Anaerobic digestion (AD) can play an important role in achieving renewable goals set within the Netherlands which strives for 40 PJ bio-energy in the year 2020. This research focusses on reaching this goal with locally available biomass waste flows (e.g. manures, grasses, harvest remains, municipal organic wastes). Therefore, the bio-energy yields, process efficiency and environmental sustainability are analyzed for five municipalities in the northern part Netherlands, using three utilization pathways: green gas production; combined heat and power; and waste management. Results indicate that the Dutch goal cannot be filled through the use of local biomass waste streams, which can only reach an average of 20 PJ. Furthermore renewable goals and environmental sustainability do not always align. Therefore, understanding of the absolute energy and environmental impact of biogas production pathways is required to help governments form proper policies, to promote an environmentally and social sustainable energy system.
The dairy sector in the Netherlands aims for a 30% increase in efficiency and 30% carbon dioxide emission reduction compared to the reference year of 1990, and a 20% share of renewable energy, all by the year 2020. Anaerobic Digestion (AD) can play a substantial role in achieving these aims. However, results from this study indicate that the AD system is not fully optimized in combination with farming practices regarding sustainability. Therefore, the Industrial Symbiosis concept, combined with energy and environmental system analysis, Life Cycle Analysis and modeling is used to optimize a farm-scale AD system on four indicators of sustainability (i.e., energy efficiency, carbon footprint, environmental impacts and costs). Implemented in a theoretical case, where a cooperation of farms share biomass feedstocks, a symbiotic AD system can significantly lower external energy consumption by 72 to 92%, carbon footprint by 71 to 91%, environmental impacts by 68 to 89%, and yearly expenditures by 56 to 66% compared to a reference cooperation. The largest reductions and economic gains can be achieved when a surplus of manure is available for upgrading into organic fertilizer to replace fossil fertilizers. Applying the aforementioned symbiotic concept to the Dutch farming sector can help to achieve the stated goals indicated by the Dutch agricultural sector for the year 2020.
Waste disposal management and the energy crisis are important challenges facing most countries. The fruit-processing industry generates daily several tons of wastes, of which the major share comes from banana farms. Anaerobic digestion (AD) technology has been applied to the treatment of wastewater, animal slurry, food waste, and agricultural residues, with the primary goals of energy production and waste elimination. This study examines the effect of organic loading (OL) and cow manure (CM) addition on AD performance when treating banana peel waste (BPW). The maximum daily biogas production rates of banana peels (BPs) with a CM content of 10%, 20%, and 30% at 18 and 22 g of volatile solids (gvs) per liter were 50.20, 48.66, and 62.78 mL·(gvs·d)−1 and 40.49, 29.57, and 46.54 mL·(gvs·d)−1, respectively. However, the daily biogas yield showed no clear interdependence with OL or CM content. In addition, a kinetic analysis using first-order and cone models showed that the kinetic parameters can be influenced by the process parameters.
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