Shaped cellulose manufacturing process combined with a pulp mill recovery system

A process for manufacturing shaped cellulose material from lignocellulose comprising the steps of:

• a) providing a feed of comminuted lignocellulosic material comprising cellulose, hemicelluloses and lignin;
• b) separating lignin from lignocellulosic feed material by cooking the material at a temperature from between about 110 to 200° C. for a time period of from about 1 hour to 6 hours in an aqueous solution comprising soluble alkali, alkali earth metal or phosphorous compounds, thereby forming a first stream of solid material enriched in cellulose and a second spent liquor stream rich in dissolved lignin;
• c) treating the first stream enriched in cellulose from step b) by at least one of oxygen delignification, bleaching, and alkali extraction, to form a cellulose pulp with a lignin content below about 2 wt %;
• d) treating the second spent liquor stream from step b) comprising dissolved lignin, alkali, alkali earth, phosphorous or sulfur compounds, in a separate chemical recovery system comprising one or more chemical recovery units selected from the group consisting of a spent liquor concentration unit, a gas generator unit, a recovery boiler unit, and a causticising unit, wherein one or more of fresh alkali, alkali earth metal, phosphorous and sulfur compounds are recovered and reformed;
• e) dissolving the cellulose pulp having a lignin content below about 2 wt % from step c) in a solution comprising one or more of alkali, alkali earth, phosphorous, sulfur and molten salt compounds, the solution optionally comprising one or more additives, thereby forming a substantially homogeneous solution comprising dissolved cellulose, thereafter shaping or coagulating the dissolved cellulose into fibers, films or cellulose derivatives, and optionally washing the shaped or coagulated cellulose;
• f) discharging spent chemicals from at least one of:
• f1) the cellulose dissolving step in e),
• f2) the cellulose shaping or cellulose coagulation step in e), and
• f3) the shaped or coagulated cellulose washing step in e);
• g) recycling the spent chemicals in one or more units of the chemical recovery system of step d);
• wherein the spent chemicals are recovered and reformed;
• h) using fresh cellulose dissolving and/or cellulose shaping chemicals recovered from the chemical recovery system in step g) in the respective cellulose dissolving and/or cellulose shaping steps in e).