TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The tar catalyst is an alkali metal, a nickel based catalyst or noble metal catalyst. The adsorption filler is sawdust, straw powder or iron.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Composition: The cyclone dust collector comprises two groups of four primary cyclone separators, where the first group comprises a first stage cyclone separator connected with a secondary stage cyclone separator. The second group comprises a third stage cyclone separator connected with a fourth stage cyclone separator. The secondary stage cyclone separator connected with the third stage cyclone separator is used for introducing the biomass gas from the air inlet side of the first stage cyclone separator, and for outputting the biomass from the upper part of air outlet of the fourth stage cyclone separator after removing the dust. The four stages of each cyclone separator comprise a vertically set outer cylinder provided with a top opening and a bottom opening. An exhaust pipe is set in the upper central position and outer position of the outer cylinder. A conical shaped tube provided at the middle position of the outer cylinder and has a diameter which is equal to the top of the upper opening, and the lower opening has a smaller diameter. An air inlet is set in the outer cylinder and is tangentially inserted into the side wall of the outer cylinder, where the biomass gas form the air inlet pipe enters the outer cylinder. The biomass gas is vortexed along the side wall of the outer cylinder to flow down along the side wall of the conical shaped tube until it reaches the bottom. The gas containing the carbon powder and dust is allowed to move along the side wall of the conical shaped tube by means of the centrifugal force. Separating and depositing along the side wall of the conical shaped tube by means of air flow and gravity, and exhausting the gas by means of reverse vortex flow from the exhaust pipe to the outer upper part and entering to the lower cyclone separator or the catalytic converter. The lower part of the cyclone dust collector is provided with a carbon powder and dust collecting hopper, and the hopper is connected at all the stages of the cyclone dust collector. The working temperature of the catalyst converter is 700-900 degrees C. The cooler is tube type heat exchanger and it comprises condensate for heat exchange of the biomass gas. The flue gas discharged from a gas output pipe of the combustion chamber in the cyclone dust collector respectively passes through the each position of four primary cyclone separators. The gas output pipe from the cyclone dust collector is connected with the steam generator, and the waste heat of the flue gas obtained by the gas output pipe of the steam generator is used for biomass pyrolysis reaction.