scholarly journals Pilot-Scale Composting Test of Polylactic Acid for Social Implementation

2021 ◽  
Vol 13 (4) ◽  
pp. 1654
Author(s):  
Nobuyuki Kawashima ◽  
Tadashi Yagi ◽  
Kouya Kojima

The chemical industry and subsequent value chain of plastics are facing significant challenges from the viewpoints of resource conversion and environmental burden. Now is the time to explore the future direction of plastics, which will require an integrated scheme using resource circulation, carbon neutrality, and a social system to promote after-use treatment under the concept of a circular economy. Polylactic acid (PLA) should help reduce greenhouse gas (GHG) emissions as a biobased material and contribute to waste management after use due to its biodegradability if managed properly. That is, it will be necessary to treat biodegradable products appropriately in closed systems such as composting facilities after use and recovery. To realize the implementation of fully approved composting facilities in society, simply evaluating biodegradability in the laboratory is insufficient. In this study, a pilot-scale test using PLA under actual composting conditions was conducted in accordance with both international standards and domestic evaluation methods. The results not only confirm its biodegradability and disintegration, but also demonstrate that the presence of a biodegradable plastic product has a negligible impact on the composting process. The obtained compost did not adversely affect plant germination or growth, demonstrating its safety and high quality. Such a multifaceted perspective makes this study unique and useful for creating a social framework.

Climate ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 41
Author(s):  
Hans Sanderson

With the Paris Agreement, countries are obliged to report greenhouse gas (GHG) emission reductions, which will ensure that the global temperature increase is maintained well below 2 °C. The parties will report their nationally determined contributions (NDCs) in terms of plans and progress towards these targets during the postponed COP26 (Conference of the Parties under the UNFCCC) in Glasgow in November 2021. These commitments, however, do not take significant portions of the consumption-related emissions related to countries imports into account. Similarly, the majority of companies that report their emissions to CDP (Formerly Carbon Disclosure Project) also do not account for their embodied value-chain-related emissions. Municipalities, on the path towards carbon neutrality in accordance with the methods outlined by C40, also do not include imported and embodied CO2 in their total emission tallies. So, who is responsible for these emissions—the producer or the consumer? How can we ensure that the NDCs, municipalities’ and companies’ reduction targets share the responsibility of the emissions in the value chain, thus ensuring that targets and plans become sustainable, climate fair, and just in global value chains? Today the responsibility lays with the producer, which is not sustainable. We have the outline for the tools needed to quantify and transparently share the responsibility between producers and consumers at corporate, municipal and national levels based on an improved understanding of the attendant sources, causes, flows and risks of GHG emissions globally. Hybrid life cycle analysis/environmentally extended input–output (LCA/EEIO) models can for example be further developed. This will, in the end, enable everyday consumption to support a more sustainable, green and low carbon transition of our economy.


Author(s):  
Hans Sanderson

With the Paris Agreement, countries are obliged to report greenhouse gas (GHG) emission reduc-tions, which will ensure that the global temperature increase is maintained well below 2C. The Parties will report their Nationally Determined Contributions in terms of plans and progress to-wards these targets during the postponed COP26 in Glasgow in November 2021. These commit-ments however do not take significant portions of the consumption related emissions related to countries imports in to account. Similarly, the majority of companies that report their emissions to CDP also do not account for their embodied value-chain related emissions. Municipalities, on the path towards carbon neutrality in accordance with the methods outlined by C40, also do not in-clude imported and embodied CO2e in their total emission tallies. So, who is responsible for these emissions - the producer or the consumer? How can we ensure that the NDC's, municipalities and companies reduction targets share the responsibility of the emissions in the value-chain thus en-suring that targets and plans become, sustainable, climate fair, and just in global value chains? Today the responsibility lays with the producer, which is not sustainable. We have the outline for the tools needed to quantify and transparently share the responsibility between producers and consumers at corporate, municipal and national level based on an improved understanding of the attendant sources, causes, flows and risks og GHG emissions globally. Hybrid LCA/EEIO models can for example be further developed. This will, in the end, enable everyday consumption to support a more sustainable, green and low carbon transition of our economy.


2020 ◽  
pp. 83-108
Author(s):  
Moon Hwy-Chang ◽  
Wenyang Yin

Although North Korea is one of the most closed countries in the world, it has long been pursuing international cooperation with other countries in order to upgrade the quality of its film industry to international standards. Preceding studies on this topic have mainly focused on the political influences behind filmmaking in general and very few studies have exclusively dealt with North Korea’s international co-productions. In this respect, in order to develop a comprehensive understanding of the internalization strategy of North Korea’s film productions, this paper uses the global value chain as a framework for analysis. This approach helps understand the internationalization pattern of each value chain activity of film co-productions in terms of the film location and the methods for collaborating with foreign partners. By dividing the evolution of North Korea’s international co-productions into three periods since the 1980s, this paper finds that although North Korea has shown mixed results with different aspects of the film value chain, it has generally improved its internationalization over the three periods. This paper further provides strategic directions for North Korea by learning some of the successful Chinese experiences in the film sector regarding collaboration with foreign partners—to foster a win-win situation for all involved parties.


