Wat zijn de mogelijkheden voor de decentrale verwerking van organische reststromen? Levert het lokaal verwerken van materialen als gft-afval, snoeiafval, horeca-afval en gewasresten in brede zin meer op dan afvoer naar grootschalige verwerkers? Die vraag staat centraal in het project RE-ORGANISE, geleid door de Hogeschool van Amsterdam in samenwerking met Aeres Hogeschool Dronten, verschillende andere kennispartners en ondernemers.In dit rapport wordt een overzicht gecreëerd van wat er technisch mogelijk is met de organische reststromen. Daartoe zijn zogenaamde factsheets opgesteld per technologie, die een beschrijving omvatten van wanneer en hoe verschillende verwerkingstechnologieën decentraal toe te passen zijn op organische reststromen.
A bacterium belonging to the Bacillus firmus/lentus-complex and capable of growth on native potato starch was isolated from sludge of a pilot plant unit for potato-starch production. Utilization of a crude enzyme preparation obtained from the culture fluid after growth of the microorganism on native starch, resulted in complete degradation of native starch granules from potato, maize and wheat at a temperature of 37°C. Glucose was found as a major product. Production of maltose, maltotriose and maltotetraose was also observed. Native-starch-degrading activity (NSDA) could be selectively adsorbed on potato-starch granules, whereas soluble-starch-degrading activity (SSDA) remained mainly in solution. The use of such a starch-adsorbed enzyme preparation on native starch resulted in a completely changed product pattern. An increase in oligosaccharides concomitant with less glucose formation was observed. An increased conversion of soluble starch to maltopentaose was possible with this starch-adsorbed enzyme preparation. It is concluded that NSDA comes from α-amylase(s) and SSDA from glucoamylase(s) and/or α-glucosidase(s). Cultivation of B. firmus/lentus on glucose, maltose, or soluble starch resulted in substantially smaller quantities of (native) starch-degrading activity.
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The possibilities of balancing gas supply and demand with a green gas supply chain were analyzed. The considered supply chain is based on co-digestion of cow manure and maize, the produced biogas is upgraded to (Dutch) natural gas standards. The applicability of modeling yearly gas demand data in a geographical region by Fourier analysis was investigated. For a sine shape gas demand, three scenarios were further investigated: varying biogas production in time, adding gas storage to a supply chain, and adding a second digester to the supply chain which is assumed to be switched off during the summer months. A regional gas demand modeled by a sine function is reasonable for household type of users as well as for business areas, or a mixture of those. Of the considered scenarios, gas storage is by far the most expensive. When gas demand has to be met by a green gas supply chain, flexible biogas production is an interesting option. Further research in this direction might open interesting pathways to sustainable gas supply chains.
