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==Introduction: Polyethylene==
==Introduction: Polyethylene==
Polyethylene (PE) is a polymer of long chains of the monomer [http://en.wikipedia.org/wiki/Ethylene ethylene] (IUPAC name "''ethene''"). It is one of the world’s most common plastics, with a wide range of uses and over 60 million tons produced worldwide every year. Several different categories exist, based on density and branching. Common types are high-density PE ([http://en.wikipedia.org/wiki/HDPE HDPE]; plastic # 2) and low-density PE ([http://en.wikipedia.org/wiki/Low-density_polyethylene LDPE]; plastic # 4). Polyethylene is not biodegradable, therefore significant environmental issues are associated with its use. Recycling of PE is relatively straightforward. When disposables are involved, every effort should be made to replace PE with biodegradable alternatives. However, resistance to biodegradation can also be a desired effect for some applications. For example, [http://en.wikipedia.org/wiki/Geomembranes geomembranes] are often made of HDPE and are widely used as liners for fish ponds, constructed wetlands and biogas digesters. Its resistance to degradation also warrants its use in the natural gas industry in transporting natural gas underground in high density PE pipes. Excellent chemical resistance of PE allows for widespread use in storage applications. PE is also useful as a material for digital fabrication. It can be used in the [[RepRap]] 3D printer.
Polyethylene (PE) is a polymer of long chains derived from the monomer [http://en.wikipedia.org/wiki/Ethylene ethylene] (IUPAC name "''ethene''"). It is one of the world’s most common plastics, with a wide range of uses and over 60 million tons produced worldwide every year. Several different categories exist, based on density and branching. Common types are high-density PE ([http://en.wikipedia.org/wiki/HDPE HDPE]; plastic # 2) and low-density PE ([http://en.wikipedia.org/wiki/Low-density_polyethylene LDPE]; plastic # 4). Polyethylene is not biodegradable, therefore significant environmental issues are associated with its use. Recycling of PE is relatively straightforward. When disposables are involved, every effort should be made to replace PE with biodegradable alternatives. However, resistance to biodegradation can also be a desired effect for some applications. For example, [http://en.wikipedia.org/wiki/Geomembranes geomembranes] are often made of HDPE and are widely used as liners for fish ponds, constructed wetlands and biogas digesters. Its resistance to degradation also warrants its use in the natural gas industry in transporting natural gas underground in high density PE pipes. Excellent chemical resistance of PE allows for widespread use in storage applications. PE is also useful as a material for digital fabrication. It can be used in the [[RepRap]] 3D printer.


==Polyethylene – the current status==
==Polyethylene from ethanol two step conversion==
Almost all PE today is derived from petroleum. In a very energy-intensive process, a petroleum feedstock is cracked at high temperatures. After distillation and purification in large, capital-intensive facilities, ethylene is produced. This is then polymerized to polyethylene, a process that again involves high temperatures, high pressures and often toxic organic solvents. Clearly not an ideal situation.
 
==Polyethylene from ethanol==
[[File:Ethanol2Ethene.jpg|right|250px]]Ethene is a very simple two-carbon organic molecule (C<sub>2</sub>H<sub>4</sub>) that does not have to be derived from petroleum. In fact, it can easily be [http://www.google.com/patents?id=SWg4AAAAEBAJ&dq=4134926 produced from ethanol] in a dehydration reaction. This has been known for many decades, but was not cost-competitive at low oil prices. Recently, a Brazilan-Japanese joint venture announced the "Green Polyethylene Project", with sugarcane as the feedstock. Commercial-scale introduction of this "BIO-polyethylene" is planned for 2011. We welcome PE to the club of bioplastics and believe that small-scale production from ethanol can be made practical.
[[File:Ethanol2Ethene.jpg|right|250px]]Ethene is a very simple two-carbon organic molecule (C<sub>2</sub>H<sub>4</sub>) that does not have to be derived from petroleum. In fact, it can easily be [http://www.google.com/patents?id=SWg4AAAAEBAJ&dq=4134926 produced from ethanol] in a dehydration reaction. This has been known for many decades, but was not cost-competitive at low oil prices. Recently, a Brazilan-Japanese joint venture announced the "Green Polyethylene Project", with sugarcane as the feedstock. Commercial-scale introduction of this "BIO-polyethylene" is planned for 2011. We welcome PE to the club of bioplastics and believe that small-scale production from ethanol can be made practical.


