Abstract: This invention relates to a method and apparatus for purifying gases such as air of unwanted gaseous compounds, in which method the gas to be purified is brought into contact with a solution (2) that binds the unwanted gaseous compounds, and in which method the gas to be purified is caused to flow through a reactor filler (3) in a space filled with the solution that binds the unwanted gaseous compounds. At least the saturation level of the solution (2) and the surface level of the solution (2) are monitored in essence continuously, and on the basis of monitoring data the solution's saturation level and surface level are maintained essentially within predetermined limit values.

Abstract: Improved method of making wood composition boards is provided wherein wood raw materials, such as wood shavings, are pressed into boards and heated at a temperature of 180.degree. - 250.degree.C after having been treated with a urea bonding and flame-proofing agent which has been pre-reacted with a catalyst which is either a water soluble salt containing non-precious metal, such as Li, Na, K, Ca, Al, Mg, Zn, Fe, Co, Sn or Pb, or a water-soluble mono- or disaccharide, or an organic amine, or a solution of these catalyts. catalysts.