Biodrying Research Articles

Evaluation of Greenhouse Gas Emission Assessment Resulting from Processing Municipal Organic Waste into Bahan Bakar Jumputan Padat for Co-firing in Power Plants; Case Study: Bagendung Landfill Cilegon City

One type of biomass that can be used as fuel for co-firing in power plants is Bahan Bakar Jumputan Padat (BBJP)/Solid Waste Fuel. BBJP is a non-hazardous waste derivative that cannot be recycled. The production process of BBJP is strictly regulated by the Indonesian national standard (SNI) 8966:2021. The definition, characteristics and specifications of BBJP are much closer to Solid Recovered Fuel (SRF) than Refuse Derived Fuel (RDF). The utilization of BBJP reflects the dedication to reducing waste in landfills with a circular economy concept approach as well as the transition of the energy mix in Indonesia. To the present day, the production capacity of BBJP at Bagendung landfill in Cilegon City, Banten Province, has successfully produced 30 tons/day of organic municipal waste with an average BBJP product yield ranging between 11-15 tons/day. This research is intended to assess the Greenhouse Gas emissions (GHG) generated from the processing of municipal waste into BBJP. There are three main processes that produce GHG emissions, namely during bio drying processing, the use of machinery that produces emissions from electricity and the transportation process that produces combustion emissions in diesel fuel. As a result, direct GHG emissions arising from all waste processing activities into BBJP consist of 10 pollutants, namely CH4, N2O, CO, NH3, CO2, NOX, SO2, NVMOC, PM2.5 and ID(1,2,3,c,d)P. CO2 emission is the largest pollutant, accounting for 96.70% of the entire BBJP process.

Mini-review of inventory data for the dewatering and drying of sewage sludge.

Technological comparison and system modelling of sewage sludge treatment are important in terms of sustainable development and climate change mitigation. Dewatering and drying are important processes for reducing volume for transportation and often a requirement for further sludge treatment. Inventory data on mass transfers and material and energy consumptions are therefore crucial in improving and understanding sludge management systems. Reviewing the scientific literature (2003-2021) revealed 55 and 21 datasets on dewatering and drying of sewage sludge, respectively. The scarcity of data did not allow for identifying detailed relationships between inputs and outputs for the technologies, but the reviewed data can serve as the first port of call when planning sludge management. The average total solid (TS) content obtained was statistically different for mechanical dewatering (MDW), deep dewatering, bio-drying (BDR) and thermal drying (TDR). Loss of volatile solids (VS) during dewatering is barely described, but a substantial VS loss was observed for TDR (8%) and BDR (27%). The use of chemical agents in MDW showed typical values of 5-15 g kg-1 TS. The use of energy is low for MDW (average of 0.12 and 0.26 kWh kg-1 TS for raw and digested sludges, respectively) but substantially higher for TDR (average of 3.8 kWh kg-1 TS). The justified inventory data for sludge dewatering and drying provide essential support to system modelling and technological comparison in future studies, but additional data from full-scale plants on energy consumption and the composition of removed water are strongly requested to improve the inventory.

Comparative Analysis of Municipal Solid Waste to RDF Pretreatment Methods in Indonesia

Municipal solid waste in Indonesia has a high potential to be used as an alternative energy source. One of the methods is by producing refuse-derived fuel (RDF) as coal substitution. Pre-treatment is needed to reduce high water content in domestic waste, especially in Indonesia, to produce high-quality RDF. This study compares and analyzes the optimal pre-treatment method to produce RDF from domestic waste based on each RDF product characteristic. The research reviewed and analyzed the data of RDF characteristics of various pre-treatment methods applied in Indonesia from pilot-scale experiments as primary data and previous research as secondary data. The methods compared are fermentation method, sun-drying, and bio drying. RDF from each method was tested to collect the proximate and ultimate characteristics data. Statistical analysis of RDF characteristics is carried out to determine whether there is a significant difference from different pre-treatment methods. This analysis shows no significant effect on the difference in the characteristics of the RDF. RDF from bio drying provides the highest average number of calorific values and lowest moisture content. The study concluded that the bio drying method is recommended in more waste treatment facilities in Indonesia to increase waste as an alternative energy resource.

