The amount of sargassum seaweed washed ashore on the beaches of Africa, Brazil, Central America and the Caribbean has increased to the point where it has become a social, environmental and financial issue. This research evaluates the potential for Sargassum spp. of the Mexican Caribbean coast to be used in the production of biomethane by estimating: a) stoichiometric methane production (SMP), b) biochemical methane potential (BMP) and c) biodegradability index (BI).The use of a sigmoidal model generalized to substrate to inoculum ratios is proposed, to predict the biomethane production during the anaerobic digestion (AD) of the sargassum. The information obtained shows the seaweed's potential for biomethane production and will be useful for estimates and scaling when implementing energy harnessing systems for sargassum in the Caribbean. The use of biomass is a key element in the move towards a circular economy. It is hoped that the use of technologies like AD leads to the integration of this seaweed into an economic value chain, thereby reducing the adverse effects of its presence on the ecosystem.

The use and transformation of biomass into highly valuable products is a key element in circular economy models. The purpose of this research was to characterise the volatile compounds and the temperature at which they are emitted during the thermal decomposition by pyrolysis of algal biomass while looking at three different types: (A1) endemic microalgae consortium, (A2) photobioreactor microalgae consortium and (A3) Caribbean macroalgae consortium. Furthermore, the ultimate (CHON) and proximate (humidity, volatile solids and ashes) compositions of the algal biomass were determined. Some volatile species were identified as having potential industrial interest for use as precursors and intermediaries, such as commercially used aromatic compounds which if not suitably managed can be harmful to our health and the environment. It is concluded that the pyrolysis of algal biomass shows potential for the generation of valuable products. The information generated is useful, especially the temperature at which volatility occurs, in order to access the valuable compounds offered by the algal biomasses, and under the concept of biorefinery convert the issue of biomass disposal into a sustainable source of raw materials.

This research studies the application of a life cycle assessment (LCA) methodology to evaluate the environmental impacts of an improvement to traditional brick manufacture. This study case was carried out using realistic combustion gas measurements and experimental results. The traditional process and the addition of one or two hopper blower (HB) devices provided the three scenarios for this study, which were evaluated quantitatively using a set of metric indicators for potential impacts while applying a "cradle-to-gate" approach. A decreasing trend was observed for most values of the potential impact categories when the device was used. An opportunity to improve the traditional process by adding this device has been identified, as a reduction in the environmental impact categories has been observed. The study suggests that the LCA tool may be valuable for quantifying the environmental impacts of improvements in the processes.

This document presents a Life Cycle Assessment (LCA) study to quantify the environmental cradle-to-gate impact of the manufacture of brick for the construction industry, produced with material of igneous source. Its mineral composition and thermal isolation properties were characterized for use in real estate construction. The LCA results for brick manufacture using this material identified the greatest environmental impact to be associated with material extraction and its proportional cement content. Additionally, this document presents an evaluation of the environmental impact of the manufacturing process by comparing traditional fired clay brick and brick of the material under study. In conclusion, the studied material shows thermal insulation qualities and suitability for the manufacture of bricks with low incorporated energy.

The purpose of this chapter is to present a generalized model for the construction of inventories for the production of electricity through biogas. This general framework can be adjusted to any power plant that uses biogas, since it complies with the main material and energy balances. This chapter describes the main technologies used in biogas power energy production, separating them into five main subsystems that integrate the general life cycle inventory, as well as the inputs and outputs considered in the development of the inventories. The life cycle assessment (LCA) of two types of plants is presented as study cases: (i) the biogas power energy generation with organic waste in landfills as substrate and (ii) the biogas power energy generation using dairy cattle manure as substrate. Both systems, in addition to using different types of substrate, present differences in their substages. It is concluded that the generation of studies of life cycle analysis of technologies facilitates decision makers, producers, and government agencies to develop and identify areas of opportunity from life cycle thinking.