Combustion characteristics of refuse-derived fuel pellets having varying plastic compositions.

The plastic fraction of refuse-derived fuel (RDF) pellets influences fuel's physico-chemical, and mechanical properties, which in turn might affect the combustion behavior of RDF. In the present study, the combustion behavior of different plastic fraction-simulated RDF pellets is reported. The simulated pellets were prepared based on the Indian commercial RDF composition. Initially, the plastic content varied from the existing fraction in Indian commercial RDF, i.e., 35% (RDF-1), to a lower plastic content of 5% (RDF-2). Physico-chemical characterization showed that a higher plastic fraction in RDF-1 reduces its pellet density by 25% as compared to RDF-2. The changes in RDF physico-chemical properties due to plastic variation are reflected in the RDF conversion process. Single-particle and packed-bed studies concluded that the lower density for higher plastic RDF-1 leads to lower conversion times (36%), and higher flame front speed (11%), which are desirable conditions for faster conversion. However, packed-bed studies also showed limitations regarding the utilization of high plastic RDF as RDF-1 has a narrow range of operating air mass flux due to the early advent of convective cooling of the bed. Finally, considering the constraints associated with the utilization of high plastic fraction (~ 35%) RDF and to maximize the effective utilization of plastic in RDF, a workable plastic fraction of 15% in RDF was proposed and tested for its combustion properties. RDF with 15% plastic showed faster conversion, higher flame front speed, and a wider range of operating air mass flux before the advent of convective cooling of the bed.

Turning trash into treasure: Torrefaction of mixed waste for improved fuel properties. A case study of metropolitan city.

Solid waste management is one of the biggest challenges of the current era. The combustible fractions in the waste stream turn out to be a good energy source if converted into refuse-derived fuel. Researchers worldwide are successfully converting it into fuel. However, certain challenges are associated with its application in gasifiers, boilers, etc. to co-fire it with coal. These include high moisture content, low calorific value, and difficulty to transport and store. The present study proposed torrefaction as a pretreatment of the waste by heating it in the range of 200 °C-300 °C in the absence of oxygen at atmospheric pressure. The combustible fraction from the waste stream consisting of wood, textile, paper, carton, and plastics termed as mixed waste was collected and torrefied at 225 °C, 250 °C, 275 °C, and 300 °C for 15 and 30 min each. It was observed that the mass yield and energy yield decreased to 45% and 62.96% respectively, but the energy yield tended to increase by the ratio of 1.39. Proximate analysis showed that the moisture content and volatile matter decreased for torrefied samples, whereas the ash content and fixed carbon content increased. Similarly, the elemental analysis revealed that the carbon content increased around 23% compared to raw samples with torrefaction contrary to hydrogen and oxygen, which decreased. Moreover, the higher heating value (HHV) of the torrefied samples increased around 1.3 times as compared to the raw sample. This pretreatment can serve as an effective solution to the current challenges and enhance refuse-derived fuel's fuel properties.

Optimizing refuse-derived fuel production from scheduled wastes through Aspen plus simulation.

This study aims to improve the quality of fuel with high calorific value namely Sfuel - a commercial high-quality refuse-derived fuel (RDF) from hazardous waste via modifying the process design and operating parameters of thermal conversion process. The study analyses key parameters of RDF quality, such as calorific value and heavy metal content, before and after process modifications based on the combination of experimental and simulation using Aspen Plus. In this study, the temperature and pressure of the simulation system are varied from 100 to 700 °C and from 1 to 5 bar, respectively. Findings indicate that there are a total of eleven heavy metals and 179 volatile compounds in the "Sfuels". The quality of the targeted product is greatly improved by the metal evaporation at high temperatures and pressures. However, the calorific value of RDF significantly decreases at 700 °C due to a large amount of the carbon content being evaporated. Although the carbon content at high temperatures is significantly lost, the heat from the vapour stream reactor outlet, which is reused to preheat the nitrogen gas stream supplied to the system, reduces energy consumption while improving the thermal conversion efficiency of the system. Besides, low pressure along with high temperature are not the optimal conditions for quality Sfuels improvement by thermal conversion. Results also indicate that electric heating is more economically efficient than natural gas heating.

