Abstract

Industrial ecosystems are supposed to improve environmental performance. However, despite proven financial profitability, environmental justification of particular symbiotic initiatives is not obvious and demands verification. The authors of previous studies have recommended application of life cycle assessment method for environmental impact estimation in case of industrial symbiosis. However, few studies presenting life cycle assessment results of industrial symbiosis have been published so far. Among the factors which contribute to the success of symbiotic exchange, the close location of collaborating companies has been often mentioned in the literature. Most researches have focused on single industrial ecosystem where cooperating companies were located relatively close to each other. The positive environmental impact of particular symbiotic initiatives has been verified, however, the results have not provided more a general conclusion for other industrial ecosystems, including virtual eco-industrial parks. The main aim of this work was to determine the maximum distance of symbiotic transmission at which the environmental impact remains positive. Life cycle assessment results concerning the environmental impact of symbiotic fly ash exchange were presented. Concepts of relative distance and critical distance for the case of industrial symbiosis were proposed and defined. Considerable differences between critical distance obtained for particular endpoints were observed. The mixing triangle method was applied to estimate the critical distance taking into account individual impact categories. The final results pointed out that the critical distance of symbiotic fly ash exchange was much longer than in case of gypsum transmission. A sensitivity analysis indicated the relationship between critical distance and the means of transport which reflected the effect of scale. The effect of fly ash pre-processing on the results was examined, and it turned out to be insignificant.

Abstract

Removing dyes used in the textile industry from the water bodies is a relevant task because of the importance of their high toxicity. The cotton industry waste is a big problem in the final disposal. Waste cotton fibrils were studied as adsorbent material to treat the coloured effluents of the textile industry. Washing with boiling water was determined as the most efficient method for cleaning. The material was physical characterized. After that, methylene blue adsorption tests were carried out to review the dry removal process at different pH. The Langmuir isotherm and the pseudo-second kinetic order models best described this adsorption process. The results would indicate that the process involve a chemisorptions.

Abstract

Bioeconomies need sustainable technologies and strategies for biomass processing.
One of the best ways to do that is to consider biorefineries as a practical way to achieve real developments in the industry for integral production of energy, food, feed and chemicals under an ideal dream of replacing today’s crude-oil and basically using the accessible biomass in the world as much as possible. Additionally, the existent biofuel facilities are constantly adding new processing lines without integral design strategies, and possibly repeating the past design and implementation errors in refineries based on crude-oil. In recent years, more as a fashion or tendency, these processing lines from biofuels industry have been integrated in a system called “biorefinery” and many sectors have supported this idea through policies to incentivize the development of the bio-based economies adopting this concept. The design of biorefineries is presented as a relevant topic due to the multiple processing paths that could be available to obtain a set of desirable products. However, after many scientific efforts in design through well validated methodologies the biorefineries currently are not working properly or are more close to a conventional standalone biomass processing. Some big facilities already implemented today as biorefineries are closed or working just as standalone process (biofuels plant), but not through a promising multiproduct biorefinery configuration for which the resulting design was developed. In this work, 13 biorefineries were analysed including 4 industrial cases that were implemented after specific design and different industrial plants that use different raw materials of renewable origin. To achieve this, different strategic cases were considered: raw materials with inherent logistics restrictions, technical, economic, environmental assessments together with social considerations and finally market restrictions. As a result, and based on different case studies (where these process engineering strategies where applied through conceptual design using Aspen Plus and Potential Environmental Impacts) the positive and negative lessons are discussed in detail. The main result is an overall learning from different cases of study for future design, analysis and implementation of new biorefineries with a real sustainability and avoiding a repetition of the same evolution that risky and controversial crude-oil refineries had.

