Thermodynamic, economic and environmental assessment of energy systems including the use of gas from manure fermentation in the context of the Spanish potential

One of the prospective technologies that can be used for energy generation in distributed systems is based on biogas production, usually involving fermentation of various types of biomass and waste. This article aims to bring novelty on the analysis of this type of systems, joining together thermodynamic, economic and environmental aspects for a cross-cutting evaluation of the proposed solutions. The analysis is made for Spain, for which such a solution is very promising due to availability of the feedstock. A detailed simulation model of the proposed system in two different cases was built in Aspen Plus software and Visual Basic for Applications. Case 1 involves production of biogas in manure fermentation process, its upgrading (cleaning and removal of CO2 from the gas) and injection to the grid. Case 2 assumes combustion of the biogas in gas engine to produce electricity and heat that can be used locally and/or sold to the grid. Thermodynamic assessment of these two cases was made to determine the most important parameters and evaluation indices. The results served as input values for the economic analysis and environmental evaluation through Life Cycle Assessment of the energy systems. The results show that the analysed technologies have potential to produce high-value products based on low-quality biomass. Economic evaluation determined the break-even price of biomethane (Case 1) and electricity (Case 2), which for the nominal assumptions reach the values of 16.77 €/GJ and 28.92 €/GJ, respectively. In terms of environmental assessment the system with the use of biogas in gas engine presents around three times better environmental profile than Case 1 in the two categories evaluated, i.e., carbon and energy footprint.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 799439. Dr. Martín-Gamboa states that thanks are due to FCT/MCTES for the financial support to CESAM (UID/AMB/50017/2019), through national funds

Evaluation of electricity generation subsystem of Power-to-Gas-to-Power unit using gas expander and heat recovery steam generator

In the last years, the European energy policy has required to increase the share of renewable energy sources in the national energy systems. It is important to diversify the energy system not to bring about a global crisis resulting from the fundamental lack of electricity. Unfortunately renewable sources are unstable and generate several problems during integration with the power grid. The solution is to store additional energy produced from renewable sources. In this way, energy can be used when there is a need. The paper discusses the study of the Power-to-Gas-to-Power installation using electrolysis and methanation processes at the energy storage stage and gas expanders during energy discharges. In addition, a part of the Heat Recovery Steam Generation installation has been implemented. The purpose of the work was to determine the impact of a given Heat Recovery Steam Generation installation on the efficiency of the entire installation and flue gas temperature at the outlet from Heat Recovery Steam Generator

The potential of using hydrogen in the Polish energy system

Realizacja strategii dekarbonizacji polskiej gospodarki wymaga wprowadzenia do eksploatacji nowych technologii energetycznych, w tym technologii wodorowych. W rozdziale zawarto informacje o potencjalnych możliwościach wykorzystania wodoru w procesach generacji elektryczności i ciepła. Struktura pozyskiwania w Polsce zarówno energii elektrycznej, jak i pierwotnej, istotnie różni się od struktury charakterystycznej dla UE. Istnieje znaczny potencjał jej dywersyfikacji. We wszystkich działach energetyki zastosowanie wodoru może ułatwić uzyskanie celów klimatycznych i ekonomicznych (efektywnościowych). Ostateczne scenariusze technologiczne wytwarzania wodoru będą zależeć od stanu rozwoju OZE i ekonomiczności poszczególnych rozwiązań. Ważne jest pytanie, który scenariusz jest najprawdopodobniejszy w Polsce. Biorąc pod uwagę aktualny potencjał OZE oraz przewidywany ich rozwój do 2040 r., wydaje się, że elektrolityczna produkcja wodoru w Polsce z wykorzystaniem OZE nie będzie zbyt wysoka. Założenie 2 GW mocy elektrolizerów w 2030 r. w Polskiej strategii wodorowej jest bardzo (zbyt) optymistyczne (Niemcy 5 GW, Hiszpania 4 GW). Trudno natomiast przesądzić, jakie będzie upowszechnienie innych technologii wytwarzania, zwłaszcza trudno ocenić udział CCS. W najbardziej optymistycznym scenariuszu sformułowanym dla UE udział wodoru w 2050 r. w końcowym zużyciu energii wynosi 24% (2251 TWh) (Hydrogen… 2019). Przewidywana struktura jego zużycia to: 112 TWh (około 5%) – wytwarzanie elektryczności, bilansowanie systemu (power generation, buffering, sektor 1); 675 TWh (30%) – transport (sektor 2); 579 TWh (25,7%) – ogrzewanie i energia dla mieszkalnictwa (heating, power for buildings, sektor 3); 237 TWh (10,5%) – energia dla procesów przemysłowych (industry energy, sektor 4); 257 TWh (11,4%) – nowe zastosowania przemysłowe (new industry feedstock, sektor 5); 391 TWh (17,4%, sektor 6) – istniejące obszary zastosowań przemysłowych (existing industry feedstock). Ten procentowy udział w zakresie sektorów 1 i 3 przeniesiony na grunt Polski można uznać za rozsądny. Aczkolwiek bardzo szkodliwa z ekologicznego punktu widzenia struktura zużycia energii w gospodarstwach domowych w Polsce w chwili obecnej, podpowiada zwiększenie udziału wodoru w tym sektorze

Assessment of Operational Performance for an Integrated ‘Power to Synthetic Natural Gas’ System

This article presents a power to SNG (synthetic natural gas) system that converts hydrogen into SNG via a methanation process. In our analysis, detailed models for all the elements of the system are built. We assume a direct connection between a wind farm and a hydrogen generator. For the purposes of our calculations, we also assume that the hydrogen generator is powered by the renewable source over a nine-hour period per day (between 21:00 and 06:00), and this corresponds to the off-peak period in energy demand. In addition, a hydrogen tank was introduced to maximize the operating time of the methanation reactor. The cooperation between the main components of the system were simulated using Matlab software. The primary aim of this paper is to assess the influence of various parameters on the operation of the proposed system, and to optimize its yearly operation via a consideration of the most important constraints. The analyses also examine different nominal power values of renewables from 8 to 12 MW and hydrogen generators from 3 to 6 MW. Implementing the proposed configuration, taking into account the direct connection of the hydrogen generator and the methanation reactor, showed that it had a positive effect on the dynamics and the operating times of the individual subsystems within the tested configuration