Process for the extraction of aqueous sugar solution resulting from the hydrolysis of lignocellulosic material

Claim 1

A PROCESS FOR THE EXTRACTION OF AQUEOUS SUGAR SOLUTION RESULTING FROM THE HYDROLYSIS OF LIGNOCELLULOSIC MATERIAL WHICH COMPRISES (A) PASSING THE AQUEOUS SUGAR SOLUTION IN CONTACT WITH CHLOROFORM SOLVENT IN AN EXTRACTION ZONE, (B) DISCHARGING FROM THE EXTRACTION ZONE THE CHLOROFORM SOLVENT CONTAINING DISSOLVED HYDROLYTIC DEGRADATION PRODUCTS AND SEPARATE STREAM OF A SUGAR SOLUTION SUBSTANTIALLY FREE FROM HYDROLYTIC DEGRADATION PRODUCTS AND CONTAMINATED WITH SAMLL AMOUNTS OF CHLOROFORM, (C) PASSING THE CHLOROFORM SOLVENT CONTAINING THE DISSOLVED HYDROLYTIC DEGRADATION PRODUCTS THROUGH A SECOND EXTRACTION ZONE IN CONTACT WITH WATER TO EXTRACT THE BULK OF THE HYDROLYTIC DEGRADATION PRODUCTS FROM THE CHLOROFORM, (D) DISCHARGING FROM THE SECOND EXTRACTION ZONE A STREAM OF CHLOROFORM AND A SEPARATE STREAM OF WATER CONTAINING THE HYDROLYTIC DEGRADATION PRODUCTS TOGETHER WITH SMALL AMOUNTS OF CHLOROFORM AND RECYCLING THE STREAM OF CHLOROFORM TO THE FIRST EXTRACTION ZONE, (E) PASSING THE STREAM OF WATER CONTAINING THE HYDROLYTIC DEGRADATION PRODUCTS TOGETHER WITH SMALL AMOUNTS OF CHLOROFORM THROUGH A THIRD EXTRACTION ZONE IN CONTACT WITH NAPHTHA TO SEPARATE THE COLOROFORM FROM THE WATER, (F) DISCHARGING FROM THE THIRD EXTRACTION ZONE WATER CONTAINING SMALL AMOUNTS OF NAPHTHA AND A SEPARATE STREAM CONTAINING NAPHTHA AND CHLOROFORM, (G) HEATING SAID WATER AND NAPHTHA DISCHARGED FROM THE THIRD EXTTRACTION ZONE TO VAPORIZE THE NAPHTHA, AND RECYCLING THE NAPHTHA BACK TO THE THIRD EXTRACTION ZONE, (H) HEATING THE CHLOROFORM-NAPHTHA SOLUTION FROM THE THIRD EXTACTION ZONE TO SEPARATE THE CHLOROFORM FROM THE NAPHTHA AND RECYCLING THE CHLOROFORM TO THE FIRST EXTRACTION ZONE, (I) RECYCLING A PORTION OF THE SEPARATED NAPHTHA BACK TO THE THIRD EXTRACTION ZONE FOR FURTHER CONTACT WITH WATER AND CHLOROFORM FROM THE SECOND EXTRACTION ZONE, (J) PASSING THE SUGAR SOLUTION DISCHARGED FROM THE FIRST EXTRACTION ZONE AND CONTAINING SMALL AMOUNTS OF CHLOROFORM IN CONTACT WITH THE REMAINING PORTION OF NAPHTHA IN A FOURTH EXTRACTION ZONE TO SEPARATE THE CHLOROFORM FROM THE WATER THEREBY PRODUCING A NAPHTHA STREAM CONTAINING DISSOLVED CHLOROFORM AND A SEPARATE STREAM OF SUBSTANTIALLY PURE SUGAR SOLUTION CONTAMINATED WITH A SMALL AMOUNT OF NAPHTHA, (K) DISCHARGING THE NAPHTHA STREAM FROM THE FOURTH EXTRACTION ZONE AND ADMIXING THE NAPHTHA STREAM WITH THE CHLOROFORM-NAPHTHA FROM THE THIRD EXTRACTION ZONE, (L) DISCHARGING FROM THE FOURTH EXTRACTION ZONE SAID SUGAR SOLUTION AND HEATING SAID SUGAR SOLUTION TO VAPORIZE THE NAPHTHA LEAVING AS RESIDUE A SUBSTANTIALLY PURE SUGAR SOLUTION AND, (M) RECYCLING THE VAPORIZED NAPHTHA BACK TO THE THIRD EXTRACTION ZONE.