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.

Selective CO Hydrogenation Over Bimetallic Co-Fe Catalysts for the Production of Light Paraffin Hydrocarbons (C2–C4): Effect of Space Velocity, Reaction Pressure and Temperature

Abstract: Synthetic natural gas (SNG) using syngas from coal and biomass has attracted much attention as a potential substitute for fossil fuels because of environmental advantages. However, heating value of SNG is below the standard heating value for power generation (especially in South Korea and Japan). In this study, bimetallic Co-Fe catalyst was developed for the production of light paraffin hydrocarbons (C2–C4 as well as CH4) for usage as mixing gases to improve the heating value of SNG. The catalytic performance was monitored by varying space velocity, reaction pressure and temperature. The CO conversion increases with decrease in space velocities, and with an increase in reaction pressure and temperature. CH4 yield increases and C2+ yield decreases with increasing reaction temperature at all reaction pressure and space velocities. In addition, improved CH4 yield at higher reaction pressure (20 bar) implies that higher reaction pressure is a favorable condition for secondary CO2 methanation reaction. The bimetallic Co-Fe catalyst showed the best results with 99.7% CO conversion, 36.1% C2–C4 yield and 0.90 paraffin ratio at H2/CO of 3.0, space velocity of 4000 mL/g/h, reaction pressure of 20 bar, and temperature of 350 °C.

Synthetic natural gas (SNG) production at pulp mills from a circulating fluidized bed black liquor gasification process with direct causticization

Abstract: Synthetic natural gas (SNG) production from black liquor gasification (BLG) replacing conventional recovery cycle at chemical pulp mills is an attractive option to reduce CO2 emissions and replace

Upscaling Effects on Char Conversion in Dual Fluidized Bed Gasification

Abstract: Dual fluidized bed gasification (DFBG) is an emerging technology that can be employed as a first step in the transformation of lignocellulosic materials into transportation fuels such as substitute natural gas, dimethyl ether, methanol, and Fischer-Tropsch diesel. The present work aims at (i) identifying challenges that arise in the upscaling of DFBG plants, (ii) determining whether the increased fuel residence time that results from the upscaling is sufficient for process optimization, and (iii) evaluating the impact of measures to mechanically control the fuel residence time. The investigations use a semiempirical 1-dimensional model, which is validated with industrial-scale measurements. The scope includes both DFBG units delivering gas as the main product and those in which the product gas is a byproduct in a heat and power plant. Moreover, both new designs and retrofit cases of existing CFB combustion plants (i.e., adding a gasifier to the return leg) are considered. Modeling results show that although there is an initial increase in the fuel residence time as the size of the gasifier increases, further upscaling eventually leads to a decrease in the degree of char gasification due to (i) a decrease in the fuel residence time, as there is a transition in lateral fuel mixing from the dispersion-dominant regime to the convection-dominant regime; and (ii) a decrease in the char gasification rate due to an increased bed material velocity, which increases the probability that pyrolysis occurs on the bed surface (leading to a less reactive char as the heat transfer is lower there compared to inside the dense bed). For DFBG units of around 100 MW, proper combinations of operational conditions (e.g., the solids circulation, the steam-fuel ratio, and the temperature of the circulating solids) result in an optimized process when heat and power is the main product, with gas as a byproduct. However, when gas is the sole targeted product, it is likely that baffles are also necessary to achieve sufficient fuel conversion for process optimization.