ASME & CE Certified Laboratory Pulp Digesters

Precise, safe, and versatile. Cook by H-Factor or Temp/Time segments

2021 MK laboratory Digester
ASME and UL certification

Increase your pulp yield

M/K Systems Inc. offers the most precise laboratory pulp digesters available.  Our liquor circulating pulp system uses an anti-turbulent design, patented shower head design, stainless steel vessels and tubing, and a multi-heater system to uniformly cook your pulp.    This laboratory pulp digester is ideal for Kraft cooks, hemicellulose cooks, or any type of cellulose product (including fine particle materials). Cook in 1 vessel, 2 vessels, or our multi-vessel systems.  Transfer liquor between vessels.  Our patented mixing module provides the best liquor/chip interaction available.  Heat by temperature/time segments or by H-factor.  Obtain low variation in your KAPPA numbers.  Extract liquor during the cook with our enhanced sampling condenser design.  Cook wood chips, hemp, fine particles, or almost any cellulose-based material.     We have options that allow you to easily and safely inject additives during your cookRent or purchase our high-pressure pulp digesters for all of your cooking needs.  The digester is easy to use, safe, and reliable.  Use our systems for kraft cooks, sulfite cooks, bleaching, extraction of hemicellulose, cooking with additives, process bagasse, etc

M/K Systems is the only company that circulates the liquor over six individual vessels. The M/K Systems circulating method offers key advantages over competitors. This is highly advantageous.,

1) Better Mixing, Better Cooks, Better repeatability: The M/K Systems Digester offers better liquor/cellulose mixing compared to competitors. The M/K Systems digester, employing a patented shower head spraying nozzles, allows the customer to rapidly flow fluids through the substrate. No competitor system can match this deep fluid penetration into the substrates. Better mixing means better, more repeatable and reliable results.
2) More realistic to larger scale systems: The M/K Systems method of flowing liquor offers a more realistic approach to larger production.
3) More accurate heating system The M/K Systems multi-heater digester uses rapid cooking methods including a jacketed-heater wrapped around the vessel as well as the inline heater. This results in greater temperature precision compared to any competitor device.

4) M/K Systems is the only company that offers a circulating digester system that records both liquor and vapor temperatures. This allows the user to understand when equilibrium is reached, as well as more thorough understanding of the cooking solutions and vapors.

5) M/K Systems is the only company to use our patented shower-dispersion nozzle. This results in the best liquor/cellulose interactions.

6) M/K Systems uses patented efficient digester vessels: Our patented top-liquor-feed (patented) vessels are the most efficient in the industry. Since most of the heating is used to heat the 316 stainless steel vessels, it is vital to make use of the vessel spacing. Inefficient vessels result in the user heating empty space, unlike the M/K Systems patented digester.

7) M/K Systems is the only company to employ resistance-designed vessel jacket heaters and inline heaters, thereby avoiding excessive inline heater temperatures that can damage the liquor. This is a significant advantage over earlier M/K Systems digesters models.

M/K Systems has 2 current technology patents used in the design (US Patent 8172984 and US Patent 7811416).

    See what M/K Systems customers say about us:

    "We have equipment from MK Systems for over 25 years. The 6-liter digesters have recently been upgraded and we have acquired new 20-liter digesters. The collaboration with the people at M/K Systems is excellent. When we have questions, we get the answers quickly. Discussions with the people at M/K Systems are very beneficial to our work. Being a research center, we work with several unconventional raw materials and their advice allows us to move our projects forward more quickly. Also, when we need spare parts, these are delivered very quickly.” -Dr. S. Duquette

KAPPA graph
GA Tech Digester
M/K Digester with options
Cooked chips
M/K Chip can with cooked chips
Digester profile

Details and industry references 

Some of our industry references include:

1.   Shell Oil, US patent 9,527,788, "Methods for hydrothermal digestion of cellulosic biomass solids in the presence of a distributed slurry catalyst".

