLDPE), fiber-reinforced LDPE
Estimates of the energy content of LDPE film are 78.1 MJ/kg and 74.0 MJ/kg (Lenzen M et al, 1999)
The benefits of using LDPE include high visible light and near infra red transmission, low UV transmission, and low cost.
In few PBRs, the chamber material is comprised of a multi-layer composite polymer, comprising one layer of nylon plastic film bonded on either side with a tie layer of bonding agent and a layer of low density polyethylene (LDPE).
The nylon-LDPE plastic film used in PBR can vary in thickness, depending on the species of algae and the corresponding level of turbulence required for light cycling, shear-stress limitations, etc.
A preferred size of the LDPE-nylon film is 3.5 thousandths of an inch thick. At this thickness, a moderate amount of turbulence within the photobioreactor chamber would have little effect on the film's structural integrity

Disadvantages
The main disadvantage of using these materials is their short lifespan as even with the addition of UV stabilizers, the maximum life of LDPE film is only 3 years
Environmental factors which can affect the film lifetime include UV radiation, temperature, thermal cycling, and contact with rigid surfaces and chemicals (including atmospheric pollutants)
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#Glass

Glass is most commonly used in tubular photobioreactors meant for biohydrogen production from algae

Features & Benefits
Reactors for photoautotrophs like microalgae must be fully translucent without any loss in transparency over time for which glass is generally employed
Among the types of glasses, borosilicate (Pyrex) glass is commonly used in the solar hot water collector of PBR.
The energy content of glass ranges between 13.0 and 18.6 MJ.kg-1 for window glass, to 15.9 MJ.kg-1 for float glass and 26.2 MJ.kg-1 for toughened glass. (Baird G et al,1998)
The glass tubes have a lifespan equal to the plant service life time of 20 years.
For a tubular photobioreactor, glass has significantly higher NERs (Net Energy Ratio) than rigid polymers such as polymethyl methylacrylate (acrylic)
A photobioreactor with low energy content is required, for which glass can be a suitable material in principle

Disadvantages
The use of glass tubes requires many more connection fittings as lengths of more than a few meters are not produced or, otherwise, are difficult to transport and assemble.
Glass tubes also require a supporting structure
The system employing glass is potentially viable, only when specific constraints on photosynthetic conversion rates, microbial H2 generation phase stabilities, and H2 collection efficiencies are met
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in Algae Fuels

Photobioreactors are of various types and each of these employs a wide variety of materials for photobioreactor construction. The materials for the construction of photobioreactors represent a significant practical issue both from the standpoint of the investment cost and biological performance. This page discusses the features and benefits along with the disadvantages of a few prevalent materials utilized for constructing photobioreactor:

in Algae Fuels

Photobioreactors are of various types and each of these employs a wide variety of materials for photobioreactor construction. The materials for the construction of photobioreactors represent a significant practical issue both from the standpoint of the investment cost and biological performance. This page discusses the features and benefits along with the disadvantages of a few prevalent materials utilized for constructing photobioreactor:

in Algae Fuels