ATTEMPTED DELIGNIFICATIONS WITH SODIUM BICARBONATE - CARBON DIOXIDE, AND WITH ANHYDROUS LIQUID AMMONIA, UNDER PRESSURE

Abstract

Finely divided spruce wood was heated with aqueous sodium bicarbonate and excess carbon dioxide up to 160° and about 400 p.s.i. in attempts to carboxylate the lignin according to the Kolbe–Schmitt method and to extract the product as a soluble sodium salt. Only small amounts of lignin were removed, together with larger amounts of the holocellulose. Heating the wood with anhydrous liquid ammonia up to 100° and about 900 p.s.i. extracted only small amounts of material from the softwood spruce, but 25 to 30% of the lignin was removed from the hard woods beech, birch, and maple and 52% from rye straw. The solution of ammonium chloride or sodium cyanide in the liquid ammonia increased these percentages substantially, and also the concomitant extraction of holocellulose.