... firewood mixed gas fuel artificial operation modeAdvantages: Use part of the cracking gas, reduce the emission.Shortage: Poor ... , safty, high efficient.Shortcomings: Increase the sets of equipments, appropriately increase investment. Gas burning systemTake the ... development, safty, high efficient.Shortcomings: Increase the sets of equipments, appropriately increase investment. 5.Cooling systemCoil pipe ...