Description:
Abstract. Slagging and Fouling are the phenomena of sticking and accumulating coal ash which melts on the heat exchanger tube or boiler wall. These two phenomena can have a major impact on boiler operations, such as heat conduction problems, decreased boiler efficiency, pipe clogging, and pipe damage. The characteristics of coal as a fuel are determined through a proximate testing process, ultimate testing, ash analysis, and AFT (Ash Fusion Temperature). The determination of the occurrence of slagging and fouling is influenced by the melting point of the ash, the element of coal ash, and the ratio of acidic and alkaline oxides. This study aims to determine the characteristics of coal used as basic data in calculating the Slagging index and the Fouling index to determine the characteristics of coal. The test methodology includes proximate analysis and ultimate analysis, as well as AFT (Ash Fusion Temperature) analysis and ash element analysis. Slagging and fouling is influenced by the melting point of the ash which is correlated with the combustion temperature. The Badcock and Wilcox method is used to determine the type of ash based on the ratio of acid to base, while the potential for Slagging and Fouling uses the calculation of the Slagging index and the Fouling index. From the results of testing the characteristics of coal, the results obtained in proximate testing, total moisture value of 36.69 %-17.54 %, inherent moisture 9.62 %-7.4 %, volatile matter 44.97 %-4.27 %, ash 13.61 %-0.76 %, and the value of fixed carbon 49.83 %-36.93 %. Ultimate testing of carbon content 76.47 %-69.94 %, hydrogen content 5.59 %-4.89 %, nitrogen content 1.65 %-1.34 %, oxygen content 23.26 %-16.1 %, and total sulfur 1.3 %-0.11 %, as well as analysis of heating values ranging from 12,609 BTU/lb (daf)-11,228 BTU/lb (daf). Sample S2 PB with lignite ash type has the largest Slagging index and Fouling index, Slagging index (Rs) 1,316.6 (medium), and Fouling index (Rf) 5.96 (high). Then the S1 KB sample of lignite ash type has the lowest Slagging index and Fouling index, the Slagging index (Rs) of 1,280.8 (medium), and the Fouling index (Rf) of 0.25 (low).Keywords: Characteristics of coal, Slagging, Fouling, melting temperature of ash.Abstrak. Slagging dan Fouling adalah fenomena menempel dan menumpuknya abu batubara yang melebur pada pipa penghantar panas (heat exchanger tube) ataupun dinding boiler. Kedua fenomena ini dapat memberikan dampak yang besar pada operasional boiler, yaitu masalah penghantaran panas, penurunan efisiensi boiler, tersumbatnya pipa, serta kerusakan pipa. Karakteristik batubara sebagai bahan bakar ditentukan melalui proses pengujian proksimat, pengujian ultimat, analisis abu, dan AFT (Ash Fusion Temperature). Potensi terjadinya Slagging dan Fouling dipengaruhi oleh titik leleh abu, unsur abu batubara, serta perbandingan oksida asam dan oksida basa. Penelitian ini bertujuan untuk mengetahui karakteristik batubara yang digunakan sebagai data dasar dalam perhitungan indeks Slagging dan indeks Fouling. Metodelogi pengujian meliputi analisis proksimat dan analisis ultimat, serta analisis AFT (Ash Fusion Temperature) dan analisis unsur abu. Keterbentukan Slagging dan Fouling dipengaruhi oleh titik leleh abu yang dikorelasikan dengan suhu pembakaran. Metode Badcock and Wilcox digunakan dalam mengetahui tipe abu berdasarkan rasio oksida asam dan basa, sedangkan potensi Slagging dan Fouling menggunakan perhitungan indeks Slagging dan indeks Fouling. Dari hasil pengujian karakteristik batubara didapatakan hasil pada pengujian proksimat, nilai kadar air total (Total Moisture) 36,69 %-17,54 %, kadar air (Inherent moisture) 9,62 %-7,4 %, zat terbang (Volatile matter) 44,97 %-4,27 %, abu (Ash) 13,61 %-0,76 %, dan nilai karbon tertambat (Fixed Carbon) 49,83 %-36,93 %. Pengujian ultimat kadar karbon 76,47 %-69,94 %, kadar hidrogen 5,59 %-4,89 %, kadar nitrogen 1,65 %-1,34 %, kadar oksigen 23,26 %-16,1 %, dan total sulfur 1,3 %-0,11 %, serta analisis nilai kalor berkisar dari 12.609 BTU/lb (daf)-11.228 BTU/lb (daf). Sampel S2 PB bertipe abu lignit memiliki indeks Slagging dan Indeks Fouling terbesar, indeks Slagging(Rs) sebesar 1.316,6 (menengah), dan indeks Fouling(Rf) sebesar 5,96 (tinggi). Kemudian sampel S1 KB bertipe abu lignit memiliki indeks Slagging dan Indeks Fouling terendah, indeks Slagging(Rs) sebesar 1.280.8 (menengah), dan indeks Fouling(Rf) sebesar 0,25 (rendah).Kata Kunci: Iklan, Kata Kunci: Karakteristik batubara,Slagging, Fouling, suhu leleh abu.