Judul: Technical and Financial Feasibility Analysis of Hydrothermal Technology for Urban Waste Treatment in Tangerang Regency
Abstrak: Peningkatan konsentrasi gas rumah kaca (GRK) di atmosfer telah menimbulkan efek pemanasan global. Salah satu kontributor emisi GRK adalah penumpukan sampah di TPA tanpa pengolahan lebih lanjut. TPA Jatiwaringin di Kabupaten Tangerang diprediksi akan mengalami overcapacity, sehingga diperlukan mitigasi untuk mengurangi sampah di TPA, salah satunya dengan teknologi hidrotermal. Namun penerapannya membutuhkan biaya yang tinggi. Penelitian ini bertujuan untuk mengestimasi potensi emisi GRK sebelum adanya proyek hidrotermal, mengestimasi potensi reduksi emisi GRK setelah adanya proyek hidrotermal, menganalisis kelayakan finansial dari proyek hidrotermal. Penelitian ini menggunakan metode Clean Development Mechanism (CDM) untuk mengestimasi potensi reduksi emisi GRK proyek hidrotermal dan analisis cashflow untuk mengevaluasi kelayakan finansialnya. Hasil penelitian ini menunjukkan emisi baseline pada tahun 2021 diestimasi sebesar 18.766 t CO2 e dan akan meningkat menjadi 21.865 t CO2 e (16,5%) pada tahun 2030. Emisi proyek diestimasi sebesar 5883 t CO2 e per tahun. Rata-rata persentase potensi reduksi emisi GRK dari proyek hidrotermal tahun 2021-2030 sebesar 70,94% (Skenario 2 putaran per hari) dan 68,26% (Skenario 3 putaran per hari). Proyek hidrotermal juga layak secara finansial, dengan syarat produk hidrotermal yaitu Refused Derived Fuel (RDF) dapat terjual setidaknya 72% dan jumlah iuran masyarakat yang terkumpul minimal 50% dari target penerimaan iuran., An increase in the atmospheric concentrations of greenhouse gases (GHGs) produces global warming effect. One of GHGs emissions contributors is waste accumulation of in the landfill. Jatiwaringin landfill in Tangerang Regency is predicted to reach overcapacity. Therefore, mitigation measures are required to reduce such waste. One of potential measures is hydrothermal treatment technology for urban scale, but its implementation is costly. This study aims to: estimate the potential GHGs emissions prior the hydrothermal project, estimate the potential GHGs emission reduction after the project, and analyze the financial feasibility of the project. This study employs Clean Development Mechanism (CDM) method to estimate the GHGs emissions reduction potential of hydrothermal projects and cashflow analysis to evaluate the project financial feasibility. The results show that baseline emissions in 2021 are estimated at 18,766 t CO2 e and would increase to 21,865 t CO2 e (16.5%) in 2030. The project emissions are estimated at 5883 t CO2 e per year. The GHGs emission reductions could reach 70.94% (2 batches per day) and 68.26% (3 batches per day) within 2021-2030. Furthermore, the hydrothermal project would be financially feasible, if the hydrothermal product i.e., Refused Derived Fuel (RDF) are sold at least 72% and the cumulative households- contribution is at least 50% of the target.
Keyword: GRK, sampah kota, sektor pengelolaan limbah, teknologi hidrotermal, GHGs, hydrothermal technology, urban waste, waste sector

Judul: The Potential Greenhouse Gas Emission from Galuga Landfill and Financial Feasibility of Refuse Derived Fuel Technology
Abstrak: Sejumlah kota menghadapi masalah serius akibat peningkatan volume sampah, keterbatasan daya tampung Tempat Pemrosesan Akhir (TPA), dan sistem pengeloaan sampah di TPA yang belum optimal. Timbulan sampah yang terus meningkat menyebabkan penumpukan sampah di TPA, berpotensi menyebabkan overcapacity, serta meningkatkan emisi gas rumah kaca (GRK). Sektor pengelolaan limbah berkontribusi terhadap peningkatan emisi GRK melalui sampah yang tidak terolah. Penelitian ini bertujuan untuk mengestimasi timbulan sampah Kota Bogor dan sampah yang masuk ke TPA Galuga, potensi emisi GRK yang dihasilkan dari TPA Galuga hingga tahun 2030, serta menganalisis kelayakan finansial rencana penerapan teknologi RDF yang dapat mereduksi jumlah sampah yang harus di landfill TPA Galuga. Penelitian ini menggunakan metode Multiple Linear Regression (MLR) untuk mengetahui faktor-faktor yang memengaruhi timbulan sampah dan mengestimasi jumlah sampah Kota Bogor yang masuk ke TPA Galuga hingga tahun 2030, Guidelines for National Greenhouse Gas Inventories Vol.5 (Waste) untuk mengestimasi potensi emisi GRK TPA Galuga, serta analisis kelayakan finansial untuk mengetahui kelayakan penerapan teknologi RDF. Hasil penelitian menunjukan jumlah sampah yang masuk ke TPA Galuga tahun 2022 sebesar 195.787,10 ton dan meningkat 2,43% pada tahun 2030 menjadi 200.544,26 ton. Potensi emisi GRK dari timbulan sampah TPA Galuga berkisar 109 kt CO2e pada tahun 2030, turun 29,48% dari tahun 2022. Rencana penerapan tekonologi RDF layak dijalankan secara finansial karena memenuhi kriteria kelayakan NPV, IRR, B/C Ratio, dan Payback Period., Many cities are facing serious problems due to increasing volume of waste, limited capacity of Final Processing Site (TPA), and waste management system at landfill that has not been optimal. The ever-increasing waste generation causes the accumulation of waste in landfills, which has the potential to cause overcapacity, as well as increase greenhouse gas (GHG) emissions. The waste management sector contributes to an increase in GHG emissions through untreated waste. This study aims to estimate Bogor City's waste generation and waste that goes to the Galuga landfill, the potential for GHG emissions generated from the Galuga landfill until 2030, as well as analyze the financial feasibility of Refuse Derived Fuel (RDF) technology implementation plan that can reduce the amount of waste that must be disposed of Galuga Landfill. This research employs three methods i.e., 1) multiple Linear Regression (MLR) to determine the factors that influence waste generation and estimate the accumulated municipality waste in Galuga landfill by 2030, 2) the IPCC guidelines for National Greenhouse Gas Inventories Volume 5 to estimate the potential GHG emission, and 3) financial feasibility analysis to assess the feasibility of RDF technology implemention. The results show that the amount of waste that goes to the Galuga TPA in 2022 is 195,787.10 tons and increases by 2.43% in 2030 to 200,544.26 tons. The potential for GHG emissions from the Galuga TPA waste generation is around 109 kt CO2e in 2030, decreases 29,48% from 2022. The plan to implement RDF technology is financially feasible because it meets the eligibility criteria for NPV, IRR, B/C Ratio, and Payback Period.
Keyword: emisi CH4, IPCC, multiple linear regression, perubahan iklim, sampah perkotaan, CH4 emission, climate change, municipal solid waste

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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