Tecnologias de Valorização e Aproveitamento Energético de Resíduos de Isolamento de Cabos Eléctricos. Uma abordagem de um sistema simplificado para aplicação na indústria

Atualmente em Portugal os resíduos de isolamento de cabos elétricos (RICE) são envia- dos em grandes quantidades para aterro e possuem um poder calorífico elevado (>22MJ/kg) que está sendo desperdiçado. Foi realizada a caracterização físico-química dos RICE e obteve-se um teor médio de cloro de 25%, o que causa problemas de corrosão em equipamentos de combustão ou gaseificação. A carbonização dos RICE e suas misturas com biomassa lenhoce- lulósica foi estudada em escala laboratorial e piloto de forma a avaliar a principalmente a re- moção do cloro. Foram realizados ensaios de carbonização com temperaturas de 300-400oC, e os biocarvões caracterizados. Os biocarvões foram lavados com água quente para remoção de iões cloreto e condensados e ativados com KOH concentrado para aumentar a sua área superficial. O biocarvão produzido a 400 oC apresentou as melhores remoções de cloro, acima de 80%, maior teor de carbono, maior poder calorífico e após ativação apresentou a maior área que foram lavados. Foram testadas temperaturas entre os 750-850oC e um (ER) de 0.3. Os resíduos de RICE e RBL foram testados em uma gaseificadora de leito com carga nominal de 5- 15KW. Com base em todos os ensaios realizados foi possível apresentar um processo de aproveitamento e valorização energética dos RICE. No processo é possível aproveitar biocarvão para a limpeza do gás e águas residuais e aproveitamento na indústria da construção civil. A avaliação económica foi realizada para o processo apenas com produção de energia elétrica e para um processo de cogeração, energia elétrica e hidrogénio. O processo de cogeração com uma linha de financiamento de 50% e tempo de vida útil de 10 anos, tem um VAL de mais de 179 mil euros e um tempo de retorno de 6.92 anos.Currently in Portugal electrical cable insulation waste (RICE) is sent in large quantities to landfill and has a high calorific value (>22MJ/kg) that is being wasted. The physical-chem- ical characterization of RICE was carried out and an average chlorine content of 25% was ob- tained, which causes corrosion problems in combustion or gasification equipment. The car- bonization of RICE and its mixtures with lignocellulosic biomass was studied on a laboratory and pilot scale in order to evaluate mainly the removal of chlorine. Carbonization tests were carried out at temperatures of 300-400oC, and the biochars were characterized. The biochars were washed with hot water to remove chloride ions and condensates and activated with con- centrated KOH to increase their surface area. The biochar produced at 400 oC showed the best chlorine removal, above 80%, higher carbon content, higher calorific value and after activation showed the largest area that were washed. Temperatures between 750-850oC and an (ER) of 0.3 were tested. RICE and RBL residues were tested in a bed gasifier with a nominal load of 5- 15KW. Based on all the tests carried out, it was possible to present a process for the use and recovery of energy from RICE. In the process, it is possible to use biochar to clean gas and wastewater and use it in the construction industry. The economic evaluation was carried out for the process with only electrical energy production and for a cogeneration, electrical energy and hydrogen process. The cogeneration process, with a 50% financing line and a useful life of 10 years, has a NPV of more than 179 thousand euros and a payback period of 6.92 years

Energy recovery via thermal gasification from waste insulation electrical cables (Wiec)

project 0330_IDERCEXA_4_E project number 88881.156267/2017-01The recovery of noble metals from electrical wires and cables results in waste materials such as polyvinyl chloride (PVC) and polyethylene (PE), that is, waste insulation electrical cables (WIEC), which have been processed by gasification for energy recovery. This study focused on the effect of blending the ratio of WIEC on the gasification feedstock composition and the lower heating value (LHV) of produced syngas, through controlled tests and tests under different loads on the generator. The controlled gasification experiments were carried out at blending ratios between pine biomass and WIEC of 90:10, 80:20, and 70:30 and with pine biomass only (100%). For the loads gasification, the experiments were carried out at a blending ratio of 80:20. The controlled experimental results presented that the highest hydrogen content, approximated 17.7 vol.%, was observed at a blending ratio of 70:30 between pine biomass and WIEC and the highest LHV of syngas was observed at a blending ratio of 90:10, with 5.7 MJ/Nm3. For the load gasification experiments, the results showed that the highest hydrogen content was obtained with a load of 15 kW in the generator, approximately 18.48 vol.% of hydrogen content, and the highest LHV of synthesis gas was observed during the 5 kW test, with 5.22 MJ/Nm3. Overall, the new processing of waste insulation electrical cables using a downdraft gasification reactor demonstrates great promise for high quality syngas production.publishersversionpublishe

Biochemical Methane Potential of Cork Boiling Wastewater at Different Inoculum to Substrate Ratios

