Pyrolysis of Alang – Alang (Imperata Cilindrica) as Bioenergy Source in Banten Province Indonesia

Abstract

Bahan bakar fosil sumber energi memiliki keterbatasan dan tidak terbarukan, penggunaan bahan bakar fosil secara terus menerus mengakibatkan krisis energy dan lingkungan. Rumput liar pada saat ini memiliki potensi untuk dikembangkan sebagai generasi kedua biomasa. Hal ini memiliki keuntungan seperti tumbuh dengan cepat, mudah tumbuh, perawatan yang minimal, dapat tumbuh pada lahan kritis dan tersedia dalam jumlah yang banyak. Dalam upaya mengembangkan generasi kedua biomasa, penelitian ini secara sistematis memberikan perspektif ekologi dan teknologi proses dalam mengembangkan bioenergi dari alang – alang di Provinsi Banten. Pada penelitian ini karakterisasi alang – alang dilakukan untuk menentukan sifat – sifat dan potensi bioenergy. Sedangkan fixed bed pirolisis dilakukan untuk mengidentifikasi potensi produksi bio-oil dari proses pirolisis. Sementara analisis karakterisasi bio-oil dilakukan untuk melihat potensi chemical building block sebagai sumber energi. Analisis sifat kimia dan fisika alang – alang dilakukan melalui thermogravimetric analysis, proximate analysis, elemental analysis, compositional analysis, calorific value. Sedangkan analisis potensi bio-oil di lakukan melalui Gas Chromatography–Mass Spectrometry (GC-MS). Dari hasil karakterisasi mengindikasikan bahwa alang – alang memiliki nilai kalori 18,05 MJ/kg, dengan ash konten yang rendah, dan tinggi kandungan volatile. Analisis dengan GC/MS menunjukan komponen utama dalam bio-oil dikelompokan ke dalam furan, ketone, phenol dan anhydrosugar yang merupakan platform yang dapat dikonversi menjadi sumber energi. Fixed bed pyrolysis atau fixed bed pirolisis alang – alang menunjukan, bahwa yield bio-oil meningkat sebagaimana peningkatan temperatur dan puncaknya pada suhu 500 0C dengan persentase 37,91%.
 Kata Kunci: Alang - alang, Pirolisis, GC/MS, Thermogravimetric analysis, Bioenergi
 
 ABSTRACT
 Fossil fuel as a source of energy have limitation and are non-renewable. Continuous utilisation of fossil fuels as energy source can lead to energy crisis and environmental impact. Perennials grasses (alang – alang) are currently being developed as a suitable second-generation biofuel feedstock. It has advantages such as rapid growth rate, easy to grow, minimal maintenance and utilise marginal land without competing with food supply. Taking into account of the various challenges attributed to the transformation of second-generation biomass for energy production, this work systematically looks at the ecological perspective and the availability for bioenergy production from alang – alang in Banten Province. Biomass characterisation is carried out to determine the properties and bioenergy potential. Fixed bed pyrolysis study was conducted to predict the potential production of bio-oil from the pyrolysis process. GC/MS study is conducted to identify the potential building blocks of value-added chemicals from alang – alang. The physicochemical properties of feedstock was thoroughly evaluated using thermogravimetric analysis, proximate analysis, elemental analysis, compositional analysis, calorific value. The analysis of the potential of bio-oil was carried out through GC / MS. Characterisation results indicate that alang - alang has a calorific value of 18.39 MJ/kg, with low ash content and high percentage of volatile matter. Analysis from Gas Chromatography–Mass Spectrometry (GC-MS) showed that majority of the chemical groups in the bio-oil contained furan, ketone, phenol and anhydro-sugars. Phenolic and furanic were found as major compounds in bio oil. Phenolic, furanic, ketonic and anhydrosugars are promising renewable platform compounds derived from pyrolysis of alang – alang. The compounds can be further converted to chemicals or fuels. The fixed-bed pyrolysis of alang - alang showed that the yield of bio-oil increases as the temperature increases and peaks at 500°C with 38.79%.
 Keywords: Alang - alang, Pyrolysis, GC/MS, Thermogravimetric analysis, Bioenergy

Studies on the Benefits of Cogon Grass (Imperata cylindrica L) in Indonesia: A Review

“…Cogon grass material can also be pyrolyzed to obtain liquid smoke which can be used for various purposes such as medicinal ingredients [55] . Cogon grass extract can also be used as bio-oil which is rich in furans, ketones, phenol and anhydro sugar which can be converted into an energy source [56] . So far, the potential benefits of cogon grass that have been most researched in Indonesia are its anti-weed properties and pharmacological properties.…”