In the long-term industry will have to find substitutes for fossil fuels as
supplies diminish and costs rise: so what is a sustainable resource for
synthesis of conventional plastics? At Green Polymer Chemistry 2012 in Cologne,
Germany, AMI brought
together experts from agriculture, chemical engineering, biotechnology, the
polymer industry and sustainability managers from brand owners and the
automotive sector to hear all the angles on this topic.
LMC International studies the agricultural including sugar, grains and
oilseeds. Worldwide, corn wheat and cassava accounted for 1.7 billion metric
tonnes in 2010/11, and sugarcane and sugar beet generated 160 million tonnes
(the lead producer is Brazil). On the vegetable oil side, palm predominates at
48 million tonnes (85% is grown in Malaysia and Indonesia) and is unique in
being harvested from trees each year – the other oils are from seeds. The
agricultural industry is already seeing a “battle for acres” globally. This
began in 2002 with the drive to use bioethanol/biofuel, which increased demand
for arable land for growing feedstock. By 2010 the area under cultivation had
expanded worldwide by 70 million hectares. Besides biofuels, there are other
factors such as the rise in per capita income in Asia, which means that
consumers are eating more meat thus increasing the demand for animal feed. More
land can be cultivated from areas such as the Black Sea, South America and South
East Asia if it is cost-effective. Bio-based plastics and other fine chemicals
are now being produced from agricultural feedstocks and the challenge is to find
sources that are sustainable in this global marketplace.
Süd-Chemie Laboratories
Image Credit: Süd-Chemie AG
Brand owners and retailers have studied sustainable sourcing extensively,
with all of the majors operating policies including Walmart, Carrefour and
Tesco. Dr Jan Kees Vis at Unilever has been involved in projects such as the
Sustainable Palm Oil roundtable; the aim of this brand owner is to double “the
size of our company while reducing our environmental impact”. This includes a
plan to source 100% of agricultural raw materials sustainably: palm oil is the
top material at 1.4 million tonnes per annum primarily for surfactants, then
paper, soy and sugar, followed by other oils. Unilever has put together a
Sustainable Agriculture Code and wants to use products with certification, such
as Rainforest Alliance and Fair Trade. There are many other issues such as the
need to ensure the security of food supplies. Thus brand owners will ask
questions of suppliers about the sustainability, not just renewable sourcing, of
new products.
The automotive industry is also pushing forward in this arena. The Ford Motor
Company has some notable new developments in using renewable sources, such as
soy polyol-based polyurethane foam, which cut CO2 emissions by 14.3 million
tonnes. One problem is the large number of cars produced, currently 4.8 million
per annum, so any material specified must be available in considerable
quantity. In the case of soy, the United Soybean Board was keen to find a use
for the oil as the bean was being grown for animal meal and oil was a
side-product. There is also use of recycled materials and natural fibre
reinforcements like hemp, sisal and wheat straw.
Ford is using a bio-TPU from Merquinsa Mercados Quimicos (now owned by
Lubrizol), which has a renewable source for the polyol component. The Brooks
running shoe was switched to part bio-TPU in the sole two years ago, it is also
used in Smith Optics ski goggles, and is compounded for injection moulding
consumer goods. The material offers up to 40% less CO2 emissions than classic
polyurethane according to the PAS 2050 greenhouse gas (GHG) emissions
standard.
The Brazilian sugar cane industry is the largest in the world. Braskem has
utilised this sugar as a source of feedstock to make its “green” polyethylene
and polypropylene with current capacities at 200kty and 30kty respectively. 86.5
tons of sugar cane gives 7200 litres of ethanol and 3 tonnes of polyethylene.
Brazil has vast areas of arable land that could be used to develop this industry
and Braskem is studying all aspects including ways to increase yield. The
company uses BonSucro-certified ethanol.
There have been several technology breakthroughs in the past year in
producing substrate from cellulose (so-called second generation feedstock). The
M&G Group has PROESA Technology and built a pilot plant in 2009. This
generates C5 and C6 sugars in a continuous process. The plant has been in
operation for 400 days continuously and many enzymes and 15 types of biomass
feedstock have been tested. The Crescentino demonstration plant will have
capacity for 40 ktpa cellulosic ethanol and will generate 15 MW of power from
the lignin by-product to the grid, as well as selling the ethanol. The VTT
Technical Research Centre of Finland has examined the feedstock potential of the
country’s forests, where growth rate of trees is expected to rise by 25% in the
next 5 years due to global warming. VTT has piloted the manufacture of ethanol
from lignocellulose with UPM including recycled paper. Biomethane can also be
used in the olefin supply chain: methanol to olefins (MTO), ethylene and
propylene was investigated by Mobil in the 1980s and Total Petrochemicals built
a demonstration unit in Feluy in 2010. VTT has also experimented with wood oils
and the manufacture of LDPE from tall oil.
