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Accurate analysis of black liquor is challenging due to the complex mixture of organics and inorganics, and the varied consistency. We are experts in this work whether it be weak or strong black, or a variant like brown/red (sulfite) orange (BL-polysulfide), or non-fired, non-sulfonated liquor from non-wood pulping processes.
Aside from analytics that support inorganics recovery and steam/power generation from black liquor concentration and incineration, we also quantify recoverable organic by-products in black liquor or the recovered product itself. Crude turpentine distilled from the digester, tall oil soap skimmed from early evaporator effects and converted crude tall oil, and methanol steam-stripped from evaporator condensates are all in scope. If you’re interested in studying recovered lignin, sugars, or organic acids we are capable with those chemical species as well.
A selection of test packages and other core tests for black liquor and recovered organics are listed below for easy reference. Others may be easily found with Find A Test.
Black Liquor Analysis Packages
Routine Evaluation
Calorific Value (gross) / Higher Heating Value (HHV)
Solids, Total (percent)
Total sulfur (S)
Total chloride (Cl)
Metal Scan
Elemental analysis (CHNO)
Extended Evaluation
Calorific Value (gross) / Higher Heating Value (HHV)
Solids, Total (percent)
Total sulfur (S)
Total chloride (Cl)
Metal Scan
Elemental analysis (CHNO)
Carbonate (Na2CO3)
Sulfate (Na2SO4)
Sulfite and thiosulfate (Na2SO3, Na2S2O3)
Active (and estimated effective) alkali
Total alkali
Organic/inorganic ratio (sulfated ash)
Viscosity of as-received liquor measured at three temps in the range of 90°C to 115°C
Tall oil content
BL Viscosity and Swelling Properties
Reduced pressure evaporation of black liquor to three solids levels followed by measurement of viscosity at three temperatures
Calorific Value (gross) / Higher Heating Value (HHV)
Organic/inorganic ratio (sulfated ash)
Swelling characteristics of dry liquor solids
Elemental analysis (CHNO)
BL Fuel Value Properties
Calorific Value (gross) / Higher Heating Value (HHV)
Proximate analysis (moisture, ash, volatile matter, fixed carbon)
Ultimate analysis (CHNOS)
Tall Oil Analysis
Tall Oil content of Black Liquor
Resin and Fatty Acids (RFA – Rosin)
Unsaponifiable Matter (Higher Alcohols, etc.)
Acid Number
Water Content
Commonly Tested Properties – Black Liquor (weak or strong)
Alkali, Total (conductimetric)
Alkali / ABC Titrations incl. Active (AA), Effective (EA)
Anthraquinone
Ash (@ 600°C)
Boiling Point
Boiling Point Rise
Calorific Value (Gross) / Higher Heating Value (HHV) of BL Solids
Carbohydrates (wood sugars: arabinan, galactan, glucan, mannan, xylan)
Carbonate
Carbonate/Sulfate Ratio
Critical Solids (Burkeite)
Density
Elemental analysis (CHNO)
Fiber content
Lignin content
Metal Scan
Proximate and Ultimate Analysis
Tall Oil content
Resin Acids + Fatty Acids (RFA – Rosin)
Solids, Total (percent)
Sulfur, Total (photocombustion)
Sulfur species (SO4, SO3, S, S2O3)
Swelling characteristics of BL solids
Viscosity – multi-point BL solids / temperature curves or at single points
Volatile Matter
Commonly Tested Properties – Recovered Lignin
Moisture content, as-received – ASTM D3173
Water extractives – NREL TP 510 42619
DCM Extractives – TAPPI T204
Ash content @ 525°C – TAPPI T211
Ash content @ 750°C – ASTM D3174
Metals by ashing, acid digestion and ICP analysis
Elemental analysis (C, H, N and O)
Calorific value (BTU/lb) – TAPPI T684
Total Sulfur content
Total Chloride content
Carbohydrates (arabinan, xylan, mannan, galactan, glucan)
Infrared spectra (FTIR)p