Comparison between Different Hybrid Life Cycle Assessment Methodologies: A Review and Case Study of Biomass-based p-Xylene Production

Abstract

Two common life cycle assessment (LCA) methods are process LCA and economic input–output LCA, which suffer from truncation error and aggregation error, respectively. Many hybridization techniques are developed to improve the accuracy of analysis by combining both methods. This work aims to review different hybrid LCA methodologies under various data availabilities through a case study of two biomass-based p-xylene production technologies using concentrated acid (CA) and molten salt hydrate (MSH) hydrolysis. The MSH process without selling electricity to the grid has a lower global warming potential than the CA process when evaluated by process LCA, tiered hybrid LCA, and integrated hybrid LCA after binary correction for double counting. With prior knowledge on LCA databases or assumptions on economic activities that are irrelevant to the production, double counting could be further eliminated, and the MSH process would behave similarly or even worse than the CA process.

Incorporating New Technologies in EEIO Models

“…Specifically, Υ i,j that correspond to the expenditures of each of the commodities i to produce one physical unit of the new-commodity in each of the new industries j are required. Then, future use, in monetary terms, follows Equation (9). It is assumed that the new industries do not use the new commodity as input.…”

“…The underlying models for LCA, life cycle inventory (LCI) models, may be constructed using traditional process-based LCI [5], environmentally extended input-output-based LCI [5][6][7] or hybrid approaches that integrate the two [5,8,9]. As EEIO models (also known as Input-Output LCA models) embed the full structure of the underlying economy represented in the input-output table, EEIO models have an inherent advantage of comprehensiveness and completeness when it is of interest to understand the impacts of new products and new technologies across the whole economy.…”

Shaping Effective Practices for Incorporating Sustainability Assessment in Manuscripts Submitted to ACS Sustainable Chemistry & Engineering: Catalysis and Catalytic Processes

“…35 Readers may find a review and application of the hybrid LCA methodology for comparing two biomass-based pxylene productions useful. 36 It should be recognized that chemical process design technoeconomic analysis (TEA) and LCA are usually performed at a low technology readiness level (TRL) based on the prevalent efficiencies of the unit operations, such as process yields and separations. Prospective LCA builds on current LCA projections to project future process and product improvement scenarios, 37 thereby providing a trajectory for current technologies to improve sustainability attributes.…”

“…In such cases, the economic input–output LCA (EIO-LCA) method based on economic activities and their environmental impacts may be useful. , A hybrid LCA method that combines the advantages of process LCA and EIO-LCA methods has also been employed and helps further delineate the upstream impacts from the gate-to-gate impacts . Readers may find a review and application of the hybrid LCA methodology for comparing two biomass-based p -xylene productions useful …”

Green Chemistry and Process Intensification: Milestones on a Sustainable Development

“…Therefore, numerous combined methods are utilized to ameliorate the total accuracy. Luo and Ierapetritou [109] examined numerous integrated LCA methods over a case study of two biomass-based p-xylene fabrication techniques and suggested essential insights appropriate to future LCA. Moreover, LCAs of the production of broadly employed titanium dioxide nanoparticles [110] and butyl acetate [111] furnished conceptual directing for more sustainable synthesis of both.…”