Biomass production amounts to 165 billion tonnes per year, 50% cellulose and
24% hemi-cellulose. Sud-Chemie AG sees sugars as the new oil and has partnered
with SABIC in the sunliquid process, which takes lignocellulose feedstock and
converts it to fermentable second generation sugars or ethanol, which can be
used to make monomers for plastics like PE and PET. Around 4 tonnes of straw
yields 1 tonne of ethanol. The sunliquid process works with different renewable
feedstocks. The biggest potential source of lignocelluloses is rice straw in
Asia at round 750 million tonnes. Sud-Chemie also has a Liquibeet technology
using enzymes to liquefy sugar beet.
Petron Scientech was founded in 1991 in Mumbai and Princeton and has ethanol
to ethylene technology with a high conversion rate around 100% with close to 99%
ethylene selectivity. Reactor design has to factor in the highly endothermic
reaction and heat recovery. It has supplied technology to companies such as
Oswal in India, which maximises use of sugar cane – sugar is sold, bagasse is
sent to fuel power stations and the molasses is used to make industrial ethanol
and from there to make polyethylene. Greencol Taiwan (JV of CMFC and Toyota
Tshuho) has taken technology to produce monomers for bio-PET and the new plant
is due to start up in 2012.
There has been great progress towards production of fully bio-based PET.
Avantium has generated a “technical drop-in” for the terephthalic acid component
from furan dicarboxylic acid synthesised by dehydration and oxidation from
carbohydrates. This FDCA can also feed into polyurethane and polyamides. The
partners in this work include Teijin, Coca Cola, Solvay, Rhodia and Danone. The
PEF material has been tested on commercial blow moulding, fibre and film lines
and has a higher gas barrier than PET. A pilot plant is being constructed at
Chemelot in the Netherlands with capacity of 40 tonnes per year.
The Wageningen University has studied crops as chemical sources, looking at
algae for fatty acids, dandelions for latex, and seaweed for biorefineries among
many other projects. They have examined pathways to a wide range of biobased
monomers including furans for polyamide and polyester production. Biocatalysis
is the preferred technology with relatively mild reaction conditions.
Novozymes has the largest market share of industrial enzymes worldwide and 60
years of experience. The company sees renewable chemicals as a key to meet the
demand from the growing world population, which is anticipated to reach 9
billion in 2050. This will move the renewable chemicals industry from ”tech
push to market pull”. Current chemical engineering has been optimized for
decades and the biotech industry needs to catch up and compete on cost and
performance. Genzyme has Cellic to produce ethanol from biomass at USD 2-2.5
per gallon and more competitive enzymes coming on stream now. The company is a
partner in the M&G cellulosic ethanol plant and also involved in projects
with Cargill, Braskem and ADM. The work with Cargill involves bio-acrylic acid
production for applications from diapers to coatings and adhesives.
Other companies focus on the enzymatic routes to make monomers from renewable
sources, like Global Bioenergies. The focus is on direct fermentation to give
products such as propylene and butadiene. Synthos is a partner in the latter
project. The company develops possible synthetic pathways with corporate clients
and uses databases of enzymes to find suitable catalysts for cloning in
bacteria. A pathway to isobutene has already been established.
The use of more conventional catalysts has been reviewed by the Leibniz
Institute for Catalysis, which has been studying the production of monomers from
vegetable oils. The vegetable oil market in Germany amounts to 5.16 Mtonnes of
rape seed, 50 ktonnes of sunflower, and imported sunflower, linseed, soybean
(from USA), castor oil (India), palm and coconut oil (Malaysia, Indonesia).
