39,545 research outputs found

    Dry anaerobic digestion of organic residues on-farm - a feasibility study

    Get PDF
    Objectives The feasibility study shall answer the following questions: Are there economical and ecological advantages of on-farm dry digestion biogas plants? How the construction and operation parameters of a dry digestion biogas plant influence environment, profit, and sustainability of on-farm biogas production? The aim of the feasibility study is to provide facts and figures for decision makers in Finland to support the development of the economically and environmentally most promising biogas technology on-farm. The results may encourage on-farm biogas plant manufacturers to develop and market dry anaerobic digestion technology as a complementary technology. This technology may be a competitive alternative for farms using a dry manure chain or even for stockless farms. Results Up to now farm scale dry digestion technology does not offer competitive advantages in biogas production compared to slurry based technology as far as only energy production is concerned. However, the results give an over-view of existing technical solutions of farm-scale dry digestion plants. The results also show that the ideal technical solution is not invented yet. This may be a challenge for farmers and entrepreneurs interested in planning and developing future dry digestion biogas plants on-farm. Development of new dry digestion prototype plants requires appropriate compensation for environmental benefits like closed energy and nutrient circles to improve the economy of biogas production. The prototype in JĂ€rna meets the objectives of the project since beside energy a new compost product from the solid fraction was generated. On the other hand the two-phase process consumes much energy and the investment costs are high (>2000 € m-3 reactor volume). Dry digestion on-farm offers the following advantages: Good process stability and reliability, no problems like foam or sedimentation, cheap modules for batch reactors, less reactor capacity, reduced transport costs due to reduced mass transfer in respect of the produced biogas quantity per mass unit, compost of solid digestion residues suitable as fertiliser also outside the farm gate, use of on-farm available technology for filling and discharging the reactor, less process energy for heating because of reduced reactor size, no process energy for stirring, reduced odour emissions, reduced nutrient run off during storage and distribution of residues because there is no liquid mass transfer, suitable for farms using deep litter systems. These advantages are compensated by following constraints: Up to 50% of digestion residues are needed as inoculation material (cattle manure does not need inoculation) requiring more reactor capacity and mixing facilities. Retention time of dry digestion is up to three times longer compared to wet digestion requiring more reactor capacity and more process energy, filling and discharging batch reactors is time and energy consuming. We conclude that only farm specific conditions may be in favour for dry digestion technology. Generally, four factors decide about the economy of biogas production on-farm: Income from waste disposal services, compensation for reduction of greenhouse gas emission, compensation for energy production and - most important for sustainable agriculture - nutrient recycling benefits. Evaluation of the results We did not find any refereed scientific paper that includes a documentation of an on-farm dry digestion biogas plant. It seems that we tried first. We also could not find any results about the biogas potential of oat husks, so we may have found these results first. Farm scale production of anaerobically treated solid manure for composting is new. Dry fermentation biogas plants offer the possibility to design solid manure compost by variation of fermentation process parameters. From different scientific publication databases we found about 10 000 references concerning biogas research during the past 10 years. Less than ten are dealing with biogas reactors for non-liquid substrates on-farm. Recent research mainly concentrates on basic research, biogas process research for communal waste, large-scale biogas plants, and research on laboratory level. This mirrors the fact, that production of research papers is rather financed than product development on site. Our conclusion is that it seems worldwide to be very difficult or even impossible to find financial support for on site research, especially for on-farm prototype biogas reactors. We suppose the following reasons for this fact: biogas plant research requires proficiency in many different scientific disciplines, lack of co-operation between engineering and life sciences, high development costs to transfer basic research results into practical technical solutions, low interest of researchers because on site and on-farm research enjoys low appreciation in terms of scientific credits, portability of farm specific design and process solutions is difficult. Our conclusion is that on site and on-farm research has to be supported by funding agencies if integration of biogas and bio energy into the farm organism is considered as an important target within the agricultural policy framework. Future research on both dry fermentation technique and biogas yield of solid organic residues may close present knowledge gaps. Prototype research may offer competitive alternatives to wet fermentation for farms using a solid manure chain and/or energy crops for biogas production. To encourage farmers and entrepreneurs to foster the development of dry fermentation technology support in terms of education and advisory services is also necessary

    Environmental Efficiency, Emission Trends and Labour Productivity: Trade-Off or Joint Dynamics? Empirical Evidence Using NAMEA Panel Data