Abstract

The total resistance of ship in waves is composed of calm water resistance and added resistance in waves. The added resistance in waves is one of the main causes of an involuntary speed reduction of a ship. It may cause a significant increase in ship resistance and consequently increased fuel consumption and carbon dioxide emission, especially at heavier sea states. Thus, the added resistance is very important from both an economic and environmental point of view. In this paper, an increase in fuel consumption is calculated for container ship on a typical North Atlantic route. The calm water resistance is calculated utilizing Computational Fluid Dynamics based on the viscous flow theory at model scale and the obtained results are extrapolated to full scale. The added resistance in waves is calculated using three-dimensional panel code based on the free surface Green function, for the sake of simplicity. It is calculated at regular waves and the mean value of the added resistance at certain sea states is obtained by means of spectral analysis. Two-parameter Bretschneider wave spectrum recommended for the North Atlantic, defined by significant wave height and zero crossing period, is used in the spectral analysis. The obtained results may provide valuable insight into the important environmental issue of pollution reduction.

Abstract

The objective of this work is to simulate pretreatment steps on a laboratory scale with the purpose of producing a higher quality permeate for feed reverse osmosis process. Pretreatment steps involved in this work are a combination of physical and chemical processes, such as coagulation-flocculation, sand filtration, and microfiltration. Samples of seawater next to Itaqui thermoelectric power plant in Maranhão, State of Brazil, powered by coal, were collected and characterized. The characterization indicated high levels of turbidity, which is unusual for seawater, indicating the need of pretreatment to reverse osmosis. The combination of polyaluminum chloride dosages of 30 mg/L and 0.3 mg/L of Nalclear 8,173 anionic polymer allowed the reduction of turbidity values to below 1 Nephelometric Turbidity Unit (NTU). The use of coagulation and microfiltration membranes provided values of silt density index next to 3, while with sand filter, the silt density index values were higher than 4.

Abstract

Energy efficiency at the city level is mainly dependent on buildings and requires sustainably designed strategies. In this research, an energy index that leads to a classified measurement of sustainability at a building level is defined and evaluated based on a selected building in Istanbul. Sensitivity analysis is assisted by determining the precision of the outcome when certain interventions are applied to improve the building energy efficiency. Each intervention’s energy consumption is evaluated based on the overall building energy consumption, which includes all building related energy consuming parameters. There are 6 different scenarios which are composed of various combinations of 8 interventions affecting 7 energy consuming parameters. A matrix is prepared for conducting sensitivity analysis with the particular effects of the applicable interventions. Furthermore, specific values are evaluated to find their sensitivity to affect the building energy performance. The most important improvements among all interventions are automation and monitoring with an energy consumption reduction of 26.07%, ground source heat pump at 16.43% and light emitting diode lighting with sensors at 9.26%. These interventions are also remarked as highly sensitive. As a result, the prepared matrix directly describes the effect of variables in the system numerically, which also assists to determine each intervention’s sensitivity levels.

Abstract

Many studies and scientific papers have been published that consider the integration of renewable sources in energy systems, using the least-cost optimization models as a long-term generation expansion planning tool. Supplementary to these analyses, this paper focuses on the transmission network capacity for acceptance of variable renewable energy. The hypothesis is that the simplified electric power transmissions system in the long-term planning modelling tools does not reflect properly the capacity for integration of the variable renewable energy. An integrated approach is applied with aim to incorporate the grid expansion needs and costs (using direct current load flow analysis), necessary for increased renewable electricity penetration. The already developed MARKAL-Macedonia model will be used as a case study. After several iterations and feedback loops between the MARKAL-Macedonia and the network model, the expected outcome is to achieve a new cost-effective solution for deployment of variable energy on a larger scale.

Abstract

To improve biomass gasification efficiency through process control, a lot of attention had been given to development of models that can predict process parameters in real time and changing operating conditions. The paper analyses the potential of a nonlinear autoregressive exogenous model to predict syngas temperature and composition during plant operation with variable operating conditions. The model has been designed and trained based on measurement data containing fuel and air flow rates, from a 75 kW_th fixed bed gasification plant at Technical University Dresden. Process performance changes were observed between two sets of measurements conducted in 2006 and 2013. The effect of process performance changes on the syngas temperature was predicted with prediction error under 10% without changing the model structure. It was concluded that the model could be used for short term predictions (up to 5 minutes) of syngas temperature and composition as it strongly depends on current process measurements for future predictions. For long term predictions other types of dynamic neural networks are more applicable.

