Biobased polyolefins - Biobased Polyethylene (bio-PE)
Section: BIOBASED PLASTICS
Series: Biobased Vinyl Polymers.
- Biobased Polyethylene (bio-PE).
Biobased
Polyethylene (bio-PE) / Green Polyethylene /
Renewable Polyethylene
- Its biobased carbon content can reach
100%.
- Renewable resource. It is produced from renewable
biomass feedstocks as sugars or vegetable oils.
- It reduces GHG emissions. Each ton
produced captures and sequesters CO2 from the atmosphere.
- 100% drop-in. Chemically identical
to its petrochemical counterpart. It has the same processing characteristics
as fossil PE, therefore, it can be processed in the same equipment.
- Non-biodegradable. It cannot be
composted or biodegraded.
- Thermoplastic. It can be molten and
remoulded into the desired shape.
- It can be recycled and processed
into new bio-PE products using conventional technologies without
requiring additional investments.
- Building block or monomer: biobased
ethylene.
|
Figure 1. Bio-PE is chemically identical to its
petrochemical counterpart (extracted from Braskem I'm greenTM
Polyethylene website)
1. Structure and types
Polyethylene (PE) has the simplest basic
structure of any polymer. It consists of a long chain of carbon atoms with two
hydrogen atoms attached to each carbon atom (a repetition of CH2
units).
There are many different types of PE which each
have their own unique characteristics and applications. The main types are:
high density PE (HDPE), low density PE (LDPE) and linear low density PE (LLDPE)
and very low-density polyethylene (VLDPE).
2. Biobased production routes
The building block for bio-PE is biobased ethylene. The
bio-ethylene is transformed into bio-PE through conventional catalyst-driven
polymerization.
Route 1 for biobased ethylene: Bioethanol dehydration
One of the old applications of ethylene was its
hydration to produce synthetic ethanol. The reverse process (dehydration) enables
to generate ethylene from ethanol. In the industry, the alcohol dehydration mainly
occurs in the vapor phase of two-catalyst systems. Most old technologies used
phosphoric acid while the activated alumina became predominant later. The
vapour phase dehydration of ethanol at 400ºC gives ethylene with >99%
conversion and >99% selectivity. The production of 1 ton of ethylene
requires 1.7 tons of ethanol.
Bioethanol can be produced from biomass through
biochemical and thermochemical routes.
Route 2 for biobased ethylene: Cracking of bio-naphtha
Ethylene can be produced via steam cracking of
naphtha in which feed streams are preheated and then mixed with steam with a
1:1 ratio at 750–850ºC for a short period of time (less than 0.5 s). The yield of
ethylene depends on the type of feedstock used in the process.
Bio-naphtha is generating during the processing
of renewables feedstocks through technologies as Fischer-Tropsch conversion or hydrotreating.
Route 3 for biobased ethylene: Direct production from
microorganisms
Several bacterial and fungal ethylene producers
have been reported since the discovery of microorganisms able to produce ethylene
in the mid-1900s. This technology is in the early stages.
3. Market
Bio-PE faces direct competition with its petrochemical
counterpart. It has been on the market for several years (since 2010) due to
the activities performed by Braskem (see Section 4.1) via bioethanol
dehydration, but hitherto the production capacity of this route remains the
same. One of the pathways to obtain fossil-based ethylene is based on natural
gas and its lower prices cause margins to increase to the detriment of
renewable ethylene. Further projects based on bioethanol dehydration were discontinued
because of the shale gas boom (see Sections 4.1 and 4.2).
In 2014, SABIC was the first company to
announce a portfolio of bio-polyolefins via cracking of bio-naphta. They partially
replaced fossil feedstocks by renewable feedstocks (waste fats and oils). After
five years of hiatus, last months have seen a rise of bio-polyolefins projects related
to this route. It is still difficult to know what the current production volume
of bio-PE is. Also, the biobased carbon content varies from one project to
another. This section will be updated once the picture becomes clearer.
The market is still small when compared to global
PE market. It has the potential to grow.
Global PE production volume (2016) = 103,000 kton/y.
Global bio-PE production volume - Route 1 = 200
kton/y.
Global bio-PE production volume - Route 2 =
Unknown.