==Possible use in carbon sequestration==
Dehydration of ethanol seems fairly simple to do with an [http://www.chemguide.co.uk/organicprops/alcohols/dehydration.html aluminum oxide catalyst]. This method is well suited to small batches and could be easily scaled up to larger batch sizes. It sounds fairly easy to test out. They don't mention the required temperature but it has to be lower than the ignition point of ethanol(~362°C). If we want food-independent ethylene production, especially for larger scale use, we could go from carbon dioxide and water to syngas (a mixture of carbon monoxide and hydrogen) and then finally to ethylene [http://spot.colorado.edu/~meyertr/rwgs/rwgs.html]. This [https://share.sandia.gov/news/resources/releases/2007/sunshine.html] may be useful for producing the syngas.using a fluid bed reactor or recently in a microreactor. The production of a distillation chamber capable of lowering pressure may also benefit the aluminum refining process. Aluminum is a favored catalyst for ethanol dehydration to ethylene but additional compounds such as transition metals increase yield and selectivity while other zeolite catalysts have also been described (Chen et al.).
If renewable energy is used in the polymerization step, bio-PE could even be considered a carbon-negative plastic. Recently, wood-HDPE or bamboo-HDPE composite materials have become popular, combining good structural properties with durability. Taking this idea further, a form of carbon sequestration can be proposed, in which completely dry biomass is stored above ground. Plastic sheets are then used to limit moisture, preventing biodegradation ("plastic-enabled carbon landfill").  


==Links==
Polymerization of ethylene is an exothermic reaction with multiple generations of catalysts. Phosphoric acid is the earliest catalyst under high pressure and temperature. Zeolite initially of silicates and then other matrices made the second generation of catalysts and still operated under elevated pressures and temperature. The third and currently evolving class of catalysts are known as Ziegler-Natta catalyst use an activator molecule of the (Al)C2H5n  organoaluminum cocatalyst or methylaluminoxane and a titanium catalyst (TiCl3 or TiCl4 etc).
*Patent: [http://www.google.com/patents?id=SWg4AAAAEBAJ&dq=4134926 production of ethylene from ethanol] (issued Jan. 1979)
*Patent: [http://www.google.com/patents?id=yYAzAAAAEBAJ&dq=4670620 process for obtaining ethylene from ethanol] (issued Jun. 1987)
*News article: [http://www.ethanolproducer.com/article.jsp?article_id=5203 "Brazilian company to make renewable polyethylene"]
*Treehugger: [http://www.treehugger.com/files/2009/12/polyethylene-made-from-ethanol-9times-more-efficient-to-make-with-sugar-cane-over-corn.php "Polyethylene Made From Ethanol 9 Times More Efficient To Source From Sugar Cane, Over Corn"]
*Wikipedia entries on [http://en.wikipedia.org/wiki/Polyethylene polyethylene] in general, [http://en.wikipedia.org/wiki/HDPE high-density polyethylene (HDPE)] and [http://en.wikipedia.org/wiki/Low-density_polyethylene low-density polyethylene (LDPE)]


==Collaboration Discussions==
There are a number of steps involved in polyethylene production from a biotic feedstock;  selection of a feedstock, construction of open source fermentors, purification equipment, and fluid bed reactors, along with methods of measuring yield and quality of each step will be require bringing a diverse background of knowledge together.
Can someone research the patents to the point of proposing a rigorous procedure for producing a test batch of bio-polyethylene, with the hope of scale-up for small-scale production?


