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Abstrak :
Lignocellulosic biomass has great potential for biogas production, but there are various factors which affect the performance of lignocellulosic biomass. Among the various factors, temperature is one of the important factors which play a significant role in biogas production from lignocellulosic biomass. Biogas production was studied for bamboo dust, sawdust, sugarcane bagasse and rice straw, all separately mixed with cattle dung. The effect of temperature on biogas production from various lignocellulosic biomasses was studied for temperature range from 35°C to 55°C at steps of 5°C. The objective of this work is to develop a mathematical model for evaluating the effect of temperature on the rate of biogas production from various lignocellulosic biomasses. The new mathematical model is derived by modification of the modified Gompertz model. The new model is found to be suitable for lignocellulosic biomass mixed with cattle dung in the temperature range 35°C to 55°C. The resulting estimated biogas production is found to be highly correlated to the experimental data of present study.

Abstrak :
This paper presents the structural behavior of newly-developed hybrid structural insulated panels (SIPs) formed by incorporating lignocellulosic composites—jute fiber composite (JFC) and medium-density fiber (MDF)—as intermediate layers between aluminum skin and an expanded polystyrene (EPS) core. The investigation was conducted as an experimental work. A four-point bending load was performed to create pure bending conditions, and the samples were prepared in accordance with ASTM C 393-00 standards. Testing was performed using a 100 kN servo-hydraulic machine with a loading rate of 5 mm/min. The results show that the incorporation of intermediate JFC or MDF layers enhanced the flexural behavior of the SIPs. The ultimate loads of hybrid SIPs with JFCs or MDF were, respectively, approximately 62.59% and 168.58% higher than the ultimate load achieved by SIPs without intermediate layers. Hybrid SIPs exhibited a much larger area under the load-deflection curve than those of conventional SIPs; this points to the toughness of the material and its ability to sustain larger compression strain prior to reaching their ultimate loads, which prevents them from prematurely failing under buckling or indentation.

Abstrak :
ABSTRAK
Sektor industri yang memproduk bahan kimia dan polimer sintetik sangat bergantung pada sumber daya fosil. Sumber daya fosil seperti minyak bumi semakin berkurang sehingga berdampak pada efektivitas biaya dan daya saing polimer. Biomassa lignoselulosa non-pangan seperti jerami padi sangat melimpah di Indonesia dan dapat digunakan sebagai pengganti sumber daya fosil untuk memproduksi prekursor petrokimia. Diketahui bahwa komponen selulosa adalah sumber utama untuk pembentukan levoglucosan LG . Karena kandungan selulosa yang tinggi, potensi jerami padi dapat diubah dengan pirolisis untuk menghasilkan bio-oil dan produk turunan menuju levoglucosan LG harus dikembangkan. Levoglucosan adalah senyawa intermediet penting karena dapat diubah menjadi prekursor bio-polimer asam adipat, bio-etanol, dll. Saat ini masih jarang penelitian yang berfokus pada rute yang menghasilkan LG melalui pirolisis. LG kemudian dapat mengalami reaksi lebih lanjut dan menghasilkan produk turunan. Untuk mendapatkan hasil tertinggi dari LG dalam bio-oil pada akhir pirolisis, suatu kondisi yang dapat menghambat reaksi lebih lanjut dari LG selama pirolisis berlangsung. Faktor sumber biomassa lignoselulosa dan komposisi, suhu, dan waktu tinggal disesuaikan dengan mengatur laju alir gas N2 kemungkinan besar sangat mempengaruhi komposisi produk yang terbentuk pada akhir pirolisis. Dalam penelitian ini, fast-pyrolysis jerami padi dilakukan dalam reaktor unggun tetap 5 gram biomassa pada rentang suhu yang berbeda 450 hingga 600oC , laju alir N2 antara 1200 hingga 1582 ml / menit untuk memaksimalkan hasil LG . Untuk mengkonfirmasi konten LG pada produk pirolisis diukur dengan instrumen GC-MS. Diketahui suhu dan waktu tinggal optimum adalah 500oC dan 1.582 ml/menit untuk mendapatkan yield levoglucosan sebesar 67,64 area kromatogram GC-MS . Kata kunci: biomassa, fast-pyrolysis, levoglucosan, lignoselulosa, waktu tinggal