Company
|
Location
|
Route
|
Start-up
|
Production volume (kton/y)
|
Braskem
|
Triunfo
Petrochemical Complex (Brazil)
|
1
|
2010
|
200
|
SABIC
|
Geleen (Netherlands)
|
2
|
2014
|
- (see
Section 4.3)
|
LyondellBasell
(bio-naphta from Neste)
|
Wesseling
(Germany)
|
2
|
2019
|
Several thousand
tons (see Section 4.4)
|
Total
|
La Mède
(France)
|
2
|
2019
|
- (see
Section 4.5)
|
Dow (bio-naphta
from UPM Biofuels)
|
Terneuzen
(Netherlands)
|
2
|
2019
|
- (see
Section 4.6)
|
Ineos (bio-naphta
from UPM Biofuels)
|
Köln
(Germany)
|
2
|
2020
|
- (see
Section 4.7)
|
4. Main players
4.1 Braskem - I'm greenTM Polyethylene (Route 1)
After years dedicated to research and
development, in September 2010, Braskem commissioned a production unit of 200
kton/year of bio-PE with bioethanol from sugarcane as raw material. The plant,
located at the Triunfo Petrochemical Complex in Rio Grande do Sul (southern
region of Brazil) received an investment of 290 M$ and made Braskem the first
and largest global producer of bio-ethylene. The company was planning the
construction of a second 400 kton/year plant. However, in mid-2012 Braskem
announced that the project was postponed.
The transformation of the green ethylene into bio-PE
is performed in the same polymerization plants that produce polyethylene from
fossil source. The bio-PE is commercialized under the trademark “I'm greenTM
Polyethylene”. The ethanol used in the production of I'm greenTM
Polyethylene is provided largely through contracts with major domestic
producers, whose relationship with Braskem is governed by the "Responsible
Ethanol Sourcing".
There are currently available in the Braskem product
portfolio the following families of I'm greenTM Polyethylene: HDPE, LDPE
and LLDPE. They cover a wide range of applications. The vast majority of these
grades have renewable carbon content between 80% and 100%, based on their
biogenic carbon content measured in accordance with the standard ASMT D6866.
In 2011, Braskem's I'm greenTM
Polyethylene received the certification from the Belgian company Vinçotte, a
global reference in the renewable content assessment. Samples from the HDPE and
LLDPE families were evaluated, with the entire line receiving the maximum
rating of four stars for its proven renewable content. Also, its units and
production processes are certified by the seal from ISCC Plus (International
Sustainability and Carbon Certification), an international certification system
for biomass and sustainable fuels.
4.2 Dow Chemical and Mitsui Chemicals (Route 1)
A Dow Chemical and Mitsui Chemicals joint venture
was investing in the construction of a production plant in Brazil to
manufacture bio-HDPE and bio-LLDPE from ethylene of renewable origin. The plant
was expected to have a capacity of 350 kton/year and to be operational in 2015.
As in the case of the new Braskem plant, the project was postponed and there
are no known dates to resume it.
4.3 SABIC (Route 2)
SABIC launched its portfolio of certified
renewable polyolefins in 2014. By using its existing infrastructure there are
no changes in the value chain, not even in recycling. They are based on
second-generation, biobased feedstock. Its certified renewable polymers have
been accredited through the International Sustainability and Carbon
Certification (ISCC PLUS).
Figure 2. Chain of custody of SABIC certified
renewable polyolefins (extracted from Reference [7])
Having conducted an internal cradle-to-gate
life-cycle analysis of their renewable polyolefins, SABIC found that from
sourcing of raw feedstock to final production, each ton of renewable PE and PP
polymer can remove up to two tons of CO2 compared to fossil-based
polyolefins.
Moreover, SABIC uses pyrolysis oil feedstock
created from the recycling of low quality, mixed plastic waste (otherwise
destined for incineration or landfill) for the manufacturing of its certified
circular polymers.
4.4 LyondellBasell and Neste - Circulen (Route 2)
LyondellBasell and Neste jointly
announced the first parallel production of biobased polypropylene (PP) and
biobased low-density polyethylene (LDPE) at a commercial scale in June 2019. The joint project used Neste's
renewable hydrocarbons to successfully produce several thousand tons of
biobased plastics. LyondellBasell's cracker flexibility allowed it to introduce
the new renewable feedstock at its Wesseling site (Germany), which was converted
directly into biobased polyethylene and polypropylene.
The biopolymers are approved for the production
of food packaging and they are being marketed under Circulen and Circulen Plus,
the new family of LyondellBasell circular economy product brands. Circulen
range is created using the mass balance approach. The biobased amount is
allocated mathematically to specific products. Circulen products are produced
according to the requirements of the certification scheme REDcert². Over 30%
renewable content has been verified.
