Xun Liao | EPFL Graph Search

I'm a LCA sustainability consultant, focusing on R&D and applications of integrating LCA with traditional corporate ESG reporting and management, as well as bridging the gap between LCA, Supply chain management (SCM) , risk assessment and business sustainability investment and decision-making.

As a Marie Curie PhD fellow in EPFL, I'm working on sustainability (social/economic/environmental) assessment, design and optimization of different biorefinery concepts.

As a sustainability consultant, I'm researching and developing methodologies and tools for the following field:

Corporate ESG and sustainability investment

-Assess and manage GHG emissions, Water and land, renewable energy, human health, Biodiversity, social issues

-Materiality, CDP report, GRI and other reporting initiatives

-Competitive advantage through investment in sustainability (ESG) programs

Strategy, Supply chain management and risk assessment within the framework of Life Cycle thinking

Commodity, Supply chain, Operational risks due to regulatory, physical factors.
Life cycle costing
Risk assessment
Integration of assessment, optimization and management of supply chain, downstream and corporate operational data

I have many years experience in life cycle assessment, with expertise in water database modeling and assessment, energy analysis and life cycle inventory modeling. Worked with various industries, including energy, agri-food, packaging, tire, oil & gas, semi-conductor, pet food, pharmaceutical and textile sectors, for clients such as World Business Council for Sustainable Development, Mondelez, Kraft Foods, Nestlé, Michelin, Bayer, Pfizer, Huntsman, GE, Intel, and many others.

Regionalized Life Cycle Assessment of Food and Energy Systems

Xun Liao

To steer the sustainable transition in the food and energy sectors, reliable environmental data is required to answer environmental questions related to single agricultural crop, food product or energy technologies. Life cycle assessment (LCA) has been widely applied to assess the environmental footprints and mitigation potentials of a product. Given the large spatial variabilities of food and electricity production, regionalized LCA is regarded to provide more accurate environmental impact. When the sourcing country of production origin for a purchased product is unknown, a process-based regionalized LCA is often conducted arbitrarily with subjective choices of estimating sourcing countries of production origins. This thesis developed a general process-based regionalized LCA computational structure to improve the inclusion of spatial details of tracing the spatial locations of cross-border product flows from origin of production to destination of consumption, based on the commodity balancing of a product on the country level. The model is validated with a numerical example and demonstrated with a case study from literature for an improved accuracy of impact results. The proposed model offers a coherent and transparent way of analyzing the influence of different trade assumptions or truncation errors. It can be used to improve the global value chain modeling of agricultural commodities. Increasingly, companies are making product footprint and comparative claims available on the individual product level. International food companies often have a global footprint in their product supply chain and a large product portfolio for the same functionality sold in various consumer markets. This thesis developed a stepwise framework for operationalizing the application of regionalized LCA to assess a large-scale portfolio of food product. Its feasibility and reliability are tested with a case study comparing 212 plant-based fat spreads and 40 dairy butters sold in 21 countries. It shows large inter-product variabilities, ranging from 0.98 to 6.93 (mean 3.3) kg CO2-eq/kg for 212 plant-based spreads and 8.08 to 16.93 (mean 12.1) kg CO2-eq for 21 dairy butters. The key drivers and main uncertainties of impact are the assumptions of the sourcing country of production and GHG emission from land use change. This thesis further assessed the influence of different regionalized LCA model assumptions and temporal resolutions on the carbon footprint of power to gas (PtG) applications. When the electricity input is based on a renewable electricity mix with guarantee of origin, PtG under study have a 32-65% reduction of carbon footprint compared to fossil natural gas. With current national average consumption mix on a yearly basis, PtG production in Switzerland could be operated to provide climate benefits. However, when moving from yearly average to hourly resolution, PtG has a higher carbon footprint for more than 50% of time over the year. Thus, the deployment of PtG should be guided in a finer temporal resolution to gain potential climate benefits. The regionalized LCA model and methodology as well as case studies contribute to advance our understanding in the methodological aspect of regionalized LCA model and key issues related to its practical operationalization and applications.

