Refuse Derived Fuel Research Articles

Composition and characteristics of excavated materials from a legacy waste dumpsite: Potential of landfill biomining

Landfill biomining (LFBM) has been proposed as a viable method for the reclamation of legacy waste dumpsites as well as the subsequent recovery of valuable resources and land value spaces. Despite these advantages, the potential of LFBM faces a significant challenge due to the composition, characteristics and end-use of the excavated materials. This paper assesses the composition of the excavated waste obtained during the LFBM operation of the four legacy waste heaps at the Boragaon dumpsite in North-East India and determines the physicochemical characteristics crucial for the material and energy recovery from the key reclaimed fractions. The compositional analysis revealed that the proportion of combustible and non-combustible fractions decreases from the youngest heap HP4 to the oldest heap HP1 due to variations in the consumption habits of the local community and the inadequate recycling of recyclable materials. However, the proportion of fine fraction (FF) shows an increasing trend from HP4 to HP1, suggesting enhanced biodegradation of easily degradable waste over the years. The proximate and energy content analysis suggest that refuse-derived fuel (RDF) preparation is the most suitable valorization option for the combustible fractions since surface defilements are too high for good quality material recovery. The elevated amount of organic matter and leachable heavy metals indicate that unrestricted reuse of FF as earth-fill material can cause long-term settlements and groundwater contamination, respectively. Even though every dumpsite is different in characteristics, the findings of this case study can assist in developing new strategies for recycling excavated waste.

Characteristics of Refuse-Derived Fuel (RDF) at The Waste Processing Facility (WPF) of The Faculty of Engineering, Untirta

Characteristics of Refuse-Derived Fuel (RDF) at The Waste Processing Facility (WPF) of The Faculty of Engineering, Untirta

Optimization of Integrated Solid Refuse Fuel and Solid Oxide Electrolyzer Cell System for Hydrogen Production

In this study, a performance predictive model for hydrogen production was developed for the commercialization of the integrated solid refuse fuel (SRF) and solid oxide electrolyzer cell (SOEC) system. A SRF system was developed, and reliability was verified in the steam conditions for the SOEC application. Systems optimization according to parametric analysis was conducted in the predictive model based on the experiments. When the steam temperature varies between 973 and 1,373 K, hydrogen production increases by 14% to 64 tons per year at 1,373 K; meanwhile, when the steam pressure varies between 0.1 and 0.7 MPa, the performance deteriorates significantly. Under optimal conditions (temperature: 1,373 K; pressure: 0.3 MPa; mass flow rate 200 kg/h), the amount of steam that can be produced by the integrated SRF–SOEC system is 1,752 tons per year, which can yield 87.6 tons of hydrogen per year. When SRF was used as a heat source, compared with the use of LNG, a total annual cost saving of approximately 2.6% was realized. The break-even point can be reduced by approximately 5 months, which reflects economic efficiency.

Determination of the statistical distribution of drag and lift coefficients of refuse derived fuel by computer vision

This research investigates the flight behavior of refuse-derived fuel (RDF) in a drop shaft using Computer Vision to obtain statistical data on the aerodynamic properties of the particles.Methods to determine 3D geometry models of complex-shaped particles by photogrammetry and to obtain time resolved particle positions and velocities are described. Furthermore, an approach to obtain the frequency distribution of drag and lift coefficients from photogrammetric analysis and drop shaft experiments is presented. The image evaluation is based on algorithms of the open-source libraries OpenCV, COLMAP as well as MeshLab and Open3D. The precision of the system is validated employing model particles with known geometry. The 3D particle models overestimate the particle surface area by 4.58 %, the position detection works with a mean deviation of 2.73 %. The average sink rate is calculated with an accuracy of 4.87 % and the drag coefficient with an accuracy of 2.08 %. Finally, the frequency distribution of four RDF fractions, namely, textiles, cardboard, 3D plastic particles and 2D plastic foils are presented.

