Studi Numerik Distribusi Temperatur Dan Karakteristik Emisi Nox, Co₂, Dan H₂O Pada Co-Firing Amonia Menggunakan Drop Tube Furnace

Al Hakim, Winandra Fajar (2025) Studi Numerik Distribusi Temperatur Dan Karakteristik Emisi Nox, Co₂, Dan H₂O Pada Co-Firing Amonia Menggunakan Drop Tube Furnace. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Krisis energi global dan meningkatnya emisi gas rumah kaca yang disebabkan karena CO2. Hal ini mendorong pengembangan teknologi pembangkit listrik yang lebih ramah lingkungan. Salah satu pendekatan dengan melakukan co-firing, yaitu pembakaran campuran batubara dengan bahan bakar batubara dengan bahan bakar ramah lingkungan seperti amonia (NH₃). Penelitian ini bertujuan menganalisis karakteristik pembakaran co-firing batubara–amonia menggunakan Drop Tube Furnace (DTF) melalui simulasi numerik berbasis Computational Fluid Dynamics (CFD). Variasi rasio campuran amonia yang digunakan adalah 25%, 50%, dan 75% terhadap batubara. Analisis difokuskan pada distribusi temperatur, pembentukan emisi NOx, H₂O, dan CO₂, serta pengaruhnya terhadap karakteristik pembakaran. Hasil simulasi menunjukkan bahwa peningkatan rasio amonia menurunkan temperatur puncak di DTF dari 1334 °C (100% batubara) menjadi sekitar 1224 °C pada campuran 75% NH₃ dengan disertai pergeseran zona pembakaran akibat laju penyalaan amonia lebih tinggi dibandingkan dengan batubara. Hal ini menyebabkan adanya delay combustion. Emisi NOx meningkat signifikan, dengan nilai maksimum mencapai 0.002935 kg/kg gas pada campuran 25% NH₃, sejalan dengan tingginya kandungan nitrogen pada amonia. Fraksi massa H₂O tertinggi tercatat sebesar 0,24 pada campuran 25% NH₃, kemudian menurun pada rasio lebih tinggi akibat penurunan temperatur dan pembakaran yang tidak sempurna. Sementara itu, fraksi massa CO₂ menurun drastis seiring bertambahnya NH₃, dari 0,16 (100% batubara) menjadi 0,02 pada 75% NH₃. Hasil ini membuktikan bahwa cofiring amonia dapat dilakukan dengan mempertimbangkan presentase karena adanya penurunan temperatur, delay combustion dan penambahan NOx pada ==================================================================================================================================
presentase amonia tinggi walaupun adanya penurunan CO2.
The global energy crisis and increasing greenhouse gas emissions caused by CO2 have encouraged the development of more environmentally friendly power generation technologies. One approach is co-firing, which is the combustion of a mixture of coal with environmentally friendly fuels such as ammonia (NH₃). This study aims to analyze the combustion characteristics of coal–ammonia co-firing using a Drop Tube Furnace (DTF) through numerical simulations based on Computational Fluid Dynamics (CFD). The variations in the ammonia mixture ratio used are 25%, 50%, and 75% to coal. The analysis focuses on temperature distribution, the formation of NOx, H₂O, and CO₂ emissions, and their effects on combustion characteristics. The simulation results show that increasing the ammonia ratio reduces the peak temperature in the DTF from 1334°C (100% coal) to around 1224°C in a 75% NH₃ mixture accompanied by a shift in the combustion zone due to the higher ignition rate of ammonia compared to coal. This causes a combustion delay. NOx emissions increased significantly, with a maximum value reaching 0.002935 kg/kg gas at a 25% NH₃ mixture, in line with the high nitrogen content of ammonia. The highest H₂O mass fraction was recorded at 0.24 at a 25% NH₃ mixture, then decreased at higher ratios due to decreased temperature and incomplete combustion. Meanwhile, the CO₂ mass fraction decreased drastically with increasing NH₃, from 0.16 (100% coal) to 0.02 at 75% NH₃. These results prove that ammonia cofiring can be carried out by considering the percentage due to the decrease in temperature, delayed combustion and the addition of NOx at high ammonia percentages despite the decrease in CO2

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	co-firing, ammonia, coal, NOx, CO₂, H₂O, temperature distribution, CFD
Subjects:	T Technology > TJ Mechanical engineering and machinery T Technology > TJ Mechanical engineering and machinery > TJ254.7 Combustion chambers T Technology > TJ Mechanical engineering and machinery > TJ808 Renewable energy sources. Energy harvesting.
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21101-(S2) Master Thesis
Depositing User:	Winandra Fajar Al Hakim
Date Deposited:	01 Aug 2025 07:35
Last Modified:	01 Aug 2025 07:35
URI:	http://repository.its.ac.id/id/eprint/125495

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