Process for production of lignin, organic acids, organic chemicals, pure co2, and water from kraft black liquor with operational efficiencies

A method of obtaining components from a kraft black liquor feedstock, comprising:

• passing a BL feedstock through a NF membrane to remove a first portion of lignin in the BL feedstock to generate a NF permeate;
• acidifying, with an acidification unit, the NF permeate to generate an aqueous stream and an off-gas stream including CO2;
• filtering, with a filtration unit, the aqueous stream to remove a second portion of lignin from the aqueous stream to generate a delignified BL stream;
• removing, at least a portion of organic acids in the pretreated BL stream to generate a reduced-acid pretreated BL stream and a recovered organic acid stream;
• passing the reduced-acid pretreated BL stream through a membrane to generate a water permeate and a raffinate comprising salt and recovering the water permeate;
• passing the raffinate comprising salt through a membrane electrolyzer to generate an acidic stream and a basic stream;
• and
• liquifying gaseous CO2 from within the off-gas stream into a liquified CO2 stream and recovering the liquified CO2 stream.