Life cycle environmental and cost assessment of prefabricated components manufacture

Prefabrication is regarded as a pivot for realizing sustainable building construction. Nevertheless, the sustainable manufacture level of prefabricated components remains unclear. To fill this gap, this study analyzed the environmental impact and optimization potential of prefabricated components via a life cycle assessment (LCA) method. Additionally, social and economic cost were assessed through LCA-based life cycle costing method to reveal the sustainability of prefabricated components. Results indicated that prefabrication rates of 50% and 30% could reduce the potential global warming impact by 31.78% and 13.94%, respectively, compared with the conventional construction method. However, prefabricated components production in China generated up to $ 4.35 × 109 social cost, with critical optimization areas focused on the provinces of Shandong and Hubei. By using artificial neural network estimation, 30% replacement of concrete by demolished concrete lumps could reduce potential fossil depletion and social cost by 10%, decreasing 5.08 × 109 kg CO2 eq potential global warming for China. Meanwhile, partial replacement of fuels with refuse-derived fuels and improved steel scrap utilization could contribute to further improving environmental performance.

Techno-economic Analysis of co-firing waste Refused Derived Fuel (RDF) in coal-fired power plant

Massive efforts have been made to reduce CO2 emissions around the world from the used of fossil fuels by seeking alternative fossil fuels in power plants. The utilization of waste in the energy sector with co-firing technology is one way to reduce the impact on the environment. The Indonesian government is currently issuing SNI 8966:2021 to take advantage by using of biomass waste as raw material for making Refused Derived Fuel or RDF in power plants (BSN, 2021. RDF which has a calorific value of 1800 kcal/kg will be tested in PLTU Indramayu which the coal has caloric value 4100 kcal/kg. The mass ratio for blending is 1% RDF and 99% Coal. This study aims to analyze the feasibility of economical, operational, and environmental if co-firing test carried out with waste RDF at PLTU. RDF is processed from waste using the concept of collaboration with DLH Indramayu. RDF processing site is carried out at PDU Indramayu using the peuyeumization method. Within 11 days, the plant produced RDF 14 tons which will be supplied as mixed fuel for co-firing PLTU Indramayu. Operational observations at the Indramayu PLTU during the 1% BBJP co-firing process showed parameters that were still within operational safe limits, but there was an increase in SO2 and NOx emissions which were still below the KLHK emission standards. The results of the techno-economic analysis show that if there is an increase in LCOE of 0.16-rupiah in the co-firing test with 1% BBJP, while for the Net Present Value (NPV) parameter a value of Rp.40,437,359 is obtained, the Internal rate return (IRR) parameter is 8.25%, the Profitability index (PI) parameter is 1.011 and the last payback period (PBP) is 6.63 years indicating the feasibility of investing in the BBJP processing project. From an economic point of view, the surrounding community provides opportunities for employment and business provision of consumable materials for BBJP processing projects.

Possibility of Municipal Waste Management with Refuse-Derived Fuel (RDF) Mixed Paper and Garden in Depok City

Paper and garden waste is one of the types of waste that can be found in big cities in Indonesia, one of which is Depok City. Garbage collectors can recycle not all paper waste into new products. In addition, garden waste is also garbage, one of the wastes found produced every day from gardening activities. This study aimed to analyze the potential for reducing the use of paper and garden waste to be used as RDF in Depok City. This study analyzes the quality of RDF based on the parameters of water content, ash content, density, and calorific value resulting from the material substitution. The results were analyzed using the multicollinearity method and the Kepner-Tregoe Decision Analysis (KTDA). The results of the multicollinearity test show that the ash content and water content can reduce the calorific value of RDF mixed with paper and garden waste. The addition of garden waste composition can increase the calorific value. Based on the results of decision analysis using KTDA, it shows that the variation of the mixture of 75% paper waste and 25% wood waste has the largest points compared to other variations. Material Flow Analysis (MFA) utilization of this waste can reduce the generation of paper waste and garden waste by 3.5% and 12.3%, respectively.

Simulation and experimental study of refuse-derived fuel gasification in an updraft gasifier

Refuse-derived fuel (RDF) made from the mixture of wood and loose rice husk increases the porosity of the fuel in the furnace to facilitate the gasification process. Simulation results show that CO is concentrated in the incomplete combustion zone and CO2 forms mainly in the fully burned area; CH4 forms in the reduction region, while H2 forms in the region of high temperature of the furnace. When the mixture composition was f=0.3, the CO concentration in the syngas reached about 21%, the H2 concentration reached about 2% and the CH4 concentration was too low to be ignored. When the mixture composition increased to f = 0.5, the CO concentration reached about 26%, the H2 concentration remained almost unchanged and the CH4 content increased to 6%. The calorific value of the syngas reached a maximum when f = 0.5 and the temperature of the reduction zone is in the range of 900K to 1200K. Air humidity affects CO concentration but not much on CH4 and H2 concentration as well as the syngas calorific value. The difference between simulation and experimental results is not more than 10% for CH4 concentration and not more than 14% for CO2 concentration. The power of the spark ignition engine is reduced by 30% when running on syngas compared to when running on gasoline.