Effects of biodegradable- and non-biodegradable-rich waste separation on ash deposition behaviour during coal and refuse-derived fuel co-combustion.

The potential impact of ash deposition during the combustion of separated biodegradable- and non-biodegradable-rich waste of refuse-derived fuel (RDF) was evaluated in this study. Theoretical prediction, drop tube furnace experimental combustion, and ash observation were performed to comprehensively investigate their ash deposit behaviour. The results show that high CaO and Cl in RDFs result in severe sintering and rust in the metal surface. The high ash deposit weight and aggregated sticky particles are observed during single-firing RDFs. Furthermore, adding 5 wt% of biodegradable-rich RDF or mixed RDF to coal has a less significant effect on ash deposition. However, several aggregate particles and metal degradation are observed during the combustion of mixed coal with the addition of 5 wt% non-biodegradable-rich RDF. The high Cl in non-biodegradable-rich RDF affects the ash deposition behaviour significantly. This research provides valuable insights into optimising coal-RDF co-combustion, especially with separating biodegradable- and non-biodegradable-rich RDFs.

Smart-sight: Video-based waste characterization for RDF-3 production.

A material recovery facility (MRF) can transform municipal solid waste (MSW) into a valued commodity called refuse-derived fuel (RDF) as a promising solution to waste-to-energy conversion. The quality of the produced RDF significantly relies on the composition of in-feed waste and waste characterization method applied for auditing purposes, a process that is both time-consuming and fraught with potential hazards. This study focuses to enhance the workflow of the waste characterization process at an MRF. A solution named Smart Sight is proposed to detect and classify waste based on videos recorded after processing MSW through a mechanical sorting line consisting of bag breakers and trommel screens. A comprehensive dataset is created encompassing thirteen mixed waste classes from single and multi-family streams. The dataset is preprocessed with motion compensation techniques and frame differencing methods to extract and refine valuable frames. A one-stage YOLO detector model is then trained over the dataset. The experimental results show that the proposed method works efficiently at detecting and classifying waste objects in indoor MRF environments. Accuracy, precision, recall, and F1 score related to the proposed solution are found to be 0.70, 0.762, 0.69 and 0.72, respectively, with a mAP@0.5 of 0.716. The proposed approach is validated using data collected from local MRF by comparing the estimated waste composition values of the proposed solution with laboratory results obtained through current standardized industrial practices. Comparison reveals that waste characterization estimation obtained is consistent with the laboratory results, inferring that Smart-Sight is a viable tool for estimating waste composition.

Municipal solid waste management instruments that influence the use of the refuse as fuel in developing countries: A critical review.

Landfills are the destination of most of the refuse generated whereas composting, material recycling, and Waste-to-Energy (WtE) technologies are not commonly employed in developing countries. However, the destination for energy purposes could be supplied with this refuse, improving the viability of energy use. Thus, this article raises some questions to identify aspects that could encourage its use as refuse-derived fuel (RDF) in these countries. Among them, does environmental education affect the municipal solid waste (MSW) source separation with emphasis on a destination? Can selective collection and extended producer responsibility (EPR) affect the MSW for energy recovery? Is there competition between the recycling market and the energy market for RDF? A systematic review of the literature was conducted to gather data and provide answers to such questions. This enabled to observe that EPR, selective collect expansion and source separation influence the quantity and quality of waste sent for energy use. Both internal and external factors impact on source separation. Additionally, there is evidence to support that despite several studies showing their technical, economic, environmental and social viability, the methods of energy usage of the refuse still need to improve their deployment in developing countries. In addition to identifying the main research gaps to be filled in future studies, the article also identified the instruments of MSW management that are to be applied in developing countries to divert recyclable and organic waste from landfill.

Optimization of low-grade coal and refuse-derived fuel blends for improved co-combustion behavior in coal-fired power plants.

