The organic matters in make-up water entering the water-steam cycle of a power plant will decompose at high temperatures and produce low molecular organic acids such as formic acid and acetic acid

which causes the steam cation conductivity rises and the pH value reduces

resulting in corrosion of thermal equipments. By using autoclave as the reactor and humic acid as the organic solution

the decomposition characteristics of organic matters at high temperatures were experimentally studied

and the influence of temperature

retention time and organic concentration on decomposition products from the humic acid was investigated. The results show that

the major decomposition products were acetic acid and formic acid

and the concentration of acetic acid increased with the temperature and retention time. However

the concentration of formic acid decreased due to its low thermal stability. Oxygen had great effect on the thermal stability of organic matters

the presence of oxygen decreased the thermal stability of organic matters and formic acid

improved the decomposition of organic matters and formic acid

and reduced the concentration of organic acids in water.