SLRP by Liquid Lignin Company

Summary 

Using vessel sizes determined by Liquid Lignin Company, EnviroSep generated a 3D diagram of the demonstration SLRP capable of making ten (10) metric ton per day (Te/d). 

Figure 1. 3D Diagram of Demo-SLRP 

The skid size is 20-feet wide, 40-feet deep and 40-feet high. 

Discussion 

Vessels: All of the vessels are included: 

  • Black Liquor Sand Filters (2) 

  • Carbonation Column 

  • Carbonation Column Knock-Out 

  • Carbonation Settler 

  • Vent-Gas Absorber 

  • Vent-Gas Stripper 

  • Carbonated (lignin-depleted) Black Liquor Neutralization 

  • Acidification Reactor 

  • Acidification Knock-Out 

  • Lignin Slurry 

  • Lignin Filter (2) 

  • Acid Brine Recycle 

  • Acid Brine Neutralization 

  • Concentrated Sulfuric Acid Totes (2) 

  • Concentrated Sodium Hydroxide Totes (2) 

Not included in the 3D are: 

  • Pre-Carbonation Column (very small); 

  • Sulfuric Acid Mixing Tee with Recycled Brine (very small); 

  • 18 process pumps; 

  • Piping and control valves; 

  • Sensors, including nine (9) pH and three (3) viscosity measurements; 

  • H2S monitor and alarm; 

  • Master control system; 

  • Collection bins under each filter and lignin supersacks; 

  • CO2 dewar or tank- wagon; 

  • Air compressor dedicated to Lignin Filter; and 

  • Forklift for removing lignin supersacks. 

Acid Side ↔ Base Side: The skid is in two equal halves separated by a short (≈ one-foot high) dike so that inevitable spills are separated. A sunken sump will be incorporated into each half with the concrete floor graded slightly to direct liquids to their respective sumps. 

The base-side vessels are: Carbonation Column/Settler; Carbonation Column Knock-Out; Vent-Gas Absorber/Scrubber; Acid Brine Neutralization, Carbonated Black Liquor Neutralization; Sand Filters; and Concentrated NaOH totes. The acid-side vessels are: Acidification Reactor; Acidification Reactor Knock-Out; Lignin Slurry, Lignin Filters (2); Acid Brine Recycle; and Concentrated H2SO4 totes. 

Filters: Two Watermark filter will operate in parallel. One will be accumulating lignin while the other goes through wash cycle which includes: 

  • Wash with pure water at 80 °C; 

  • Squeeze cakes with pressurized bladders within each cell to remove water; 

  • Blow filter with air to remove residual water; 

  • Separate plates to allow lignin cakes to dump; and 

  • Reclosing plates to begin filtering lignin.