EPFL2022

Toward waste valorization by converting bioethanol production residues into nanoparticles and nanocomposite films

Muhammad Farooq, Xun Liao

A "waste-valorization" approach was developed to transform recalcitrant hydrolysis lignin (HL) from secondgeneration bioethanol production into multifunctional bio-based products. The hydrolysis lignin (HL) was extracted with aqueous acetone, yielding two fractions enriched in lignin and cellulose, respectively. The soluble hydrolysis lignin (SHL) was converted into anionic and cationic colloidal lignin particles (CLPs and c-CLPs). The insoluble cellulose-rich fraction was transformed into lignocellulosic nanofibrils that were further combined with CLPs or c-CLPs to obtain nanocomposite films with tailored mechanical properties, oxygen permeability and antioxidant properties. To enable prospective applications of lignin in nanocomposite films and beyond, CLPs and c-CLPs were also produced from a soda lignin (SL) and the influence of the lignin type on the particle size and ecotoxicity was evaluated. Finally, the carbon footprint of the entire process from hydrolysis lignin to films was assessed and an integration to industrial scale was considered to reduce the energy consumption. While most previous work utilizes purified lignin and pristine and often purified cellulose fibers to produce nanomaterials, this work provides a proof of concept for utilizing the recalcitrant lignin-rich side stream of the bioethanol process as raw material for functional nanomaterials and renewable composites. (C) 2021 The Authors. Published by Elsevier B.V.

ELSEVIER2021

Large-scale regionalised LCA shows that plant-based fat spreads have a lower climate, land occupation and water scarcity impact than dairy butter

Xun Liao

Purpose In light of the sustainable diet debate, we conducted a large-scale regionalised LCA to answer the following questions: (i) does the climate advantage hypothesis of plant-based fat spreads and creams over dairy butter and cream hold regardless of the variabilities of product recipes, geographies and the influence of land use change (LUC)? (ii) Considering the climate-water-land nexus, is there a risk of shifting impacts from climate to water scarcity and land occupation, and what are the key opportunities for impact mitigation? Methods A framework for conducting a large-scale regionalised LCA was developed and applied to compare the environmental impacts of 212 plant-based fat spreads, 16 plant-based creams and 40 dairy alternatives sold in 21 countries per 1 kg of product. Data was compiled for different product recipes, key ingredient sourcing countries, production factory locations, energy mixes, packaging designs, transportation and end-of-life scenarios. Spatially (archetype) differentiated agricultural life cycle inventory data were generated, as well as LUC emissions for agricultural ingredients. A total of 18 environmental indicators were assessed. Results and discussion All plant-based spreads had a significantly lower climate impact than butter, with and without LUC inclusion. The regionalised analysis highlighted large variabilities across products, ranging from 0.98 to 6.93 (mean 3.3) kg CO2-eq for 212 plant-based spreads and 8.08 to 16.93 (mean 12.1) kg CO2-eq for 21 dairy butter with 95th confidence interval. The main drivers of GHG emissions for plant-based products are oilseed farming and the associated LUC emissions, which can vary significantly depending on type of oilseeds, quantity and sourcing country; in the worst-case scenario, the climate advantage is no longer valid due to LUC. Thus, the inclusion of LUC is essential for a robust assessment and hotspot identification. Overall, the risk of shifting impact was small, as most of the plant-based spreads also had lower impacts for water scarcity footprints and land occupation; 8 of the 212 products were not lower, due to oilseed ingredients with high embodied impacts. Conclusions This study confirmed that plant-based spreads had lower climate, water and land impacts than butter, despite variability of product recipes, geographies and influence of LUC. This research offers a framework for performing regionalised agricultural LCA for a large portfolio of products thereby enabling identification of inter-product variabilities and hotspots for the development of mitigation strategies. Key mitigation opportunities include reducing oilseed ingredients' embodied impacts by optimising product recipe design and adapting supply chain sourcing and agricultural practice.

2020

Large-scale regionalised LCA shows that plant-based fat spreads have a lower climate, land occupation and water scarcity impact than dairy butter

Xun Liao

2020

Regionalized Life Cycle Assessment of Food and Energy Systems

Xun Liao

EPFL2022