Πέμπτη, 20 Ιουνίου 2019

Clean Technologies and Environmental Policy

The role of clean technology research in disaster debris management


Waste energy recovery improves price competitiveness of artificial forage from rapeseed straw

Abstract

Increasingly frequent droughts are causing repeated shortages of forage and are creating imbalances in the livestock economy in many parts of the world. More and more rapeseed is being cultivated for biodiesel production, and its straw has to be removed from fields to minimize disease vectors. Despite good drought resistance, rapeseed straw cannot replace forage because of its poor palatability. Our work objective was to design a pilot plant that would be the first of its kind to turn rapeseed straw into artificial forage on a commercial scale and would enable a first techno-economical assessment. Rapeseed straw is intracellularly disintegrated (by steam explosion technology which uses waste heat from a biogas station to minimize the energy demands) and subsequently enzymatically hydrolysed. A series of in vitro and in vivo analyses of nutrition quality were accompanied by a cost breakdown. The findings obtained in pilot scale dimensions revealed for the first time that rapeseed straw can be turned into artificial forage that has, according to the world standard forage price indicator, a relative feed value rated at the same level as alfalfa hay. However, despite energy savings, the cost of processing makes the cost of the artificial forage about 61% higher than conventional forage of the same quality. On the other hand, the potential for further reduction of production costs has been identified. It can be assumed that the price competitiveness can be achieved during extended periods of drought.

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Startup, performance, and microbial communities of an anammox reactor inoculated with indigenous sludge for the treatment of high-salinity and mesophilic underground brine

Abstract

Anaerobic ammonium oxidation (anammox) has been implemented as a cost-effective nitrogen removal process in wastewater treatment. To apply the process to saline wastewater treatment at temperatures below 30 °C, the effectiveness of marine anammox bacteria has been demonstrated in a pilot-scale reactor. Nevertheless, mesophilic conditions, often found in underground brine containing high NH4+ concentrations, have yet to employ an anammox process. The objective of this study was to enrich anammox bacteria capable of removing nitrogen from underground brine possessing a salinity of 3% and at a temperature over 30 °C. To select a promising inoculum, biomass from a brine settling tank in a natural gas plant was subjected to quantifying transcripts of anammox 16S rRNA and hydrazine oxidoreductase (hzo) genes by quantitative reverse transcription polymerase chain reaction. A fixed-bed column anammox reactor was fed with the selected inoculum and operated feeding underground brine mixed with NaNO2 solution at a temperature of 38 °C. As a result, a nitrogen removal rate (NRR) of 1.42 kg-N/m3/day was obtained on day 167. An average NRR of 1.21 kg-N/m3/day and nitrogen removal efficiency of 88% were maintained for 50 days. Amplicon sequencing based on the 16S rRNA revealed that anammox bacteria which are phylogenetically close to Candidatus Kuenenia were successfully enriched in the reactor. These results indicate that nonmarine anammox bacteria can be active and predominant under both high-salinity and mesophilic conditions, making it a likely candidate for effective nitrogen removal from underground and waste brine.

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The suitability of Polish lignite for gasification

Abstract

The article discusses the impact of the lithotype of lignite on the suitability for gasification in CO2 atmosphere. The research was aimed at determining the influence of lithotype, petrographic composition, and physical and chemical properties of coal on the composition and release of syngas. The examined coals were humic coals. The first step was to determine the impact of lithotype on the degree of carbon conversion at a temperature of up to 815 °C. The gasification process was conducted in the temperature range of 600–1100 °C. During the experiment, two gas samples, used for determining the chemical content of gas, were collected at 950 and 1050 °C, respectively. What is more, continuous monitoring of the gas density during the gasification was carried out. Depending on the lithotype, the content of ash, moisture, and the degree of coalification, the intensity of gas release is different for different temperatures. In addition, it has been found that coals with a high content of poorly gelified xylite and a low ash content are the fastest reacting and the most responsive. The importance of this research lies in determining that the gasification of coal with a low degree of coalification requires technologies carried out at reactor temperatures above 1000 °C.

