Investing in a new route to DPC - Shell Chemicals Magazine Winter ...

6 Shell Chemicals Magazine Winter/Spring 2012 DIPHENYL CARBONATEPlans for Singapore demonstration unit to produce polycarbonate intermediateINVESTING INA NEW ROUTETO DPCPaul Hampson, Singapore Venture Manager,who will oversee the DPC investment project.

Shell Chemicals Magazine Winter/Spring 2012 7Shell has announced its intention to invest in the construction of a demonstrationunit to manufacture diphenyl carbonate (DPC), a key chemical intermediate usedin polycarbonate production. Proprietary process technology developed by Shelloffers a new route to DPC that is expected to have significant advantages interms of its cost, safety and CO2 footprint.Polycarbonate is a versatile and fast growingengineering plastic, used in a wide variety ofapplications from optical media and householdgoods to car parts and glazing. Demand forpolycarbonate comes mainly from the largeconstruction, electronics and automotive sectors,and particularly by the rapid expansion of theseindustries in China.Healthy demand growth predicted forpolycarbonate has prompted major producersto look more closely at the efficiency andsustainability of their manufacturing supply chains.Traditionally, polycarbonate has been madewith phosgene, a highly hazardous material thatrequires stringent safety controls and carefulhandling procedures. The use of phosgeneadds cost and complexity to the manufacturingprocess and raises questions over the long termsustainability of this form of production.The new DPC process also has potential to The reaction conditions involved are mild,provide Shell with a sustainable platform as while efficient catalysts developed for the processa key supplier of polycarbonate intermediates. can achieve 99% selectivity, which translatesShell’s process has a number of innovative into high product yields.approaches in terms of both the process design The DPC technology is a good fit for Shell’sand catalysis, and has been piloted at itsportfolio and intermediates supply strategy.Technology Centres in Houston and Amsterdam. “The beauty of this chemistry for us is that all theIt is based on a multi-stage reaction involving raw materials, as well as the co-products, arecarbon dioxide, phenol and either propylene already part of our core portfolio,” says Pauloxide or ethylene oxide, and produces DPC Hampson, Singapore Venture Manager, whotogether with mono-propylene glycol (MPG) or will oversee the DPC investment project.mono-ethylene glycol (MEG) co-product.Figure 1: Polycarbonate capacity growth by process technology.ALTERNATIVE PROCESSTo address this, the industry has in recent yearsdeveloped a different process route that uses thechemical intermediate diphenyl carbonate (DPC)instead of phosgene as one of the primarypolymer feedstocks. All recent and planned newpolycarbonate investments are based on this‘melt’ production method (see Figure 1).However, while these processes eliminatephosgene from the polymer stage, a significantnumber of producers still have to use phosgenein the initial manufacture of DPC.Although not a producer of phosgene orDPC currently, Shell is a strategic supplier to thepolycarbonate industry. It is one of the world’slargest producers of phenol and acetone (seepage 20), the precursors for bisphenol A (BPA),the other main raw material used in ‘melt’polycarbonate production.Some of its process and catalyst technologiesare also closely related to DPC, and so Shellhas been looking at the issue of phosgene in thepolycarbonate supply chain for more than 10years. As a result of this research, it has developeda new a phosgene-free route to DPC that isexpected to have significant advantages interms of its cost, safety and CO2 footprint.ABOUT POLYCARBONATEPolycarbonate is a versatile engineering plastic that is used in a wide varietyof applications that make the most of its key properties of: impact strengthand toughness; clarity; high mechanical strength; rigidity; and good insulatingcharacteristics. A major application is in electronics where casings for manyelectronic devices are made of polycarbonate or mixtures of polycarbonateand other polymers such as ABS.Polycarbonate is also the material of choice for CDs and DVDs althoughthis application has begun to decline. Polycarbonate is also used in householditems from chairs to kitchen utensils. A major growth area is in automotiveapplications where polycarbonate has already replaced traditional materialsin components such as headlamps and is helping to make cars lighter.

8 Shell Chemicals Magazine Winter/Spring 2012 DIPHENYL CARBONATETechnical impression of the DPCdemonstration unit to be constructedon Jurong Island in Singapore.“WE ARE STRATEGICALLYWELL PLACED TO PROVIDETHIS KEY INTERMEDIATE FORPOLYCARBONATE PLAYERSAND THIS IS A LOGICAL PLACETO SPLIT THE SUPPLY CHAINPaul Hampson, Singapore Venture Manager.““We are using intermediates readily availableto us to make a product that is in high demandamong many of our existing phenol customers.We believe we are strategically well placedto provide this key intermediate for the industryand that this is a logical place to split thepolycarbonate supply chain.“It could also allow new players to enter thepolycarbonate industry without the complexityand challenges of managing phosgene orchlorine used in traditional processes.”The efficiency of the catalyst, low energyconsumption and high throughput, plus the factthat it consumes carbon dioxide, are expected tomake the process world-class in terms of cost andcarbon footprint. “In addition to the intellectualproperty involved in the individual elements of theDPC process, it is the clever and unique way ourscientists have been able to fit them together thatmakes this process so different,” says Hampson.As the final step in the commercialisation of theDPC process, Shell has committed to build ademonstration plant on Jurong Island, Singapore.When complete this will be able to supplysemi-commercial scale quantities of DPC toselected customers in the polycarbonate industryfor testing and acceptance.“We need to establish a specification for DPCproduced via this new route, which meets theneeds of the users,” says Hampson. If successful,he says Shell intends to become a major supplierof DPC to the polycarbonate industry.SUPPORTING GROWTH PLANS“We are excited about taking this important steptowards commercialising DPC as a new productfor Shell and are working closely with partners inthe polycarbonate industry to ensure that we meettheir needs,” says Ben van Beurden, ExecutiveVice President, Shell Chemicals.“All the growth in polycarbonate production isin Asia, and this and any future investment willput us in a strong position to support the growthplans of our partners.”DPC production will integrate neatly with Shell’sexisting manufacturing footprint in Singapore,taking advantage of the huge front end capacityof Shell’s newest ethylene oxide/glycolsunit on Jurong Island.Sven Royall, Vice President Intermediates, says:“DPC is a natural extension to our manufacturingportfolio and marketing of chemical buildingblocks to customers worldwide.“We are in familiar territory and so well placedto serve polycarbonate producers in the sameway as customers of other bulk derivatives suchas styrene monomer and mono-ethylene glycol,particularly if they choose to co-locate.“We have also developed an innovativetransport solution (see box below) that will allowus to supply DPC to customers wherever theychoose to invest.”Detailed engineering work on the DPC unitis well underway and a site has been identifiedwithin Shell’s existing Seraya Chemicals complex.Expected startup is in 2013.For more information visit:www.shell.com/chemicals/dpcELEGANT SUPPLY C HAIN SOLUTIONIn addition to the process technology behind DPC Shell has also patenteda new and potentially elegant solution for supplying this importantintermediate to polycarbonate producers.DPC is a high melting point solid and its natural crystal flake state (left)would make it more costly and complex to transport. Keeping it in liquidform makes logistics simpler and could have other supply chain benefitsfor the customer.Shell’s solution involves dissolving DPC in acetone for easy bulk transportto the customer’s premises. Once there, the acetone can be distilled off andduring processing customers can also recover the phenol component for usein BPA production. Using this approach, customers can receive both theirnecessary raw materials for polycarbonate production in one shipment.