Biomass treatment for hydrothermal hydrocatalytic conversion

A method for selective removal of detrimental metals and their anion species from a cellulosic biomass solids, said method comprising a plurality of vessels:

• a. providing each of said vessels with one of detrimental species-containing cellulosic biomass solids;
• b. introducing a quantity of an acidic solution having a pH of at most 4 from an inlet into a first vessel of said plurality of vessels containing said detrimental species-containing cellulosic biomass solids at a temperature in the range of about 0° C. to about 60° C.;
• c. repeating step (b) for a second vessel of said plurality of vessels;
• d. introducing a quantity of aqueous solution having a pH of at least 5 from an inlet into said first vessel of said plurality of vessels treated according to step (b) thereby discharging the acidic water effluent;
• e. repeating step (d) for the second vessel of said plurality of vessels treated according to step (c);
• f. introducing a quantity of gas or organic solvent from an inlet into the first vessel of said plurality of vessels treated according to step (d) and discharging the aqueous solution;
• g. repeating step (f) for the second vessel of said plurality of vessels treated according to step (e);
• h. recycling at least a portion of the discharged aqueous solution as a portion of the acidic solution;
• i. transferring at least a portion of the biomass treated according to steps (f) and (g) to a digestion and/or reaction vessel;
• j. wherein at least 2 of the vessels are undergoing at least one of the steps (b) through (i) at the same time;
• and
• k. wherein the amount of the total acidic water effluent from the plurality of vessels is in the range of from about 3 parts to about 0.5 parts relative to about 1 part of detrimental species—containing cellulosic biomass solids (dry basis).