of all these processes the Oxo reaction (equation 1) is the most important . the carbonylation of methanol with the rhodium iodide catalyst (equation 6) ranks second. it is a relatively new process, but it is expected that this process will dominate the manufacture of acetic acid in the future. the other processes are applied on a smaller scale in industry or are of only potential industrial importance . during the 1970s and early 1980s , when the crude oil prices were high, reactions such as the homologation of methanol and the glycol synthesis found considerable interest. it was thought that coal-based synthesis gas could replace oil as the major feedstock of the chemical industry. the rapid oil price decrease in the mid 1980s prevented these new syngas processes from going on stream.