Search Results (4)

Liquefaction is an effective thermochemical process for converting lignocellulosic biomass into bio-oil, a hydrocarbon-rich resource. This study explores liquefied biomass electrolysis as a novel method to promote the electrocracking of organic molecules into value-added compounds while simultaneously producing hydrogen (H₂). Key innovations include utilizing water from the liquefaction process as an electrolyte component to minimize industrial waste and incorporating carbon dioxide (CO₂) into the process to enhance decarbonization efforts and generate valuable byproducts. The electrolysis process was optimized by adding 2 M KOH, and voltammetric methods were employed to analyze the resulting emulsion. The experimental conditions, such as the temperature, anode material, current type, applied cell voltage, and CO₂ bubbling, were systematically evaluated. Direct current electrolysis at 70 °C using nickel electrodes produced 55 mL of H₂ gas with the highest Faradaic (43%) and energetic (39%) efficiency. On the other hand, pulsed electrolysis at room temperature generated a higher H₂ gas volume (102 mL) but was less efficient, showing 30% Faradaic and 11% energetic efficiency. FTIR analysis revealed no significant functional group changes in the electrolyte post-electrolysis. Additionally, the solid deposits formed at the anode had an ash content of 36%. This work demonstrates that electrocracking bio-oil is a clean, sustainable approach to H₂ production and the synthesis of valuable organic compounds, offering significant potential for biorefinery applications. Full article

Existing combined heat and power plants usually operate on part-load conditions during low heating demand seasons. Similarly, there are boilers designated for winter use that remain inactive for much of the year. This brings a concern about the inefficiency of resource utilization. Retrofitting existing CHP plants (especially for those with spare boilers) for biofuel production could increase revenue and enhance resource efficiency. This study introduces a novel approach that combines biomass gasification and pyrolysis in a polygeneration process that is based on utilizing existing CHP facilities to produce biomethane, bio-oil, and hydrogen. In this work, a detailed analysis was undertaken of retrofitting an existing biomass combined heat and power plant for biofuel production. The biofuel production plant is designed to explore the polygeneration of hydrogen, biomethane, and bio-oil via the integration of gasification, pyrolysis, and renewable-powered electrolysis. An Aspen Plus model of the proposed biofuel production plant is established followed by a performance investigation of the biofuel production plant under various design conditions. An economic analysis is carried out to examine the profitability of the proposed polygeneration system. Results show that the proposed polygeneration system can achieve 40% carbon efficiency with a payback period of 9 years and an internal rate of return of 17.5%, without the integration of renewable hydrogen. When integrated with renewable-power electrolysis, the carbon efficiency could be significantly improved to approximately 90%; however, the high investment cost associated with the electrolyzer system makes this integration economically unfavorable. Full article

BioLPG is a partially renewable fuel that can be produced by different conversion routes, with vegetable oil hydrotreatment (HVO) being one of the most promising processes. This study uses the Life Cycle Assessment (LCA) approach to assess the environmental impacts associated with this processing. The analysis considered the conditions practiced in Brazil with soybean oil (SO) as raw material, different hydrogen sources, and raw materials’ feed rates in the reaction system. The model was based on secondary data collected for the 2020–2021 biennium, and the environmental impacts were determined for Global Warming Potential, Primary Energy Demand, Terrestrial Acidification, Fine Particulate Matter Formation, Terrestrial Ecotoxicity, and direct Land Use Change. The results show that the SO produced by soybeans grown in Paraná/BR and hydrotreated with H₂ obtained by electrolysis ([SO/H₂]mol/mol = 1:30) had the best environmental performance in four of the six impact categories analyzed. A complementary analysis also identified the best environmental performances for bioLPG obtained from blending SO from different sources to avoid supplier dependence. Even accumulating worse environmental performance than fossil LPG, renewable fuel has promising prospects for deployment in Brazil. Nevertheless, for this to occur, some actions must be implemented in its production cycle. Full article

Bio-oils produced from three different biomass sources, namely cork, pinewood, and olive stones, are evaluated concerning their suitability and prospects of including their electrochemical transformations in a biorefinery scenario for the production of added-value compounds. Different types and concentrations of electrolytes (e.g., H₂SO₄, KOH) are added to the bio-oils to increase the samples’ initially low ionic conductivity. The samples prepared by mixing bio-oil with 2 M KOH aqueous solution (50 vol.%) lead to a stable and homogeneous bio-oil alkaline emulsion suitable for electrochemical studies. The bio-oil samples are characterized by physicochemical methods (e.g., density, viscosity, conductivity), followed by analyzing their electrochemical behavior by voltammetric and chronoamperometric studies. The organics electrooxidation and the hydrogen evolution reaction in the bio-oils are assessed using Pt electrodes. Single- and two-compartment cell laboratory bio-oil electrolyzers are assembled using nickel plate electrodes. Electrolysis is carried out at 2.5 V for 24 h. Attenuated Total Reflection-Fourier-Transform Infrared Spectroscopy and Mass Spectrometry are applied to identify possible changes in the bio-oil samples’ chemical structure during the electrolysis experiments. Comparing the analyses of the bio-oil samples subjected to electrolysis with the blank samples demonstrates that bulk electrolysis significantly changes the bio-oil composition. The bio-oil obtained from cork biomass shows the most promising results, but further studies are required to understand the nature of the actual changes. Full article