Process Design and Simulation of Biodimethyl Ether (Bio-DME) Production from Biomethane Derived from Agave sisalana Residues

This study presents the design and simulation of an integrated pathway to produce Biodimethyl ether (Bio-DME) from biomethane derived from Agave sisalana residues, focusing on the downstream sections such as: (i) steam reforming of biogas and water-gas shift to generate syngas and (ii) indirect methanol synthesis followed by methanol dehydration to Bio-DME, including separation and recycle steps. The modeled scope excludes the anaerobic digestion stage. Benchmarking against the literature was used to validate model fidelity. The simulation delivered a single-pass methanol conversion of 81.8%, a Bio-DME reactor conversion of 44.6 mol%, and a Bio-DME yield/selectivity of ≈99 mol%; product purities reached ≈99.99 mol% Bio-DME at the first distillation column and ≈99.9 mol% MeOH in the recycle, indicating efficient separation. Compared to the literature, Bio-DME conversion in this study is slightly below the reported values (0.446 vs. 0.499, Δ = 0.053), while yield is very close to literature (0.99 vs. 0.9979, Δ = 0.0079). Incomplete methanol conversion emerges as the primary optimization lever, pointing to adjustments in operating conditions (T, p), recycle/purge strategy, and H2/CO control. Overall, the results confirm the technical feasibility of the simulated sections and support the development of a sisal-based, low-carbon Bio-DME route relevant to Northeast Brazil.