Studi Kelayakan Penerapan Blending Fuel Batubara-Ekstraks Ampas Kopi pada Ketel UAP DZL-20 di PT. DDD. jls [Internet]. 2019 Sep. 9 [cited 2025 Aug. 23];2(2):147-59. Available from: http://ejournal.lppm-unbaja.ac.id/index.php/jls/article/view/675