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ABSTRACT

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The industrial sectors that produce synthetic chemicals and polymers rely heavily on fossil resources. Fossil resources such as petroleum are diminishing thus impacting on the cost effectiveness and competitiveness of polymers. Non food lignocellulosic biomass such as rice straw is very abundant in Indonesia and can be used as a substitute for fossil resources to produce petrochemical precursors. It is known that cellulose component is the main source for LG formation. Due to high contain of cellulose, the potential of rice straw can be transform by pyrolysis to produce bio oils and derivative products towards levoglucosan LG should be developed. Levoglucosan is important intermediet compound as it can be convert to the precursor of bio polymer adipic acid, bio ethanol, etc. Nowadays it rsquo s still rarely research focused on this mechanism route producing LG through pyrolysis. LG then can run into a further reaction and produce derivative products. In order to obtain the highest yield of LG in bio oil at the end of pyrolysis, a condition that may inhibit the further reaction of LG during pyrolysis takes place. The factor of lignocellulosic biomass source and composition, temperature, and holding time adjusted by N2 feed most likely greatly affect the composition of the product formed at the end of pyrolysis. In this study, fast pyrolysis of rice straw was performed in fixed bed reactor 5 grams of biomass under different temperatures ranges 450 to 600 oC , N2 flow rate 1200 to 1582 ml min to maximize the yield of LG. To confirm the content of LG on the pyrolysis product was measured by GC MS instruments. The maximum yield of LG was obtained at an optimal pyrolysis temperature of 500 C, 1.35 s of holding time.

Abstrak :
Lignocellulosic biomass (LCB) merupakan salah satu sumber daya yang paling banyak tersedia di alam yang kerap digunakan dalam penelitian pembakaran membara. Contoh biomasa lignoselulosa antara lain adalah tanah gambut, kertas, sabut kelapa, tembakau, jerami, dan batu bara. Sebelumnya, telah dilakukan beberapa penelitian terkait pembakaran membara pada tanah gambut di Laboratorium Thermodinamika, Fakultas Teknik, Universitas Indonesia. Oleh sebab itu, perlu adanya penelitian pembakaran membara pada biomasa lignoselulosa lainnya, seperti kertas. Penyalaan dan pembakaran bahan kertas dipengaruhi oleh moisture content (MC) sehingga perlu adanya pengeringan pada temperatur dan dalam waktu tertentu. Eksperimen dilakukan menggunakan lima sampel dengan tingkat MC yang berbeda (9.9%, 7.2%, 5.7%, 4.4%, dan 4.3%). Hasil percobaan menunjukkan bahwa hahan kertas sukar untuk membara dan mempertahankan pembakarannya pada MC >10% (tanpa pengeringan), bahan kertas dapat membara dan mempertahankan pembakarannya hingga ±10 menit setelah igniter dimatikan pada MC 7 – 10%, dan bahan kertas dapat membara dan mempertahankan pembakarannya hingga ±80 menit setelah igniter dimatikan pada MC ≤5.7%. Kemudian dapat diketahui hubungan antara moisture content dengan karakteristik penyebaran pembakaran membara bahan kertas dan besaran emisi yang dihasilkan. Hasil percobaan menunjukkan bahwa sampel dengan MC 4% (~4.4 cm²/min dan 500 cm²) menghasilkan laju perambatan dan luas area bakar yang lebih besar dibandingkan dengan sampel dengan MC 5.7% (2.86 cm²/min dan 387.72 cm²). Konsentrasi CO dan rata – rata partikulat yang dihasilkan pada eksperimen dengan MC 4% adalah ~550 ppm(vol) dan 380.82 μg/m³ serta MC 5.7% adalah ~500 ppm(vol) dan 347.48 μg/m³. ......Lignocellulosic biomass (LCB) is one of the most abundant resources available in nature and is often used in smoldering combustion research. The examples of lignocellulosic biomass are peat, paper, coconut fiber, tobacco, straw, and coal. Previously, several studies had been carried out regarding smoldering of peat soil at the Thermodynamics Laboratory, Faculty of Engineering, University of Indonesia. Therefore, there is a need for research on smoldering combustion on other lignocellulosic biomass, such as paper. Ignition and burning of paper are influenced by moisture content (MC), thus drying at a certain temperatue within certain minutes is necessary. Experiments were carried out using five samples with different MC levels (9.9%, 7.2%, 5.7%, 4.4%, and 4.3%). The experimental results show that paper material is difficult to smolder and maintain its combustion at MC > 10% (without drying). paper material can smolder and maintain its combustion up to ± 10 minutes after the igniter is turned off at MC 7 – 10%, and paper material can smolder and maintain its combustion up to ±80 minutes after the igniter is turned off at MC ≤5.7%. Therefore, we can find out the relationship between moisture content and the characteristics of the smoldering of paper and the amount of emissions produced. The experimental results show that the sample with MC 4% (~4.4 cm²/min and 500 cm²) produces a greater propagation rate and burn area compared to the sample with MC 5.7% (2.86 cm²/min and 387.72 cm²). The average concentration of CO and particulates produced in the experiment with MC 4% was ~550 ppm(vol) and 380.82 μg/m³ and MC 5.7% was ~500 ppm(vol) and 347.48 μg/m³.

