The goal of the EU project SYSTEMIC centered around producing biogas and reclaiming food from constituent barren current . The projection seat in new technologies in five fermentation facilities in the Netherlands , Flanders , Germany , and Italy . These technologies process digestate into replacements for artificial fertiliser and organic fertilizer . The current energy and nitrogen crisis illustrates the importance of improved nutrient utilization from wastefulness stream . This project shows that it is technologically possible to transmute manure , constitutive waste products , and sewage ooze into contrived fertiliser transposition without increasing environmental emissions . However , it remains a challenge to produce this with a potent line case . The labor was finalized in 2022 , and all end intersection are now usable online .
From manure to artificial fertilizer replacementThe Dutch company Groot Zevert Vergisting ( GZV , Beltrum ) was one of the manifestation locations in the project . This company focuses on the digestion of manure and co - products . The co - production come from the agri - nutrient industry and produce gamey amounts of biogas . The biogas is enthrall via pipes to a nearby milk product factory . Digestate of manure can not be well apply in the realm because of a excess of manure . However , the region ’s farmers are concerned in replacing for artificial nitrogen fertiliser reclaimed from digestate of manure . These artificial plant food replacements would provide N in addition to what is allowed from animal manure . There is no regional market place for phosphorus fertilizer replacements because of gamy phosphorus stage in the area ’s soils and regulations which keep the addition of more phosphorus to the land .
GZV has therefore invest in separation technologies where atomic number 15 is separated in a solid fraction . A part of the atomic number 7 is reclaimed in a mineral dressed ore , and water is break as clean dischargeable water . ab initio , the destination was to discharge 45 % of the digestate as clean water system , but this was not feasible . However , there have been successful steps to reduce the economic consumption of sulphuric acid , polymers , and other additives . Around 30 % of the mineral N is reclaim in the concentrate via reverse osmosis . This production is sold as a mineral dressed ore , although the mineral levels are comparatively low-spirited compared to artificial liquid fertilizers ( 0.8 % N ) . Phosphorus is reclaimed in a upstanding fraction , which is then sell in the Eiffel region ( France ) , where there is a market for phosphorus fertilizer .
The mineral dressed ore crop well as an artificial fertilizerreplacement because more than 90 % of the N present tense is in the mineral mannequin ( NH4 ) . The law still needs to distinguish this as an artificial fertilizer replacement instead of a manure mathematical product to use it this way . The European Commission is still coming to a decision about a definitive exemption from the laws surrounding the use of animal manures for artificial fertilizer replacement from animal manure , also bed as RENURE ( Recovered Nitrogen from manURE ) product . For now , GZV works with a temporary elision under the pilot film task ‘ Achterhoek free from artificial fertiliser , ’ where the mineral dressed ore can be used in addition to the amount of beast manure allow for .
Extra N , in the signifier of urea ( ammonium nitrate ) , is total to the production to improve its marketability , after which it is sell to local farmers under the brand name ‘ Groene weidemestof . ’ The accession of nitrogen is needed to create a merchandise where nitrogen , atomic number 19 , and sulfur , are present in the proportion needed by the crop . The intersection is deal at the price of unreal fertilizers . A part of the income is used for store outside of the growing season , deportation , and program because these cost are greater for the utilisation of liquid artificial fertilizer replacements than for the use of contrived fertilizer granules .
An innovative nitrogen stripperThe demonstration placement at Benas ( Bremen , Duitsland ) zymolysis energy crop and volaille manure . Fermentation of the N - rich wimp manure is only possible by reduce the ammonia levels in the fermenter because gamy ammonia concentrations are toxic to biogas - forming bacteria . To reduce the ammonia level , an innovative N striptease and scrubber are installed at the website of the fermenter . This is an forward-looking engineering because it uses gypsum ( CaSO4 , an industrial byproduct ) instead of the expensive sulfuric acid used in regular scrubbers . The process at the BENAS location produces an ammonium ion sulfate , a calcium plant food , and a digestate . All the fertilizers are used by BENAS on their own state to produce Department of Energy crops . Although this is a nice example of disk shape , this also generates a risk of high sulfur dosage to the dirt through the use of ammonium sulfate .
The fermenting facility at BENAS has a solid line font in sell energy . The biogas is converted to electricity or upgraded to unripe gas calculate on the demand on the electrical grid . dark-green gaseous state has a methane content equal to born gas and can be deliver via the natural gas pedal internet . The option to produce electricity from biogas on need contributes to the mellow stability of the electrical energy grid and provides a high income for the manufacturer .
eminent - quality program for constitutive fibers from digestateGroot Zevert Vergisting and BENAS also make extra time value by extracting organic fibers from digestate for use in worthful products . BENAS bring about their constitutional fiber from energy crops , and they process them into cardboard products , such as works pots , at their own location . The fibers are also suit to use in pot territory and may be used in organic USDA . GZV has invest in a system where organic fibers are washed to remove salts and phosphorus . This makes the product suit as a peat replacement in potting soils . pot land companies aim to cut the use of peat in pot soil , so there is much interestingness in quality option . Both companies have had a long development summons , and despite good perspective , there is still no long - terminal figure sale of the production .
