Ethanol, widely known as a biofuel, has a growing presence
in the chemical industry. In itself, ethanol is a low volume speciality
chemical with various uses as a solvent, but with a single chemical transformation
it is readily transformed to ethylene, the largest volume chemical intermediate
in the world.
Passing ethanol over an alumina or zeolite catalyst produces
high purity ethylene in high yields, allowing the production of derivatives
including high and low density polyethylenes, PVC, PET and ethoxylates. The
ethylene value chain represents an annual production volume of over 130 million
tonnes and a global market forecast to be valued at almost $250billion by the
end of the decade.
Traditionally produced from petrochemical naphtha, the
biggest consumers of ethylene are the polyethlyenes (high density, low density
and linear low density). They are also the largest consumers of biobased
ethylene. The Brazilian chemical giant Braskem has been producing biobased
polyethylene from sugarcane-derived ethanol since 2007. In 2010, Braskem inaugurated
its 200,000tons per year biobased ethylene plant in Triunfo, Rio Grande do Sul.
The Braskem product line, marketed under the ‘I’m Green™’ brand, includes high-density,
low-density and linear-low-density polyethylene, for rigid packaging
applications, films, caps and closures, and bags. Braskem’s biobased
polyethylene has been used as a 3D printer filament aboard the international
space station, with the first printed item being a pipe connector for a
vegetable irrigation system.
Braskem also uses ethanol in the production of Ethyl
Tertiary-Butyl Ether (ETBE), and has developed an ethylene based metathesis
route to polypropylene (which they have yet to commercialise).
Ethanol is the key intermediate in the production of
biobased polyethylene terephthalate (PET) plastic. PET is produced from
monoethylene glycol (MEG) and terephthalic acid: dehydration of ethanol to
ethylene is followed by conversion to ethylene oxide, and finally MEG. This
process provides a route to PET with a 30% biobased content. The PET market is
not only large - over 70million tons of PET is used as plastic resin and
textile filament - but is also a consumer touch point for the biobased
chemicals industry. Plastic bottles are commonly produced from PET and with
iconic brands such as Coca Cola, Heinz and Pepsi looking for new opportunities
to demonstrate their sustainable credentials the potential for biobased PET has
not been overlooked. Under the PlantBottle® brand Coca Cola have distributed
over 35 billion packages and have the ambition to convert all new PET plastic
bottles, to PlantBottle packaging (up to 30% plant-based) by 2020.
In 2012, Coca-Cola, Ford, H.J. Heinz, NIKE and Procter &
Gamble announced the formation of the Plant PET Technology Collaborative (PTC),
a strategic working group focused on accelerating the development and use of
100% plant-based PET materials and fibre in their products. There are numerous
companies - including the chemical giants BASF - who have formed a joint
venture with Dutch technology developer Avantium, working towards the
production of 100% biobased PET or its analogue PEF. Commercial production
could be realised by 2020.
Ethylene oxide also has important derivatives beyond
monoethylene glycol. It is used to produce ethoxylates, chemicals with a wide
range of applications in many sectors, including cleaning products, cosmetics,
and paints. Although many ethoxylates are partially biobased, being produced
from fatty acids, the lack of access to biobased ethylene oxide has prevented
the sale of 100% biobased ethoxylates.
Thanks to the UK speciality chemical ingredients company
Croda, the situation is now changing.
Croda is a company rooted in the production of high performance chemicals from renewable resources. Founded in 1925, the company’s first product was lanolin, the refined form of wool grease, a product still widely used today across health, personal and industrial sectors. Over the subsequent nine decades Croda has grown into a £1billion business.
For Croda, the high performance of their ingredients is
paramount and goes hand in hand with their longstanding commitment to investing
in sustainability and putting innovation into action. This commitment and drive
has resulted in the company having an impressive 70% of its raw materials derived
from renewable sources.
In 2015, Croda began work on a $170million project at its
Atlas Point manufacturing site in New Castle, Delaware. Their aim was to produce
biobased ethylene oxide as basis for their ethoxylate product range. The
project has now come to fruition with the plant successfully up and running,
and later in 2017 Croda will release a full range of 100% biobased ethoxylates.
Although “Greener”, non-ethoxylated ingredients, have been
used in the development of more natural formulations, many in the industry feel
the performance has not yet met the levels of the traditional ethoxylates.
According to Croda the 100% Bio-based ECO Range of ingredients will enable its
customers to meet their goals of delivering 100% renewable, high-performance
products to their consumers and reduce the reliance on fossil fuels. Croda’s
Bio-based ECO range will contain more than 60 different ingredients, making it
the widest range in the industry. Additionally, Croda will also produce a
non-ECO branded range of products, not attaining 100% biobased content, but having
a highly improved biobased profile over traditional versions.
Croda is a participant in the USDA’s BioPreferred program,
and through the program are supporting the uptake of biobased products. Many of
Croda’s products are among the 2,500 products, in 100 different product
categories, certified by the program and the ECO range is expected to join this
list. Their achievements have been recognised by their receiving the award for
“Most Innovative Use of Green Chemistry” from the New York Society of Cosmetic
Chemists for their biobased ethoxylate development.
The next addition to ethanol derivatives family is likely to
be ethyl acetate. Through its subsidiary Prairie Catalytic, the renewable
micals company Greenyug is targeting the $4 Billion ethyl acetate market. The
Prairie Catalytic production facility will be located next to Archer Daniels
Midland Company's (ADM) Corn Processing Plant in Columbus, Nebraska, with ADM supplying
the project with bioethanol feedstock and other services. Construction of the
50,000ton facility is anticipated to start during 2017 with production set to
begin in 2018.
Without doubt the political drive to develop biofuels such
as ethanol has created an industrial base from which the biobased chemical
industry can grow. As with the petrochemical industry, fuel may create the
volume but chemicals offer the value, and we are likely to see further strings
added to ethanol’s bow in the future. However, these chemical projects remain
large scale investments and are not without risk, with this in mind and staying
with the archery theme we should complement companies like Croda and allow them
the honour of wearing the proverbial feather in their cap.