A preliminary energy analysis of a commercial chp fueled with h2ng blends chemically supercharged by renewable hydrogen and oxygen

Currently, Power-to-Gas technologies are considered viable solutions to face the onset problems associated with renewable capacity firming. Indeed, carbon-free hydrogen production converting renewable electricity excess and its injection into natural gas pipelines is considered a short- to medium-term solution. In this way, the so-called H2NG blends can be fired within internal combustion engines and micro gas turbines operating in CHP mode, offering better environmental-energy performances in machines. As regards the distributed energy generation scenario, the local H2 production by means of electrolysis for methane enrichment will be more cost-effective if the oxygen is fruitfully used instead of venting it out like a by-product, as usually occurs. This study focuses on the usefulness of using that oxygen to enrich the air-fuel mixture of an internal combustion engine for micro-CHP applications, once it has been fuelled with H2NG blends. Thus, the main aim of this paper is to provide a set of values for benchmarking, in which H2NG blends, ranging in 0%-15% vol., burn within an ICE in partial oxy-fuel conditions. In particular, a preliminary energy analysis was carried out based on experimental data, reporting the engine operating parameters, gains and losses in both electrical and heat recovery efficiency. The oxygen content in the air varies up to 22% vol. A Volkswagen Blue Tender CHP commercial version (19.8 kWel. of rated electrical power output) was considered as the reference machine and its energy characterization was reported when it operated under those unconventional conditions

An overview on safety issues related to hydrogen and methane blend applications in domestic and industrial use

The share of electrical energy hailing from renewable sources in the European electricity mix is increasing. The match between renewable power supply and demand has become the greatest challenge to cope with. Gas infrastructure can accommodate large volumes of electricity converted into gas whenever this supply of renewable power is larger than the grid capacity or than the electricity demand. The Power-to-Gas (P2G) process chain could play a significant role in the future energy system. Renewable electric energy can be transformed into storable hydrogen via electrolysis and subsequent methanation. The aim of this paper is to provide an overview of the required technical adaptations of the most common devices for end users such as heating plants, CHP systems, home gas furnaces and cooking surfaces, wherever these are fuelled with methane and hydrogen blends in variable percentages by volume. Special attention will be given to issues related to essential safety standards, firstly comparing existing Italian and European regulations in this regard, and secondly highlighting the potential need for legislation to regulate the suitability of hydrogen methane blends. Finally, a list of foreseeable technical solutions will be provided and discussed thoroughly

Adsorption gas Heat Pump fuelled with hydrogen enriched natural gas blends: the analytical simulation model development and validation

This study deals with the implementation of an analytical model to simulate the energy performance associated to a commercial Gas adsorption Heat Pump, when H2NG (Hydrogen Enriched Natural Gas) blends are used as fuel. In detail, a water source heat pump manufactured by Robur (GAHP-WS) has been used as a reference device for building the simulation model within the MATLAB-Simulink environment. Thereafter, the simulation results have been validated by the experimental campaign, testing on field and in actual operating conditions the heat pump. Specifically, the model has been developed by implementing the WaterAmmonia mass and energy balances for each component. It is able to evaluate fuel consumption, efficiency in terms of GUE, required thermal power from the cold heat sink as well as the water outlet temperature at the evaporator, once the heating load is used as the main input. The experimental campaign for the model calibration and validation has been carried out over the winter season. Additionally, the heat pump performance has been detected when it operates to supply hot water at 60 °C and 55 °C, and it is fuelled with growing hydrogen fractions, starting from 0% vol., 5% vol. up to 10% vol. In the end, the standard errors as well as the relative ones affecting the main output parameters have computed for the validation process. From the outcomes it emerges that the average relative standard error related to all load conditions is lower than 2.5% for natural gas operation. On the contrary, it ranges between 2.5% and 4% when H2NG at 5% and 10% by volume have been burnt