###### Abstract
Computer-aided exergy analysis is a valuable tool to identify process hot spots from the energy viewpoint. Three processes for extracting microalgae oil from _Chlorella_ sp. were examined using exergy analysis [19], and a maximum resource efficiency of 51% was reported, based on hexane extraction. [PERSON] et al. [20] assessed the energy profile for four ethanol processes through this method. They found that second-generation biofuendal could reach an exergy efficiency of 80% through steam-explosion, saccharification, fermentation and dehydration pathways. [PERSON] and [PERSON] [21] analyzed the energy and exergy aspects of biomass gasification. They presented a new process setting with built-in heat, power, and liquified natural gas cogeneration. Recently, [PERSON] et al. [22] assessed pyrolysis processes based on different feedstock, in a semi-continuous reactor setting. In addition to exergy evaluation, sustainability assessment emerges as a valuable tool for improving a process or system at the early design stage. Different methods and approaches are used to accomplish this purpose [23]. Among the reported frameworks, indicator-based methods have shown successful results, while keeping an uncomplex formulation. [PERSON] et al. [24] presented a taxonomy for several sustainability indicators, to assess economy, environment, efficiency, and energy areas within a gate-to-gate approach. These scholars continued with this work to extend this methodology by identifying data needs to estimate these indicators. Estimating these indexes involves connecting the mathematical formulas based on data requirements [25]. The GREENSCOPE approach was successfully combined with design principles and computer-aided process engineering to show the advantages of coupling these tools in chemical process sustainability [26]. Exergy performance metrics have also been used in sustainability evaluation, as separate indicators in multiple-indicator analyses [27] and in aggregated approaches [28]. Still, many of these studies have focused on indicator-based analysis, but have not included a comprehensive framework that embodies all the aligned stages from feedstock selection to sustainability evaluation, involving exergy assessment in the process. In addition, there are still missing studies that comprehensively connect process simulation, analysis, and optimization from a sustainability perspective. The development of such methods could contribute to taking low/mid-TRL second-generation technologies to commercialization levels. This work is aimed at the current needs of improving thermochemical technologies for second-generation biofuel production, including new know-how in the simultaneous application of process simulation and exergy analysis, to assess the performance of biofuels from lignocellulosic biomass. Besides, the approach enables process simulation and exergy analysis to be used in decision making, to compare thermochemical technologies. This method represents a new way of selecting and optimizing second-generation biofuel technologies that remain at low- to mid-TRL. The assessment is complemented by a further evaluation of sustainability indicators, based on process benchmarks, taking the assessment to the next level. The presented assessment is introduced to respond to the need and lack of comprehensive and straightforward studies for analyzing and improving bio-based processes from a broader sustainability dimension, by including exergy assessment. This approach is presented as a way of including exergy indicators in sustainable development, bringing new knowledge in process analysis for research and development in biomass transformation technologies. This work presented a practical framework that combines feedstock selection, process simulation, exergy analysis, and sustainability evaluation to compare pyrolysis and gasification as promising technologies to produce second-generation biofuels.