Formaldehyde is considered one of the most valuable and high consumable chemical compounds in the petrochemical industry, which always have explored and optimized manufacturing processes due to its high potential in research activities and operational circumstances. The objectives of this comprehensive study, the methanol oxidation and its conversion factor to formaldehyde have been investigated. Since water and methanol are used as two strategic components in chemical industries, the feed stream is used to produce formaldehyde in a pilot reactor. Furthermore, formaldehyde production from methanol, considerable influence of operating parameters such as temperature and pressure, dimensionless temperature and pressure, catalytic bed length, residence time of fluid flow, dimensionless bed length, flow hydrodynamics, and oxygen feed components ratio have been experimentally investigated in the laboratory circumstances. Consequently, the results of the experiments show that by increasing the percentage of water to methanol, the conversion factor increases from 50.21% to about 82%, this is due to the presence of oxygen in the composition of water and the availability of methanol for the methanol oxidation process and eventually transforming it into formaldehyde.