Abstract

The efficiency of composting method with yard waste and rumen residue amendments to reduce soil pollution by total petroleum hydrocarbon in Wonocolo public oilfields was investigated in the laboratory scale for 150 days. Crude oil contaminated soil was mixed with yard waste and rumen residue mixture at 1:1 ratio then composted in 2 replicates. Pure crude oil contaminated soil was composted in parallel. The results showed that total petroleum hydrocarbon degradation efficiency of soils amended with yard waste and rumen residue mixture was 31 times higher than contaminated soil, which fulfilled the soil quality standard (6,974.58 mg/kg). The degradation of total petroleum hydrocarbon might be performed by Bacillus sp., and Bacillus cereus as the dominant bacteria at the end of composting process. These results showed that yard waste and rumen residue transformation could accelerate the degradation of aliphatic and aromatic fractions of petroleum hydrocarbon in crude oil contaminated soil. Both of these wastes are generally easy to obtain around Wonocolo public oilfield and highly recommended to use as the main substrate in the composting process.

Abstract

Discarding waste in open spaces, commonly called dumps, is highly damaging to the environment. High concentrations of heavy metals are observed, which creates the need to carry out restoration processes in such places. The use of plants for the remediation of soils contaminated by heavy metals in the garbage dump, is a strategy. The work was carried out in the garbage dump of Quitasol-Imponeda de Abancay, with three native plant species. The objective was to evaluate the levels of contamination by the heavy metals: lead, cadmium, nickel, chromium and zinc in the waste matrix in root, stem and leaves. A complete factorial design was applied: three species and five treatments with heavy metals, each with two repetitions applied and in three selected plots (A, B, C).
The results show that the highest accumulation of zinc, lead and cadmium was obtained in Amaranthus hybridus, with 23.03 parts per million in the root, 5.87 parts per million in the stem and 8.83 parts per million in the leaves, in plots two and three. In Brassica rapa, the highest values of accumulation were recorded for zinc, lead and cadmium in the roots, and showed a decrease in leaf growth and stem thickness. Amaranthus spinosus obtained higher values of zinc accumulation of 24.28 parts per million in the roots and in leaves, zinc 11.63 parts per million, lead 1.74 parts per million and cadmium 0.55 parts per million. It is concluded that the three native species present rapid growth, do not require chemical controls, with absorption of high levels of heavy metals, becoming an alternative for the restoration of the garbage dump, due to its high phytoremediation potential.

Abstract

Due to the phenomenal growth in the transport sector as a part of rapid urbanization, especially in the Indian sub-continent where transportation of goods and people are essentially done through the existing road associated with production of tyres and to identify the grey areas  in which enough network, tyre industries have seen a rapid growth. In view of this, it is important that sustainability of tyre industry is maintained without its adverse effect on the environment. The objectives of this particular study are to identify and quantify the potential environmental impacts scope is there for further improvements. Life cycle assessment is a tool to evaluate the environmental impacts of any product or a process. In this work, life cycle assessment has been used to identify the environmental impacts associated with the tyre manufacturing process. The gate-to-gate approach has been used for this study of tyre production. The detailed data required for this study were obtained from MRF Industries, Usgao, Goa, India. Computations of the life cycle impact assessment results are achieved using SimaPro software with
IMPACT 2002+ method. From the results it is noted that there is a significant impact on the environment due to emissions from the generation of electrical energy and steam in the plant under study along with emissions due to various operations in the tyre production process. The major environmental impact categories which are affected due to these processes are respiratory inorganics, aquatic acidification, terrestrial acidification/nitrification and to some extent aquatic eutrophication. Further, it is also observed that there is significant emission of particulate matter from the Banbary section of the tyre production process. This study reveals that the emissions of particulate matter, sulphur dioxide and nitrogen dioxide from tyre production process are significant.
The life cycle assessment results obtained for the MRF tyre are compared with the life cycle assessment results of the Tweel tyre invented by Michelin, Bridgestone tyre, Goodyear tyre, Nokia tyre and comparative life cycle assessment results for a conventional tyre and a guayule rubber-based tyre. From a comparison among all above mentioned case studies, it is observed that major environmental impacts of tyres depend primarily on product design and usage. Significant reduction in environmental impact due to tyre production is possible if the source of electricity is nonconventional.  Reduction in weight and rolling resistance of the tyre will also lead in significant reduction in greenhouse gas emissions during its use.

