Gamma-valerolactone biorefinery: Catalyzed birch fractionation and valorization of pulping streams with solvent recovery.

In this study, we propose a full gamma-valerolactone (GVL) organosolv biorefinery concept including the utilization of all pulping streams, solvent recovery, and preliminary material and energy balances. GVL is a renewable and non-toxic solvent that fractionates woody biomass. The silver birch chips were pulped (45-65 wt% GVL, 150 °C, 2 h) under a series of acid-catalyzed conditions (5-12 kg HSO/t), and the fully bleached pulp was spun into fibers by the IONCELL® process and knitted into the fabric.

Chemical Recovery of γ-Valerolactone/Water Biorefinery.

We introduce the optimization of the pulping conditions and propose different chemical recovery options for a proven biorefinery concept based on γ-valerolactone (GVL)/water fractionation. The pulping process has been optimized whereby the liquor-to-wood (L:W) ratio could be reduced to 3 L/kg without compromising the pulp properties as raw material for textile fibers production. The recovery of the pulping solvent was performed through combinations of lignin precipitation by water addition, distillation at reduced pressure, and liquid CO extraction.

Solubility of Organosolv Lignin in γ-Valerolactone/Water Binary Mixtures.

The solubility of lignin in a mixture of γ-valerolactone (GVL) and water at different weight ratios was measured using the Hildebrand solubility parameters. Based on the molecular structure of lignin, its solubility parameter (δ-value) was calculated as 25.5 MPa .

Spinal hyperbaric ropivacaine-fentanyl for day-surgery.

Background: Adequate intraoperative analgesia combined with faster mobilization might be achieved by replacing hyperbaric ropivacaine partly with fentanyl.

Methods: Sixty spinal anesthesia patients were randomized into 2 groups of either fentanyl 20 microg mixed with hyperbaric ropivacaine 10 mg (group FR10) or hyperbaric ropivacaine 15 mg (group R15). Forty-five patients underwent inguinal hernia repair and 15 patients had lower extremity surgery.