One potential renewable energy resource is green gas production throughanaerobic digestion (AD). However, only part of the biogas produced (up to50-60%) contains the combustible methane; the remainder are incombustiblegasses with the biggest being carbon dioxide. These gasses are often not usedand expelled in the atmosphere. Through the use of BIO-P2M where hydrogenis mixed with the remaining CO2 additional methane can be produced,increasing the yield and using the feedstocks more effectively. Within thisresearch the environmental sustainability and effectiveness of BIO-P2M isevaluated using the MEFA and aLCA method, expressed in; net green gasproduction, efficiency in (P)EROI, emissions in GWP100, and environmentalimpact in Ecopoints. The functional unit is set as a normal cubic meter ofGroningen quality natural gas. Results indicate a net improvement of allindicators when applying BIO-P2M in several configurations (in situ, ex situ).When allocating the production of renewable energy to the BIO-P2M systemenvironmental impacts for wind the results are still positive; however, whenusing solar PV as an energy source the environmental impact in Ecopointsexceeds that of the reference case of Groningen natural gas. An additionaloption for improving the indicators is optimization of the process. When usingBIO-P2M combined with heat and power unit for producing the internalelectricity and heat demands all indicators are improved substantially. On anational scale when utilizing al available waste materials for the BIO-P2Msystem around 1217 MNm3/a of green gas can be produced, which is 3% ofthe total yearly consumption in the Netherlands and around 60% more thanwhen using normal AD systems. Within the context BIO-P2M is an interestingoption for increasing green gas output and improving the overall sustainabilityof the AD process. However, the source of green electricity needs to be takeninto account and process optimization can ensure better environmentalperformance.
Innovations are required in urban infrastructures due to the pressing needs for mitigating climate change and prevent resource depletion. In order to address the slow pace of innovation in urban systems, this paper analyses factors involved in attempts to introduce novel sanitary systems. Today new requirements are important: sanitary systems should have an optimal energy/climate performance, with recovery of resources, and with fewer emissions. Anaerobic digestion has been suggested as an alternative to current aerobic waste water treatment processes. This paper presents an overview of attempts to introduce novel anaerobic sanitation systems for domestic sanitation. The paper identifies main factors that contributed to a premature termination of such attempts. Especially smaller scale anaerobic sanitation systems will probably not be able to compete economically with traditional sewage treatment. However, anaerobic treatment has various advantages for mitigating climate change, removing persistent chemicals, and for the transition to a circular economy. The paper concludes that loss avoidance, both in the sewage system and in the waste water treatment plants, should play a key role in determining experiments that could lead to a transition in sanitation. http://dx.doi.org/10.13044/j.sdewes.d6.0214 LinkedIn: https://www.linkedin.com/in/karel-mulder-163aa96/
MULTIFILE
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.
A major challenge for the Netherlands is its transition to a sustainable society: no more natural gas from Groningen to prevent earthquakes, markedly reduced emissions of the greenhouse gas carbon dioxide to stop and invert climate change, on top of growth of electricity in society. Green gas, i.e. biogas suitable for the Dutch gas grid, is supposed to play a major role in the future energy transition, provided sufficient green gas is produced. This challenge has been identified as urgent by professional, academic and private parties and has shaped this project. In view of the anticipated pressure on biomass (availability, alternative uses), the green gas yield from difficult-to-convert biomass by anaerobic digestion should be improved. As typically abundant and difficult-to-convert biomass, grass from road verges and nature conservation areas has been selected. Better conversion of grass will be established with the innovative use of new consortia of (rumen) micro-organisms that are adapted or adaptable to grass degradation. Three-fold yield increase is expected. This is combined with innovative inclusion of oxygen in the digestion process. Next green hydrogen is used to convert carbon dioxide from digestion and maximize gas yield. Appropriate bioreactors increasing the overall methane production rate will be designed and evaluated. In addition, new business models for the two biogas technologies are actively developed. This all will contribute to the development of an appropriate infrastructure for a key topic in Groningen research and education. The research will help developing an appropriate research culture integrated with at least five different curricula at BSc and MSc level, involving six professors and one PhD student. The consortium combines three knowledge institutes, one large company, three SMEs active in biogas areas and one public body. All commit to more efficient conversion of difficult-to-convert biomass in the solid body of applied research proposed here.
