And, amid these rich and potent devices of the culinary art (not one of which, probably, had been tested, within the memory of any man's grandfather), poor Hepzibah was seeking for some nimble little titbit, which, with what skill she had, and such materials as were at hand, she might toss up for breakfast.
Early kraft pulp mills discharged black liquor to watercourses. Black liquor is quite toxic to aquatic life, and causes a very dark caramel color in the water. The invention of the recovery boiler by G.H. Tomlinson in the early 1930s, was a milestone in the advancement of the kraft process.
However, black liquor retains more than 50% of the woodâs biomass energy. With the invention of the recovery boiler in the 1930s, black liquor could be recycled and used to power the mill. In the U.S., paper mills use nearly all their black liquor to run their mills, and the forest industry is one of the most energy-efficient in the nation as a result.