Refining of Wood to Aromatics
While the conversion of cellulose and hemicellulose to fuels and chemicals has already been extensively studied, the conversion technology for lignine valorsization is developed significantly less. This evolution is mainly due to the structural complexity and heterogeneity of this aromatic biopolymer. Both the pulp and paper industry, as in the growing bio-ethanol production, the lignin residual is currently mainly used as low-value energy source.
Publications and patents concerning lignine conversion are mainly focused on the production of biofuels and oxygen-free hydrocarbons. This pioneering work offers interesting opportunities, but there is a huge competition in those markets from other biomass types and petrochemicals. The discovery of shale gas and oil complicates the justification to generate fuels from biomass. In addition, biomass has a problem of scale, which makes that future bio-refineries will/can not provide mega ton production of chemicals, so that a clear choice must be made for the production of a handful of (valuable) chemicals in stead of a very wide range of products. For this reason, building blocks for polymers are to be preferred.
While already a lot of building blocks are produced from renewable resources, sustainable production of molecules with aromatic structure is still very challenging. The ARBOREF project intends to propose a bio-refinery for aromatics, describing chemical routes for the production of some essential aromatics from renewable raw materials such as wood and grasses.
Central to the project is a recently developed KU Leuven technology, which converts wood into high yields of mono-phenols (from lignin), and a fixed (hemi) cellulose pulp (1). Useful aromatics will be produced from both fractions in this project. On the one hand, the phenols are reduced to building blocks that can be used in the polyurethane, polyester, polyamide, polycarbonate and phenolresin industry. On the other hand, the sugar pulp is also used for the production of aromatics such as benzene, styrene, and terephthalic acid. The ultimate ambition is to set up a biorefinery, which produces aromatics from timber with 90% carbon efficiency.
This multidisciplinary project will work on the following issues and challenges:
- What is the ideal raw material (plant species) for bio-aromatics synthesis? Understanding the structure of the plant components and their relative proportions in the cell wall in relation to the convertibility of the plant species is very important.
- How can we best address the separation of different chemicals that result from the conversion technology?
- How convertible is the sugar pulp fraction in yeast fermentation processes and chemical catalysis and thermal processes to aromatic building blocks for the chemical industry?
- What are the most interesting synthetic routes from the lignin fraction, which allow both synthesis of existing chemicals such as phenol, but also new chemicals for polymer and fine chemical applications?
(1) Van den Bosch et al. Reductive lignocellulose fractionation into soluble lignin-derived phenolic mono- and dimers and processable carbohydrate pulp Energy Environ. Sci., 2015, DOI: 10.1039/C5EE00204D
||01/04/2015 – 31/03/2019