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Waste-to-energy is compatible and complementary with recycling in the circular economy

Abstract

This paper reviews the role of conventional waste-to-energy, i.e. incineration of (mainly) municipal solid waste with energy recovery, in the circular economy. It shows that, although waste-to-energy figures on a lower level in the European waste hierarchy than recycling, it plays, from an overall sustainability point of view, an essential, complementary and facilitating role within the circular economy. First of all, waste-to-energy combusts (or should combust) only waste that is non-recyclable for economic, technical or environmental reasons. This way waste-to-energy is compatible with recycling and only competes with landfill, which is lower in the waste hierarchy. Furthermore, waste-to-energy keeps material cycles, and ultimately the environment and humans largely free from toxic substances. Finally, waste-to-energy allows recovery of both energy and materials from non-recyclable waste and hence contributes to keeping materials in circulation. These arguments are elaborated and illustrated with many examples. This paper also points out the pitfalls of a circular economy if it merely focuses on material cycles, disregarding economic, environmental, social and health aspects of sustainability.

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Eco-efficiency and techno-economic analysis for maleic anhydride manufacturing processes

Abstract

Maleic anhydride may be obtained from different technological routes, being the selective oxidation of benzene and oxidation of butane the only ones that are currently in operation and, hence, represent competitive alternatives. In this paper, the said technologies are compared with regard to their economics and ecological performances in order to assert which one corresponds to the cleanest technology. The economics of each process was estimated on the basis of their respective cash flows, while the environmental comparison was carried out through the Eco-efficiency Comparison Index method by estimating six different categories of eco-indicators and seven life cycle metrics. To the best of our knowledge, such technologies have not been compared in terms of a joint evaluation of life cycle and eco-efficiency metrics, let alone considering the design of their respective utility plants. Finally, a sensitivity analysis was performed in order to analyze how the heuristic parameters for the utility plants considered in this work affect the estimation of the said indicators. The butane technology was shown to be more sustainable than the benzene process, since it was approximately 72% more profitable and 38% more eco-efficient than the latter.

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Enhancing the dewaterability of anaerobically digested sludge using fibrous materials recovered from primary sludge: demonstration from a field study

Abstract

Sludge dewatering is an important process for determining the operation cost of sludge disposal. Hence, improving the dewaterability of anaerobically digested sludge containing high water content is of paramount significance. For this challenge, we developed a novel process in which fibrous materials initially collected from a primary sedimentation tank, namely recovered fibers, were used as an auxiliary agent to improve the dewaterability of anaerobically digested sludge. The objective of this study was to investigate the feasibility of using the developed process to improve sludge dewaterability. Three fibrous materials individually recovered from the respective primary sedimentation tanks in different wastewater treatment plants (WWTPs) were used to investigate sludge dewaterability, organic C compositions, and calorific values. The recovered fibers showed comparable compositions irrespective of the WWTP. Six different WWTP sludge samples after anaerobic digestion were continuously supplied to three different dewatering devices, i.e., screw press, centrifuge, and belt press machines, with or without the supply of recovered fibers. Irrespective of the type of a dewatering device, the supply of recovered fibers mixed with the tested sludge samples at a feed ratio of 0.18–0.20 g-fibers/g-sludge (dry weight) reduced the amount of polymer flocculant by 13–50%, thereby displaying the superiority of the addition of recovered fibers. Furthermore, at fiber feed ratios of 0.20 g-fibers/g-sludge and 0.40 g-fibers/g-sludge when the rates of sludge supply and polymer flocculant were kept constant, the corresponding water contents in the dewatered sludge cakes decreased to about 74–76% and 69–72%, respectively. The consistent results regardless of the dewatering device or sludge sample showed the significance of the addition of recovered fibers for improvement in sludge dewaterability.