Bio polyethylene background and patent review
==Status Brief==
 
Almost all PE today is derived from petroleum. In a very energy-intensive process, a petroleum feedstock is cracked at high temperatures. After distillation and purification in large, capital-intensive facilities, ethylene is produced. This is then polymerized to polyethylene, a process that again involves high temperatures, high pressures and often toxic organic solvents. Clearly not an ideal situation.
Background:
The general route of carbon dioxide to ethylene polymer involves fixation of carbon dioxide into high energy sugar, which is fed to ethanol fermenting yeast and/or bacteria. Ethanol free of  water must be obtained and is catalyzed using a fluid bed reactor or recently in a microreactor. The production of a distillation chamber capable of lowering pressure may also benefit the aluminum refining process. Aluminum is a favored catalyst for ethanol dehydration to ethylene but additional compounds such as transition metals increase yield and selectivity while other zeolite catalysts have also been described (Chen et al.).
There are a number of steps involved in polyethylene production from a biotic feedstock;  selection of a feedstock, construction of open source vacuum distillers and fluid bed reactors, along with methods of measuring yield and quality of each step will be require bringing a diverse background of knowledge together.  


An OSE project to replace this process with a constructive route from organic feedstocks rather than degradative oil based processes is currently in the research and development phase. The process is being developed [[Extreme Manufacturing]] system and according to OSE guidelines. A literature review on [[Polyethylene from Ethanol/Research Development]] details the major steps of the process, technologies employed, and applicable details to an OSE standard. Scrum project management will be a used if a team comes together or an individual wants to take on a project.


Completed work: system process reviewed, OSE concept, SEBD preliminary, catalysts reviewed, 1st generation catalysts proposed, preliminary reactor protocols outlined.


1. Ethanol production
==Documentation Brief==
a. Ethanol can be produced on-site or purchased.
A thorough review of the process of creating polyethylene from ethanol is underway on [[Polyethylene from Ethanol/Research Development]]. Catalysts for the two-step process have been reviewed and an OSE protocol derived. Assistance is needed summarize unreviewed literature and provide summaries of important information. An examination of the processes full product (substrate and catalysts) ecology is needed and proposals for import replacements for petroleum derived substrates investigated and proposed. A thorough review of the operation of an [[Fluidized_bed_reactor#FBR_for_bioplastic_production | FBR]] applied to the proposal is needed.
b. Sugar cane is the commercially preferred feed stock for the production of ethanol for ethylene production and other industrial uses and has an efficiency 4 times that of corn.


2. Ethanol purification
==Current Challenge==
a. Ethanol can be purified via distillation and has a boiling point of 78.1 C, however the product is azetropic and may not be suitable. Several methods exist and are detailed on wikipedia. Yield of ethanol can be measured via spectroscopic methods with wavelength 2300 cm-1. http://www.erowid.org/archive/rhodium/chemistry/equipment/distillation4dummies.html http://www.umsl.edu/~orglab/documents/distillation/dist.htm
Current blockages to further development include review by a subject matter expert to evaluate and critique the current proposal. Help from interested parties with technical review and people is needed to work on [[Ethanol | substrate production]] and [[Polyethylene_from_Ethanol/Research_Development#High_purity_ethylene_product_purification | purification]], and [[Polyethylene_from_Ethanol/Bill_of_Materials | sourcing information for catalysts]]. Expertise in fluid mechanics is needed for the [[Fluidized_bed_reactor#Prototype_1 | reactor]] design. Graphic design or CAD of the system would be a big benefit to many aspects of the proposal. Development work for applications, specifically greenhouse coverings is needed.


US patent 4,399,000 issued to Tedder on August 16, 1983 details a method to extract alcohols from its water component using an organic solvent to form a lowhead aqueous phase and a high head alcohol-solvent phase. The patent details a device for mixing an extractant with an organic solvent and passage of the solvent-alcohol phase to a vacuum distiller that separates the highly pure alcohol from the solvent. Solvents for use include aryl or alkyl phosphates, a phosphonate, a phosphine oxide, a sulfoxide, a sulfone, an amine oxide or  a quarternary ammonium or a phosphonium salt in a ratio of 1 to 10 parts by weight solvent to 1 unit alcohol.
==System Engineering Breakdown Diagram==


Ethanol to ethylene conversion
[[File:Preliminary polyethylene SEBD (2).png | center | 300 pixels]]
Fluid bed reactor allows easy interface solid catalyst and gas phase reagents and separation of gas phase products. Designs can incorporate a number of features for continuous use with features such as catalyst recycling, and constant input and output of substrate and product. Production of ethylene from ethanol and the polymerization of polyethylene from ethylene are carried out in fluid bed reactors and development of this machine would be necessary for both processes involved.