This study is aimed at utilizing three waste materials, i.e., solid refuse fuel (SRF), tire derived fuel (TDF), and sludge derived fuel (SDF), as eco-friendly alternatives to coal-only combustion in co-firing power plants. The contribution of waste materials is limited to ≤5% in the composition of the mixed fuel (coal + waste materials). Statistical experimental design and response surface methodology are employed to investigate the effect of mixed fuel composition (SRF, TDF, and SDF) on gross calorific value (GCV) and ash fusion temperature (AFT). A quadratic model is developed and statistically verified to apprehend mixed fuel constituents' individual and combined effects on GCV and AFT. Constrained optimization of fuel blend, i.e., GCV >1,250 kcal/kg and AFT >1,200 °C, using the polynomial models projected the fuel-blend containing 95% coal with 3.84% SRF, 0.35% TDF, and 0.81% SDF. The observed GCV of 5,307 kcal/kg and AFT of 1225 °C for the optimized blend were within 1% of the model predicted values, thereby establishing the robustness of the models. The findings from this study can foster sustainable economic development and zero CO2 emission objectives by optimizing the utilization of waste materials without compromising the GCV and AFT of the mixed fuels in coal-fired power plants.

Investigating the effect of waste age and soil covering on waste characteristics prior to landfill mining using an electrical resistivity tomography technique.

This study analyzed the potential of landfill mining for refuse-derived fuel (RDF) production based on waste electrical resistivity, including the influence of waste age and soil cover. Electrical resistivity tomography (ERT) was used to determine the resistivity value of landfilled waste in four active and inactive zones, with two to four ERT survey lines collected per zone. Waste samples were collected for composition analysis. Linear and multivariate regression analyses were used to constrain the data correlation based on the waste's physical characteristics. An unexpected finding was that soil cover, rather than the waste's age, influenced the characteristics of the waste. To evaluate the RDF recovery potential, multivariate regression analysis showed a significant correlation between electrical resistivity, conductive materials, and moisture content. However, the obtained correlation between electrical resistivity and RDF fraction using linear regression analysis can be more conveniently used to evaluate RDF production potential in practice.

The evaluation of energy consumption in transportation and processing of municipal waste for recovery in a waste-to-energy plant: a case study of Poland.

Refuse-derived fuel (RDF) can be produced from combustible materials contained in municipal waste. This article investigates energy and material flow of waste in different scenarios for production of RDF from bulky waste, separately collected waste, and mixed municipal solid waste (MSW). We compare the proportion of energy consumption in transportation, handling waste, and processing using data from the waste collection company in South Poland. The findings show the components of the reverse supply chain consuming the highest value of energy. A model of material and energy flow has taken into consideration collection of waste and transportation by two categories of waste collection vehicles: light commercial vehicles and garbage trucks. The shipping of RDF from pre-treatment facilities uses tipper semi-trailers and walking floor trailers. The findings of the study show production of RDF from municipal solid waste consumes almost 10% of energy potential in RDF. Less energy is required for the production of RDF from bulky waste (2.2-4.8%) or separately collected waste (1.7-4.1%) depending on the efficiency of collection and selected vehicles. Transportation consumes the greatest portion of energy. For mixed municipal solid waste (MSW), it can reach 79%; for separated collection waste, 90%; and for bulky waste, up to 92% of the total energy consumed. Comparing emissions for two categories of the collection vehicles, no significant difference was found for the bulky waste collections. For mixed MSW and separately collected waste, the emissions are higher for garbage trucks. A recommendation for practitioners is optimization of routing to achieve a higher collection rate at a minimized route length. For transportation of RDF to WtE plants, vehicles with higher loading capacity are essential.

Prediction of the proximate analysis parameters of refuse-derived fuel based on deep learning approach.

Determination of proximate characteristics can be achieved using conventional analyses methods that require a certain amount of time. In cement factories, refuse-derived fuel (RDF) is continuously fed to a kiln by a conveyor belt, so even if an inappropriate proximate characteristic is determined, it would be too late to prevent the feeding of RDF to the kiln. To overcome this problem, there is a need for instant measurement of the proximate characteristics (moisture, volatile matter, ash) that enables the feeding to be stopped. In such cases, the deep learning (DL) is a useful method based on the prediction of proximate characteristics. Therefore, in this study, the aim is to estimate the mentioned parameters developed by near-infrared spectroscopy (NIR) combined with deep learning models. For this purpose, the spectrographic measurements taken from RDF samples with an NIR spectrometer, and the results of proximate analysis in a laboratory, were used together as a dataset. A fully convolutional neural network (FCNN) and ResNet were used as a network, and they were trained using images of RDF samples and proximate analysis values. The FCNN model was more successful in prediction studies. According to the FCNN model, the results show that the models in the study can predict the moisture, ash, and volatile matter content of RDF with satisfactory R2 values between 0.979, 0.983, and 0.952.

