Following the rising global demand for sustainable solutions within the chemical industry, this narrative review evaluates dimethyl ether (DME) production routes focusing on both economic performance and environmental sustainability. Special focus is given to landfill biogas (LFB) as a source to obtain DME. Assessment was performed through narrative comparison of facility capacity, DME pricing, environmental impacts, and Technology Readiness Level (TRL). Studies from 2015 onwards are considered, unless well-established methods are referenced. We searched for industrial-scale studies reporting economic viability and techno-economic-environmental feasibility, including modeling plants, government reports, and conference papers in English. Two primary routes for DME synthesis are identified: the commercially proven indirect route, and an emerging, future-focused direct synthesis in a single reactor. A comparative analysis reveals that natural gas (NG) and coal are the most economical feedstocks for DME synthesis (305–485 €/t), but carry the highest environmental impacts. Biogenic feedstocks offer economic competitiveness (270–550 €/t for biomass and 350–785 €/t for biogas) with lower CO₂ emissions, while renewable hydrogen and carbon capture CO₂ are recognized as long-term solutions (910–2610 €/t). The timeline for their industrial realization will be determined by advancements in innovation, research, and economic incentives to bridge the price gaps existing today.

The objective of this work is to evaluate how spent catalyst from fluid catalytic cracking (SCFCC) affects the physical, mechanical and durability properties of fly ash (FA) and blast furnace slag (BFS)-based alkali-activated materials (AAMs). Recycling of SCFCC by integrating it in a AAM matrix offers several advantages: valorization of the material, reducing its disposal in landfills and the landfill cost, and minimizing the environmental impact. Mineralogical, physical and mechanical characterization were carried out. The durability of the specimens was studied by performing acid attack and thermal stability tests. Mass variation, compressive strength and porosity parameters were determined to assess the durability. BFS- and FA-based AAMs have a different chemical composition, which contribute to variations in microstructure and physical and mechanical properties. Acid neutralization capacity was also determined to analyse the acid attack results. Porosity, including the pore size distribution, and the acid neutralization capacity are crucial in explaining the resistance of the AAMs to sulfuric acid attack and thermal degradation. Herein, a novel route was explored, the use of SCFCC to enhance the durability of AAMs under harsh operating conditions since results show that the compositions containing SCFCC showed lower strength decay due to the lower macroporosity proportions in these compositions.

Herein we evaluate four biomass-to-1,3-butadiene pathways that use ethanol as an intermediate platform. The pathways evaluated were two first-generation routes based on sugarcane and cereal crops and two second-generation routes using lignocellulosic feedstocks. An analysis based on technological performance and economic profitability comparison is given. The reference facility is designed at 200,000 tonne/year of ethanol as intermediate product (dry basis), which leads to an annual production of 89,400 tonne of 1,3-butadiene. Process simulation in AspenPlus® leads to mass and energy, while the economic evaluation quantifies Net Present Value (NPV) and Minimum Selling Price (MSP) as key performance indicators. Under baseline conditions, the sugar-based route proves to be the only profitable pathway with a NPV of 27 M€ and an MSP of 891 € per tonne of 1,3-butadiene. On the other hand, starch-based and second-generation pathways show negative economic outcomes. Sensitivity analyses show profitability is highly sensitive to 1,3-butadiene market price, biomass purchase price, and ethanol-to-1,3-butadiene yield and selectivity. All in all, the results highlight great potential for bio-based 1,3-butadiene production in regions with cost-competitive sugar feedstocks.