Industrial chemistry heavily relies on traditional separation methods which are both energy-demanding and environmentally detrimental. This thesis addresses critical separation challenges, specifically carbon capture applications and the separation of ethylene from ethane. The potential of Metal-Organic Frameworks (MOFs) and Covalent Organic Frameworks (COFs) as sustainable and efficient separation solutions is explored in depth. Throughout my doctoral research, I have harnessed both classical and quantum simulation techniques to understand the separation capabilities of MOFs and COFs. In the first part of this thesis book, I present comprehensive computational-experimental evaluations of diverse MOFs, spotlighting various structural modifications and designs tailored for carbon capture tasks. For instance, the initial chapter sheds light on how metal choice and topology in Pyrene-based MOFs impact CO2 absorption. The subsequent chapter introduces Al-Cu-PyC (named "MIP-212"), a novel bimetallic MOF tailored for carbon sequestration, followed by an in-depth look at the post-synthetic grafting of amines onto the NH2-Cr-BDC MOF, aimed at optimizing post-combustion CO2 capture. The fourth chapter deviates from the earlier focus on individual MOFs, spotlighting the vast CURATED COFs database — a collection of numerous COF structures extracted from experimental work. This database, underpinned by our group’s dedication to open science, ensures data authenticity and traceability underscoring the curation process backed by the workflow manager AiiDA. My contributions centered on updating the database, maintaining technical dependencies, and leveraging a data-driven approach to discern COF features pivotal for Ethane/Ethylene separation.