The fundamental significance of using cattle manure as a case study is the risk of continuing pollution, caused by its poor management in connection to the increasing demand for animal-derived food. Pyrolysis and gasification, effective solutions with real valorization potential, are the proposed techniques of converting this type of waste into valuable products. After a complete initial characterization, cattle manure is converted into hydrogen-rich syngas, using a modular hybrid fixed-bed reactor, at a generous thermal range, 700 degrees C to 875 degrees C, under different process agents, without the use of steam or the addition of catalysts. In comparison to gasification, the quantification of syngas demonstrates higher yields in pyrolysis processes, but with a lower energy potential. The content of the syngas in hydrogen, - 25 vol% and hydrocarbons, - 25 vol%, emphasized by an energetic value of - 17 MJ/m3, holistically places the gasification process in a slight advantage in relation to pyrolysis, exceeding the values presented by other studies on similar matrices and technical conditions. The forecast investigation of syngas composition through polynomial functions shows a significant drop in hydrogen and hydrocarbon concentrations after the 80-min sampling period.

In this work we report synthesis and characterization of integrated SWCNT-Pt-P2O5-based sensors for absolute humidity (AH) measurement. The sensors were obtained by direct deposition of an active doped layer to the surface of an interdigitated planar sensor type, by drop cast method. For the experimental investigation two sensors with the same active layer were fabricated and tested for detecting water humidity in inert gas at room temperature. The sensing mechanism of the fabricated sensors is characterized by the electrical variations in sensors resistance, as a function of the AH related to the water trapping effect produced at the surface of the active layer. This physical behavior confirms the existence of a resistive path formed between the structured microelectrodes. The resistivity of the layer increases or decreases proportional to the raise or decline of the AH values in the range of 1% to 90% for the tested gas, as a result of an electrolysis process that takes place under sensors supply voltage, influenced also by the Pt catalyst. The sensors, so fabricated, exhibit remarkable sensing, stability and recovery capabilities and could be integrated in an efficient low-powered sensor-platforms for industrial usage.

This work addresses the detection of hydrogen stable isotopes, deuterium and protium, an important consideration towards safety matters in the design and operation of industrial facilities (e.g. heavy water detritiation plants), using a reliable and low cost sensor structure. The presented sensor platform approach is based on deposition of a hydrogen high affinity metal, namely palladium (Pd), on purified and functionalized single wall carbon nanotubes (SWCNTs) known for their good electronic, chemical-stability and sensitivity characteristics. The proposed Pd/SWCNTs based sensor was tested for different concentrations of protium and deuterium mixtures in air, from 0.1 to 4%. It allows discriminating between protium and deuterium due to the different adsorption/desorption behavior given by the sensor response. Embedded in a measurement integrated platform, this proposed alternative of flexible sensor matrix can be a suitable tool for deuterium/protium leak detections in facilities used for tritium separation.

An integrated SWCNT-Pt-P2O5-based sensor type was fabricated by direct deposition of the films on a commercial planar sensor substrate without any conventional coating and using the dropcast procedure. For the humidity sensing experimental work, two sensors were prepared by the authors using this facile solution and a system for data acquisition. The measurements showed that the integrated SWCNT sensors exhibit high and fast response (of approximately 25 s) toward a humidity range from 1% to 90% AH. The high sensitivity and dynamic reproducibility of these sensors materials reveal that the proposed composition and morphology can be applied to fabricate sensing devices for detecting water humidity in nitrogen gas from low to medium concentration range. The experimental results also confirm that the proposed solution fits in the class of proper structures for humidity sensing in inert gas and can show remarkable sensing and recovery capabilities for industrial usage. The sensing mechanism is attributed to the fact that electrical changes in sensors resistance, as a function of the AH, are related to the attraction and trapping of water molecules produced on the surface of the film. Due to this physical behavior, a resistive path is formed between the microelectrodes. The resistivity of the system increases as the AH increases, or decreases when the AH values decreases due to an electrolysis process taking place under sensors supply voltage and using Pt catalyst.