Abstract

The difficulties of efficiently operating a chiller cooling system are manifest in the high-energy consumption under partial-cooling loads. The performance of a chiller cooling system declines when operating away from the optimal design conditions, which is typically 75% of chiller capacity. One pathway has been found to overcome this problem using multiple smaller chillers within the same chiller plant, accompanied by a smart control system that is designed and constructed based on the cooling demand profile. Thermal energy storage integration with chiller cooling system is proposed to shave the cooling peak demand. This can be achieved by storing chilled water during the lower electricity-tariff period by the thermal energy storage system, which will then be discharged during the higher tariff-rate, thus, aiming for sustainable operating cost. The present paper studies the feasibility of sensible thermal energy storage to be integrated with two chillers, of 30-ton capacity each, under hot-and-humid climates. A computational model validated with experimental results is developed for three chiller cooling system case scenarios. The smart control scenario, as well as the thermal energy storage scenario results, showed great potential for energy and electricity cost saving. In addition, the carbon dioxide emissions reduction is calculated based on the amount of energy saving.

Abstract

The aim of this work is to evaluate the potential application of a new sustainable technology, called Acid Gas to Syngas, on steam reforming process in order to reduce the carbon dioxide emissions. Indeed, steam reforming has high emissions of carbon dioxide, at almost 7 kg of carbon dioxide per 1 kg of hydrogen produced. The key idea of the new technology is to convert carbon dioxide and hydrogen sulfide coming from natural gas desulfurization into additional hydrogen. Coupling different software, i.e. Aspen HYSYS and MATLAB, a complete plant model, able to manage the recycle of unconverted acid gases, has been developed. The importance of introduced innovations is highlighted and a comparison between the old process and the new one with Acid Gas to Syngas technology is built up. With Acid Gas to Syngas technology the natural gas consumption and carbon dioxide emissions can be reduced up to 3%.

Abstract

Bioenergy villages can be defined as villages, municipalities, settlements or communities, which produce and use most of their energy from local bioenergy and other renewable energy sources. A bioenergy village approach has not been applied in Macedonia yet, and it is at a nascent stage of implementation in other South-Eastern European countries. This work aims to integrate a techno-economic, social and environmental assessment and an implementation strategy into a bioenergy village concept, which is not often seen in works dedicated to bioenergy villages and biomass based heating systems. The assessment was conducted by means of energy audit and project-related tools, whilst the strategy was composed by bioenergy working group meetings. Results show that a biomass based district heating system is a more attractive solution for heating several public buildings instead of a fossil fuelled system, with numerous associated benefits. Such concepts can be replicated with variety of renewables, thus contributing to sustainable development pathways of small communities.