Characteristics of Density and Hardness on Caloric Value of Substitution of Biomass and Pet Plastics as Refused Derived Fuel Pellets

The utilization of biomass and polyethylene terephthalate (PET) waste as raw material for refuse-derived fuel (RDF) has been studied. However, physical such as density and hardness are still not widely used. This study aimed to determine the relationship between variations in the composition of PET and physical garden waste density and hardness on the quality of the caloric value of RDF. Density measurements were carried out with the Ultrapyc 1200e instrument. While for hardness, using the Shore D method. The Shore D Hardness test is a standardized test that involves evaluating the amount of depth that may be penetrated by a certain indentation. The lowest density is RDF pellets for food waste at 1,537 kg/m3 and consists of RDF pellets for plastic waste at 2,560 kg/m3. In line with the density, the hardness value increases with the addition of the PET composition. The density and hardness values in the RDF mixture show a simultaneous relationship to the heating value. The highest caloric value achieved is the use of 100% PET as pellets which can reach 5765 kcal/kg.

A Novel Plenoptic Camera-Based Measurement System for the Investigation into Flight and Combustion Behavior of Refuse-Derived Fuel Particles.

In the past several decades, refuse-derived fuels (RDFs) have been widely applied in industrial combustion processes, for instance, in cement production. Since RDF is composed of various waste fractions with complex shapes, its flight and combustion behaviors can be relatively complicated. In this paper, we present a novel plenoptic camera-based spatial measurement system that uses image processing approaches to determine the dwell time, the space-sliced velocity in the depth direction, and the ignition time of various applied RDF fractions based on the obtained images. The image processing approach follows the concept of tracking-by-detection and includes a novel combined detection method, a 2.5D multiple particle tracking algorithm, and a postprocessing framework to tackle the issues in the initial tracking results. The thereby obtained complete spatial fuel trajectories enable the analysis of the flight behaviors elaborated in the paper. The acquired particles' properties (duration, velocity, and ignition time) reversely prove the availability and applicability of the developed measurement system. The adequacy and accuracy of the proposed novel measurement system are validated by the experiments of detecting and tracking burning and nonburning fuel particles in a rotary kiln. This new measurement system and the provided experimental results can benefit a better understanding of the RDF's combustion for future research.

Plastic Waste Management to Support The Circular Economy in The Pulp and Paper Industry

The pulp and paper industry is one of the leading sectors that can grow significantly due to the application of advanced technology. The development of recycled paper follows the development of the pulp and paper industry in Indonesia. The trend towards sustainability in the pulp and paper industry drives waste paper recycling. This study aims to provide recommendations for technology in waste treatment in the pulp and paper industry from the perspective of the circular economy and Sustainable Development Goals (SDGs). This research method uses a systematic literature review with descriptive and qualitative data. The research result shows that mechanical and chemical recycling methods were found in the literature. Most of the technologies are used to make alternative use of waste, such as construction material use, pyrolysis, gas-forming, Refuse Derived Fuel (RDF), incinerator, and other alternative use. Appropriate technology applied to plastic waste management should be encouraged to support a circular economy and five potential SDGs out of seventeen goals: SDG 3, SDG 6, SDG 9, SDG 12, and SDG 13. In times of diverse growth in technologies and advanced knowledge, Internet of Things (IoT) and Artificial Intelligence (AI) may be possible for relevant future research needs or reshaping the existing research. Keywords: circular economy, plastic waste management, pulp and paper waste management, sdgs, waste to energy

A Study on the Solid Refuse Fuel Characteristics of Bio-Waste Using Automatically Controlled Drying Process

A Study on the Solid Refuse Fuel Characteristics of Bio-Waste Using Automatically Controlled Drying Process

Production and characteristics of refuse derived fuel from open-dump solid waste

The objective of this study was to explore the utilization of open-dump solid waste by refuse-derived fuel (RDF) production. Eight RDF samples with different composition percentages were produced. The experimental results indicated that bulk density of eight RDF samples including RDF-A, RDF-B, RDF-C, RDF-D, RDF-E, RDF-F, RDF-G and RDF-H yield in range of 118–259 kg/m3. These were comparable to some kinds of biomass such as sawdust, soft wood chips and baled straw. Heating value, moisture content, volatile matter, ash residue, and fixed carbon were in the range of 28.34–30.93 MJ/kg, 0.00–1.47 %, 85.55–90.71 %, 5.97–10.02 % and 2.53–5.06 %, respectively. Metal compositions, such as Cr, Cu, Zn, Mn and Pb yielded lower values than values of the European RDF quality standard. For the experimental combustion results, it was shown that the emissions of CO, SO2, NO, and HCl were below the standard criteria of the Pollution Control Department.

