PENGARUH SUHU DAN WAKTU TOREFAKSI PADA LIMBAH SEBETAN KAYU MINDI (Melia azedarach) SEBAGAI SUMBER ENERGI TERBARUKAN

ARYA GULANG RAMADHAN, Dr. Ir. J.P. Gentur Sutapa, M.Sc.

2017 | Skripsi | S1 KEHUTANAN

Limbah dari industri penggergajian berupa sebetan kayu mindi belum dimanfaatkan secara optimal. Penelitian ini bertujuan untuk memanfaatkan dan mengolah limbah sebetan kayu mindi (Melia azedarach L.) untuk menjadi sumber energi terbarukan berkualitas melalui proses torefaksi, serta mengetahui pengaruh variasi suhu dan waktu torefaksi, serta kombinasi suhu dan waktu torefaksi yang optimal. Bahan penelitian limbah sebetan kayu mindi (Melia azedarach L.) berasal dari Industri Penggergajian UD. Tonoputro Kecamatan Cangkringan, Kabupaten Sleman, Provinsi DIY. Penelitian I menggunakan rancangan acak lengkap (Completely Randomized Design) dengan 2 faktor perlakuan yaitu suhu torefaksi (225oC, 250oC, dan 275oC) dan waktu torefaksi (30 menit, 60 menit, dan 90 menit) dengan masing-masing perlakuan lima kali ulangan. Kayu mindi yang telah ditorefaksi diamati rendemen, berat jenis, dan perubahan warnanya. Pada Penelitian II, kayu yang telah melalui proses torefaksi dikonversi menjadi briket. Dengan faktor yang sama, tiap briket dibuat dengan lima kali pengulangan. Briket kemudian diuji kualitasnya meliputi uji kadar air, berat jenis, kadar abu, kadar zat volatil, dan kadar karbon terikat. Hasil penelitian menunjukkan rata-rata rendemen perlakuan torefaksi 72,961%, berat jenis 0,469, dan warna berubah menjadi lebih gelap seiring kenaikan suhu dan waktu torefaksi. Briket limbah sebetan kayu mindi yang ditorefaksi memiliki karakteristik kualitas sebagai berikut : rata-rata kadar air 10,833%, berat jenis 0,779, nilai kalor 5421,735 kal/gram dengan kenaikan nilai kalor rata-rata sebesar 20,6% dari bahan baku, kadar abu 1,147%, kadar zat volatil 65,517%, dan kadar karbon terikat 22,504%.

Utilization of slabs of mindi from sawmilling process is not well developed. The aim of this research are utilizing and converting slabs of mindi wood waste to high quality renewable energy through implementation ofthe torrefaction process. Slabs of mindi wood was collected from sawmill UD. Tonoputro Kecamatan Cangkringan, Kabupaten Sleman, Daerah Istimewa Yogyakarta. Research I was conducting with Completely Randomized Design, treated by 2 factors. The 2 factors are temperatur of torrefaction (225oC, 250oC, and 275oC) and duration of torrefaction (30 minutes, 60 minutes, and 90 minutes). Each treatment was implemented with five repetition. Quality parameter of the torrefaction process was evaluated with the measuring of following indicators : mass yield/rendemen, mass density, and change of color. Research II applied with the similiar factors and the product of the torrefaction then converted to briquette with five repetition. The quality parameter of the produced briquettesuch as water content, mass density, calorific value, ash content, volatile matter content, and fixed carbon content were evaluated. The results ofthis research shows the average torrefaction mass yield 72.961%, mass density 0.469, and the color getting darker as the temperature and duration of torrefaction increased. Briquette from mindi wood slabs with torrefaction processing has quality characteristicas follows: the average of the water cotent 10.833%, mass density 0.779, calorific value 5421.735 cal/gram, ash content 1.147%, volatile matter content 65.517%, and fixed carbon content 22.504%. The best torrefaction process is achieved by combination of torrefaction process with temperature of 275oC and duration of 90 minute. The briquette has following quality characteristics as follow: the average of the water cotent 9.210%, mass density 0.825, calorific value 5711.875cal/gram increased up to 27.1% compared to the raw materials, ash content 1.207%, volatile matter content 56.197%, and fixed carbon content 33.386%.

Kata Kunci : Torefaksi, Limbah Sebetan Kayu Mindi, Suhu Torefaksi, Waktu Torefaksi, Briket;Torrefaction, Mindi Wood Slabs, Briquette