4.5 Total and Trioplast - TrioGreen (Route 2)
Following the start-up of the La Mède biorefinery, the full range of Total products
(PE / PP / PS) is commercially available as Total Certified Renewable Polymers
via mass balance certification. Trioplast is using the renewable certified PE
of Total in its TrioGreen brand.
4.6 Dow Chemicals and UPM Biofuels (Route 2)
In September 2019, Dow announced that it was
integrating wood-based UPM BioVerno renewable naphtha into its slate of raw
materials, creating an alternative source for plastics production. Dow is using
this feedstock to produce biobased polyethylene (PE) at its facility in
Terneuzen (The Netherlands). Following a successful year-long trial program,
Dow was planning to scale production and address the increasing global demand
for renewable plastics.
The renewable raw material for this wood-based
naphtha is crude tall oil. BioVerno naphtha is produced in the UPM Lappeenranta Biorefinery and is a biobased cracker feedstock
that does not compete with food production. The entire supply chain is
International Sustainability & Carbon Certification (ISCC) certified, based
on mass balance approach, meaning all steps meet traceability criteria and
reduce negative environmental impacts.
Dow has also partnered with the Fuenix Ecogy
Group, based in Weert (The Netherlands), for the supply of pyrolysis oil
feedstock, which is made from recycled plastic waste.
4.7 INEOS and UPM Biofuels (Route 2)
In February 2020, INEOS and UPM Biofuels entered into
a long-term agreement to supply renewable raw material for polymers to be
produced at INEOS Köln (Germany). INEOS will use UPM BioVerno naphtha (see previous section)
to produce “bio-attributed” (mass balance approach) polyolefins.
4.8 Enerkem and NOVA Chemicals (Route 2 – Plastic recycling)
5. Applications
In spite of its simple structure, PE has been
the most commonly used plastic in the world in previous years. It is mainly
known as packaging material (bags, films, bottles…) but is used in several
applications (for instance, flexible pipes or cable jacketing). The chemical
composition of bio-PE is the same as fossil-based PE. Therefore, it can be used
in both rigid and flexible packaging as well as all the other applications.
Figure 3. Example of end-user product available
in the market
Product: Tetra Rex®, renewable carton package
using bio-LDPE coatings.
Brand: Tetra Pak.
Bio-PE Supplier: Braskem.
REFERENCES
[1] P. Harmsen, M. Hackmann: “Green Building
Blocks for Biobased Plastics”. Wageningen UR Food & Biobased Research,
March 2013.
[2] R.M. Patel: “Multilayer Flexible
Packaging – Chapter 2: Polyethylene”. Plastics Design Library, 2016,
Pages 17-34.
[3] A. Mohsenzadeh, A. Zamani, M.J. Taherzadeh:
“Bioethylene Production from Ethanol: A Review and Techno-economical
Evaluation”. ChemBioEng Rev 2017, 4, No. 2, 75–91.
[4] “Bio-Based Chemicals: Value Added Products
from Biorefineries”. IEA Bioenergy, Task 42 Biorefinery.
[5] “Biopolymers facts and statistics”, IfBB
– Institute for Bioplastics and Biocomposites, 2017.
[6] I. Odegard, S. Nusselder, E.R. Lindgreen, G.
Bergsma, L. de Graaff: “Biobased Plastics in a Circular Economy”. CE
Delft, September 2017.
[7] J. Vachon: “Sustainability initiatives
within SABIC with examples of use of bio-based materials for polyolefins”. Circular
and Biobased Performance Materials Symposium, 19 June 2019, Wageningen (The
Netherlands).
[8] Braskem website: I'm greenTM Polyethylene.
[9] BioRefineries Blog: “LyondellBasell and Neste announce
commercial-scale production of biobased PP and LDPE”, 20/6/2019.
[10] News (SABIC): “SABIC demonstrates leadership in
sustainable packaging solutions at K 2019”, 19/10/2019.
[11] News (Dow): “Dow and UPM partner to produce
plastics made with renewable feedstock”, 24/9/2019.
[12] BioRefineries Blog: “INEOS and UPM Biofuels enter into a
supply agreement of renewable naphtha for plastics production”, 18/2/2020.
[13] BioRefineries Blog: “Enerkem and NOVA Chemicals partner to transform MSW into ethylene”, 14/5/2020.
[13] BioRefineries Blog: “Enerkem and NOVA Chemicals partner to transform MSW into ethylene”, 14/5/2020.