1985 ◽  
Vol 20 (2) ◽  
pp. 111-119 ◽  
Author(s):  
J.H. Carey ◽  
S.A. Zaidi

Abstract The use of ultraviolet light (UV) from low pressure mercury lamps for destroying iron cyanide in synthetic and actual gold mill effluents was evaluated in this study. For the light intensities used in this study, UV irradiation was not able to efficiently destroy cyanide. However, it converted iron cyanide to a weak acid dissociable form which was destroyed by chlorine. Data from several bench-scale tests and one pilot scale test were used to estimate quantum efficiencies (moles iron cyanide destroyed/einstein). These efficiencies ranged from 0.2% to 1%; approximately 30% to 90% lower than those reported in the literature for potassium ferricyanide. The data collected during the study demonstrated the technical feasibility of using UV in conjunction with chlorination for destroying iron cyanide in gold mill effluents. However, low pressure mercury lamps do not appear to be a practical UV source for this purpose. Irradiation with high intensity lamps may be more practical and is recommended for experimental evaluation.


Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1520
Author(s):  
José Teixeira Gonçalves ◽  
Stanimir Valtchev ◽  
Rui Melicio ◽  
Alcides Gonçalves ◽  
Frede Blaabjerg

The hybrid three-phase rectifiers (HTR) consist of parallel associations of two rectifiers (rectifier 1 and rectifier 2), each one of them with a distinct operation, while the sum of their input currents forms a sinusoidal or multilevel waveform. In general, rectifier 1 is a GRAETZ (full bridge) (can be combined with a BOOST converter) and rectifier 2 is combined with a DC-DC converter. In this HTR contest, this paper is intended to answer some important questions about those hybrid rectifiers. To obtain the correct answers, the study is conducted as an analysis of a systematic literature review. Thus, a search was carried out in the databases, mostly IEEE and IET, and 34 papers were selected as the best corresponding to the HTR theme. It is observed that the preferred form of power distribution in unidirectional hybrid three-phase rectifiers (UHTR) is 55%Po (rectifier 1) and 45%Po (rectifier 2). For the bidirectional hybrid three-phase rectifiers (BHTR), rectifier 1 preferably takes 90% of Po and 10% of Po is processed by rectifier 2. It is also observed that the UHTR that employ the single-ended primary-inductor converter (SEPIC) or VIENNA converter topologies in rectifier 2 can present sinusoidal input currents with low total harmonic distortion (THD) and high Power Factor (PF), even successfully complying with the international standards. The same can be said about the rectifier that employs a pulse-width (PWM) converter of BOOST topology in rectifier 2. In short, the HTR are interesting because they allow using the GRAETZ full bridge topology in rectifier 1, thus taking advantage of its characteristics, being simple, robust, and reliable. At the same time, the advantages of rectifier 2, i.e., high PF and low THD, are well used. In addition, this article also points out the future direction of research that is still unexplored in the literature, thus giving opportunities for future innovation.


1994 ◽  
Vol 30 (3) ◽  
pp. 173-181 ◽  
Author(s):  
L. Knudsen ◽  
J. A. Pedersen ◽  
J. Munck

The work presented in this paper concerns the application of a two-stage aerobic activated sludge process for treatment of effluents from paper mills in Denmark. The paper describes both pilot-scale test results and fullscale experience with the process. The treatment process is characterised by a bigh-load first stage (2-4 kg COD/kg MLSSxd) followed by a low-load second stage to secure full nitrification and denitrification of remaining nitrogen compounds. The results of continuous pilot-scale tests show that it is possible to obtain a reduction of more than 85% of the incoming COD,01 and a 99% reduction of the incoming BOD5, resulting in an effluent quality of 230 mg CODsol/l and less than 10 mg BOD5/l. As indicated, practically all the biodegradable organic substances are removed by the process. The remaining fraction of soluble organics measured as COD is considered to be non-biodegradable by conventional biological treatment systems. The results produced in the pilot-scale tests are confirmed by the effluent qualities obtained in a full-scale treatment plant at another paper mill, involving an identical process concept. During the pilot-scale tests, special attention bas been paid to the removal of organic compounds, organic nitrogen as well as nutrients and nitrification. In addition, the sludge characteristics and the oxygen requirements have been considered.


2021 ◽  
pp. 32-40
Author(s):  
Rafał M. Łukasik

The European (and global) energy sector is in a process of profound transformation, making it essential for changes to take place that influence energy producers, operators, and regulators, as well as consumers themselves, as they are the ones who interact in the energy market. The RED II Directive changes the paradigm of the use of biomass in the heat and electricity sectors, by introducing sustainability criteria with mandatory minimum greenhouse gas (GHG) emission reductions and by establishing energy efficiency criteria. For the transport sector, the extension of the introduction of renewables to all forms of transport (aviation, maritime, rail and road short and long distance), between 2021-2030, the strengthening of energy efficiency and the strong need to reduce GHG emissions, are central to achieving the national targets for renewables in transport, representing the main structural changes in the European decarbonisation policy in that sector. It is necessary to add that biomass is potentially the only source of renewable energy that makes it possible to obtain negative GHG emission values, considering the entire life cycle including CO2 capture and storage. Hence, this work aims to analyse the relevance of biomass for CHP and in particular, the use of biomass for biofuels that contribute to achieving carbon neutrality in 2050. The following thematic sub-areas are addressed in this work: i) the new environmental criteria for the use of biomass for electricity in the EU in light of now renewable energy directive; ii) current and emerging biofuel production technologies and their respective decarbonization potential; iii) the relevance or not of the development of new infrastructures for distribution renewable fuels, alternatives to the existing ones (biomethane, hydrogen, ethanol); iv) the identification of the necessary measures for biomass in the period 2020-2030


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