Technoeconomics of an alternative route to improve natural gas utilisation through pyrolysis

Among the main producers of oil and gas in the world, there is Canada, which was analysed in the Thesis as a case study. Every time oil is extracted, light hydrocarbons on top of the bituminous mass, present in the form of natural gas, are usually flared or, even worse, vented. Providing a pipeline network to recover and transport the gas is not affordable, due to the location, large distances, and the scattered nature of the extractive sites. In these cases, flaring and venting are the only available solutions. These two practices represent a severe economic and environmental issue for Canada, though, as 1% of the annual overall greenhouse gases emissions are ascribed to venting. Therefore, there is the urgent need for new technologies, possibly in situ, able to recover and make use of this natural gas, mostly made of methane, that is otherwise wasted. The main objective of the Thesis is to conceptualise and simulate through Aspen Plus an innovative process, based on methane pyrolysis at T > 800°C and atmospheric pressure, directly at the extraction site, without any catalyst. In this way, natural gas can be converted into high-valued H2 and solid carbon, that can be used in industry as reducing agent, or in the production of batteries, or again in soil amendment and environmental remediation. Two main alternatives are proposed and analysed from a technical point of view. The final step consists in the economic analysis, useful to evaluate the feasibility of the process through the computation of some economic indices such as Internal Rate of Return (IRR), Net Present Value (NPV), Return on Investment (ROI).