LIFE CYCLE ASSESSMENT PRODUKSI LISTRIK BERBASIS BIOGAS DARI LIMBAH CAIR AGROINDUSTRI

Agam Wira Sani, Ir. Muhammad Mufti Azis, ST, M.Sc., Ph.D., IPM.; Dr. Ir. Edi Iswanto Wiloso M.A.Sc.

2025 | Tesis | S2 Teknik Kimia

Penelitian ini menerapkan pendekatan Life Cycle Assessment (LCA) untuk mengevaluasi dampak lingkungan pembangkit listrik berbasis biogas dari limbah cair nanas dan tapioka di PT Great Giant Pineapple, Lampung. Unit fungsi yang digunakan adalah 1 kWh listrik dengan batas sistem meliputi budidaya, pengolahan agroindustri, anaerobic digestion (AD), kolam sedimentasi, serta pembangkit listrik Combined Heat and Power (CHP). Data primer dikumpulkan pada tahun 2023, mencakup emisi langsung dari proses AD, sedangkan data sekunder diperoleh dari literatur. Pemodelan dilakukan dengan openLCA 2.4 menggunakan database ecoinvent 3.11. Lima skenario dianalisis, mulai dari kondisi eksisting (93?tubara dan 7% biogas) hingga substitusi penuh biogas dengan strategi pemanfaatan limbah, yaitu penangkapan metana, pengomposan digestate padat, dan budidaya mikroalga dari digestate cair. Hasil menunjukkan bahwa sistem eksisting menghasilkan global warming potential (GWP) tertinggi sebesar 1,08 kg CO?-eq/kWh, sedangkan substitusi penuh biogas menurunkan GWP menjadi 0,742 kg CO?-eq/kWh. Skenario terpadu dengan pemanfaatan digestate lebih lanjut mampu menurunkan GWP hingga 0,165 kg CO?-eq/kWh, sekaligus mengurangi indikator ADF, CED, AP, dan EP secara signifikan. Temuan ini menunjukkan bahwa transisi energi dari batubara ke biogas, disertai optimalisasi pemanfaatan digestate, berpotensi menurunkan emisi hingga 87?n meningkatkan efisiensi sumber daya. Hasil penelitian ini memberikan dasar ilmiah bagi pengambilan keputusan dalam kebijakan energi, investasi, dan penerapan teknologi berkelanjutan di sektor agroindustri.

This study applies a Life Cycle Assessment (LCA) approach to evaluate the environmental impacts of biogas-based electricity generation from pineapple and cassava wastewater at PT Great Giant Pineapple, Lampung. The functional unit is defined as 1 kWh of electricity, with system boundaries covering cultivation, agro-industrial processing, anaerobic digestion (AD), sedimentation ponds, and electricity generation through a Combined Heat and Power (CHP) unit. Primary data were collected in 2023, including direct emissions from the AD process, while secondary data were obtained from literature sources. Modeling was conducted using openLCA 2.4 with the ecoinvent 3.11 database. Five scenarios were assessed, ranging from the existing system (93% coal and 7% biogas) to full biogas substitution combined with waste utilization strategies, including methane capture, composting of solid digestate, and microalgae cultivation from liquid digestate.  The results show that the existing system produces the highest global warming potential (GWP) at 1.08 kg CO?-eq/kWh. Full substitution with biogas reduces GWP to 0.742 kg CO?-eq/kWh, while the integrated scenario with further digestate utilization lowers GWP to 0.165 kg CO?-eq/kWh, alongside significant reductions in ADF, CED, AP, and EP indicators. Overall, the transition from coal to biogas, coupled with digestate valorization, can reduce emissions by up to 87% while enhancing resource efficiency. This study highlights the strategic role of biogas derived from agro-industrial wastewater as a sustainable energy solution and provides a scientific basis to support policy, investment, and technological innovation in low-carbon agro-industrial systems.

Kata Kunci : Life Cycle Assessment, Biogas, Agro-industrial Wastewater, Anaerobic Digestion, Renewable Energy Transition