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A circular economy and industrial ecology toolbox for developing an eco-industrial park: perspectives from French policy

Abstract

The twentieth century was characterized by an increase in research studies concerning the interactions between economic system growth and environmental deterioration issues. Faced with this background, circular economy (CE) and its industrial ecology (IE) pillar seem to be an efficient way to achieve sustainable development within the industrial sector. IE consists of optimizing the networking among industries by using energy and material exchange, which are generated from by-products and waste stocks. It aims to improve the environmental potentialities of integrated clusters called eco-industrial parks (EIPs). Policy in the European Union countries and in French territories has positively influenced such EIP implementation by the establishment of a set of measures to develop the industrial symbiosis performances. The present paper reviews the key drivers to identify the methods and tools to integrate the life cycle thinking approach that defines the following five phases: design, layout, commercialization, operating and renewal phases. A toolbox for developing an EIP from scratch according to French policy is developed and discussed. This study defines a framework involving a factual eco-industrial park and network. The industrial application is a new EIP, namely "Les Portes du Tarn". It is located in the south of France and acts as an experimental field. The paper provides current results for commercialization and operating, including a model of an organizational process, a decision-making process, information technology tools and systems to manage sustainable development. It highlights the CE and IE challenges surrounding enhancing the social acceptability of an industrial park project through adaptation of a relevant governance model and establishment of a continuing collaborative context and trust relationship between diverse actors. The first candidate companies' achievements are discussed and demonstrate the first benefits of toolbox. The paper delivers a toolbox, feedback and some good practices to support the development of EIP project from greenfield.

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The impacts of the sulphur emission regulation on the sulphur emission abatement innovation system in the Baltic Sea region

Abstract

According to the Porter hypothesis, regulations on environmental emissions under certain conditions can promote eco-innovation. This is why the technological innovation systems (TIS) theory sees regulatory pressure as a major system function critical in the take-off phase. In other words, the design and timing of any regulation may be decisive for the regulatory outcome. The research seeks to provide empirical evidence on how the Baltic Sea Sulphur Emission Control Area (SECA) has impacted the technological innovation system within the Baltic Sea Region maritime sectors. The results (1) show that regulatory compliance gave a knowledge development that has made it possible for clean-tech companies to engage in entrepreneurial activities that created new markets, (2) empirically support the TIS theory and the Porter hypothesis, and (3) provide qualitative evidence on how businesses see environmental regulation.

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The innovation system for ship sulphur emission abatement. 



Prediction of the resource-efficient potential of Turkish manufacturing industry: a country-based study

Abstract

As an emerging country, there is a rapid industrial development and associated excessive resource consumption in Turkey. In this case, the dissemination of cleaner production activities based on the principle of minimum resource consumption and waste generation should be regarded as the priority target to ensure efficient use of the resources, enhance the manufacturing industry's competitiveness, and reduce environmental impacts. In this paper, the potential of resource efficiency in Turkish manufacturing industry was predicted. Input saving potential in each industry and aggregate manufacturing was predicted under three different scenarios: business-as-usual, realistic, and ideal. While we used industry saving rate obtained from the field surveys in business-as-usual scenario, we used (in)efficiency scores obtained from Stochastic Frontier Analysis (SFA) conducted for the entire manufacturing industry as well as for the five selected sectors and sub-sectors by using the firm-level panel data Turkish manufacturing from 2008 to 2012 together with the sectoral saving rates. The potential of resource efficiency is estimated for five sectors: (10) Manufacture of food products, (13) Manufacture of textiles, (20) Manufacture of chemicals and chemical products, (23) Manufacture of other nonmetallic mineral products, and (24) Manufacture of basic metals. Then, it is generalized to whole Turkish manufacturing industry. The calculations were performed in both monetary and quantitative terms for energy and water inputs but only in monetary terms for raw material inputs. It is estimated that the Turkish manufacturing industry's monetary-saving potential ranges from $8.8 billion/year to $14.5 billion/year based on the three scenarios specified for all inputs. In addition, according to the realistic scenario, 44.5% of total monetary-saving potential stems from SME savings (47.3% raw material, 41.8% energy, and 9.8% water). Besides, TR10 (Istanbul) and TR42 (Kocaeli, Sakarya, Düzce, Bolu, Yalova) regions have highest raw material and energy-saving potential, respectively. According to the realistic scenario, their share of the total saving value stood at 27% and 14%, respectively. Also, TR63 (Hatay, Kahramanmaraş, Osmaniye) and TR22 (Balıkesir, Çanakkale) regions have the highest water-saving potentials. To the best of our knowledge, this study is the first attempt in examining resource efficiency in the Turkish manufacturing industry in the broadest scope. Moreover, the methodology used in this work is said to be first and unique. We believe this methodology will open new avenues to the new researches both in Turkey and other countries.

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Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
6948891480

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