Membrane gas separation technologies for biogas upgrading

Abstract

Biogas is a renewable energy source like solar and wind energies and mostly produced from anaerobic digestion (AD).

Highly permselective MIL‐68(Al)/matrimid mixed matrix membranes for CO2/CH4 separation

“…As shown in Figure , both CO 2 and CH 4 permeabilities increase with increasing temperature, but CH 4 permeability increases more obviously, thus resulting in a decrease of CO 2 /CH 4 . Similar phenomenon is seen in the work of Chen et al . The diffusion of gases relates with the amount of energy required by the penetrants to execute a diffusive jump through the membrane, and with increasing temperature, the energy provided for diffusive jumping increases.…”

“…Therefore, under a temperature range without significant thermal transitions of the polymer matrix, the diffusion coefficient typically increases considerably with increasing temperature . Larger molecules such as CH 4 will execute more jumps at high temperature because they have more limited opportunities at low temperature . Further, in this work, since CH 4 molecules have relatively weak interaction with the MIL‐68(Al) crystals and Matrimid matrix, permeation of CH 4 through the motivated polymer chains increases more than CO 2 at high temperatures, thus leading to a decrease in the CO 2 /CH 4 selectivity.…”

“…The diffusion of gases relates with the amount of energy required by the penetrants to execute a diffusive jump through the membrane, and with increasing temperature, the energy provided for diffusive jumping increases. Therefore, under a temperature range without significant thermal transitions of the polymer matrix, the diffusion coefficient typically increases considerably with increasing temperature . Larger molecules such as CH 4 will execute more jumps at high temperature because they have more limited opportunities at low temperature .…”

“…Ideal separation factor was calculated from the single gas permeabilities P i and P j as in the following equation: …”

Sentez Koşullarının ve Çinko Öncülünün ZIF-L Membranlarının Gaz Geçirgenlik Özelliklerine Etkisi

“…Zeolitler sayesinde düzenli gözenekli bir yapı ve yüksek kararlılık membran teknolojilerine katılmıştır [3]. Membranlar, geleneksel ayırma işlemlerine göre yüksek seçicilik, enerji tasarrufu, ortalama maliyet-performans oranı ve modülerlik gibi birçok avantajı da beraberinde getirmekle birlikte geleneksel ayırma araçlarıyla da hibrid süreçler de oluşturabilmektedirler [6]. Membranlarda ayırma işlemi, membranın hem kimyasal hem de fiziksel doğasıyla belirlenmekte ve basınç farkı, derişim(kimyasal potansiyel) farkı, elektriksel potansiyel farkı ve sıcaklık farkının biri veya birleşimleriyle oluşturulan itici kuvvet ile gerçekleşmektedir.…”