2. (United States),“Composition for the production of Improved Pulp”, Patent # US 6,890,404.

3. (United States),“Phenols as Additives in Kraft Pulping”, Patent Application Publication US 2019/0112757.
4. (United States), “Controlled Flocculation of Lignocellulosic Hydrolyzates”, Publication US 2016/0083808.

5. (Germany), “Method for obtaining cellulose from biomass comprising lignocellulose”, World Wide Application #2,758,038.

6. (Australia), Liquid co-extraction process for production of sucrose, xylo-oligosaccharides and xylose from feedstock, Australian Pat. App. AU 2015252695 B2, World Wide Application # 2015/164948.

7. (United States), “Tobacco-derived cellulose material and products formed thereof”, US Patent # 9,950,858.

8. (United States), “Method to separate lignin-rich solid phase from acidic biomass suspension at an acidic pH”, Patent # US 9,751,781.

9. (International Application),”Composition for inhibiting calcium salt scale formation”, Patent Application
AU 2,010,224,861.

10. (Portugal), “Method and aqueous composition for the production of improved pulp”, Patent # PT

11. (United States), Publication: “Comparison of Oxidative Alkaline Extraction Reaction's Impact on Pulp
Properties and the Environment”. T.M. Runge and A.R. Ragauskas, Int’llPulp Bleaching Conference.
Helsinki, Finland

12. (United States), Publication: Peter Hart, Daniell Connell, “The effect of digester kappa number on the bleachability and yield of EMCCTM softwood pulp", Westrock Company. 

13. (United States), Publication, "Integrated Two-Stage Alkaline–Oxidative Pretreatment of Hybrid Poplar. Part 2: Impact of Cu-Catalyzed Alkaline Hydrogen Peroxide Pretreatment Conditions on Process Performance and Economics.", Zhaoyang Yuan, Sandip Kumar Singh, Bryan Bals, Dr. David B. Hodge, and Eric L. Hegg, Ind. Eng. Chem. Res. 2019, 58, 35.

14. (United States), Publication, "Deconstruction of hybrid poplar to monomeric sugars and aromatics using ethanol organosolv fractionation", Janosch Bär, Thanaphong Phongpreecha, Sandip Kumar Singh, Melisa Kral Yilmaz, Cliff E. Foster, Jacob D. Crowe & David B. Hodge, Biomass Conversion and Biorefinery, volume 8, pages 813–824 (2018).

15.  (United States), Publication, "Relating Nanoscale Accessibility within Plant Cell Walls to Improved Enzyme Hydrolysis Yields in Corn Stover Subjected to Diverse Pretreatments", Jacob D. Crowe†, Rachael A. Zarger†, and David B. Hodge.  Journal of Agricultural and Food Chemistry.

16. (United States), Publication, "Relating Nanoscale Accessibility within Plant Cell Walls to Improved Enzyme Hydrolysis Yields in Corn Stover Subjected to Diverse Pretreatments", Jacob D. Crowe†, Rachael A. Zarger†, and David B. Hodge.   Journal of Agricultural and Food Chemistry.

17. (United States), Publication, "Evaluation of Microwave Pretreatment for Reducing the Recalcitrance of Woody Biomass to Hemicellulose Extraction and Cellulose Hydrolysis", New York State Energy Research and Development Authority, John Hokanson, Warren H. Chesner, Victor A. Barber, Arthur J. Stipanovic

18. US Department of Energy, "GO16108 Final Scientific Report",

19. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), (Argentina), "Ethanol-Water Fractionation of Sugar Cane Bagasses Catalyzed with Acids", 2009

Copyright © M/K Systems 1969-2022

Some of the typical cooking materials include:

  • All Soft Woods & Hard Woods

  • Bamboo

  • Bagasse

  • Bio-based materials

Contact Us

Get in touch with us today for more details! Our personnel will be glad to answer your inquiries.