    Get PDF
    The paper provides new empirical evidence on the relationship between environmental efficiency and labour productivity using industry level data. We first provide a critical and extensive discussion around the interconnected issues of environmental efficiency and performance, firm performances and labour productivity, and environmental and non-environmental innovation dynamics. The most recent literature dealing with environmental innovation, environmental regulations and economic performances is taken as reference. We then test a newly adapted EKC hypothesis, by verifying the correlation between the two trends of environmental efficiency (productivity, namely sector emission on added value) and labour productivity (added value on employees) over a dynamic path. We exploit official NAMEA data sources for Italy over 1990-2002 for 29 sectoral branches. The period is crucial since environmental issues and then environmental policies came into the arena, and a restructuring of the economy occurred. It is thus interesting to assess the extent to which capital investments for the economy as a whole are associated with a positive or negative correlation between environmental efficiency of productive branches and labour productivity, often claimed by mainstream theory dealing with innovation in environmental economics. We believe that on the basis of the theoretical and empirical analyses focusing on innovation paths, firm performances and environmental externalities, there are good reasons to expect a positive correlation between environmental and labour productivities, or in alternative terms a negative correlation between mission intensity of production and labour productivity. The tested hypothesis is crucial within the long standing discussion over the potential trade-off or complementarity between environmental and labour productivity, strictly associated with sectoral and national technological innovation paths. The main added value of the paper is the analysis of the aforementioned hypothesis by exploiting a panel data set based on official NAMEA sectoral disaggregated accounting data, providing both cross section heterogeneity and a sufficient time span. We find that for most emissions, if not all, a negative correlation emerges between labour productivity and environmental productivity. Though this trend appears driven by the macro sectors services, manufacturing and industry, this evidence is not homogenous across emissions. In some cases U-shapes arise, mainly for services, and the assessment of Turning Points is crucial. Manufacturing and industry, all in all, seem to have a stronger weight. Overall, then, labour productivity dynamics seem to be complementary to a decreasing emission intensity of productive processes. The extent to which this evidence derives from endogenous market forces, industrial restructuring and/or from policy effects is scope for further research. The relative role of manufacturing and services in explaining this pattern is also to be analysed in future empirical analyses. In addition, the role of capital stocks and trade openness are extensions which may add value to future analyses carried out on the same NAMEA dataset.Decoupling, NAMEA Emissions, Labour Productivity, Sectoral Added Value, Kuznets Curves, Environmental Efficiency

    Economic Analysis of Sub-Surface Drainage under Indira Gandhi Nahar Priyojna Command Area - A Case Study

    Get PDF
    This paper has attempted to ascertain whether the sub-surface drainage (SSD) in waterlogged and saline lands of Indira Gandhi Nahar Priyojna Command area is a cost-effective technique. The study has shown that waterlogging adversely affects crop yields. The cost on SSD installation in the command area comes out to be Rs 23767 per hectare. The returns on crop yields before and after the drainage system have been compared. Land utilization has been intensified after the installation of drainage, as a sizeable area of formerly fallow land has been brought under cultivation. The B-C ratio and the NPV have been found as 2.44 and Rs 34275/ha, respectively. The IRR has been found to be 25.88 per cent. These indicators have well established the financial feasibility of the project in the IGNP area.Resource /Energy Economics and Policy,

    Space benefits: The secondary application of aerospace technology in other sectors of the economy

    Get PDF
    Benefit cases of aerospace technology utilization are presented for manufacturing, transportation, utilities, and health. General, organization, geographic, and field center indexes are included

    Applicability of siberian placer mining technology to Alaska

    Get PDF
    The result of Perestroyka and Glasnost has been an awakening of potential for cooperation between East and West. Nowhere has that been better demonstrated than between Alaska and Magadan Province, USSR. This report summarizes a one year effort financed by ASTF, with participation from several technical organizations, to establish contacts with the Siberian placer mining industry. The purpose of the project was to provide initial assessment of the Soviet technology for placer mining in permafrost. A ten day trip to Magadan province by an ASTF team and a similar length visit to Alaska by the Soviet mining group representing the All Union Scientific and Research Institute of Gold and Rare Metals, (VNII-I), Magadan are described. The report also reviews translated data on mining in permafrost and describes surface and underground placer mining technology developed by the Soviets. The report also lists relevant publications on Soviet mining research and state of the art Soviet mining technology and expertise

    Assessing carbon dioxide emission reduction potentials of improved manufacturing processes using multiregional input output frameworks

    Get PDF
    Evaluating innovative process technologies has become highly important within the last decades. As standard tools different Life Cycle Assessment methods have been established, which are continuously improved. While those are designed for evaluating single processes they run into difficulties when it comes to assessing environmental impacts of process innovations at macroeconomic level. In this paper we develop a multi-step evaluation framework building on multi regional input–output data that allows estimating macroeconomic impacts of new process technologies, considering the network characteristics of the global economy. Our procedure is as follows: i) we measure differences in material usage of process alternatives, ii) we identify where the standard processes are located within economic networks and virtually replace those by innovative process technologies, iii) we account for changes within economic systems and evaluate impacts on emissions. Within this paper we exemplarily apply the methodology to two recently developed innovative technologies: longitudinal large diameter steel pipe welding and turning of high-temperature resistant materials. While we find the macroeconomic impacts of very specific process innovations to be small, its conclusions can significantly differ from traditional process based approaches. Furthermore, information gained from the methodology provides relevant additional insights for decision makers extending the picture gained from traditional process life cycle assessment.DFG, SFB 1026, Sustainable Manufacturing - Globale Wertschöpfung nachhaltig gestalte
    • 

    corecore