Abstrak :
Commercialization of bioethanol has recently intensified due to its market stability, low cost,sustainability, alternative fuel energy composition, greener output and colossal fossil fuel depletion. Recently, because of greenhouse intensity worldwide, many researches are ongoing to reprocess the waste as well as turning down the environmental pollution. With this scenario, the invention of bioethanol was hailed as a great accomplishment to transform waste biomass to fuel energy and in turn reduce the massive usages of fossil fuels. In this study, our review enlightens various sources of plant-based waste feed stocks as the raw materials for bio ethanol production because they do not adversely impact the human food chain. However, the cheapest and conventional fermentation method, yeast fermentation is also emphasized here notably for waste biomass-to-bio ethanol conversion. Since the key fermenting agent, yeastis readily available in local and international markets, it is more cost-effective in comparison with other fermentation agents. Furthermore, yeasthas genuine natural fermentation capability biologically and it produces zero chemical waste. This review also concerns a detailed overview of the biological conversion processes of lignocellulosic waste biomass-to-bio ethanol, the diverse performance of different types of yeasts and yeast strains, plus bioreactor design, growth kinetics of yeast fermentation, environmental issues, integrated usages on modern engines and motor vehicles, as well as future process development planning with some novel co-products.

Abstrak :
Sebagai upaya memenuhi kebutuhan bahan bakar penerbangan yang meningkat, sintesis bioavtur dari bahan biomassa lignoselulosa bisa menjadi solusi saat ini. Bonggol jagung sebagai bahan baku dipilih karena kelimpahannya di Indonesia mencapai 7,2 juta ton/tahun dan kandungan holoselulosa yang tinggi sehingga akan menguntungkan saat dikonversi menjadi bio-oil dengan pirolisis. Tujuan penelitian ini untuk mendapatkan analisis kandungan bio-oil dan mendapatkan analisis literatur potensi senyawa yang dominan pada langkah peningkatan mutu bio-oil dan katalisnya dari penelitian eksperimental. Pirolisis ditempuh dengan laju pemanasan rendah sebesar 50C/menit hingga temperatur 5000C dengan kecepatan pengaduk 100 rpm. Berdasarkan analisis GC-MS, komposisi senyawa terbanyak pada bio-oil berupa asam benzoat sebesar 44,45%, yang terbentuk dari oksidasi aldehid yang didahului oleh oksidasi alkohol. Ditinjau dari analisis NMR, ikatan kimia dominan yang terdeteksi ialah membentuk siklopentenon, dengan ikatan C pada siklopentena dan karbonil keton yang masing-masing sebesar 55,61% dan 34,81% pada C-NMR, serta ikatan H pada siklopentena dan C-alfa di keton dengan kelimpahan 47,41% dan 25,19% pada H-NMR. Pembentukan siklopentenon memperlihatkan ciri khas proses slow pyrolysis dengan menghadirkan lebih banyak reaksi siklisasi yang terjadi dari hasil dehidrasi cincin glukosa yang terbuka. Bio-oil dengan dominan siklopentenon ini merupakan basis awal untuk pembentukan bioavtur dengan densitas dan nilai kalor yang tinggi seperti bi(siklopentana). Berdasarkan tinjauan pustaka, rute