Alternative Fuels Substitution in Cement Industries for Improved Energy Efficiency and Sustainability

The conventional energy source in cement industries is fossil fuels, mainly coal, which has a high environmental footprint. On average, energy expenditures account for 40% of the overall production costs per ton of cement. Reducing both the environmental impact and economic expenditure involves incorporating alternative energy sources (fuels) such as biomass, solid-derived fuel (SDF), refuse-derived fuel (RDF) etc. However, within cement plants, the substitution of conventional fossil fuels with alternative fuels poses several challenges due to the difficulty in incorporating additional fuel-saving techniques. Typically, an additional 3000 MJ of electricity per ton of clinker is required. One of the most effective solutions to this is thermal optimization through co-processing and pre-processing, which makes it possible to implement additional fossil-fuel-saving techniques. In developing nations such as Togo, waste-management systems rely on co-processing in cement factories through a waste-to-energy relationship. Also, there are some old cement plants with low-efficiency, multi-stage preheaters without pre-calciners, reciprocating huge coolers, low-efficiency motors etc., which still operate and need to be made environmentally sustainable. However, compared to modern kilns which can have up to 95% of energy recovery from waste, an old suspension preheater kiln can recover only up to 60% of its heat energy depending on the cooler type, and due to the lack of a bypass and combustion chamber (pre-calciner). This research paper evaluated the performance of a cement plant incorporating AF and presents the procedures and recommendations to optimize AF substitution in cement plants. To achieve this, a comparative performance study was carried out by assessing the alternative fuel characteristics and the equipment performance before and after the incorporation of the alternative fuel. Data were collected on the optimum substitution ratio, pre-processing and co-processing performance, raw-meal design and economic analysis. Results indicated that the cost to be covered per ton of waste input is €10.9 for solid-derived fuel (SDF), €15 for refuse-derived fuel (RDF), and that the co-processing cost optimization for the cement plant could have a cost saving of up to 7.81€/GJ. In conclusion, it is recommended that appropriate kiln and alternative-fuel models be created for forecasting production based on various AF.

Refuse derived fuel hydrogasification coupled with methane steam reforming

The hydrogasification of Refuse Derived Fuel (RDF) consisting of non-recyclable plastic polymers was combined with methane steam reforming in a “hydrogen self-sustained” loop configuration. The hydrogasification unit fed by 1000 kg/h of RDF was initially modeled by Aspen plus to define best operating conditions, namely temperature, pressure and hydrogen feed flow rate. After the simulations, the temperature of the hydrogasification process has been fixed at 300 °C, the pressure at 10 bar and the hydrogen feed flow rate at 140 kg/h. The steam reforming unit operates at 850 °C while the water-gas shift is conducted at 350 °C. When all the methane produced by hydrogasification is used to feed the steam reformer, which yields H2 that is recycled back to the hydrogasifier, the net hydrogen production is 222 kg/h with an amount of CO2 released of 2265 kg/h. For the different process configurations adopted, the energy efficiency of the process ranges 84–89%.

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.

Refuse-derived fuel-3 production simulation using network flow modeling: Predicting the uncertainty in quality standards

Municipal solid waste management requires intelligent and integrated decision-making to achieve sustainable waste treatment processes. In particular, a waste treatment system that transforms municipal solid wastes into a commodity called refuse-derived fuel (RDF) is being researched as a promising waste to energy solution. This waste processing faces limitations in maintaining consistent production and quality control standards of RDF. In this context, a network flow modeling technique is used to design a stochastic discrete-event simulation model for the production in a general material recovery facility (MRF) to evaluate its performance. The developed model supports revisions in the strategic, tactical, and operational decision levels and is integrated with varied uncertainties like probability distributions of in-feed waste compositions, moisture content, and calorific value of individual waste components, affecting the energy performance of a MRF. The model provides improvements to operating conditions and enables prediction for quality standards of RDF, enabling the waste management authority to meet their outlined quality specification for the final product. The validation of the model is conducted in a way, where the quality measures of the final product collected from an MRF are compared with the estimated values those from the simulation. The comparison reveals that precision in results from the developed model, in all performed tests is consistent with actual observed results, inferring the developed simulation model as a viable tool for estimating quality measures for RDF. The foundations of the model are based of assumptions like emphasis on general representation but not physical properties of MRF, only selected sets of uncertainties are studied, and variations in the operating conditions can affect estimated quality of RDF.

