Determination of the emission factor of carbon monoxide for jewelry making workshops

Air pollution has become a problem in the city of Isfahan, Iran. Jewelry making workshops are one of the city’s sources of pollutants. No studies had yet been conducted to determine the emission factor for Isfahan’s jewelry making workshops. The purpose of this study was to determine the carbon monoxide emission factor obtained from the Isfahan emission factor. In the first step, jewelry making workshops were visited in Isfahan and it was found that the only source of carbon monoxide was the use of an oxy-fuel welding system for melting gold. In the second step, a pilot experiment determined the emission rate for carbon monoxide. Then, the gas consumption was measured for the oxy-fuel welding system. Next, the amount of carbon monoxide produced per cubic meter of consumed natural gas in an oxy-fuel welding system was calculated. The results of this study showed that the carbon monoxide emission factor for an oxy-fuel welding system is 0.715 kg/kg of consumed natural gas. Interviews with the managers of some of the jewelry making workshops found that on average 22 kg of natural gas is used per month by each of Isfahan’s jewelry making workshops. Each month, each jewelry making workshop produces about 15.73 kg of carbon monoxide. The emission factor introduced in this study can be used to calculate the air pollutants emissions of jewelry making workshops in Isfahan to find their share of Isfahan’s air pollution.