Pyrolysis and Gasification of a Real Refuse-Derived Fuel (RDF): The Potential Use of the Products under a Circular Economy Vision.

Refuse-Derived Fuels (RDFs) are segregated forms of wastes obtained by a combined mechanical-biological processing of municipal solid wastes (MSWs). The narrower characteristics, e.g., high calorific value (18-24 MJ/kg), low moisture content (3-6%) and high volatile (77-84%) and carbon (47-56%) contents, make RDFs more suitable than MSWs for thermochemical valorization purposes. As a matter of fact, EU regulations encourage the use of RDF as a source of energy in the frameworks of sustainability and the circular economy. Pyrolysis and gasification are promising thermochemical processes for RDF treatment, since, compared to incineration, they ensure an increase in energy recovery efficiency, a reduction of pollutant emissions and the production of value-added products as chemical platforms or fuels. Despite the growing interest towards RDFs as feedstock, the literature on the thermochemical treatment of RDFs under pyrolysis and gasification conditions still appears to be limited. In this work, results on pyrolysis and gasification tests on a real RDF are reported and coupled with a detailed characterization of the gaseous, condensable and solid products. Pyrolysis tests have been performed in a tubular reactor up to three different final temperatures (550, 650 and 750 °C) while an air gasification test at 850 °C has been performed in a fluidized bed reactor using sand as the bed material. The results of the two thermochemical processes are analyzed in terms of yield, characteristics and quality of the products to highlight how the two thermochemical conversion processes can be used to accomplish waste-to-materials and waste-to-energy targets. The RDF gasification process leads to the production of a syngas with a H2/CO ratio of 0.51 and a tar concentration of 3.15 g/m3.

Efficiency of municipal packaging waste recovery chain and suitability of separated residual waste fractions for use in alternative fuels production.

Due to the sheer quantity and quality of material, packaging waste is separately collected by municipal waste management systems, with a primary goal of its use in material recovery. The residual waste, i.e. rejected waste in the separation process can be energy recovered. Both recovery options have specific input material quality requirements. Therefore, it is important to know the characteristics of individual waste streams. This research analysed the composition and morphological characteristics of separately collected packaging waste from municipal waste management system, residual (rejected) waste fractions after separation steps and produced refuse-derived fuel (RDF). The efficiency of primary and secondary (manual) waste separation, as well as of the RDF production step, are tracked. Results show that primary waste separation produces material with under 7% of contaminants and secondary manual waste separation efficiency ranges between 45% and 55%. Physico-chemical comparison of simulated RDF strongly coincides with analysed properties of RDF as a final product which indicates very high separation efficiency in the RDF production. From the energy recovery/conversion standpoint, this can be quantified through deviations in the lower heating value (LHV) and the effective H/C molar ratio between simulated and real RDF samples, which are on the level of 1.8% and 1.1% respectively. The following conclusion can be made from the estimated relation between changes in separation efficiency and RDF energy-related characteristics; the separation efficiency of individual components plays important role in alternative fuel production as chemical compositions directly influence suitability for high-quality liquid fuel production. Results of this analysis shed a light on the connection between aspirations to increase material recovery share and the suitability of produced residual waste for further recovery and valorisation. The material and energetic valorisation are competitors, and further evaluation should be done to understand the investments needed to increase valuable fractions of wastes separation that, in turn, could diminish the energetic value of residual fractions and, therefore, the economic viability of energy recovery facilities.

Numerical and experimental analysis of pyrolysis process of RDF containing a high percentage of plastic waste.

