The direct synthesis of dimethyl ether (DME) from landfill gas: A techno-economic investigation

Abstract

The use of fossil fuels is primarily responsible for the increasing amounts of greenhouse gas emissions in the atmosphere and, unless this issue is quickly addressed, the effects of global warming will worsen. Synthesis gas (syngas) is an attractive target chemical for carbon capture and utilisation and dry reforming of methane (DRM) enables the conversion of methane (CH4) and CO2, the two most abundant greenhouse gases, to syngas. This paper presents a techno-economic analysis of a syngas-to-dimethyl ether (DME) process, by utilising landfill gas as feedstock. The process developed herein produces DME, methanol and high-pressure steam as products, resulting in an annual income of €3.49 m and annual operating expenses of €1.012 m. Operating profit was calculated to be €2.317 m per year and the net present value (NPV) was €11.70 m at the end of the project’s 20-year lifespan with a profitability index of 0.83€/€. The process was expected to have a payback time of approximately 10 years and an internal rate of return of 12.47%. A key aspect of this process was CO2 utilisation, which consumed 196,387 tonnes of CO2 annually. The techno-economic analysis conducted in this paper illustrates that greenhouse gas utilisation processes are currently feasible both in terms of CO2 consumption and profitability.