Hydrothermal Carbonization of Green Harvesting Residues (GHRs) from Sugar Cane: Effect of Temperature and Water/GHR Ratio on Mass and Energy Yield.

The Valle del Cauca region in Colombia is a significant producer of sugar cane, resulting in large quantities of agricultural residues (green harvesting residues (GHRs)). To ensure sustainable management of these residues, it is crucial to implement proper treatment and disposal technologies while also reusing waste to produce biogas, bioelectricity, or biofuels. The biomass hydrothermal carbonization process offers a means to convert these residues into useful products that serve as fuels or valuable energy materials. This thermal treatment involves the use of water as a solvent and reagent within the biomass's internal structure. In this study, sugar cane cutting residues were collected with relatively high moisture content of 8.5% wt. These residues were subjected to carbonization temperatures ranging from 200 to 300 °C, along with water/GHR ratios between 5/1 and 10/1. The properties of the resulting hydrocarbons were analyzed by using proximate and ultimate analysis. The objective was to produce hydrochar samples with the highest higher heating value (HHV) and energy density compared with the GHRs. The HHV value of the hydrochar showed a significant increase of 69.6% compared with that of the GHRs, reaching 43.5 MJ/kg. Besides, process parameters were optimized for mass yields, energy yields, and ash content. This exploration led us to investigate a new temperature range between 280 and 320 °C, allowing us to establish an optimal value for the hydrochar's properties.

Imperative of Integrating Process Safety Education in Chemical Engineering Curricula.

The integration of process safety education into chemical engineering programs has become a pressing necessity for chemical engineers worldwide. However, some chemical engineering programs have not yet incorporated process safety into their curricula. The purpose of this Viewpoint is to encourage a discussion on the imperative of mobilizing a global update of chemical engineering education and integrating process safety. This initiative will not only inspire experts in the field to support those seeking this change but also encourage new participants, especially from countries that have not yet embraced this much-needed transformation in chemical engineering education.

Thermochemical behavior of agricultural and industrial sugarcane residues for bioenergy applications.

The Colombian sugarcane industry yields significant residues, categorized as agricultural and industrial. While bagasse, a widely studied industrial residue, is employed for energy recovery through combustion, agricultural residues are often left in fields. This study assesses the combustion behavior of these residues in typical collection scenarios. Additionally, it encompasses the characterization of residues from genetically modified sugarcane varieties in Colombia, potentially exhibiting distinct properties not previously documented. Non-isothermal thermogravimetrical analysis was employed to study the thermal behavior of sugarcane industrial residues (bagasse and pith) alongside agricultural residues from two different sugarcane varieties. This facilitated the determination of combustion reactivity through characteristic combustion process temperatures and technical parameters like ignition and combustion indexes. Proximate, elemental, and biochemical analyses revealed slight compositional differences. Agricultural residues demonstrated higher ash content (up to 34%) due to foreign matter adhering during harvesting, as well as soil and mud attachment during collection. Lignin content also varied, being lower for bagasse and pith, attributed to the juice extraction and milling processes that remove soluble lignin. Thermogravimetric analysis unveiled a two-stage burning process in all samples: devolatilization and char formation (~170°C), followed by char combustion (~310°C). Characteristic temperatures displayed subtle differences, with agricultural residues exhibiting lower temperatures and decomposition rates, resulting in reduced ignition and combustion indexes. This indicates heightened combustion reactivity in industrial residues, attributed to their elevated oxygen percentage, leading to more reactive functional groups and greater combustion stability compared to agricultural residues. This information is pertinent for optimizing sugarcane residues utilization in energy applications.

Weather in collection time affects composition of sugarcane agricultural residues.Combustion of sugarcane residues occurs over similar temperature ranges.Industrial residues are more reactive to combustion than agricultural residues.Overall thermal behavior of sugarcane residues depends on their composition.