TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Conditions: The temperature of the hot coke that enters the CDQ oven (1) is 900-1050 degrees C and its temperature can be reduced to 180-200 degrees C through CDQ by the cooling air, and can be discharged out of the CDQ oven (1). The temperature of the low pressure steam that enters the CDQ oven as the cooling air is 120-200 degrees C and its pressure is 0.1-1.5 MPa. The temperature of the mixture gas of the low pressure steam and the coke oven gas that enters the CDQ oven as the cooling air is 120-200 degrees C and its pressure is 0.1-1.5 MPa. The temperature of the synthetic gas that is discharged from the CDQ oven is 800-900 degrees C and its pressure is 0.1-0.2 MPa. The temperature of the overheat steam that is produced by the overheat steam waste heat boiler (3) is 450 plus minus 10 degrees C and its pressure is 3.5-4.0 MPa. Preferred Composition: The content of methane is 20-30 vol.%. The synthetic gas comprises (vol.%) H2 (39-60), CO (35-45), CO2 (4-10), methane (CH4) (0.5-1.5), and other component (0.5-5). Preferred Process: The synthetic gas having heat that is recycled and is output is delivered to the gas purifying system to be processed, and used as raw material to be delivered to the methanol compounding system to produce methanol. The oxygen or air is added in the cooling air, mixture gas of steam and oxygen, or steam and air is added at upper part of the pre-storing section of the CDQ oven (1) or prechamber is set in the passage through which the CDQ oven can run to the overheat steam waste heat boiler (3), and the oxygen or air is added in the prechamber. The synthetic gas can be used to prepare the methanol by washing, purifying air, converting, circulating and compressing, methanol compounding, and rectifying methanol. Rectifying methanol is from the overheat steam that is produced by the overheat steam waste heat boiler (3). Rectifying methanol can separate the uncondensable light-component gas with CH4, H2, CO and dimethyl ether (CH3OCH3) and it is used in the cooling air.