Ethanol’s hydroxyl group can be removed and replaced with a double bond via a dehydration reaction. The endothermic reaction is best catalyzed between 500-700 C and a reactor device capable of controlling the mixing of reaction reagents and catalysts under ideal conditions will be necessary to produce high quality ethylene capable of being polymerized. Steam has been used successfully to provide heat for the reaction and should by modular with the OSE steam generator and solar concentrator.  http://www.cheresources.com/invision/topic/7179-ethylene-from-ethanol/
[[File:Detailed_Fluidized_bed_reactor_for_ethylene_production.jpg|300px| Component configuration for ethanol dehydration to ethylene]]
[[File:Detailed_fluidized_bed_reactor_for_polyethylene_polymerization.jpg|300px| Component configuration for ethylene polymerization]]


== Process design ==




===Design Rationale===
The design rationale for the OSE agroecological approach is based upon OSE standards. The process design is meant to produce a needed product ecology using local feedstocks. By starting with high purity substrate and selective catalysts purification steps can be minimized and the process conducted on a small scale. A fluid bed reactor is a key piece of hardware that is used by the industry due to its superior performance. An OSE reactor is designed to be reconfigurable to a number of processes and be of appropriate scale.


Producing polyethylene from locally produced base materials and open source hardware will require the production of high purity molecules and machines capable of conversion at high efficiency and selectivity. The project can be broken down based on producing high quality substrates: ethanol, ethylene, and polyethylene. The tasks need to be further divided into catalyst selection, hardware components, and substrate requirements to be worked on separately as part of the scrum process. Dehydration of ethanol to ethylene, will be the first goal of the project as it has the largest value margin between substrate and product and the catalyst requirements are within the scope of OSE's currently proposed product ecology.


The reactor device above is detailed in U.S. patent 4,134,926 belonging to Tsao and Zasloff issued Jan 6 1979  which utilizes a fluid bed reactor (11) to contain a catalyzed reaction of ethanol dehydration. The reactor contains powdered catalyst supported on a distributor which can dispense feed ethanol through the catalyst. Ethanol is passed through the distributor in gas phase at 750 C into the reactor chamber at the same temperature. The catalyzed reaction takes place on the surface of the catalyst powder, and the product escapes as gas. The product is equal parts water and ethylene. Catalyst may be removed and loaded into reactor using hopper chambers, which offer the advantage of preparing the new catalyst to ideal temperature and conditions increasing control of the main reactors conditions. According to the patent ethylene yields of 99% are possible with fluidized bed reactors.
Starting with commodity ethanol will allow OSE to apply itself to an area where the open source information and demonstration is lacking. Reactor and catalysts are selected based upon demonstrated and easily available chemicals and could open a new sector to open source entrepnuers. Demonstration of a few base applications thermomolding and greenhouse glazing will allow incremental development. Production of feedstock will be conducted as part of an integrated plant at FeF and fermentation and purification technology built to utilize it.  


Acids or metals may be used for catalysts for this reaction, however aluminum silcate is a catalyst that offers high yields and is easy to obtain and work with. AlO3 is a favored catalyst which will be produced by the soil aluminum extractor. However the addition of other compounds as either supporting material or doping of the catalyst has been found to increase yield and purity. 
Tools including catalysts and process control should be developed to be multipurpose and modular. Development of multiple uses at once will maintain that focus. The [[aluminosilicate chemistry]] learned from this process may allow other products.
US patent 4,234,752 issued to Wu et al. on November 18, 1980 details a method of using treated gamma-alumina as a catalyst for the dehydration of alcohols. The catalyst is base treated to remove excess surface acid sites which contribute to isomerization. An inert gas is to transport gaseous alcohol through the catalyst and minimizes side reactions. The described method has been found be effective with primary, secondary, and tertiary alcohols of 2 to 20 carbons and under temperatures 200 to 500 C and pressures of 50 to 3500 kPa.
US patent 4,302,357 issued Nov 24, 1981 to Kojima et al. details a catalyst of high purity aluminum silcate of at least 99.6% purity with a phosphate of group IIa, IIb, IIIa, IVb in the wt% of .05 to 5 with a process for its preparation. Aluminum starting material that is capable of producing aluminum silcate under hydrolysis conditions should be utilized and higher purity organic aluminum salts or metallic aluminum is preferred. The primary factor influencing yield is purity of catalyst but pore volume and specific surface area also affect the reaction and ranges 0.15 to 0.50 cc/g and 100 to 350 m2/g respectively are recommended. Magnesium, calcium or zinc is recommended as a phosphate metal cation. The catalyst should be maintained at a temperature between 300 and 450 C.
A paper published by Chen et al. gives a general description of microreactors, catalyst configurations, and details a AlO3 catalyst with TiO2. Microreactors are small precision engineered devices to mix small reactions with a catalyst and heat. Microreactors may be a more suitable design for OSE specifications over traditional fluid bed reactors and were found to be more efficient than fixed bed reactors in this study. Chen et al found AlO3 doped with 10% wt TiO2 have high ethanol conversion efficiency, ethylene selectivity, and long-term stability of over 400 hrs. TiO2 increases that range of active lewis base configurations in the AlO3 matrix and enhances catalytic activity. Temperatures of 420+ C and ethanol concentration of 30-50% were found to be optimal.


