Substitute natural gas

About: Substitute natural gas is a research topic. Over the lifetime, 1216 publications have been published within this topic receiving 23604 citations. The topic is also known as: synthetic natural gas.

Impact of choice of CO2 separation technology on thermo-economic performance of Bio-SNG production processes

Abstract: Three different CO2 separation technologies for production of synthetic natural gas (SNG) from biomass gasification – amine-based absorption, membrane-based separation and pressure swing adsorption – are investigated for their thermo-economic performance against the background of different possible future energy market scenarios. The studied scale of the SNG plant is a thermal input of 100 MWth,LHV to the gasifier at a moisture content of 20 wt-% with a preceding drying step reducing the biomass' natural moisture content of 50 wt-%. Preparation of the CO2-rich stream for carbon capture and storage is investigated for the amine-based absorption and the membrane-based separation technology alternatives. The resulting cold gas efficiency ηcg for the investigated process alternatives ranges between 0.65 and 0.695. The overall system efficiency ηsys ranges from 0.744 to 0.793, depending on both the separation technology and the background energy system. Amine-based absorption gives the highest cold gas efficiency whereas the potential for cogeneration of electricity from the process' excess heat is higher for membrane-based separation and pressure swing adsorption. The estimated specific production costs for SNG cSNG for a process input of 90.3 MWth,LHV at 50 wt-% moisture vary between 103–127 €2010/MWhSNG. The corresponding production subsidy level csubsidy needed to achieve end-user purchase price-parity with fossil natural gas is in the range of 56–78 €2010/MWhSNG depending on both the energy market scenario and the CO2 separation technology. Sensitivity analysis on the influence of changes in the total capital cost for the SNG plant on the production cost indicates a decrease of about 12% assuming a 30% reduction in total capital investment. Capture and storage of biogenic CO2 – if included in the emission trading system – only becomes an option at higher CO2 charges. This is due to increased investment costs but, in particular, due to the rather high costs for CO2 transport and storage that have been assumed in this study.

Parametric, cyclic aging and characterization studies for CO2 capture from flue gas and catalytic conversion to synthetic natural gas using a dual functional material (DFM)

Abstract: Solid sorbents have attracted extensive research attention for enhanced adsorption of effluent CO2. A Dual Functional Material (DFM), composed of a CO2 adsorbent (“Na2O” derived from hydrogenated Na2CO3) in combination with Ru both supported on the same Al2O3, overcome limitations of traditional sorbent technology. It captures CO2 from a simulated flue gas and catalytically converts it to synthetic natural gas (CH4) in the same reactor and temperature utilizing H2 generated from renewable sources. The methane produced is recycled to the plant inlet for repeated combustion maintaining a closed carbon loop. The process is envisioned to operate with parallel reactors, containing DFM, where one captures CO2 and the other methanates and vis versa for continuous operation. We report parametric, cyclic aging and characterization studies in a simulated natural gas power plant flue gas using 10 g of 5 mm × 5 mm tablet DFM. This material shows stable CO2 capture and conversion to CH4 performance for over 50 adsorption and conversion aging cycles (equivalent to 80 h of operation) with no loss in BET surface area, CO2 capture capacity nor Ru dispersion.