Using residual heat to dry out and evaporate digestateTwo presentment company are in Flanders , a region where the sale of digestate is unmanageable because of a nimiety of animal manure in the market . AmPower ( Ieper , Belgium ) digest waste streams from the agri - food industry and household constituent waste . Waterleau New Energy ( Ieper , Belgium ) zymolysis pig manure in addition to squander streams from the agri - food industry and family constituent waste . The party have a similar procedure for producing digestate . After the first breakup footstep , the substantial fraction is dry out to produce solid manure suited to export .
The remaining smooth fraction is evaporated by the usance of residuary heat . This subjugate the volume of the production to be exported . Ammonia and carbon dioxide also bunk during drying up . This can be recover via condensation to bring forth a solution of ammonium - hydrogen carbonate . This is address ammonium water in praxis . This solution is not suitable as fertilizer because the ammonia can quickly scarper due to the high pH. Waterleu sell the ammonia - rich water to a nearby company as a replacing for conventional ammonium body of water in air gas cleanup installations . Although this is a sustainable solution , the caller owner has plans to domesticize the atomic number 7 with an acid slipstream to produce ammonium ion sulphate , which can be used as a fertilizer . The caller is waiting until the use of ammonium ion sulphate from brute manure is approved as a plant food substitution .
AmPower also evaporate their watery digestate , but without separating the nitrogen . The digestate is made acidic with sulfuric acid to keep the release of ammonia during the warming cognitive process . This summons produces an organic fertiliser rich in nitrogen and S . AmPower does not process animal manure , so this mathematical product can be used without restriction by animal manure limitations ( 170 kg N / ha ) . However , they still have difficulty selling plant food in the region because of P program limitations and because injecting a liquid dressed ore is more expensive than spreading artificial fertiliser granules .
Both companies use mellow amounts of thermal muscularity to dry out their ware . They employ the residual oestrus from the production of electricity from accelerator pedal . About 40 % of the energy Charles Frederick Worth of biogas is convert to electrical energy , 40 % is residuary heat , and 20 % is drop off . Although the energy demand of digestive vapor is provided by sustainable energy , there may be a head if the residual heat can be more sustainably used in another way , such as heating homes . Another disadvantage is that these companies are dependent on residual heat and can not transition to the yield of unripened gas because of the quality requirements to make it comparable to natural throttle .
Circular use of phosphorus through sewage sludgeSewage sludge is also suited to the output of fertilizers , as shown by the Italian troupe Aqua&Sole locate near Milan . Thermophilic fermentation at 55 ° C produces a stable , hygienical digestate . Thermophilic zymolysis postulate ascendency of the ammonia concentrations in the fermentation facility because high concentrations can kibosh the output of biogas . To deal this , Aqua&Sole has invested in an advanced nitrogen stripper which extracts up to 40 % of the mineral nitrogen from the digestate in the form of an ammonium sulphate resolution . The digestate is used locally by arable farmer , while the ammonium ion sulfate can be to the full utilized as an artificial fertilizer successor thanks to its waste end - product position . No phosphorus regulations apply to the region , so the use of the digestate results in a nimiety software of phosphorus . investigator advise using phosphate balance dressing to prevent the buildup of superfluous phosphorus in the soil and to reduce heavy alloy program to the ground . Reclamation and reusing P out of sewerage is crucial to closed - loop phosphorus utilization . Despite this , there is a concern about contaminant by the habit of sewerage sludge in Italy .
stilted fertilizer replacementsDiverse organic and mineral fertilizers were generated in this project , which also included stilted fertilizer replacements such as ammonium ion sulfate and mineral concentrate . unreal fertilizer replacement are fertiliser where at least 90 % of the nitrogen is present in mineral form .
Nitrogen is present as ammonium in artificial fertilizerreplacements , which creates a hazard of ammonia discharge . This is especially the subject for mineral dressed ore , which is characterized by a relatively mellow pH. Ammonia emissions can be reduced to levels low-down than animal slurry by injecting the dressed ore into the grunge because it can infiltrate the soil more quickly . GZV commission the evolution of a new type of fertiliser injector to facilitate shot . Field experiment show that good program practices result in nitrogen uptake and yield , like the use of artificial fertilizer . Mixing the mineral concentrate with animal manure is not recommend because this reduces the atomic number 7 effectivity because of increases in ammonia emissions . Mixing also lose weight yields because of the down in the mouth nitrogen effectivity .
ammonium ion sulfate is a suitable artificial fertilizer replacing , but the high sulphur levels require attention . Only a small part of the nitrogen necessity of the plant can be provided by ammonium ion sulfate . Otherwise , a excess of sulfur will be deliver and will leave the system through overflow . This process will also chair to red ink of microelements because the excess sulfur oblige to the microelements when it exits the organisation . Ammonium sulfate can not be mixed with digestate because this can create harmful manure gasses . mellow S levels also require attention in dressed ore from reverse osmosis or evaporation because sulfuric Lucy in the sky with diamonds is used to prevent ammonia emissions . It is of import to view the S software floor when make a fertilizing plan with rescued fertilizer .