Ethylene yield measurements
===Information architecture===


Ethylene to polyethylene polymerization  
===Conceptual Design===
1. Dehydration of ethanol using a catalyst and fluid bed reactor.<br/>
A. Selecting a catalyst. AlO3 can be utilized as an initial catalyst after production by the aluminium extractor. A base wash with KOH or NaOH can be used to increase the specificity of catalyst. Improvements to the catalyst can be incrementally made as OSE technology becomes available. The current proposal calls for a AlO3 doped with TiO2, a demonstrated highly efficient and selective catalyst.<br/>
B. Constructing a reactor chamber capable of mixing the catalyst and substrates under optimal conditions. The reactor chamber must allow control over temperature, pressure, addition and removal of catalyst, control of feedrate and interaction time of substrate, and separation of production and should incorporate features that allow easy reconfiguration and recycling of catalysts, solvents, and unconverted substrate.<br/>
C. A three phase temperature (50, 0, -70 °C) fractionation condenser will be used to remove byproducts, unreacted substrate, and inert gas, producing high purity ethylene suitable for polymerization.<br/>
D. Methods for measurement of ethylene yield and purity must be further investigated (maybe using spectroscopic methods).


Polymerization from ethylene to polyethylene should be conducted in
2. Polymerization of polyethylene from ethylene using Ziegler-Natta catalyst and fluid bed reactor.<br/>
A. Selection of a components of catalyst for polymerization: triethylalumina, Ti/Mg Cl, electron donating solvent.<br/>
B. Optimal configuration of reactor for polyethylene polymerization.<br/>
C. Measurement of PE yield and purity.<br/>
D. Ability to pass newly formed polyethylene to an extruder or storing as pellets for future extrusion.<br/>
E. Investigate production of other polymers such as polyethylene vinyl acetate (for greenhouse materials).


Polyethylene measurement
3. Extrusion to final product<br/>
A. Identify most desirable products for OSE product ecology and research optimal extrusion processes. Materials for greenhouses or windows are a high priority as mentioned by Marcin and this application could be the first aim. Identify ways to maximize translucence, increase UV resistance and filtering, and maximize material use with strength and durability (film versus panels).<br/>
B. Value adding processes such as tensile polymer incorporation or shaping into useful products.


Value adding
4. Production of ethanol on-site from sorghum utilizing yeast fermentation.<br/>
A. Selection of yeast and/or bacterial strains that are optimal for sorghum fermentation and finding their optimal conditions.<br/>
B. Construction of fermentation equipment.<br/>
C. Construction of distillation equipment capable of operating under vacuum, which could possibly be attached to fermentation chamber.<br/>
D. Method for measuring alcohol purity.
Measuring specific gravity is means of getting a rough estimating ethanol yield and with internal improvements can achieve higher accuracy. Measurements against as internal standard and a pure ethanol standard can improve hydrometers accuracy.


Polyethylene recycling
===Specifications===
Conformity to OSE specifications and eventual use of entirely locally produced components.


Proposal of action:
Ability to produce high and low density polymers for use in thermomolding in injection, die, and blow molding.


