Defining of criteria for flue gas decarbonization efficiency in methanation reactors with membrane technology

Abstract

The paper presents an investigation on the conditions for implementing a methanation membrane decarbonator coupled to an energy installation that generates flue gases. The retention of the carbon dioxide content in the flue gases and its conversion to methane is envisaged. For start, low thermal power installations, employing natural gas as main fuel supply, are considered. Internal combustion engines (also working with natural gas fuel) are taken into account for the testing of the carbon dioxide retention process. For this, a classification of the flue gas composition by fuel categories is initially carried out. The decarbonation efficiency is defined and clarifications are made withal regarding the connection between the decarbonation installation and the energy plant. The first practical achievements are also presented, resulting from a decarbonator with a volume of 940 cm3 (having the inner diameter of 12 cm and a height of 50 cm). The results prove that the proposed solution has great potential for practical applications, further research being however necessary. In terms of operating costs (including hydrogen consumption), it is remarked that they can be reduced by exploiting the methane production and eliminating the carbon tax, extending the integration perspective form economic point of view.

Particularities of flue gases from energy installations on the process of continuous flow capture for CO2 by direct methanation

“…In relation (20), the values for 𝑉 𝐶𝑂 2 𝑜 and 𝑉 𝑎 𝑒𝑥 are determined by the calorific value of the fuel and the excess air λ, respectively. For certain values of the excess air, the ignition conditions are not met [12], [13], [14], [15]. For a single combustible gas (H2), the limits of the ignition concentrations have the lower and upper value as follows: 𝐶 𝑖 = 4.1% and 𝐶 𝑠 = 74%.…”