Modular chemical process intensification improves chemical processes by reducing capital investment, operating costs, and inefficiencies of chemical production. Process intensification is achieved using microscale operations and devices with high surface-to-volume ratios. Microscale chemical device components can be produced using additive manufacturing and conventional powder metallurgy processes. The technical and environmental advantages and disadvantages of these processes have been investigated individually. However, their relative sustainability performance requires further research. The objective of this research is to characterize the economic and environmental performance of metal additive manufacturing and powder metallurgy processes for producing a 316 l stainless steel microscale chemical reactor used in dimethyl ether production. Laser powder bed fusion (LPBF) and binder jet (BJ) additive technology, and metal injection molding (MIM) were studied for producing two reactor plates for a range of market sizes. To quantify cost and environmental impacts, manufacturing process design and life cycle assessment (LCA) methods were applied, respectively. Cost analysis showed MIM has significantly lower unit costs than BJ (by 11–30 %) and LPBF (by 62–82 %) for the range of production volumes studied. However, at low production volumes, LCA results indicated MIM has greater environmental impacts than BJ and LPBF, due to consumables. As production volume increases, environmental impacts per part reduce significantly (up to 85 %) for MIM due to amortization of impacts across more products. Raw materials and utilities have little sensitivity to production volume and are the main environmental impact drivers for BJ and LPBF. Process step yield directly impacts tool count, resulting in the highest sensitivity to unit cost for the three processes. This work reports on model development and a single use case, motivating future investigation to understand process suitability for a range of part sizes and geometries, as well as alternative production routes.