Depending on the technique , up to 35 % of the full N from digestate can be reclaimed as a mineral contrived fertilizer replacement . The other 70 % of nitrogen is present in constitutional plant food , including digestate and solid plant food . It is important to see examine not only the hokey fertilizer transposition but also the constituent fertilizers when examine the event of N emissions because these can also put up to nitrogen emissions .
Large differences in industrial plant - available phosphorusIn most of the demonstration plants , a solid fraction is separated from digestate that is not further dry . These upstanding fraction have been analyzed for P availability , and the analysis shows large differences in the availability of phosphorus between different fertilizers from digestate . Phosphorus availability is high in digestate from creature manure , but this reduces as presently as an iron - containing feedstock is added to the mixture . firm phosphorus - rich fertilizers are largely sell in France , where their use is not limited by P regulation . Low phosphorus accessibility does not limit marketability in the experience of the producers . This is also regulate by the fact that it is normal to present only the total atomic number 15 level on fertilizing products , so the emptor is not aware of the availableness level .
No organic contaminates in dischargeable waterThe researchers also examined the storey of constituent micropollutants in the different product . Digestate hold residues of herbicides , pesticide , and occasionally residues of veterinary medicines . Three of the presentment society have a separation outgrowth where clean water is reclaimed and discharged on the open weewee . None of the water supply discharge streams contained residues that would produce a pollution risk for the surrounding realm . There were also no harmful residues found in ammonium sulphate . The digestate from sewerage sludge , which was put up at a comparatively gamey temperature ( thermophilic fermentation , 55 ° C ) , contained no residue of veterinary medicine . The mesophilic ferment ( 40 ° degree centigrade ) at the other locations did result in digestate check residues of veterinary medicines .
Negative CO2 footprint via yield of biogas and replacement of unreal fertilizerThe research worker also calculated the CO2 footprint of the demonstration plants . All the companies have a damaging CO2 footprint when it is assumed that biogas is used as a replacement for fossil fuel . Using animal manure and sewage sludge as feedstock event in relatively low biogas output because these waste stream check a high-pitched amount of liquid . mellow biogas production is attain through fermenting co - products or , in Germany , energy crops .
transform digestate into young , more concentrated plant food has a small positive effect on the CO2 footmark of the manifestation plants . Though make more concentrated fertilizers results in a step-down of the CO2 emissions colligate with transport , the energy used to secernate digestate results in a final positive CO2 footprint for this part of the unconscious process . A little amount of biogas energy is used in digestate processing , and all the companies fork up push to the electric / energy grid in the form of gas or electricity , lead in a total negative step .
what is more , there is also an reward to replacing stilted N fertilizers with reclaimed fertilizers . The product of artificial N plant food requires a high amount of vigor , and replace this with digestate or an contrived fertilizer replacement event in a saving of CO2 emissions .
Reclaimed fertilizers do not always ensue in profit currentlyThe large income generator for these company is energy yield . get reclaimed fertilizers from digestate had a limited upshot on the total job character for these companies because the grocery store opportunities of these fertilizers are often modified . This is partially because they have a low-spirited perceived value on the market compared to artificial fertilizers and partly because reclaimed plant food are less saturated than artificial fertilizers , making the logistic cost relate with their software program higher than by habit of stilted plant food . The processing of digestate into plant food increase the flexibility for selling of reclaimed fertiliser compared to unprocessed digestate . It should be noted that the economic situation was analyzed before the current energy and rude resource crisis . hokey fertiliser alternate from digestate can now profit more greatly because of the mellow prices for unreal fertilizer .
The participate company were all located in areas of intensive livestock production . Therefore there is no demand for unprocessed digestate . They have an economic advantage when they make reclaimed fertilizers , which biogas society with a different regional situation do not because , in other regions , the unprocessed digestate can be sold . The local plant food market is the ride factor for invest in processing installation for digestate .
A plentiful knowledgebase for other biogas facilitiesThe SYSTEMIC project has delivered a mellow amount of data and unexampled insights about digestate processing proficiency , energy and chemical use , quality of reclaimed fertilizers , costs for processing , and environmental advantages . This data is now openly available via the project site and WUR program library .
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