A mixture of hexane isomers (hexanes) is used in a parts cleaning and degreasing operation. A portion of the used solvent is recycled for further use by the following process. Used cleaning solvent containing 84.7 wt% hexanes, 5.1 wt% soluble contaminants, and the remainder particulates, is first filtered to yield a cake that is 72.0 wt% particulates and the remainder hexanes and soluble contaminants. The ratio of hexanes to soluble contaminants is the same in the dirty hexanes, the filtrate, and the residual liquid in the filter cake. The filter cake is then sent to a cooker in which nearly all of the hexanes are evaporated and later condensed. The condensed hexanes are combined with the liquid filtrate and then recycled to the parts cleaning operation for reuse. The cooked filter cake is further processed off site. a. How many lbm of cooked filter cake are produced for every 100 lbm of dirty solvent processed?
b. What is the weight percent of soluble contaminants in the cooked filter cake?