Abstract

Soluble-lead-flow-batteries suffer from dendrite formation and thus shorting of the electrodes. Utilizing hexadecyltrimethylammonium-ion as an additive to the electrolyte, as well as periodic electrochemical renewal of electrode surfaces, the problem of dendrite formation has been eliminated. Laboratory scale cells have been designed and constructed that were able to cycle for more than 7,000 full cycles at 100% depth of discharge without intervention to the system. These cells have very high coulombic efficiencies of more than 97%, as well as energy efficiencies of 70% and greater for each individual cycle. The strategy of in situ renewal of electrode surfaces at certain cycle intervals allows these cells to be reconditioned and start with new electrode surfaces each time such a maintenance is performed. Thus, these cells can be reset to their starting condition with each of these maintenance cycles.

Abstract

Phase change materials are considered a very promising technology to reduce energy consumption for space heating and cooling purposes in buildings. In this framework, this paper presents a comprehensive energy performance analysis of building envelopes integrating phase change materials to provide suitable selection and design criteria of such technology. To this aim, an in-house dynamic simulation model implemented in a computer code, and validated by means of experimental data, has been used.
The performance of phase change materials embedded in building enclosures and their optimal configuration (i.e., positions with respect to the construction layers) are evaluated. The results obtained by applying the code to suitable case studies (several climate zones and buildings are investigated) return that the energy saving percentage potentials per cubic meter of phase change materials range from 1.9%/m³ to 18.8%/m³. Finally, interesting design criteria for their adoption in buildings are provided.

Abstract

Abstract

The effects of climate change on Earth already exist in different forms – as an increase in global average temperatures, as a sea level rise or as extreme weather events, and it is necessary to take significant measures to mitigate and adapt to the climate change. One of the tools that can help in attempts to mitigate climate change is the use of carbon footprint concept, as a measure of the greenhouse gas emissions. Since there are different approaches, it is necessary and possible to establish a harmonised approach for calculating the organisations’ carbon footprint, in order to obtain comparable results and benchmarks for different kinds of organisations. The Croatian version of the Bilan Carbone model, fully in accordance with appropriate international standards, with country-specific emission factors database, was tested on the case of the Energy Institute Hrvoje Požar for the period 2015-2017. The carbon footprint for 2017 was 650.6 tonnes or 7.31 tonnes per employee of carbon dioxide equivalent emissions, with dominant shares of people transport (59%) and energy sources (22%). This harmonised approach for carbon footprint calculation will lead to comparable results for the same kinds or groups of organisations and therewith, lighten the process of establishing the carbon footprint mitigation strategies.

Abstract

Electric vehicles are considered as an important means to cope with increasing environmental problems in the transport sector. Many governments worldwide have set targets to increase the number of electric vehicles, although their environmental benignity is not ensured in the scope of the policies implemented. The core objective of this paper is to investigate the overall environmental impact of electric vehicles in different regions. The analysis is based on a life cycle assessment of electric vehicles including emissions from electricity generation, vehicle production and disposal, and vehicle use. The major conclusion is that the environmental benignity of electric vehicles is very sensitive on: electricity mix (a); number of km driven per year (b) and embedded emissions in car production (c), as well as battery recycling. Yet, as shown in this paper the highest sensitivity is with respect to the electricity mix. Hence, to make electric vehicles more environmentally friendly it is most important to increase the share of renewable energy sources in electricity generation.

Abstract

Mixing of semi-dry flue gas desulfurization solids and fly-ash from coal-fired power plants results in a solid waste contaminated by calcium sulfite. Therefore, it becomes useless for industry and is often landfilled. To support decision-making on process configurations to monetize this solid residue a gate-to-gate life cycle assessment was performed, considering three scenarios: BASE case – standard 360 MW power plant, CASE I – base plant adopting dry thermal oxidation treatment of spray dryer solids, CASE II ‒ bypass of desulfurization system. Cases I and II allow commercialization of the solid residue as class C fly-ash. Evaluated alternatives were compared based on quantitative potential environmental impacts, using United States Environmental Protection Agency waste reduction algorithm. Based on the results, the BASE case was more aggressive to the environment, due to solid waste production. CASE II increased photochemical oxidation and acidification potentials. CASE I was the more environmentally friendly but demands additional capital and operational expenditure.