Juan Gabriel Segovia-Hernández

Sustainable aviation fuel (SAF) deployment requires simultaneous coordination of spatially distributed biomass supply chains and nonlinear conversion technologies. This study develops an integrated multiscale optimization framework for SAF production in Mexico using second-generation sugarcane bagasse as the lignocellulosic resource for alcohol-intermediate production, followed by an intensified Alcohol-to-Jet (ATJ) upgrading stage targeting Mexico City Airport. A multi-period mixed-integer linear programming model optimizes harvest-area selection, biorefinery location, biomass allocation, inventory, production, and distribution, while an Aspen Plus model of an intensified Alcohol-to-Jet (ATJ) process with reactive distillation is optimized using Differential Evolution with Tabu List. In this framework, the ATJ block is not modeled as direct biomass-to-jet conversion. In the base case, ethanol is used as the representative alcohol intermediate. Therefore, the upstream biomass-to-alcohol section is represented through an effective bagasse-to-ethanol coefficient, whereas the Aspen Plus–DETL model explicitly describes the downstream ethanol-to-ATJ-range hydrocarbon blendstock upgrading section through dehydration, ethylene oligomerization, hydrogenation, and fractionation. Process yield, production cost, environmental impact, and feasible capacity are fed back into the supply chain model, making process performance endogenous rather than fixed. Results show that the decoupled supply chain baseline favors large production capacities, reducing TAC from approximately 1010 to 340 USD/tSAF and system-level EI99 from 1.110 to 1.059 kPt EI99/tSAF as capacity increases from 80,000 to 490,000 tSAF/year. This corresponds to an environmental reduction of approximately 5.2%. In contrast, isolated ATJ optimization exhibits nonlinear scale-dependent behavior, with process-only EI99 decreasing from approximately 1.70 to 0.55 kPt EI99/tSAF. The integrated framework identifies an intermediate capacity region of 120,000–300,000 tSAF/year, with TAC values of approximately 3400–6800 USD/tSAF and total EI99 values of approximately 0.78–1.31 kPt EI99/tSAF. The integrated base case at 200,000 tSAF/year has an EI99 value of approximately 1.063 kPt EI99/tSAF.

This work presents the conceptual design, rigorous simulation, and multi-objective optimization of an integrated multiproduct biorefinery focused on the sustainable valorization of lignin into catechol and a portfolio of high-value aromatic derivatives, including guaiacol, vanillin, and vanillic acid. The proposed methodology combines a critical review of synthesis pathways and kinetic data with detailed process modeling in Aspen Plus® V14. The process framework begins with lignocellulosic biomass pretreatment via acid hydrolysis, followed by catalytic lignin depolymerization to obtain catechol as a platform intermediate. Subsequently, dedicated reaction and separation sections are designed for the selective conversion of catechol into value-added derivatives, incorporating energy-efficient and thermally integrated separation schemes. A stochastic multi-objective optimization strategy based on Differential Evolution with a Tabu List (DETL) is implemented to simultaneously assess economic and environmental performance indicators. The results demonstrate that lignin can be effectively upgraded into commercially relevant fine chemicals, confirming its strategic role within next-generation biorefineries and reinforcing the transition toward circular, low-emission chemical processes.

The valorization of lignocellulosic biomass represents a key pathway toward sustainable chemical production, as it enables the development of circular economy products with reduced dependence on fossil resources. Among the platform molecules derived from biomass, furfural stands out as a versatile intermediate that can be transformed into several high-value chemicals, such as furfuryl alcohol, 2-methylfuran, tetrahydrofurfuryl alcohol, furan, tetrahydrofuran, and maleic anhydride. In this work, an integrated biorefinery scheme for producing the main furfural derivatives is proposed and evaluated through process simulation and sustainability metrics. The process was modeled in Aspen Plus V14, using furfural obtained from lignocellulosic biomass (corn stover) as raw material, following hydrogenation and oxidation routes. The process is multi-product, meaning that the main furfural derivatives are produced simultaneously within the same plant. This was achieved by implementing splitters that work at 50% capacity in the division of raw materials. The mass and energy balances from the simulation were used to evaluate environmental, economic, energy, and efficiency performance using a set of indicators. Economic data were obtained from Aspen Economics, yielding a total capital cost of 7.65 MUSD and a total annual cost of 1.93 MUSD/year. The environmental assessment resulted in an EI99 of approximately 2.0×108 mPt/year, mainly influenced by hydrogen consumption and carbon monoxide emissions. From an efficiency perspective, the process shows favorable performance, with an MLI of 0.07 and an MCI of 69%, indicating high material efficiency despite the inherent complexity of multi-stage hydrogenation and oxidation pathways. Overall, the results demonstrate the technical and sustainability potential of an integrated furfural-based biorefinery, while highlighting opportunities for further improvement through process integration and hydrogen recovery.

Green hydrogen constitutes a strategic energy vector for achieving the Sustainable Development Goals (SDGs 7, 9, 12, and 13) due to its high energy density, flexibility for renewable energy storage, and direct emission-free operation. However, its production critically depends on the supply of high-purity water, which is unsustainable in the context of a projected 40% global water deficit by 2030. Given that more than 97% of available water is saline, integrating desalination processes with electrolysis constitutes an essential strategy for transitioning toward circular economy models in water resource management. This work presents the conceptual design, detailed modeling, and optimization of an integrated process for the sustainable production of green hydrogen from saline water. The system couples a desalination technology (Solar Distillation) with two electrolysis technologies (AEL and SOEC), modeled through physicochemical, electrochemical, and thermodynamic principles. The objective is to determine technological configurations, materials, and operating conditions that maximize the energy efficiency and minimize the LCOH, contributing to the development of viable routes within the energy transition and circular economy. The results shows that the viability of a integrated Seawater Green Hydrogen system with a detail model is possible. In contrast to black-box models, this model yielded a detailed, geometrically accurate simulation that captures phenomenological effects. It enables the development of processes that contribute to the energy transition, reduce freshwater consumption, and assess their economic viability. The sensitivity analysis revealed promising solutions, with LCOH values ranging from 4.22 to 7.10 USD/kg and overall energy efficiencies between 67% and 82%.