The paper industry used 18 percent less fossil fuel and purchased power in 1987 than in 1972 by switching further to self-generated power sources such as wood residues, bark and spent pulping liquors, reports Energy User News.

According to the industry journal, production of pulp, paper and paperboard by the industry was increased by 34 percent during the same period.The industry used almost 50 percent more self-generated energy in 1987 than in 1972.

The largest reductions in fuel purchases were in residual fuel oil, which fell from 21.4 percent of the fuel bought by the industry in 1972 to only 7.4 percent in 1987. This was followed by natural gas, which fell from 20.4 percent to 15.8 percent.

At the same time, wood residues experienced a jump in use from 2.1 percent in 1972 to 10.1 percent in 1987. Spent pulping liquors moved to 40.2 percent from 33.6 percent.