The present study evaluates the digestion of cork boiling wastewater (CBW) through a biochemical methane potential (BMP) test. BMP assays were carried out with a working volume of 600 mL at a constant mesophilic temperature (35 °C). The experiment bottles contained CBW and inoculum (digested sludge from a wastewater treatment plant (WWTP)), with a ratio of inoculum/substrate (Ino/CBW) of 1:1 and 2:1 on the basis of volatile solids (VSs); the codigestion with food waste (FW) had a ratio of 2/0.7:0.3 (Ino/CBW:FW) and the codigestion with cow manure (CM) had a ratio of 2/0.5:0.5 (Ino/CBW:CM). Biogas and methane production was proportional to the inoculum substrate ratio (ISR) used. BMP tests have proved to be valuable for inferring the adequacy of anaerobic digestion to treat wastewater from the cork industry. The results indicate that the biomethane potential of CBWs for Ino/CBW ratios 1:1 and 2:1 is very low compared to other organic substrates. For the codigestion tests, the test with the Ino/CBW:CM ratio of 2/0.7:0.3 showed better biomethane yields, being in the expected values. This demonstrated that it is possible to perform the anaerobic digestion (AD) of CBW using a cosubstrate to increase biogas production and biomethane and to improve the quality of the final digestate

Thermochemical and Economic Analysis for Energy Recovery by the Gasification of WEEE Plastic Waste from the Disassembly of Large-Scale Outdoor Obsolete Luminaires by LEDs in the Alto Alentejo Region (Portugal)

The recovery of urban waste is a social demand and a measure of the energy-environmental sustainability of cities and regions. In particular, waste of electrical origin, waste of electrical and electronic materials (WEEE) can be recovered with great success. The plastic fraction of these wastes allows their gasification mixed with biomass, and the results allow for producing syngas with a higher energy potential. This work allows for obtaining energy from the recovery of obsolete materials through thermochemical conversion processes of the plastic waste from the disassembly of the luminaires by mixing the said plastic waste in different proportions with the biomass of crop residues (olive). The gasification tests of these mixtures were carried out in a downstream fixed-bed drown daft reactor, at temperatures of approximately 800 °C. The results demonstrate the applied technical and economic feasibility of the technology by thermal gasification, for the production of LHV (Low Heating Value) syngas with highest power energy (more than 5 MJ/m3) produced in mixtures of up to 20% of plastic waste. This study was complemented with the economic-financial analysis. This research can be used as a case study for the energy recovery through gasification processes of plastic waste from luminaires (WEEE), mixed with agricultural biomass that is planned to be carried out on a large scale in the Alentejo (Portugal), as a solution applied in circular economy strategies

Properties and Uses of Biochars Incorporated into Mortars

Funding Information: The authors would like to acknowledge financial support from the PigWasteBioRefinery Project—Pig biorefinery based on biological, thermal, and electrochemical processes—Demonstrator mobile pilot project, code ALT20-03-0246-FEDER-000054, and co-financed by the European Regional Development Fund (ERDF), through the Regional Operational Program of the Alentejo (ALENTEJO 2020). Publisher Copyright: © 2023 by the authors.The construction industry is responsible for a large amount of CO2 emissions and an intensive energy consumption. Cement production is the third largest source of anthropogenic CO2 emissions and is responsible for about 1.8 Gt of CO2 emissions into the atmosphere. The use of waste materials to replace a fraction of cement in the mortar makes it more economically and ecologically friendly. In this work, the main objective was to test incorporations of biochar produced at temperatures of 300, 350, and 400 °C, as a partial replacement for cement in the production of mortar. The materials used for the tests were residual lignocellulosic biomass (WBL) and electrical cable insulation waste (WIEC) mixed in a ratio of 1:1. The biochars produced were crushed and sieved after production to reduce the particles. A sample of biochar was used and tested under these conditions and another sample was washed in water and dried before being incorporated; all tests were carried out with a 5% replacement. Waste recovery tests were also carried out without thermochemical treatment. The specimens were studied for compressive strength and water absorption by immersion. All tests were replicated and were analyzed and compared with a control mixture with no incorporation of biochar in the mixture. It was possible to observe that the tests with the incorporation of biochars at 400 °C showed better results, with only a 24% reduction in resistance to compression.publishersversionpublishe

Production, Characterization, and Activation of Biochars from a Mixture of Waste Insulation Electric Cables (WIEC) and Waste Lignocellulosic Biomass (WLB)

Waste insulation electrical cables (WIEC) currently do not have an added value, due to their physical–chemical characteristics. Carbonization is known to enhance feedstock properties, particularly fuel and material properties; as such, this article aimed to study the production and activation of biochars using WIEC and lignocellulosic biomass wastes as feedstock. Biochars were produced in a ceramic kiln with an average capacity of 15 kg at different temperatures, namely 300, 350 and 400 °C. After production, the biochars were further submitted to a washing process with water heated to 95 °C ± 5 °C and to an activation process with 2 N KOH. All biochars (after production, washing and activation) were characterized regarding an elemental analysis, thermogravimetric analysis, heating value, chlorine removal, ash content, apparent density and surface area. The main results showed that the increase in carbonization temperature from 300 to 400 °C caused the produced biochars to present a lower amount of oxygen and volatile matter, increased heating value, greater chlorine removal and increased ash content. Furthermore, the activation process increased the surface area of biochars as the production temperature increased. Overall, the carbonization of WIEC mixed with lignocellulosic wastes showed potential in enhancing these waste physical and chemical properties, with prospects to yield added-value products that activates biochar