Yanet Villasana

Microwave pretreatment (MWP) has emerged as a promising strategy to enhance the pyrolysis of lignocellulosic biomass due to its rapid, volumetric, and selective heating. By disrupting the recalcitrant structure of cellulose, hemicellulose, and lignin, MWP improves biomass deconstruction, increases carbohydrate accessibility, and enhances yields of bio-oil, syngas, and biochar. When combined with complementary pretreatments—such as alkali, acid, hydrothermal, ultrasonic, or ionic-liquid methods—MWP further reduces activation energies, facilitating more efficient saccharification and thermal conversion. This review systematically evaluates scientific progress in this field through bibliometric analysis, mapping research trends, evolution, and collaborative networks. Key research questions are addressed regarding the technical advantages of MWP, the physicochemical transformations induced in biomass, and associated environmental benefits. Findings indicate that microwave irradiation promotes hemicellulose depolymerization, reduces cellulose crystallinity, and weakens lignin–carbohydrate linkages, which facilitates subsequent thermal decomposition and contributes to improved pyrolysis efficiency and product quality. From an environmental perspective, MWP contributes to energy savings, mitigates greenhouse gas emissions, and supports the integration of renewable electricity in biomass conversion.

This review critically evaluates the scientific progress in this field through a bibliometric analysis that maps research evolution, trends, and collaborative networks. In its second part, the article addresses key research questions regarding the technical advantages of microwave pretreatment, the physicochemical transformations induced in biomass, and the associated environmental benefits. Reported findings demonstrate that microwave irradiation promotes hemicellulose depolymerization, reduces cellulose crystallinity, and partially removes lignin, thereby facilitating higher pyrolysis efficiency, increased yields of bio-oil and syngas, and improved biochar properties. From an environmental perspective, MWP contributes to energy savings, mitigating greenhouse gases, and integrating renewable electricity sources into biomass conversion pathways. By consolidating current evidence, this review highlights both the opportunities and challenges of microwave-assisted strategies, providing a foundation for future research and positioning this technology as a promising enabler for sustainable biomass valorization.

Posters sessions are popular informal forums to share emerging scientific results as they encourage discussion beyond results to include methodology, problems, and solutions. On the other hand, when there are too many posters, people suffer from cognitive overload and so are incapable of seeing and appreciating all of the research. Moreover, posters sessions are less well attended than presentations and as a consequence some authors leave the poster unattended. Poster competitions are one means to encourage presenters to stay at their post and people to come (especially when there are free refreshments). To identify the best poster(s) requires a simple scoring scheme, motivated judges who necessarily examine half‐a‐dozen or more posters, and a calibration method to account for differing opinions between judges. Judging is imperfect but we should be capable of agreeing which posters are among the top 10%.

Ecuador as an international leader in the production of cocoa beans produced more than 300 000 tons in 2021; hence, the management and valorization of the 2 MM tons of waste generated annually by this industry have a strategic and socioeconomic value. Consequently, appropriate technologies to avoid environmental problems and promote sustainable development and the bioeconomy, especially considering that this is a megadiverse country, are of the utmost relevance. For this reason, we explored a low-cost pyrolysis route for valorizing cocoa pod husks from Ecuador's Amazonian region, aiming at producing pyrolysis liquids (bio-oil), biochar, and gas as an alternative chemical source from cocoa residues in the absence of hydrogen. Downstream catalytic processing of hot pyrolysis vapors using Mo- and/or Ni-based catalysts and standalone γ-Al₂O₃ was applied for obtaining upgraded bio-oils in a laboratory-scale fixed bed reactor, at 500 °C in a N₂ atmosphere. As a result, bimetallic catalysts increased the bio-oil aqueous phase yield by 6.6%, at the expense of the organic phase due to cracking reactions according to nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS) results. Overall product yield remained constant, in comparison to pyrolysis without any downstream catalytic treatment (bio-oil ∼39.0-40.0 wt % and permanent gases 24.6-26.6 wt %). Ex situ reduced and passivated MoNi/γ-Al₂O₃ led to the lowest organic phase and highest aqueous phase yields. The product distribution between the two liquid phases was also modified by the catalytic upgrading experiments carried out, according to heteronuclear single-quantum correlation (HSQC), total correlation spectroscopy (TOCSY), and NMR analyses. The detailed composition distribution reported here shows the chemical production potential of this residue and serves as a starting point for subsequent valorizing technologies and/or processes in the food and nonfood industry beneficiating society, environment, economy, and research.

In the Ecuadorian Amazonia, there is a concern about the presence of high concentrations of cadmium (Cd) in rivers and sediments because of changes in land use and anthropogenic activities, e.g., mining and oil exploitation. Hence, the research related to water treatment processes to meet environmental standards has gained relevance. The use of biochar (BC) as adsorbent is considered a promising and low-cost alternative to improve the water quality in developing countries. In this work, lignocellulosic wastes from Guadua angustifolia were transformed through thermochemical treatments, into a promising carbonaceous material, such as BC. BC samples were prepared by pyrolysis (termed pyrochar, PC) and hydrothermal carbonization (termed hydrochar, HC). Their physicochemical properties were correlated with the Cd adsorption removal performance, analyzing the effect of adsorbent dosage, initial solution pH, adsorption kinetics and adsorption isotherms. HC showed the highest Cd adsorption performance, due to the presence of a higher number of oxygenated functional groups, as confirmed by FTIR, XPS and Raman spectroscopy. This research has proposed a sustainable alternative for the recovery of an available waste, contributing to mitigate the effects of the presence of metals on the health and economy of the most vulnerable sectors of society.

All chemical, biochemical, and biological processes depend on pH. Since the 1920s, when the first electrode was introduced to determine the concentration of hydrogen ions, pH measurement techniques have been evolving to fit the application at laboratory and industrial scales. These techniques include conventional methods based on electrical and optical methods like glass electrodes and variants. Most of the current methods still require a probe to be immersed in a solution. However, biomedical applications in the development stages involve non‐invasive probes that measure hydrogen ion concentration or electrical conductivity, which is related to the concentration of all ions. Instruments also measure both these properties simultaneously for water analysis, agriculture, and electrochemistry. pH drops by as much as 90% increasing temperature from 5–45°C (for MgSO₄, NaCl, and an acetate buffer). The repeatability is excellent for a glass electrodes, which continues to be the measurement technique of choice for most laboratories, with a standard deviation of better than 0.08% for low molar concentrations (0.05 M) that increases to above 0.2% at high molar concentrations (>0.7 M). Besides the standard potentiometric methods, emerging techniques include ion‐sensitive field transistors, pH imaging, conductometric, acoustic microsensors, microcantilevers, and spectroscopy. In the first 6 months of 2020, Web of Science indexed almost 10 000 articles that mentioned pH as a keyword; most were in environmental sciences, multidisciplinary chemistry, and chemical engineering. Here, we review the latest developments, including spectroscopic methods, progress towards miniaturization, in particular for bio‐medical applications like skin and bio‐fluids, unconventional sampling, repeatability, and uncertainty.