1. Production of ethanol on-site from sorghum utilizing yeast fermentation.
Later ability to incorporate comonomers.
2. Construction of distillation equipment capable of operating under vacuum, which could possibly be attached to fermentation chamber.
3. Method for measuring alcohol purity.
4. Dehydration of ethanol using a catalyst and fluid bed reactor.
5. Measurement of ethylene yield and purity using spectroscopic methods.
6. Polymerization of polyethylene from ethylene using transition metal catalyst and fluid bed reactor.
7. Measurement of PE yield and purity.
8. Value adding processes such as tensile polymer incorporation or shaping into useful products.


==Making Ethylene==
===Interface design===
Dehydration of ethanol seems fairly simple to do with an [http://www.chemguide.co.uk/organicprops/alcohols/dehydration.html aluminum oxide catalyst]. This method is well suited to small batches and could be easily scaled up to larger batch sizes. It sounds fairly easy to test out. They don't mention the required temperature but it has to be lower than the ignition point of ethanol(~362°C).


If we want food-independent ethylene production, especially for larger scale use, we could go from carbon dioxide and water to syngas (a mixture of carbon monoxide and hydrogen) and then finally to ethylene [http://spot.colorado.edu/~meyertr/rwgs/rwgs.html]. This [https://share.sandia.gov/news/resources/releases/2007/sunshine.html] may be useful for producing the syngas.
===Safety Concerns===


==Polymerization==
Both ethanol and ethene are flammable, so be careful to ensure against vapor ignition. Initial runs should be done in small batch sizes to ensure greater safety. Ethanol is toxic to the liver but poisoning symptoms should be obvious. Ethylene gas is highly flammable and should be kept away from any source of sparks or static electricity. Technicians running this process should wear a lab coat, eye protection and gloves. A thermal and impact jacket will be a modular piece of the reactor design. A secondary firebrick jacket will be used for this application and can incorporate venting to prevent buildup of dangerous gases.
* Patent: [http://www.google.com/patents/about?id=6dRTAAAAEBAJ&dq=3004020 Ethylene Polymerization using a Mixture of Metals and a Halogen as Catalyst] (issued Oct. 1961)
* Patent: [http://www.google.com/patents/about?id=hDcoAAAAEBAJ&dq=4975485 Ethylene polymer and process for preparing same] (issued Dec. 1990)
* Patent: [http://www.google.com/patents/about?id=H4sgAAAAEBAJ&dq=4975485 Method for producing an ethylenic polymer composition] (issued Jun. 1995)
* Patent: [http://www.google.com/patents/about?id=F9UFAAAAEBAJ&dq=4975485 Ethylene polymer and processes for obtaining it] (issued 2001)

Latest revision as of 00:49, 30 November 2018

Main > Materials > Bioplastics


Polyethylene from Ethanol
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Introduction: Polyethylene

Polyethylene (PE) is a polymer of long chains derived from the monomer ethylene (IUPAC name "ethene"). It is one of the world’s most common plastics, with a wide range of uses and over 60 million tons produced worldwide every year. Several different categories exist, based on density and branching. Common types are high-density PE (HDPE; plastic # 2) and low-density PE (LDPE; plastic # 4). Polyethylene is not biodegradable, therefore significant environmental issues are associated with its use. Recycling of PE is relatively straightforward. When disposables are involved, every effort should be made to replace PE with biodegradable alternatives. However, resistance to biodegradation can also be a desired effect for some applications. For example, geomembranes are often made of HDPE and are widely used as liners for fish ponds, constructed wetlands and biogas digesters. Its resistance to degradation also warrants its use in the natural gas industry in transporting natural gas underground in high density PE pipes. Excellent chemical resistance of PE allows for widespread use in storage applications. PE is also useful as a material for digital fabrication. It can be used in the RepRap 3D printer.

Polyethylene from ethanol two step conversion

Ethanol2Ethene.jpg

Ethene is a very simple two-carbon organic molecule (C2H4) that does not have to be derived from petroleum. In fact, it can easily be produced from ethanol in a dehydration reaction. This has been known for many decades, but was not cost-competitive at low oil prices. Recently, a Brazilan-Japanese joint venture announced the "Green Polyethylene Project", with sugarcane as the feedstock. Commercial-scale introduction of this "BIO-polyethylene" is planned for 2011. We welcome PE to the club of bioplastics and believe that small-scale production from ethanol can be made practical.

