A thermal reactor was designed and built to produce coal from date stones by pyrolysis. Five specimens of coal have been prepared at different maximum charring temperatures. It was found that, as the temperature increases, the properties of coal are improved (the percentage of carbon content increases). It was also found that, at 700 degrees C, the percentage of carbon content remains constant. The coal prepared at this temperature was used as a filtering medium in an adsorption filter to purify the exhaust gases of a two stroke spark ignition engine. The results showed that the frlter has a high adsorption ability for CO and CO2 gases. An ORSAT apparatus was used to measure the concentration of CO and CO2 in the exhaust gases before and after the filter. The filter reduced the concentration of CO and CO2 by 62 and 59%, respectively.