From Offal to Valuable Ingredient: How Animal Protein Producers Power the Circular Food Chain
The modern food chain faces a defining challenge: how to feed a growing world without exhausting natural resources. Specialised producers of animal proteins and fats are emerging as a quiet but powerful answer. By transforming slaughter by-products, which account for roughly 25% of total slaughter weight, into high-quality ingredients, they help close the global protein gap while advancing a truly circular economy.
What are animal protein producers?
Animal protein producers process category 3 by-products from slaughterhouses into premium ingredients for the animal feed industry. Materials such as feathers, blood, bones and meat trimmings, collectively known as offal and once discarded as waste, are converted into valuable proteins and fats that replace less sustainable raw materials across many industries.
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By-products, not waste
Feathers, blood, bones and meat trimmings are upgraded into premium proteins and fats. -
Roughly 25% of slaughter weight
A large share of every animal is recovered as useful ingredients rather than lost. -
Replacing scarcer raw materials
Recovered proteins and fats substitute for less sustainable inputs across feed, pet food and energy. -
Closing the protein gap
Turning by-products into nutrition helps feed a growing world within a circular economy.
Why Lechler spray technology is ideally suited for gas scrubbing
The rendering of animal by-products releases process gas that must be cleaned before it can be emitted. The efficiency of a scrubber stands or falls with the quality of liquid atomization, and this is precisely where Lechler nozzle technology excels.
What sets Lechler nozzles apart
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Clog-free design
Tangential hollow-cone nozzles keep operating reliably even in fouling-prone streams, minimizing downtime and maintenance. -
Fine, uniform droplets
A large droplet surface area captures the maximum amount of dust and gas particles for high removal efficiency. -
No packing required
The overlapping spray pattern wets the entire wash section, so a contact body becomes superfluous and pressure loss stays extremely low. -
Low pressure drop
With no packing, pressure drop stays low and consistent, so the upstream production process is not affected. -
Robust under fluctuating loads
The counter-current washing principle copes well with irregular concentrations and peak emissions. -
Self-cleaning effect
The high combined flow continuously rinses the inner walls, while dedicated full-cone nozzles keep the pre-separator wet and clean.
From warm, saturated process gas to clean emission
The rendering of animal by-products releases a warm, fully water-saturated process gas. With a nominal gas flow of 25,000 to 30,000 Am³/h at 70 °C and 100% relative humidity, this is exactly the odour and particle-laden duty that wet scrubbing is built for.
Quench stage
Hot process gas is rapidly cooled and saturated by water injection, conditioning it for effective absorption in the washing stages that follow.
Droplet separator
A separator housing between the quench and the first stage removes hot droplets carried over from the quench, keeping the scrubber cool and efficient. It is built in stainless steel 316L with a fully removable PP lamella cassette, and captured liquid drains by gravity back to the quench buffer tank.
Washing stages
Each stage recirculates wash water from an integrated buffer tank through removable spray lances and back, capturing particles and gases in an intensive, overlapping spray curtain.
Tailored dosing
Caustic soda (NaOH), sodium hypochlorite (NaOCl) or sulphuric acid (H₂SO₄) is dosed into the buffer tank based on measured pH and free-chlorine values, while conductivity governs automatic blow-down and fresh-water make-up.
Agglomerating pre-separator
A lamella pre-separator strips out coarse droplets and acts as an agglomerator, merging fine droplets into larger ones so they are easier to capture downstream.
Wire-mesh demister
A final wire-mesh demister delivers high separation efficiency at low pressure drop before the gas passes to the next stage or to atmosphere.
High efficiency at consistently low pressure drop
A multi-stage design combines a quench, droplet separator, several washing stages, an agglomerating pre-separator and a fine wire-mesh demister for high capture of dust, particles and gaseous pollutants with minimal wash-medium loss.
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Low, stable pressure drop. The overlapping spray pattern wets the whole cross-section, so no packed contact body is needed and pressure drop stays low over time.
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Robust against peak loads. The counter-current washing principle copes with the irregular concentrations and peak emissions typical of rendering.
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Minimal wash-medium loss. Efficient droplet capture keeps water and reagent consumption low across the process.
The outcome is lower energy consumption and reliable, long-term compliance with emission limits, even under the variable, aggressive conditions of an animal-protein rendering plant.
Engineered for demanding rendering duty
Every scrubber is dimensioned and specified around the real process conditions of a rendering plant, from gas characteristics and materials to chemistry, water balance and maintenance.
Process conditions
Nominal gas flow of 25,000 to 30,000 Am³/h, design temperature 70 °C, 100% relative humidity and design pressure 1 bar(a).
Scrubber dimensions
Total height 7,600 mm, column diameter 2,350 mm and gas inlet and outlet of ø 850 mm per scrubber housing.
Integrated buffer tank
A buffer tank of 3,000 mm diameter and 1,000 mm height feeds the recirculation loop for each washing stage.
Droplet separation
Stainless steel 316L separator housing with a fully removable PP lamella cassette; captured liquid drains by gravity back to the quench buffer tank.
Tailored chemistry
Integrated dosing of NaOH, NaOCl or H₂SO₄ with pH, free-chlorine and conductivity monitoring keeps absorption optimal and water use efficient.
Built for maintenance
UV-stable hdPE housings with fully removable spray lances and droplet separator for easy inspection and service.
Water balance
A conductivity measurement governs automatic blow-down and fresh-water make-up to keep the wash water within specification.
Multi-stage efficiency
Quench, droplet separator, washing stages, agglomerating pre-separator and wire-mesh demister combine for high capture with minimal wash-medium loss.
Sustainability, circularity and value
Beyond clean emissions, valorising slaughter by-products, or offal, delivers benefits that reach across the food chain and the wider environment.
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Lower carbon footprint. Valorising by-products instead of destroying or digesting them cuts the carbon footprint of the entire chain.
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Shared circularity. Heat recovery from residual steam and reuse of purified process water with neighbouring businesses amplify the circular impact.
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Protecting fish stocks. Protein-rich products reduce demand for fishmeal in aquaculture, relieving pressure on marine ecosystems.
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Full traceability. Every link from raw material to finished product is documented, giving customers confidence in quality, safety and sustainability.
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Broad end markets. Ingredients reach pet food, aquaculture, animal feed, biofuel and fertiliser applications worldwide.
Why partner with Lechler
Lechler combines a fine, uniform droplet spectrum with clog-free, packing-free scrubber design, turning responsible gas cleaning from an obligation into a competitive advantage for producers operating around the clock.
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Maximum contact surface hollow-cone nozzles create an exceptionally fine droplet spectrum for high absorption of contaminants
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Clog-free and packing-free tangential nozzles and overlapping spray patterns remove the need for a contact body and keep pressure loss low
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Reliable around the clock robust performance under fluctuating loads supports long-term emission compliance
Discuss your rendering gas-cleaning challenge with our specialist
Get targeted advice on odour, particle and acid-gas control for your rendering or animal-protein plant.
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