The current COVID-19 pandemic situation and the associated restrictions have increased the amount of generated waste. It results from the necessity to wear personal protective equipment. Thus, the disposal of masks and gloves is a topical issue and requires immediate investigation. The main aims of this work are management and environmental studies of municipal solid wastes (MSW), which have been generated during the COVID-19 pandemic time. Effective waste management in relation to a circular economy is presented. A sample of refuse derived fuel (RDF) with a high content of plastics was used for the experimental and calculation studies. Pyrolysis was selected as the best thermal decomposition process for this kind of wastes. Proximate and ultimate analyses were performed for RDF and its products. Pyrolysis was carried out using a pilot-scale reactor with a continuous flow of 250 kg/h at 900 °C. Thermogravimetric analysis was applied during the pyrolysis investigation and showed that the main decomposition of RDF took place in the temperature range of 250-500 °C. The pyrolysis gas contained combustible compounds like CO (19.8%), H2 (13.2%), CH4 (18.9%) and C2H4 (7.1%), giving a high calorific value - 24.4 MJ/m3. The experimental results were implemented for numerical calculations. Chemkin-Pro software was applied to predict the chemical composition of the pyrolysis gas. The performed computer simulations demonstrated very good agreement with the results obtained during the experiments. They also indicated that there is a strong relationship between the chemical composition of the pyrolysis gas, the process temperature and residence time in the reactor.

Optimal use of glycerol co-solvent to enhance product yield and its quality from hydrothermal liquefaction of refuse-derived fuel.

Refuse-derived fuels (RDF) are rich in resources that make them an attractive feedstock for the production of energy and biofuels. Hydrothermal liquefaction (HTL) is a promising thermochemical conversion technology to handle wet feedstocks and convert them to valuable bio-crude, bio-char and aqueous products. This study highlights the advantages of using glycerol as the co-solvent along with water in different proportions to produce bio-crude from RDF via HTL. The ratio of water:glycerol (vol.%:vol.%) was varied for each experiment (100:0, 90:10, 80:20, 70:30, 60:40, 50:50), and the product yields and their quality were studied. The results demonstrate that increasing the proportion of glycerol until 50 vol.% in the solvent enhances the bio-crude yield (36.2 wt.%) and its higher heating value (HHV) (30.9 MJ kg-1). Deoxygenation achieved in the bio-crude was 42%. The production of bio-char was minimum (9.5 wt.%) at 50 vol.% glycerol with HHV of 31.9 MJ kg-1. The selectivity to phenolic compounds in the bio-crude increased, while that of cyclic oxygenates decreased when the glycerol content was more than 20 vol.%. The gas-phase analysis revealed that the major deoxygenation pathway was decarboxylation. The yield of aqueous products drastically increased with the addition of glycerol. The minimum amount of glycerol in the co-solvent that favours an energetically feasible process with low carbon footprint is 30 vol.%. Using 50 vol.% glycerol resulted in the highest energy recovery in the bio-crude and bio-char (80%), the lowest energy consumption ratio (0.43) and lowest environmental factor (0.1). The mass-based process mass intensity factor, calculated based on only bio-crude and bio-char as the valuable products, decreased with an increase in addition of glycerol, while it was close to unity when the aqueous phase is also considered as a valuable product.

Characterization of Mixed Pellets Made from Rubberwood (Hevea brasiliensis) and Refuse-Derived Fuel (RDF) Waste as Pellet Fuel.

The objective of this study was to investigate the production and properties of mixed pellets made from rubberwood (Hevea brasiliensis Muell. Arg) and refuse-derived fuel (RDF) waste with no added binder. Three different conditions of mixed pellets were developed to compare their chemical and physical properties to rubberwood pellets. The produced samples were subjected to both ultimate and proximate analyses. The contents of C, H, N, S, and Cl significantly increased with the increasing amount of refuse-derived fuel in the samples, resulting in reduction of the volatile matter. The mechanical durability of the pellet samples ranged between an average value of 98 and 99%. Mixed pellets containing 50% of rubberwood and 50% of refuse-derived fuel have improved heating values by 22.21% compared to rubberwood pellets. Moreover, mixed pellets having 50% of wood and 50% of refuse-derived fuel had the highest density and the highest energy compared to the other samples. Based on the findings of this study, it appears that the manufactured mixed pellets have the potential to be used as high-energy fuel.

