Syngas Production, Storage, Compression and Use in Gas Turbines

This chapter analyses syngas production through pyrolysis and gasification, its compression and its use in gas turbines. Syngas compression can be performed during or after thermal treatment processes. Important points are discussed related to syngas ignition, syngas explosion limit at high temperatures and high pressures and syngas combustion kinetics. Kinetic aspects influence ignition and final emissions which are obtained at the completion of the combustion process. The chapter is organized into four subsections, dealing with (1) innovative syngas production plants, (2) syngas compressors and compression process, (3) syngas ignition in both heterogeneous and homogeneous systems and (4) syngas combustion kinetics and experimental methods. Particular attention is given to ignition regions that affect the kinetics, namely systems that operate at temperatures higher than 1000 K can have strong ignition, whereas those operating at lower temperatures have weak ignition. Keywords: Pyrogas Pyrolysis Ignition Syngas Compression GasificationacceptedVersio

Chemical and physical characterization of food waste to improve its use in anaerobic digestion plants

8 figures, 4 tables.Considerable amounts of expired food waste are generated every day. They are rich in organic carbon and in other elements, including nitrogen, phosphorus and potassium, which cannot be wasted. The present work tested expired food waste in terms of biogas production efficiency in anaerobic digestion (AD) process. A database was extrapolated from the tests carried out in order to obtain a complete list of physico-chemical and biochemical methane potential (BMP) of 88 expired food waste. Many studies are based on the analysis of a small number of samples, which are don't present a complete picture of all the types of food waste. The organic composition and other factors such as pH, temperature, C/N ratio of the samples varies considerably with the region, the season and the processing characteristics, resulting in methane yield variations, ranging from 216 to 1476 mL CH4/gVS. Therefore, knowledge of the appropriate physical and chemical properties of the feedstock, working conditions and the effects of the inhibition of various components on the anaerobic digestion processes is a key element, necessary to optimize energy production from food waste.This research is part of the LIFE16ENV/IT/OOO574 i-REXFO project funded by the EU under the LIFE 2016 program and the database is a deliverable of the project i-REXFO (http://irexfo.eu)Peer reviewe

Methane enrichment of biogas using carbon capture materials

20 figures, 5 tables.An important percentage of biogas is made of CO2, which decreases its heating value. If CO2 is adsorbed two advantages can be achieved: CO2 capture and the increase of biogas heating value. Biomethane is a renewable fuel, which can provide energy autonomy and a reduction of greenhouse gases emissions. CO2 capture from power plants by using solid adsorbents is an effective method for the reduction of CO2 emission and an excellent solution for methane enrichment of biogas. This work evaluates the CO2 removal and methane enrichment of biogas by adsorption of gas molecules to solid surfaces of sorbents in a pilot-scale biogas upgrading system. The materials selected to remove CO2 from gases were three: calcium hydroxide, commercial activated carbon and solid amine adsorbent, loaded on commercial activated carbon. The amine adsorbent used in this work was polyethylenimine (PEI). The adsorbents were characterized by thermal stability through thermogravimetric analyzer (TGA), X-ray diffraction analysis (XRD), specific area, pore size distribution and particle size distribution. The CO2 adsorption capacities of the sorbents were measured using a thermogravimetric analyzer with pure CO2 at atmospheric pressure. The CO2 adsorption capacity test was 0.00653 mol/g for calcium hydroxide, 0.00219 mol/g for commercial activated carbon with 0,1 wt% of amine and 0.00168 mol/g for commercial activated carbon. The effect of adsorbent dosage as a function of time was also investigated. The result showed that the CO2 adsorption of the sorbents increases with adsorbent dosage. The results obtained from the upgrading tests conducted in the lab-scale system showed that a purity of 99.9 % methane was obtained using 15 g of calcium hydroxide, a purity of methane of 87 % was obtained using 30 g of commercial activated carbon with 0.1 wt% amine and a purity around 86 % methane was obtained using 30 g of commercial activated carbon.The authors would like to thank H2CU for the possibility of performing the exchange with the Columbia University. Authors want to acknowledge for funding, the project: “Technical, Environmental and Socio-Economic study of power-to-fuel solutions for a sustainable path towards a green future: achieving 80 % renewable electric energy and 40 % renewable primary energy supply within the next two decades”. Funded in 2020 by PRIN Italian national funds and registered with the code: 2020AA9N4M. This work has been funded by the GTCLC-NEG project that has received funding from the Euro-pean Union’s Horizon 2020 research and innovation programme under the Marie Sklodow-ska-Curie grant agreement No. 101018756.Peer reviewe