Comparative evaluation of the effect of pore size and temperature on gas transport in nano-structured ceramic membranes for biogas upgrading

Abstract

As a result of rising economies and environmental constraints, the demand for clean and renewable sources of energy is fast increasing. Biogas is a renewable form of energy that fits all expectations in terms of delivery, cost, and greenhouse emissions reduction. Biogas utilization is advantageous because it is a means of creating wealth from daily human, agricultural, household and municipal waste that could otherwise be polluting the environment as waste is deposited on a daily basis which are potential biogas sources; it is not dependent on weather conditions as other renewable forms (solar and wind). Biogas can also be compressed, stored and transported, and therefore easily responds to changes in demand. This paper entails the use of nano-structured membranes to upgrade biogas (which contains primarily methane and carbon dioxide). The benefits of membranes include their compact structure and ease of usage with low maintenance, their low running costs and minimal loss of the upgraded gas. 15nm, 200nm and 6000nm membranes were used to ascertain the flux of the model biogas mixture passing through it under various operating conditions. In each case, the exit flowrate of methane was higher than that of carbon dioxide and this is attributed to the pore sizes of the membrane and its ability to filter the heavier gases. The results show that the molecular weight of the gases also play a role in their permeation rate as it follows the Knudsen regime.

A Study of Gas Transport Mechanisms for CH4/CO2 Using Ceramic Membranes

“…In order to make efficient use of resources and achieve effective membrane separation, high permeability and selectivity are required. There are several factors that have been identified by previous authors to affect gas flow in porous media [5][6][7][8][9][10][11]. This study classified them into fluid properties and structural parameters.…”

Nano-Structured Carbon: Its Synthesis from Renewable Agricultural Sources and Important Applications

“…Nanocarbon has attracted attention because of its eminent properties and received much research attention due to its low toxicity, desirable biocompatibility, substantial synthesis of raw substances, and low fabrication cost. Few of the literature suggests the cost of the materials where these renewable sources are placed, and notable observations found that these materials are a quite reasonable cost [ 6 , 7 , 8 , 9 , 10 ]. Various nanoforms of carbon show tunable emission spectra, good photoluminescence stability, resistance to picture bleaching, large two-photon absorption area, and smooth functionalization [ 11 , 12 , 13 , 14 , 15 ].…”