Design and evaluation of sustainable biorefineries in Mexico: a modeling and experimental approach

Abstract

Biorefineries are an alternative to replace crude oil refineries and reduce fossil fuels consumption worldwide. Mexico has a wide variety of renewable biomass resources with great potential for being used in a biorefinery for production of multiple high value products, as alternatives to crude oil-derived products. To make it work, biorefineries require simultaneous implementation of several conditions such as the use of abundant and renewable biomass feedstocks, production of multiple value-added bioproducts, lignin valorization, integral use of biomass, reuse of residues and byproducts, energy efficiency, to name the most important ones. However, sustainable biorefineries in Mexico require further investigation to determine its feasibility and sustainability. In this thesis, the aims were to develop sustainable designs of biorefineries, based on renewable and abundant biomass in the context of Mexico, for replacing the consumption of fossil resources for production of multiple high value products, such as biopharmaceutical products, chemicals, biofuels, energy, and so on. For doing this, sustainability evaluation, modeling, optimizations tools, and an experimental extraction process were performed. The main results are described as follows. First, the sustainable design of a castor oil-based biorefinery located in Michoacan State in Mexico was developed. Azelaic, sebacic, and undecylenic acids, as well as biodiesel, heat, and power were the major marketable products. An optimization assessment allowed to minimize the environmental impact and maximize the economic revenues. Second, the sustainable design of a biorefinery with lignin valorization that uses birch and pine wood as feedstock, located in Michoacan State, was performed. Ethylene and propylene, the two largest chemicals worldwide produced, were the main products. An energy optimization assessment allowed to reduce several environmental impacts related to the consumption of fuels and energy. Third, the extraction and evaluation of value-added compounds from birch leaves was done in order to determine how feasible is the integral valorization of the birch tree in a biorefinery. Finally, the economic and environmental evaluation of the production of neuroprotective orange residue extracts was done. In conclusion, the castor oil plant and lignin from birch and pine wood are promising alternatives as biorefinery feedstocks for bio-based chemical production that can replace important petrochemical products in Mexico. Furthermore, the optimal distribution of castor oil feedstock allows to upgrade the environmental and economic biorefinery’s performances. Moreover, energy optimization improves the lignin biorefinery's environmental performance and the impact can be measured using the LCA. Also, valorization of the birch leaves is a promising option for production of extracts with high content of phenolic compounds and high antioxidant capacity in a biorefinery based on the birch tree. Additionally, orange residue valorization for production of neuroprotective extracts is a promising approach that can be included in a biorefinery based on orange fruit. Finally, this work contributes to the development of sustainable biorefineries in Mexico using renewable an abundant biomass in Mexico, replacing the consumption of fossil resources.