mekanisme reaksi upgrading dengan katalis dapat dilakukan melalui urutan proses hidrogenasi dengan katalis Cu-Ni-Al dengan yield siklopentanon 95,8%, kondensasi aldol siklopentanon dengan katalis MgO-ZrO2 mampu mencapai yield 2-siklopentilidin-siklopentanon sebesar 84,6%, dan hidrodeoksigenasi disertai katalis Ni/SiO2 menghasilkan bi(siklopentana) dengan yield sebesar 93%. Katalis untuk reaksi hidrogenasi dan hidrodeoksigenasi harus bersifat asam dan untuk reaksi kondensasi aldol bersifat asam-basa. Sebagai produk bioavtur potensial berupa bi(siklopentana) dengan rasio H/C sebesar 1,8 dinilai telah mendekati bioavtur komersial dengan rasio H/C 1,92. Kuantifikasi biomassa yang terkonversi menjadi bioavtur potensial berupa bi(siklopentana) melalui mekanisme senilai 15,96%. ......To fulfill the need of aviation fuel, the synthesis of bioavtur from lignocellulosic biomass can be the current solution. Corn cobs as raw material was chosen because of its potential abundance in Indonesia reaching 7.2 million tons/year and high holocellulose content so that it will be more profitable when converted to bio-oil by pyrolysis. The purpose of this study is to obtain the the bio-oil compositions analysis and obtain a literature analysis of the potential of dominant compounds in the step of improving the quality of bio-oil and its catalysts from experimental research. Pyrolysis is pursued at a low heating rate of 50C/min to a temperature of 5000C with a stirring speed of 100 rpm. Based on GC-MS analysis, the composition of most compounds in bio-oil is benzoic acid with 44.45%, which is formed from oxidation of aldehydes preceded by oxidation of alcohol. In terms of the NMR analysis, the dominant chemical bonds detected were to form cyclopentenone, with C bonds on cyclopentene and carbonyl ketones which were 55.61% and 34.81% on C-NMR, and H bonds on cyclopentene and C-alpha to ketones with an abundance of 47.41% and 25.19% in H-NMR, respectively.The formation of cyclopentenone shows the special characteristics of slow pyrolysis process by presenting more cyclization reactions that occured from the dehydration results of an opened-glucose ring. Bio-oil with cyclopentenone dominant composition is the initial basis for bioavtur synthesize with high density and high heating value characteristics such as bi(cyclopentane). Based on literature review, the mechanism of upgrading reactions with catalysts can be carried out through a sequence of hydrogenation processes with a Cu-Ni-Al catalyst with a cyclopentanone yield of 95.8%, aldol condensation of cyclopentanone with MgO-ZrO2 catalyst was able to reach a yield of 2-cyclopentylidine-cyclopentanone for 84, 6%, and hydrodeoxygenation with Ni/SiO2 catalyst produced bi(cyclopentane) with a yield of 93%. The catalyst for the hydrogenation and hydrodeoxygenation reactions must be acidic and for the aldol condensation reaction is acidic-base. As a potential bioavtur product in the form of bi(cyclopentane) with an H/C ratio of 1.8, it is considered to have approached a commercial bioavtur with an H/C ratio of 1.92. Quantification of biomass converted into bi(cyclopentane) as bioavtur potential was 15.96%.