西湖大学BEM实验室

We live in a world with limited environmental resources to meet increasing demand of water, food, energy, raw materials and better healthcare. There are trade-offs within this Food-Energy-Water-Human health Nexus. Lignocellulosic biomass is the most abundant biomass on Earth, with an estimated 181.5 billion tonnes produced annually, and thus has great opportunities to replace petroleum derived chemicals and fuels.In our Biomass Energy and Materials Lab, our long term goal is to enable lignocellulosic bioeconomy via:

1. Efficient and sustainable solvent-based pretreatment technology

2. Exploring the innovative application in the form of materials to enable a bioeconomy

3. Establish multi-scale and multi-perspective sustainable assessment for above technology and supply chain designs

Obtaining high quality lignin through mild pretreatment and value-added products from polysaccharides to realise the full valorisation of lignocellulosic biomass are key to an economically viable and environmentally sustainable biorefinery. As an emerging approach, solvent-based pretreatment has great potential to meet these requirements. Using Hanssen Solubility Parameters (HSP) and COSMO-RS approaches, we screened a potential bio-based solvent (DMI), dimethyl isosorbide, which can fractionate lignocellulosic biomass efficiently and yield high quality lignin. In addition, DMI could also be an excellent solvent for dissolving and regenerating plastics. DFT and Molecular Dynamics (MD) have been used to understand the mechanism of lignin removal and plastic dissolution. Other solvents of interest include deep eutectic solvents (DES) and ionic liquids (IL).

The cellulose stream obtained from the pre-treatment could be modified to contain functional groups and/or to produce nanocellulose by defibrillation. In addition to being a solvent, we design it to be a reactant, e.g. to modify cellulose fibrils via quaternisation. The strategy of modification first followed by defibrillation could reduce energy consumption and produce a range of quaternised nanocellulose for innovative applications, e.g. thin films with a full range of colours and additives for fertilisers to enhance the deposition of water droplets. A conductive DES system has also been synthesised to utilise phytoremediation biomass with synergistic effects of lignin removal and metal extraction. The conductivity of DES enables solvent cleaning and recycling via electrodeposition. In the future, we are interested in developing an approach to design these solvents to fulfil the purpose of the functions.

To support the development of 'green solvent' based technology/biorefinery/industry, a quantitative sustainable life cycle assessment (LCA) framework and model were developed. Firstly, a perspective LCA coupled with process simulation was proposed to generate a life cycle inventory for analysis. This approach enables the design, optimisation and expansion of the biorefinery supply chain. Secondly, a quantitative and USEtox-based assessment framework was developed to quantify the environmental impact of Chemicals of Emerging Concern (CECs) such as decamethylcyclopentasiloxane (D5), IL and PFAs. To the best of our knowledge, this framework is the first of its kind and will support the selection of degradation pathways for emerging chemicals and green design.