Industrial Production of Formaldehyde Using Polycrystalline Silver Catalyst

Industrial & Engineering Chemistry Research

5 years ago

Industrial Production of Formaldehyde Using Polycrystalline Silver Catalyst

Mary Collins, Graeme J. Millar

We report the first comprehensive review of the industrial process for the catalytic partial oxidation of methanol to formaldehyde using silver catalyst. Formaldehyde remains a key, large volume industrial chemical which is ubiquitous to household, commercial, aviation, pharmaceutical and automotive products due to its high reactivity and versatility. Critical analysis of the various technological approaches used to manufacture formaldehyde, characteristics of silver catalysts employed, process conditions, and performance values has been presented. The three common plant types are almost complete conversion (BASF type); incomplete conversion followed by distillation (ICI type); and the off-gas recycle process which dominates world production due to its extensive use in China. Polycrystalline silver remains the most popular catalyst, with only minimal use of alternate supported catalysts or gauze materials. Catalyst physical properties such as bulk density, purity, mechanical strength, size fraction and shape are important in relation to overall formaldehyde synthesis performance. Process yields majorly range from ca. 82 to 92% and catalyst lifetimes vary from 4 weeks to 12 months. There is a research need to not only raise overall yields consistently to in excess of 90% but to also maximize catalyst life. Aspects which should be taken into account include: purification of feed components; development of a systematic means for catalyst bed design; improvement and standardization of process configuration; equipment optimization; investigation of the benefits of feed or catalyst additives; protection of the catalyst bed from poisoning events and discovery of preferred process operating conditions. In the near term, focusing on optimization of the current formaldehyde synthesis industry is seen as more prospective from a commercial point of view, than longer term investigation of alternate pathways for manufacturing formaldehyde from methane or carbon dioxide which may not be viable for at least a decade.

Publisher URL: http://dx.doi.org/10.1021/acs.iecr.7b02388

DOI: 10.1021/acs.iecr.7b02388