Dehydration of ethanol seems fairly simple to do with an aluminum oxide catalyst. This method is well suited to small batches and could be easily scaled up to larger batch sizes. It sounds fairly easy to test out. They don't mention the required temperature but it has to be lower than the ignition point of ethanol(~362°C). If we want food-independent ethylene production, especially for larger scale use, we could go from carbon dioxide and water to syngas (a mixture of carbon monoxide and hydrogen) and then finally to ethylene [1]. This [2] may be useful for producing the syngas.using a fluid bed reactor or recently in a microreactor. The production of a distillation chamber capable of lowering pressure may also benefit the aluminum refining process. Aluminum is a favored catalyst for ethanol dehydration to ethylene but additional compounds such as transition metals increase yield and selectivity while other zeolite catalysts have also been described (Chen et al.).

Polymerization of ethylene is an exothermic reaction with multiple generations of catalysts. Phosphoric acid is the earliest catalyst under high pressure and temperature. Zeolite initially of silicates and then other matrices made the second generation of catalysts and still operated under elevated pressures and temperature. The third and currently evolving class of catalysts are known as Ziegler-Natta catalyst use an activator molecule of the (Al)C2H5n organoaluminum cocatalyst or methylaluminoxane and a titanium catalyst (TiCl3 or TiCl4 etc).

There are a number of steps involved in polyethylene production from a biotic feedstock; selection of a feedstock, construction of open source fermentors, purification equipment, and fluid bed reactors, along with methods of measuring yield and quality of each step will be require bringing a diverse background of knowledge together.

Status Brief

Almost all PE today is derived from petroleum. In a very energy-intensive process, a petroleum feedstock is cracked at high temperatures. After distillation and purification in large, capital-intensive facilities, ethylene is produced. This is then polymerized to polyethylene, a process that again involves high temperatures, high pressures and often toxic organic solvents. Clearly not an ideal situation.

An OSE project to replace this process with a constructive route from organic feedstocks rather than degradative oil based processes is currently in the research and development phase. The process is being developed Extreme Manufacturing system and according to OSE guidelines. A literature review on Polyethylene from Ethanol/Research Development details the major steps of the process, technologies employed, and applicable details to an OSE standard. Scrum project management will be a used if a team comes together or an individual wants to take on a project.

Completed work: system process reviewed, OSE concept, SEBD preliminary, catalysts reviewed, 1st generation catalysts proposed, preliminary reactor protocols outlined.

Documentation Brief

A thorough review of the process of creating polyethylene from ethanol is underway on Polyethylene from Ethanol/Research Development. Catalysts for the two-step process have been reviewed and an OSE protocol derived. Assistance is needed summarize unreviewed literature and provide summaries of important information. An examination of the processes full product (substrate and catalysts) ecology is needed and proposals for import replacements for petroleum derived substrates investigated and proposed. A thorough review of the operation of an FBR applied to the proposal is needed.

Current Challenge

Current blockages to further development include review by a subject matter expert to evaluate and critique the current proposal. Help from interested parties with technical review and people is needed to work on substrate production and purification, and sourcing information for catalysts. Expertise in fluid mechanics is needed for the reactor design. Graphic design or CAD of the system would be a big benefit to many aspects of the proposal. Development work for applications, specifically greenhouse coverings is needed.

System Engineering Breakdown Diagram

300 pixels

Component configuration for ethanol dehydration to ethylene Component configuration for ethylene polymerization

Process design

Design Rationale

The design rationale for the OSE agroecological approach is based upon OSE standards. The process design is meant to produce a needed product ecology using local feedstocks. By starting with high purity substrate and selective catalysts purification steps can be minimized and the process conducted on a small scale. A fluid bed reactor is a key piece of hardware that is used by the industry due to its superior performance. An OSE reactor is designed to be reconfigurable to a number of processes and be of appropriate scale.

