NOVELTY - The apparatus comprises a batch pyrolysis chamber (12) for generating synthetic gas, a reformer unit (14) having mixing and collecting chambers (18, 20) and a water-gas shift reaction zone, conduits (22, 24) forming a loop for repeatedly circulating gases between the chamber and the water-gas shift reaction zone, a unit for adding hydrogen to the gas circulating in the loop by water-gas shift reaction, and a control system for monitoring the hydrogen content of the synthetic gas in the reformer unit and controlling the gas circulation between the chamber and the water-gas shift reaction zone.    USE - The apparatus is useful for producing synthetic gas, which is useful in internal combustion engines and to produce alcohols such as methanol, ethanol and propanol and hydrogen.    ADVANTAGE - The apparatus efficiently and economically produces the controlled and high quality synthetic gas with less consumption of energy.    DETAILED DESCRIPTION - The apparatus comprises a batch pyrolysis chamber (12) for generating synthetic gas, a reformer unit (14) having mixing and collecting chambers (18, 20) and a water-gas shift reaction zone, conduits (22, 24) forming a loop for repeatedly circulating gases between the chamber and the water-gas shift reaction zone, a unit for adding hydrogen to the gas circulating in the loop by a water-gas shift reaction, a control system for monitoring the hydrogen content of the synthetic gas in the reformer unit and controlling the gas circulation between the chamber and the water-gas shift reaction zone, a unit for injecting steam into the gas in the mixing chamber of the reformer unit, and blower units in the conduits for circulating the gases. The control system is operable to control the supply of the gas to a gas synthesizer or a steam generating unit. The control system has a unit for monitoring the composition of the synthetic gas in the reformer unit, and a unit for controlling the movement of gases to the gas synthesizer and the steam generating unit. The mixing chamber is located downstream of the water-gas shift reaction zone in the circulation loop. The collecting chamber is located between the water-gas shift reaction zone and the gas synthesizer and the steam generating unit. The control system is operable to control the injection of steam into the gas in dependence on the hydrogen content of the synthetic gas in the reformer unit, to control the blower units in dependence on the hydrogen content of the synthetic gas in the reformer unit, to monitor the hydrogen content of the synthetic gas in the mixing chamber to control the circulation of gas between the pyrolysis chamber and the water-gas shift reaction zone, to monitor the composition of the synthetic gas in the collecting chamber, and to circulate the synthetic gases for 3-10 times between the pyrolysis chamber and the reformer unit. An INDEPENDENT CLAIM is included for a method of producing synthetic gas in a batch process.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of an apparatus for producing synthetic gas.    Pyrolysis chamber (12)    Reformer unit (14)    Mixing chamber (18)    Collecting chambers (20)    Conduits. (22, 24)