Desain Proses Konversi Limbah Kelapa Sawit Menjadi Pupuk (fertilizer) dalam Kerangka Penerapan Ekonomi Sirkular

Abstract

Peningkatan produksi industri kelapa sawit menghasilkan limbah yang terus meningkat, limbah utamanya berupa tandan kosong kelapa sawit dan palm oil mill effluent. Teknologi seperti elektrokoagulasi, pirolisis, dan adsorpsi digunakan untuk mengolah limbah ini, namun masih menghasilkan limbah akhir berupa sludge dan biochar jenuh. Penelitian ini fokus pada karakterisasi dan konversi limbah akhir kelapa sawit, yaitu sludge dan biochar jenuh menjadi pupuk organik. Dalam basis basah, Sludge memiliki pH 7,5, C-organik 43,36%, rasio C/N 9,403 dan unsur NPK 5,226%. Biochar jenuh memiliki pH 10, C-organik 75,13%, rasio C/N 2,968, NPK 23,898%, Mg 0,2%, K 0,6%, Ca 0,4%, Si 0,3%, dan Al 0,2%. Meski hampir seluruh kriteria pupuk organik terpenuhi, kadar air sludge 61,32% dan biochar jenuh 34,96% masih belum memenuhi dan memerlukan penanganan lebih lanjut. Pengolahan lanjutan melibatkan pengeringan dengan unit sludge drying bed dan bak pengeringan menggunakan rumah kaca dan solar system, dengan efisiensi pengeringan dalam 2,66 hari untuk sludge dan 18 jam untuk biochar jenuh. Solusi ini berpotensi menghasilkan 5390,18 ton/tahun pupuk organik dengan kadar air sludge 15.28% dan biochar 9,16% (basis basah), yang berpotensi menggantikan kebutuhan pupuk sintetis di PKS, berpotensi menjadi sumber pendapatan tambahan dari penjualan surplus pupuk, lapangan tenaga kerja baru, pemenuhan regulasi lingkungan, menutrisi tanaman, memperbaiki struktur tanah, carbon sequestration hingga 631,52 ton/tahun, mengurangi cemaran dan beban lingkungan yang sejalan dengan konsep ekonomi sirkular bagi industri kelapa sawit.

The increasing production of the palm oil industry generates an increasing amount of waste, mainly in the form of oil palm empty fruit bunches and palm oil mill effluent. Technologies such as electrocoagulation, pyrolysis, and adsorption are used to treat these wastes, but still produce final wastes in the form of sludge and saturated biochar. This research focuses on the characterization and conversion of palm oil final waste into organic fertilizer. In wet base, sludge has pH 7.5, C-organic 43.36%, C/N ratio 9.403 and NPK nutrients 5.226%. Saturated biochar had a pH of 10, C-organic 75.13%, C/N ratio 2.968, NPK nutrients 23,898%, Mg 0.2%, K 0.6%, Ca 0.4%, Si 0.3%, Al 0.2%. Although almost all organic fertilizer criteria are met, the sludge moisture content of 61.32% and saturated biochar of 34.96% still do not meet required. Advanced processing involves sludge drying bed units and drying tubs using greenhouses and solar systems, with a drying efficiency of 2.66 days for sludges and 18 hours for saturated biochar. This solution has the potential to produce 5390,18 tons/year of organic fertilizer, potentially replace the need for synthetic fertilizers at the mill scale, becoming income and profit from fertilizer sales, employment and environmental benefits such as nourishing plants, improving soil structure, carbon sequestration up to 631,52 tonnes/year, reducing environmental contamination, in line with the concept of a circular economy for the palm oil industry.