From CO₂ to DME: Catalytic advances, challenges, and alternatives to conventional gas-phase routes
Abstract
Dimethyl ether (DME) is gaining attention as both a biofuel and electro-fuel (e-fuel) due to its high volumetric energy density (0.16 kg H2/l) and rich hydrogen content, making it a promising energy carrier. Global DME production is around 10 million tons annually, primarily derived from synthesis gas. This process typically requires high temperatures above 250°C and elevated pressures, involving two catalysts and multiple stages of separation and distillation. A major breakthrough in DME production would involve utilizing CO2 and H2 mixtures under milder conditions in a single-step process. Such advancements could create a circular DME synthesis-consumption cycle, leading to significant reductions in greenhouse gas emissions. This work explores recent developments in both direct and indirect DME production methods, with a focus on enhancing CO2-to-DME processes. It highlights the design of highly active, durable, and selective catalysts, as well as scalable synthesis methods that eliminate the need for expensive separation and distillation stages.