Modification of the Aeration-Supplied Configuration in the Biodrying Process for Refuse-Derived Fuel (RDF) Production

Biodrying is an essential part of the mechanical–biological treatment process that minimizes moisture content and simultaneously maximizes heating value for refuse-derived fuel (RDF) production. Although the mechanical separation process operates effectively in Thailand’s RDF production, high organic content levels and their degradation cause moisture contamination in RDF, producing wet RDF. Aeration is essential for an effective biodrying process, and can reduce RDF’s moisture content as well as increase its heating value. To maximize the biodrying effect, aeration should be optimized based on the waste conditions. This study proposes a modified aeration-supplied configuration for wet RDF biodrying. The aeration rate was modified based on the period within the biodrying operation; the first period is from the beginning until day 2.5, and the second period is from day 2.5 to day 5. The optimal aeration supply configuration was 0.5 m3/kg/day in the first period and then 0.3 m3/kg/day until the end of the process; this configuration yielded the greatest moisture content decrease of 35% and increased the low heating value of the biodried product by 11%. The final moisture content and low heating value were 24.07% and 4787 kcal/kg, respectively. Therefore, this optimal aeration-supplied configuration could be applied to meet the moisture content and low heating value requirements of the RDF production standard for Thailand’s local cement industry.

IN SEARCH OF THE MATERIAL COMPOSITION OF REFUSE-DERIVED FUELS BY MEANS OF DATA RECONCILIATION AND GRAPHICAL REPRESENTATION

Differenciating between material fractions in refuse-derived fuels (RDF) is relevant to determining the climate relevance of RDF (fractions of biomass and fossil matter). This differentiation is associated with analytical challenges. A method was applied using balance equations, which contain the elemental composition (C, H, N, S, O) of the RDF and the sought for material fractions. For the first time this so-called adapted Balance Method (aBM) was applied to oil-contaminated RDF with the aim of not only distinguishing between biomass and fossil matter but between fossil matter from plastics and from oil-contamination as well. Thus, the balance equations and the following data reconciliation was adapted. It is shown that the balance method is based on mathematics that provides valuable insight far beyond the basic types of calculation since the calculation takes place in higher dimensions. It is also shown that the operation of the algorithm can be represented graphically in the lower third dimension. The mass of oil contamination as well as the mass of biogenic and fossil matter could be determined for the RDF considered. Problems concerning relatively high uncertainties still need to be solved due to the similar elemental composition of plastics and oil. However, it is shown that the aBM is capable of distinguishing between more than two material fractions in RDF, which the other available methods cannot and which can be relevant for greenhouse gas reporting but also for process control purposes.

The Possibility of Achieving Zero CO2 Emission in the Indonesian Cement Industry by 2050: A Stakeholder System Dynamic Perspective

According to the SDG on climate change, Indonesia is expected to achieve net-zero emissions by 2060 or sooner, as outlined in the long-term low-carbon and climate resilience strategies implemented by the country’s president. Therefore, this research aims to apply the system dynamic model to simulate sustainable targets for CO2 emission reductions until 2050. The simulation was limited to factors influencing the cement industry’s CO2, as described in the IEA’s recommendations, and the scenarios were based on the AHP (analytical hierarchy process) results from the stakeholders. The simulation results showed that the realistic target for sustainable CO2 emission reduction in Indonesia by 2050 was the scenario from the combined stakeholders with 450 kgCO2eq/ton cement, corresponding to a 27% decrease in emissions from the 2020 baseline. This serves as input for interested parties to showcase the efforts of reducing CO2 emissions, and provides recommendations for the achievements by (1) determining carbon taxes and revising cement product standards to further increase the clinker substitution rate; (2) developing an RDF (refused derived fuel) waste-processing plant independently to increase alternative fuel use; (3) ensuring the efficiency of electrical energy by increasing renewable energy sources; (4) integrating carbon capture and storage technology in cement plants.