Terpene-based Manufacturing for Sustainable Chemical Feedstocks

Our aim is to develop a sustainable, integrated platform for manufacture of industrial chemicals based on biological terpenoid feedstocks to complement carbohydrate, oil and lignin-based feedstocks that will be available to sustainable chemistry-using industries of the future. Our focus will include production of aromatics and amines which are particularly challenging targets from other biofeedstocks.

Transition from fossil-based feedstocks to renewable alternatives is a key challenge for the 21st Century. Major efforts are underway to address this with work currently focused on carbohydrates, fats and oils, and lignins all of which give rise to fundamental technological barriers due to the incompatibility of complex and oxygen-rich materials with conversion technologies developed for simple hydrocarbon-based petrochemical feedstocks. This often requires biological feedstocks to undergo costly and inefficient transformations and separations prior to deployment in existing supply chains.

In contrast, terpenes are an abundant class of natural products based on the C5 isoprene unit. As hydrocarbons they are easily separated from aqueous environments and can be readily upgraded using existing petrochemical technologies. While terpenes have been used in limited quantities since antiquity (notably as flavours and fragrances) they have yet to be exploited systematically for the production of platform chemicals even though they represent a potentially vast resource: global biogenic production of terpenes is 10^9 t/yr. Significant volumes of useful terpenes are already available on global markets at low cost (production of turpentine oils and limonene are 330,000 and 30,000 t/yr, respectively, the former costing 0.09-0.19 Euros per L). While this is sufficient in itself to justify a viable value-added chemical platform (metrics comparable to those for lignin: 1.1m t/yr at £250-2,000 per t) such figures will be dwarfed in the near future through the large-scale (multimillion t/yr) microbial production of terpenes such as farnesene for biofuels via the engineering of isoprene metabolic pathways. This industrial biotechnology (IB) approach, developed by Amyris and others, promises large-scale and geographically flexible supplies of terpenes via fermentation of plant sugars and cellulosic waste. Thus, the exploration of new generic technologies for the chemical exploitation of terpenes is timely, not only in terms of sustainable utilization of current global resources, but also to take advantage of major developments in IB.

However, key challenges to be addressed in the context of terpene-based manufacturing include: (i) development and optimization of sustainable chemical transformations; (ii) scale-up of intensive conversion processes; (iii) development of new terpene sources; and (iv) systems-level understanding of technical, environmental and economic factors associated with new terpene-based manufacturing technologies. This project will address these challenges directly in four interconnected workpackages.

Outputs from the project will provide a competitive advantage for one of the UK's most successful industries. Chemistry-reliant industries contributed an equivalent of 21% GDP to the UK economy in 2007, they support 6m jobs (RSC 2010), and turnover is growing at 5% pa (UKTI, 2009). The utilization of IB is vital to sustaining competitive advantage, with the value of the UK IB market in 2025 estimated at £4b to £12b (BERR 2009). Specific to this project, the development of new integrated technologies for terpene-based manufacturing, ultimately via microbial fermentation of waste cellulose, will provide competitive advantage for UK industries through new sustainable manufacturing processes, reduced feedstock costs, security of supply and reduced environmental impact. The UK will benefit further from export of new technologies and services and from development of new skills vital to future low carbon manufacturing.

This programme has been designed with impact at the core and with a focus on manufacturing in conjunction with both industrial and dissemination project partners to ensure maximum benefit to the widest range of beneficiaries. It is about future-proofing and a transformational approach to manufacturing.

Focus is on developing integrated chemical processes to sustainably convert terpene raw materials into useful chemicals, to complement those from other renewable feedstocks. Both supply chain and manufacturing pathways are addressed by, respectively: integration of future, IB-based terpene production routes and development of supply chain emergence models. Holistic process design and application of metrics (LCA) will provide confidence in the scalability of the technology, to be demonstrated during the project.

Other disciplines:
This project will influence a number of research areas in the short to medium term: development of integrated catalytic chemical pathways and intensified processes (chemistry/chemical engineering); application of "cell factories" to production of terpenoids including fermentation and separation appropriate to scale-up (molecular biology/chemical & process engineering); combined exploration of potential industrial configuration options and evaluation of supply network dynamics with technology routes still under development (manufacturing/process chemistry & engineering); and application of a life cycle approach (systems analysis).

Public:
In the medium term, society will benefit from the cleaner production of chemicals not otherwise readily available from sustainable feedstocks. By taking a systems approach, our outputs have the potential to support the UK's chemical manufacturing base to be competitive and innovative in the growing Bio-based Economy thus enhancing job creation. This project provides a next step in the manufacturing chain for products from the developing IB industry and supports a growing consumer demand for non-petrochemical based products. In the longer term this will decrease reliance on fossil-based resources - a direct impact on the environment and security of supply.

Skills:
This interdisciplinary project brings together biologists, chemists, chemical engineers and manufacturing and supply chain management experts. All PDRAs will be exposed to all parts of the programme, thus producing trained, technically astute personnel for a truly cross-disciplinary workforce, who understand the science, engineering, sustainability metrics and manufacturing contexts of chemicals production.
The PhD students supported will also benefit from this multidisciplinary environment and from the extra training and activities afforded through the EPSRC Doctoral Training Centre in Sustainable Chemical Technologies.

Industrial end-users:
In addition to the industrial partners, this work will impact on chemical manufacturers such as Shell, BP, DSM, Purac, Solvay, Croda and users of the materials in a range of sectors, such as Innovia, BP, JLR, EADS, Ford, and Unilever. Many of these companies already engage with the project partners and CI-KTN will assist in engaging further end-users. Current suppliers of the feedstock terpenes, such as wood biorefineries, will benefit from a possible new customer base while IB-based companies specialising in microbial fermentation (e.g. project partners TMO and Amyris), will benefit from a potential new customer base for their products. A widening of TMO's product portfolio and value adding to Amyris' large volume fuel product streams is envisaged. The choice of non-oxygenated terpene feedstocks provides opportunities to integrate processes into current production systems using unit operations familiar to chemical producers, while process integration and intensification offer enhanced throughput and cost-effectiveness. Supply chain analysis will provide a basis for sound commercial cases for the development of terpene-based chemicals manufacturing.