Perancangan dan Evaluasi Sistem Terintegrasi Wet Scrubber dan Biofilter untuk Pengendalian Emisi Asap Penyangraian Biji Kopi

Abstract

Proses penyangraian kopi menghasilkan emisi karbon monoksida (CO), senyawa organik volatil (VOC), partikulat, aerosol minyak, dan senyawa penyebab bau. Penelitian ini bertujuan mengidentifikasi karakteristik emisi, merancang sistem pengendalian terintegrasi, mengevaluasi kinerjanya, dan menyusun skema pengelolaan limbah sekunder. Sistem terdiri atas cyclone, venturi self-induced wet scrubber, dan biofilter. Pengujian dilakukan pada kapasitas penyangraian 500 dan 1.250 g dengan pengukuran CO dan VOC pada outlet cyclone, scrubber, dan biofilter menggunakan multigas detector dengan photoionization detector. Konsentrasi emisi cenderung meningkat pada tahap akhir penyangraian dan lebih tinggi pada kapasitas 1.250 g. Wet scrubber menurunkan suhu gas dari sekitar 150–200°C menjadi 31–34°C. Pada kapasitas 500 dan 1.250 g, efisiensi wet scrubber masing-masing mencapai 90% dan 79% untuk CO serta 92% dan 76% untuk VOC. Efisiensi keseluruhan sistem mencapai 96% untuk CO dan VOC. Limbah cair dirancang diolah melalui sedimentasi dan rotary drum filter agar sebagian air dapat disirkulasikan kembali. Sistem berpotensi diterapkan sebagai teknologi pengendalian emisi nontermal pada industri penyangraian kopi skala kecil, meskipun masih memerlukan validasi berdasarkan laju massa polutan dan pengujian pada kapasitas penuh.

Coffee roasting generates carbon monoxide (CO), volatile organic compounds (VOCs), particulate matter, oil aerosols, and odor-causing compounds. This study aimed to characterize roasting emissions, design an integrated emission-control system, evaluate its performance, and develop a secondary-waste management scheme. The system consisted of a cyclone, a self-induced Venturi wet scrubber, and a biofilter. Tests were conducted at roasting loads of 500 and 1,250 g, with CO and VOC concentrations measured at the cyclone, scrubber, and biofilter outlets using a multigas detector equipped with a photoionization detector. Emissions generally increased during the final roasting stage and were higher at the 1,250 g load. The wet scrubber reduced gas temperature from approximately 150–200°C to 31–34°C. At loads of 500 and 1,250 g, scrubber efficiencies reached 90% and 79% for CO and 92% and 76% for VOCs, respectively. Overall system efficiencies were 96% for CO and VOCs. Wastewater was designed to undergo sedimentation and rotary drum filtration to enable partial water recirculation. The system shows potential as a non-thermal emission-control technology for small-scale coffee roasting, although validation based on pollutant mass flow and full-capacity testing is still required.