Qualitative analysis of post-consumer and post-industrial waste via near-infrared, visual and induction identification with experimental sensor-based sorting setup.

Sensor-based sorting in waste management is a method to separate valuable material or contaminants from a waste stream. Depending on the separation property different types of sensors are used. Separation properties and their corresponding sensors are e.g. molecular composition with near-infrared sensors, colour with visual spectroscopy or colour line scan cameras, or electric conductivity with electromagnetic sensors. The methods described in this paper deal with the development of sorting models for a specific near-infrared, a visual spectroscopy and an induction sensor. For near-infrared and visual spectroscopy software is required to create sorting models, while for induction only machine settings have to be adjusted and optimized for a specific sorting task. These sensors are installed in the experimental sensor-based sorting setup at the Chair of Waste Processing Technology and Waste Management located at the Montanuniversitaet Leoben. This sorting stand is a special designed machine for the university to make experiments on sensor-based sorting in lab scale. It can be used for a variety of waste streams depending on the grain size and the pre-conditioning for the sensor-based sorting machine. In detail the methods to create these sorting models are described and validated with plastic, glass and metal waste.•Near-infrared spectroscopy measures the molecular composition of near-infrared-active particles.•Visual spectroscopy measures the absorption of visible light by chemical compounds.•Induction sensors use induced currents to detect nearby metal objects.

Energy generation and revenue potential from municipal solid waste using system dynamic approach.

The Municipal Solid Waste (MSW) generation per capita in developing countries is generally said to grow in proportion to the gross national product. Composting and waste to energy have a brief history as management strategies for MSW in India and as alternatives to landfilling. Analysis of Energy generation and compost potential from waste can minimize the impact of MSW on the environment with the added advantage of providing a local source of energy. The study has been carried out to develop a system dynamic (SD) model to predict the energy generation, treatment, and cost analysis for MSW up to 2030. The predictive model developed in this study showed the generation rate of electrical energy potential augmented from 0 in 2001 to 58,380 MWh in 2007 and 319,875 MWh in 2030. Whereas, the production rate of compost reduced from 77,000 tonnes in 2001 to 45,000 tonnes in 2006 and then improved to 390,000 tonnes in 2030. In addition, the predicted revenue generated from different treatment facilities increased from 0 in 2001 to Rs.335 million (4.36 million USD) in 2007 and Rs.2569 million (33.4 million USD) in 2030. As a result, revenue generated could cover the budgets required for MSW treatment and disposal services in 2030, where the required budget is negative because revenue exceeds expenditures. The developed SD model can improve a municipal solid waste management system for any City.

Implementation of an early warning system with hyperspectral imaging combined with deep learning model for chlorine in refuse derived fuels.

Chlorine content is one of the most important parameters in Refuse Derived Fuels (RDFs) used as a fuel in cement kilns. The main problem with the use of RDF is that chlorine in the waste weakens the cement, increases the risk of corrosion in the kiln and forms toxic gas emissions. Alternative fuels containing high amounts of chlorine, such as plastic waste should be used in limited quantities with the quality of the kiln used and the cement being should be preserved by preparing the appropriate RDF mixture. Analyses conducted on the samples taken before the RDF is given to the furnace are time consuming and costly. Therefore, in this study, the aim is to present a more efficient solution to classify by using chlorine analysis results with hyperspectral imaging and a deep learning model study. For this purpose, a model was created using validated laboratory results and spectral data from samples, the model was tested on a prototype conveyor belt, and was implemented using an online early warning system for high chlorine concentrations. The chlorine content of the RDF samples used in the study ranged from 0.10% to 1.41%, with an average of 0.27%. According to the results, the accuracy, precision, Recall and F1 Score related to the early warning system were found to be 0.8909, 0.8889, 0.8889, 0.8889, respectively. In addition, chlorine measurements were performed at 200, 500 and 1000 mm/s belt speeds and accuracy values of 78.39%, 76.35% and 69.94 %, respectively were obtained.

