Manure refinery -solution for closing the mineral cycleName Luuk Gollenbeek (luuk.gollenbeek@wur.nl)

Organisation Wageningen Livestock Research

Event name Farming and Circular economy

Closing nutrient cycles utopia?Studying nutrient cycles learns us that turning the following knobs can strongly effect the cycles:• Feed and food import and export• Use of chemical fertilizers• Losses of nutrients by human waste treatment• Emissions and losses of nutrients

To close nutrient cycles is an utopia, to finda balance with high efficiency, a possibility

How to close nutrient cycles?

Smit, A.L. ; Middelkoop, J.C. van; Dijk, W. van; Reuler, H. van (2015)Nutrient Cycling in Agroecosystems 103 (1). - p. 1 - 13.

Manure refinery goalsGoal of refinery can be:• Increase flexibility of manure, adapt product to demand

chemical and physical• Make export/transport possible/cheaper• Create resources for production of chemical fertilizer

Every step of refinery produces two or more streams. All products should be usable.

Manure refinery Netherlands

Refinery in the Netherlands: • Export: Increase of nutrient levels.• Regional market: Adapt manure to needs.• Produce fertilizer resources• Extract fibres

• Focus mainly on P and N.• Refinery effects macro- (other than N and P) and micronutrients,

salts, heavy metals, organic matter and the physical condition

Progress

Techniques: • Refinery is a combination of techniques.• Physical separation, proven techniques.• Ca phosphate and struvite production.• Nitrogen extraction, evaporation and air scrubber.• Potassium salts.

Social/economical:• Techniques increase costs, increase of value needed.• Constant adaptation to regulations.

Progress

MgCl2reservoir

FANN Separator (700 µm)

Rotatingseparator

(300-400 µm)

Silo 1

MgCl2 addition

Silo 2 rotating cloth sieve

(three compartments: 80, 120,

120 µm)

Pilot plant: Struvite recovery

Source: Schoumans et al, in prep

Interesting topics

Not mentioned yet:• Separation of manure and urine in barn• Quick removal of manure from barn• Precision farming • Adaptation of feed • Extract specific organic compounds (for example protein's)

Conclusion

Manure refinery is not a direct instrument to close cycles, it increases possible solutions, and decrease losses.

When nutrients are regained losses decrease problems (in the Dutch case) become more visible.

Wild ideas?• Extraction of P from food (milk) and feed• Save good quality organic matter• Built up strategic stockpile of P

(luuk.gollenbeek@wur.nl)