This thesis evaluates the technical and economic feasibility of producing methane (CH4) via the electrochemical reduction of carbon dioxide (CO2), offering a pathway to valorize captured CO2 while integrating surplus renewable electricity into established natural gas infrastructure. A dual-modeling framework was developed: an Excel-based electrolyzer model captures key electrochemical parameters including Faradaic efficiency (FE), current density (CD), cell voltage, and resulting power demand while an ASPEN Plus simulation rigorously models downstream separation, employing cryogenic distillation to achieve high-purity CH4 and co-products. The study systematically investigates multiple operational scenarios, reflecting variations in electricity pricing (including projected low-LCOE renewables), CO2 feedstock costs (derived from different capture strategies), and market values for methane and by-products. A detailed techno-economic assessment quantifies capital expenditure (CAPEX) requirements, dominated by electrolyzer sizing due to constraints on CD and FE, and operational expenditure (OPEX), primarily driven by electricity consumption. Sensitivity analyses reveal that electricity price, electrolyzer CAPEX (tied to CD and cell voltage), and product stream valuations are the most influential parameters affecting the net present value (NPV). Base case simulations show that under current market conditions (25=C/MWh electricity, 9,000=C /m2 electrolyzer CAPEX), the process yields a strongly negative NPV. However, scenario analyses demonstrate that moderate improvements across several fronts, reducing cell voltages to 2.5V, increasing CDs beyond 5000 A/m2, and securing electricity prices under 15=C /MWh can collectively transition the process towards economic breakeven within a 30-year project horizon. Environmental performance was assessed via a simplified CO2 balance, indicating that for each ton of CH4 synthesized, approximately 2.75 tons of CO2 are sequestered. However, this benefit is partially offset by indirect emissions from electricity generation, underscoring the need to combine the process with low-carbon power sources to ensure genuine climate mitigation. This comprehensive analysis highlights both the promise and the formidable challenges of industrialscale CO2 electroreduction to methane. It underscores the critical need for integrated approaches combining advancements in catalyst selectivity and stability (to improve FE toward CH4), process intensification to achieve higher CDs with minimized overpotentials, and supportive policy mechanisms such as carbon pricing or renewable integration incentives. Ultimately, the findings provide quantitative benchmarks and strategic direction for advancing CO2-to-CH4 electrolysis towards economically and environmentally viable deployment.