IBA 2009: Principals of Organics Granulation - A Technical Overview of Fertilizer Production from Manures and other Waste Streams
1. Organics granulationBio-Fertilizer & Value-added Waste streams 31st Conference of the Institute for Briquetting and Agglomeration San Antonio, Texas, USA September 29th, 2009 Presented by: Brett Rittenhouse, FEECO International Brittenhouse@feeco.com (920) 468-1000
2. Principles of Organics Granulation A Technical Overview of Fertilizer Production from Manures and other Waste Streams FEECO INTERNATIONAL
4. Who We Are Worldwide supplier of process equipment Specializing in Thermal Processing, Agglomeration, Material Handling, and Process Systems Founded in 1951 as Fertilizer Engineering and Equipment Company. By the 1960s, we had diversified into Mining, Minerals, Pulp & Paper, and Waste Recycling – and became FEECO International. Privately held company with about 80 employees
5. What We Do Collaborate with Customers Process Development Feasibility Analysis Pilot Plant Testing Financial Modeling Plant Design and Engineering Detailed Equipment and Plant Design Equipment and System Supply Project Management – single equipment to turnkey supply
6. Strengths of our Team Engineering Staff from all major disciplines: Chemical/Process Mechanical Civil/Structural Environmental Electrical Customer-focused Project Management
7. Laboratory Services Our pilot plant can be set up for testing on a single piece of equipment or multiple pieces as a continuous process tying together agglomeration, drying, sizing, and recycling capabilities. Batch Testing/Feasibility Pilot Plant Testing (500-1000 lb/hr) Tolling Plant (24 hr Production Runs) Analytical Testing
9. Recycling? “Recycling involves processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air and water pollution, and lower greenhouse gas emissions.” – Wikipedia, September, 2009.
11. The Ag-Waste Dilemma Economic pressure pushing towards herd growth Prohibitively high land costs lead to herd growth without adequate land to dispose of waste Nutrient levels saturated on fields where it is economically viable to spread Excess nutrient run-off leads to surface and ground water pollution Nutrient value of manure does not get fully realized
12. The Ag-Waste Opportunity Source of macro and micro nutrients Nitrogen, Phosphorus, Potassium, Sulfur, Boron Source of Bio-Energy Production – Anaerobic Digestion Organic industry as a growth market
13. Waste Transformation: The Need Fertilizer demand is increasing Despite recent setbacks, non-renewable fertilizer prices will continue to rise US production capacity is shrinking World food demand is increasing Increasing competition for land resources (development, energy crops, etc.)
14. The Organic Food Industry U.S. sales of organic food and beverages have grown from $1B in 1990 to $20B in 2007, 20.9% growth in 2006. U.S. sales of non-food organic products were $17.7B in 2006, 26% growth in 2006. Source: Organic Trade Association
15. Fertilizers from Organic Wastes Generally considered a low-analysis fertilizer Macronutrient content < 10% by weight. Wide range of feedstocks: Slurries (<10% solids) – Relatively dry, composted material (>80% solids) The drier feed material can be finely divided and relatively dusty Limits application in the field. Traditional granulation approaches can be implemented to improve the handling, storage, spreading, and utilization characteristics of the material.
16. Organic Waste Utilization - Recap Major Driving Force: Growth! Demand Side Needs Rising Fertilizer Costs Trade Imbalances Local and Secure Source of Nutrients Supply Side Needs Increasing Disposal Problems Environmental Regulation Need for safe (and profitable?) means of “Nutrient Recycling”
21. Mixer – Dryer Granulation Mixer selection based on feedstock analysis Pin mixer for finely divided particles (chicken litter, compost, etc.) Pug Mill/Paddle Mixer for sludges, pastes, and filter cakes. Dewatered liquid manures from centrifuge, DAF effluent
22. Pin Mixers Used as pre-conditioning unit or stand-alone agglomerator One Rotor with Radial Pins Multiple Feeds Fluid Ports in Top Cover Relatively High Speed – Turbulent Mixing Action
23. Pin Mixer Basics Turbulent action of the mixer provides thorough mixing of liquid (binder), raw feed, and recycle Reduces the amount of liquid required for agglomeration Allows high liquid levels without over-wetting Reduces chances of segregation due to density differences in feed materials Reduces the chances of selective agglomeration Up to 90% of binder liquid can be added in mixer with 10% reserved for finish processing (if necessary)
24. Pin Mixer Basics Mechanical work compacts the agglomerate through work between the pins and shell and interaction with each other Improved crush strength, Less attrition With a retention time of seconds, the mixer delivers to a finishing pelletizer (if necessary) nuclei that are properly moistened, have adequate density, and are thoroughly mixed with binders, recycle, and multiple raw materials Can increase on-size product up to 95% (when coupled with Pan Pelletizer) Can increase capacity of pelletizing disc or drum (nuclei formation in mixer)
25. Pin Mixer Basics Mixer may be required for agglomeration to occur in pelletizing disc or drum: Chemical reaction (Phosphoric Acid Spray) Reduce moisture level in sludges by mixing with dry recycle Intimately mix liquid with raw feed (compost)
29. Mixer – Dryer Granulation Advantages: Mixer offers moisture control of granulation process Simple, closed system Minimal waste. Off-spec product recycled in granulation loop Easy binder addition in mixing step Optimization includes evaluation of: Pin arrangement Pin tip speed Retention time (function of equipment sizing and mixer speed)
30. Mixer – Dryer Granulation Disadvantages: Oftentimes a tight moisture window in pin mixer granulation limits control Material handling can be challenging for wet, sticky feed Require finely divided feedstock – pre-grinding/de-lumping may be necessary Limitations on achievable granule crush strength (feedstock specific) Small diameter granule production Might be desired for “greens” grade product
32. Pan Granulation - Fundamentals Feed from Pin Mixer fed through articulating feed chute Small particles at bottom of bed and travel furthest Largest particles remain in kidney shaped area on top of bed Competition between gravitational and centrifugal forces resulting segregation by size in tumbling bed
37. Pellet Mill Process - Overview Raw Manure Unloading Manure Drying Size Reduction Steam Conditioning Pellet Mill Crumbling Fines Classifying On-size Product
38. Pellet Mill Process Physical Product Differences Crumble vs. Spherical Product Energy Usage Reduction in drying gas requirements Increase in electrical requirements (pellet mill) Reliability & Maintenance Careful with high silica feedstocks
39. Bio-Fertilizer Plant - Emissions Gas Treatment Feedstock specific Particulate Wet scrubbing Form of Nitrogen in feedstock? Fuel Source? Biogas may involve SOx scrubbing
40. Selection of Agglomeration Equipment Parameters of Particulate Feed Size and Shape Moisture Content Material Characteristics Material Sensitivities (heat, pressure, reactivity, etc.) Bulk Characteristics Binding Characteristics Parameters of Agglomerated Product Size and Shape Strength Green Strength Final (cured) Strength Structure Source: Pietsch, Wolfgang Agglomeration in Industry, Vol 2
41. Parameters of Agglomeration Method Batch or Continuous Operation Capacity Requirements Wet or Dry Operation Space and Energy Requirements Investment and Operating Costs Site, Supply, Environment, Infrastructure Relative location to suppliers and customers (raw materials, additives/binders, energy) Site accessibility and transportation facilities Climatic conditions Availability of skilled and other labor Availability of support functions Regulations (EPA, OSHA, etc.) Source: Pietsch, Wolfgang Agglomeration in Industry, Vol 2 Selection of Agglomeration Equipment