Producing polyethylene from locally produced base materials and open source hardware will require the production of high purity molecules and machines capable of conversion at high efficiency and selectivity. The project can be broken down based on producing high quality substrates: ethanol, ethylene, and polyethylene. The tasks need to be further divided into catalyst selection, hardware components, and substrate requirements to be worked on separately as part of the scrum process. Dehydration of ethanol to ethylene, will be the first goal of the project as it has the largest value margin between substrate and product and the catalyst requirements are within the scope of OSE's currently proposed product ecology.

Starting with commodity ethanol will allow OSE to apply itself to an area where the open source information and demonstration is lacking. Reactor and catalysts are selected based upon demonstrated and easily available chemicals and could open a new sector to open source entrepnuers. Demonstration of a few base applications thermomolding and greenhouse glazing will allow incremental development. Production of feedstock will be conducted as part of an integrated plant at FeF and fermentation and purification technology built to utilize it.

Tools including catalysts and process control should be developed to be multipurpose and modular. Development of multiple uses at once will maintain that focus. The aluminosilicate chemistry learned from this process may allow other products.

Information architecture

Conceptual Design

1. Dehydration of ethanol using a catalyst and fluid bed reactor.
A. Selecting a catalyst. AlO3 can be utilized as an initial catalyst after production by the aluminium extractor. A base wash with KOH or NaOH can be used to increase the specificity of catalyst. Improvements to the catalyst can be incrementally made as OSE technology becomes available. The current proposal calls for a AlO3 doped with TiO2, a demonstrated highly efficient and selective catalyst.
B. Constructing a reactor chamber capable of mixing the catalyst and substrates under optimal conditions. The reactor chamber must allow control over temperature, pressure, addition and removal of catalyst, control of feedrate and interaction time of substrate, and separation of production and should incorporate features that allow easy reconfiguration and recycling of catalysts, solvents, and unconverted substrate.
C. A three phase temperature (50, 0, -70 °C) fractionation condenser will be used to remove byproducts, unreacted substrate, and inert gas, producing high purity ethylene suitable for polymerization.
D. Methods for measurement of ethylene yield and purity must be further investigated (maybe using spectroscopic methods).

2. Polymerization of polyethylene from ethylene using Ziegler-Natta catalyst and fluid bed reactor.
A. Selection of a components of catalyst for polymerization: triethylalumina, Ti/Mg Cl, electron donating solvent.
B. Optimal configuration of reactor for polyethylene polymerization.
C. Measurement of PE yield and purity.
D. Ability to pass newly formed polyethylene to an extruder or storing as pellets for future extrusion.
E. Investigate production of other polymers such as polyethylene vinyl acetate (for greenhouse materials).

3. Extrusion to final product
A. Identify most desirable products for OSE product ecology and research optimal extrusion processes. Materials for greenhouses or windows are a high priority as mentioned by Marcin and this application could be the first aim. Identify ways to maximize translucence, increase UV resistance and filtering, and maximize material use with strength and durability (film versus panels).
B. Value adding processes such as tensile polymer incorporation or shaping into useful products.

4. Production of ethanol on-site from sorghum utilizing yeast fermentation.
A. Selection of yeast and/or bacterial strains that are optimal for sorghum fermentation and finding their optimal conditions.
B. Construction of fermentation equipment.
C. Construction of distillation equipment capable of operating under vacuum, which could possibly be attached to fermentation chamber.
D. Method for measuring alcohol purity. Measuring specific gravity is means of getting a rough estimating ethanol yield and with internal improvements can achieve higher accuracy. Measurements against as internal standard and a pure ethanol standard can improve hydrometers accuracy.

Specifications

Conformity to OSE specifications and eventual use of entirely locally produced components.

Ability to produce high and low density polymers for use in thermomolding in injection, die, and blow molding.

Later ability to incorporate comonomers.

Interface design

Safety Concerns

Both ethanol and ethene are flammable, so be careful to ensure against vapor ignition. Initial runs should be done in small batch sizes to ensure greater safety. Ethanol is toxic to the liver but poisoning symptoms should be obvious. Ethylene gas is highly flammable and should be kept away from any source of sparks or static electricity. Technicians running this process should wear a lab coat, eye protection and gloves. A thermal and impact jacket will be a modular piece of the reactor design. A secondary firebrick jacket will be used for this application and can incorporate venting to prevent buildup of dangerous gases.

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