Comparison of temperature and oxygen concentration driven aeration methods for biodrying of municipal solid waste

In this study, we used a model bio drying reactor to optimize the drying of municipal solid waste (MSW). Two methods of aeration were used: one involved controlling the concentration of oxygen (16–20%) and the other the temperature in the upper part of the reactor (temperature 42–45 °C, oxygen concentration 16– 20%). In terms of moisture content, the highest increase recorded was 0.94% and the highest decrease was 27.54%. The highest decrease in lower calorific value recorded was 9.23% and the highest increase was 41.12%. The energy balance in all the trial runs was positive. We noted that aeration using different concentrations of oxygen is strongly influenced by organic content. Thus, it is suitable only for drying wastes with known and stable compositions. The outcomes of the different methods used were influenced by ambient relative air humidity. Moisture gradients, which are often described in the literature, were not consistently reproduced in this study.

English

English

Addition of Solid Recovered Fuel (SRF) to the Bio-drying Process and the Effects of Variation in Air Discharge on Temperature Parameters and Urban Waste Water Content

Bio-drying is a technology used to reduce water content in waste using microorganisms that naturally increase the temperature in the decomposition process. With this process, the water content can drop more within a month. Bio-drying produces a product in the form of Solid Recovered Fuel (SRF) which is produced from partially degraded waste. To obtain a waste that is not fully stabilized and maintains a high biomass content, degradation of organic compounds is carried out partially. During the bio drying process, temperature affects the degradation process. Temperature affects the bio drying, which will also affect the bio drying product that is indicated by the value of water content. Therefore, in this study, the change of process parameters will be explained, which is in the form of temperature and water content, that is caused by the difference in the air discharge entering the reactor (0, 2, 4, and 6 l/m) with the initial water content of 60%-65%. After 30 days, the optimum airflow is 4 l/m with a decrease in water content of 58.29%; on the last day of the bio drying process (30th day).

Bio-drying Technology of Solid Waste to Reduce Greenhouse Gas

Bio-drying technology is a solid waste treatment with a decentralized system, in which solid waste will undergo biological-mechanical bioconversion. The heat generated from the aerobic decomposition process of organic compounds combined with excess air serves to drain solid waste. The bio-drying process will emit VOCs and other gases that potentially cause global warmings such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) gases. The research method used variation of airflow from 0, 2, 3, 4, 5, and 6 l/m. N2O gases were analyzed using Chromatography gas. The results showed that the bio-drying process was able to reduce the water content from 69% to 40% by the thirtieth day. N2O concentration difference between control (no aeration) and waste with bio-drying processing is 534.69 ppb and 175.48 ppb respectively at 1st day. N2O concentration are known when the bio drying process uses a 4 l / m discharge.

Potential application of biodrying to treat solid waste

The generation of solid waste around the world creates problems if not properly managed. The method of processing solid waste by burning or landfill is currently not optimal. The availability of land where the final processing (TPA) is critical, looking for a new TPA alternative will be difficult and expensive, especially in big cities. The processing of solid waste using bio drying technology has the potential to produce renewable energy and prevention of climate change. Solid waste processing products can serve as Refuse Derived Fuel (RDF), reduce water content of solid waste, meningkatkan kualitas lindi and increase the amount of recycled solid waste that is not completely separated from home. Biodrying technology is capable of enhancing the partial disintegration and hydrolysis of macromolecule organic compounds (such as C-Organic, cellulose, hemicellulose, lignin, total nitrogen). The application of biodrying has the potential to reduce greenhouse gas emissions such as carbon dioxide (CO2), methane (CH4), and dinitrooksida (N2O). These gases cause global warming.