These oils can be used in synthesis of polyurethane, polyester, polyamide,
polyacrylate and epoxy resin. For example, Emery Oleochemicals has achieved
ozonolysis of oleic acid which can be used in polyamide 6.9; Evonik has chemical
pathways for ricinoleic acid to give polyamide 10.10 and 6.10; Arkema has
polyamide 11 from 11-undecanoic acid from castor oil, and BASF has made
polyamide 6.10 and polyols from sources such as castor oil. The industry needs
to become more competitive and this includes breeding strains of plant with
higher levels of useful fatty acids, like high oleic sunflower oil. There is
also potential to produce oils from bacteria or algae.
Several major chemical companies have prioritised sustainability including
Royal DSM. The company is producing polyamide 410, thermoplastic copolyester and
UP resin from bio-sources and comments that OEMs ask, “Is it competing with the
food chain?” Another factor is that like all renewable technology the price has
to be comparable to existing products as the markets are not prepared to pay
extra. The Biosuccinium project with Roquette to produce succinic acid in a
yeast-based process is scheduled for large scale production (10kt) in Italy in
2012. There are also plans to make bio-based adipic acid, a precursor for
polyamide 66.
Cathay Industrial Biotech based in China is the largest global producer of
biobutanol with over 7 million gallons produced in 2011 and it is moving into
lignocellulose technology. The company has also commercialised a polyamide 5
monomer from lysine via decarboxylation to pentamethylenediamine, which can be
combined with a biobased di-acid. One issue was bioprocess impurities, which
represented a new challenge. The new monomer could be used in polyamide 5,10,
5,6, 5,4 or 5,X. The company is looking for partners to develop these
materials.
There is a lot of interest in technology to synthesise polymers from carbon
dioxide. Several companies worldwide are involved in the production of
polypropylene carbonate including Bayer Material Science (BMS) and BASF in
Europe, Novomer in the USA, SK Innovation in Korea, and Mengxi in China. BASF
is motivated by low monomer costs, reducing CO2 emissions trading and the
abundant feedstock from power plants. It is testing the material in several
applications such as an ABS replacement in electrical appliances, in
agricultural films and in paper coatings. One issue is the low activity of
catalysts and the need to remove the catalyst after polymerisation.
BMS has generated polyether-polycarbonate polyols from CO2 for use in
polyurethane, as well as producing the plastic polypropylene carbonate. The CO2
supply is scrubbed at the coal-fired power plant and then reacted with propylene
oxide. It has taken the company time to reduce the by-products and improve
catalyst use towards its “dream production” target level. Slab stock foam has
been produced and tested.
The biobased chemical industry for fine chemicals is moving toward reality.
One driver is the changes in cracker operation that will reduce the supply of
elastomer C4-C5 monomers. The Materia Nova Institute has reviewed the research
into building blocks for polymers, including succinic acid (DSM, Bioamber,
Roquette, Mitsubishi Chemical), sorbitol (Cargill, ADM, Roquette), propylene
(Braskem, DuPont/Tate & Lyle), butadiene (Goodyear, Lanxess, Michelin,
Synthos, Genomatica) and caprolactam (Draths). Solvay has a pilot plant to
generate 60,000 tonnes of partly biobased PVC in Brazil as another example.
Vincent Berthe speculates that the biobutanol platform could become bigger than
bioethanol: it can be made directly by glucose fermentation.
The question of sustainability revolves around the competition for land and
the impact on agriculture. The NNFCC in York has studied crops for non-food use
for many years and this is not novel – 40% of sugars and starch in the EU are
already grown for other purposes than food. John Williams calculates that around
250-800 million hectares of land are available for crops for bioenergy and fine
chemicals excluding forest, protected areas and land for increased food
production. The EU has renewable energy mandates that put pressure on the
biomass supply chain. This makes predicting the future more difficult and 2030
and 2050 calculations are usually given based on several scenarios. The NNFCC
overall prediction is that bio-based plastics will reach around 1% of the market
by 2020 at 3-5 million tonnes, up to 10% by 2030 at 43 million tonnes and to 20%
of the market in 2050 at 155 million tonnes.
The Green Polymer Chemistry conference in Cologne provided a unique
opportunity for agriculture, biotechnologists, brand owners, venture capitalists
and polymer experts to gather and debate the issues. Green Polymer Chemistry
2013 will be held at the Maritim Hotel, Cologne, Germany from 19-21 March 2013.
Paper offers should be sent to Dr Sally Humphreys (sh@amiplastics.com) before the deadline of
14th September 2012.