Rotas tecnológicas, desafios e potencial para valoração energética de resíduo sólido urbano por coprocessamento no Brasil / Technological routes, challenges and potential for municipal solid waste energetic valorization by coprocessing in Brazil

RESUMO Mais de dez anos depois da implantação da Política Nacional de Resíduos Sólidos, por meio da Lei federal n° 12.305/2010, a elaboração e a execução de políticas públicas com resultados positivos na gestão dos resíduos sólidos urbanos são precárias. O coprocessamento desses produtos em fornos de clínquer pode ser uma alternativa viável para melhorar esse cenário, mas encontra diversas dificuldades de ordem técnica e econômica. Neste trabalho, estimou-se a composição e a gravimetria dos resíduos no Brasil com base em dados secundários, de forma a estimar o poder calorífico inferior resultante de diferentes formas de pré-tratamento desses produtos: triagem de orgânicos, triagem de orgânicos e inertes, secagem para redução da umidade e combinação das três estratégias. Com base nos valores obtidos de poder calorífico, estima-se a capacidade de coprocessamento de resíduos pré-tratados pelas indústrias nacionais que possuem licenciamento ambiental para essa atividade. O tratamento prévio dos resíduos resultou em aumentos entre 20 e 56% em relação ao cenário-base. Observou-se que, para o cenário sem triagem, mas com secagem térmica do resíduo, até 8% dos resíduos com destinação inadequada no Brasil atualmente podem ser recebidos por indústrias de cimento para o coprocessamento, desde que haja viabilidade técnica para sua substituição e transporte.

ABSTRACT More than ten years after the implementation of the Solid Waste Nacional Policy by Brazilian Federal Law nº 12.305/2010, elaboration and execution of public policies with positive results in Municipal Solid Waste management is precarious. Coprocessing of Municipal Solid Waste in cement kilns can be a viable alternative for improving this scenario, but still encounters many technical and economical challenges. In this study, an estimate of the mean gravimetric composition of Municipal Solid Waste in Brazil is presented, based on secondary data, so as to estimate the resultant lower heating value resultant of different Municipal Solid Waste pre-treatment alternatives; separation of the organic fraction, separation of organic and inert fraction, drying of Municipal Solid Waste and all strategies combined. Based on the obtained lower heating value, an estimate of the yearly potential of Municipal Solid Waste coprocessing in industries already licensed for coprocessing of waste in Brazil is presented. Pre-treatment of Municipal Solid Waste resulted in lower heating value improvements ranging from 20 to 56% when compared to the base scenario. It is observed that, in the scenario where the Municipal Solid Waste is dried but not triaged, up to 8% of the Municipal Solid Waste that is currently disposed inappropriately in Brazil could be received by cement industries for coprocessing, as long as there is technical feasibility for the substitution and transportation.

Characterization of municipal solid waste residues for hydrothermal liquefaction into liquid transportation fuels.

This paper presents and evaluates a new method for characterising municipal solid waste residues for assessing the performance of thermochemical conversion technologies to produce fuels. The method combines information from three complementary analytical techniques to estimate the quantity of key organic waste fractions and was demonstrated using two commercial waste residues: 'BRDF' and 'Floc' produced from the mechanical processing of domestic waste. Cellulose content (mostly paper and textiles) is estimated using acid hydrolysis, while thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) are combined to determine the plastics (LDPE and PET) and non-volatile fractions such as lignin of the wastes. High mass balance closures were achieved for both residues, although the nature of the non-volatile fraction was difficult to verify. Hydrothermal liquefaction (HTL) of cellulose rich BRDF (34.0% cellulose) produced much higher biooil yields than Floc (26.8% and 12.2%, respectively), with a cellulose content of only 22.4%. In both cases, most of the plastic and non-volatile waste fractions partitioned into the solid HTL product, representing a potential method for separating the plastic fractions from other waste components. Importantly, this combined waste characterization method can be used for characterization of any municipal waste residue using acid hydrolysis, TGA and FTIR data, providing accurate information about feedstock composition. It enables comparison between different waste valorisation studies of complex waste residues.