In this study, the optimization of microwave-assisted alkaline (MAA) pretreatment is performed to attain the optimal operating parameters for the delignification of cocoa pod husk (CPH). The MAA performance was examined by heating the CPH solid with different particle sizes (60–120 mesh) and NaOH solution with a different sample to a solvent (SS) ratio (0.02–0.05 g/L), for short irradiation time (1–4 min). Box-Behnken Design (BBD) was utilized to optimize the percentage of lignocellulose composition changes. The results show that by enlarging particle size, the content of lignin and cellulose decreased while hemicellulose increased. By prolong irradiation time, the content of lignin and hemicellulose decreased while cellulose elevated. On the other hand, increasing the SS ratio was not significant for hemicellulose content changes. From FTIR and SEM characterization, the MAA drove the removal of lignin and hemicellulose of CPH and increased cellulose slightly. Supported by kinetic study which conducted in this work, it was exhibited that MAA pretreatment technology is an effective delignification method of CPH which can tackle the bottleneck of its commercial biofuel production. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA   License (https://creativecommons.org/licenses/by-sa/4.0).

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The development of biofuel in Indonesia is rife to reduce the consumption of fuel oil. Bioethanol has advantages compared to fuel oil, such as lower carbon monoxide emissions making it environmentally friendly. Besides that, from being used as a fuel, bioethanol is used as raw material for alcohol, pharmaceutical, and cosmetics derivatives. Biomass is one of the bioethanol’s raw materials available in Indonesia, one of which is tobacco stem. In this research, the tobacco stem hydrolysis process carried out using the ultrasonic-assisted hydrolysis method. The variable of the hydrolysis process is H2SO4 solution, particle size, and time. The data analysis used Design Expert with a Central Composite Design method. The purpose of this research was to determine the optimum of particle size, H2SO4 concentration, and the time in the hydrolysis process of tobacco stems with the ultrasonic-assisted hydrolysis method. The optimum resulting in reducing sugar of ultrasonic-assisted hydrolysis is 6.921 µg/µL.

Biobutanol is well-known as a suitable substitute for gasoline which can be applied without enginemodification. Butanol toxicity to the producer strain causes difficulties to grow strain with more than 4 g/L dry cellweight and to produce butanol more than 20 g/L. Fermentation with high initial cell density was reported to enhancebutanol productivity. In addition, oleyl alcohol has been recognized to perform effective extraction for butanol because ofits selectivity and biocompatibility so that reducing toxicity effect. Butanol fermentation with high cell density and largeextractant volume has not been reported and is expected to improve butanol production in minimum medium volume.Clostridium saccharoperbutylacetonicum N1-4, C. beijerinckii NCIMB 8052 (8052), and C. acetobutylicum ATCC 824(824) were used in this study. Three kinds of media, TYA, TY, and TY-CaCO3, were used to investigate in conventionalextractive fermentation. Then, in situ extractive fermentations with Ve/Vb ratios at 0.1, 0.5, 1.0, and 10 were operated.Total butanol concentration was defined as the broth based total butanol, that is total amounts of butanol produced inbroth and extractant per the volume of broth. TYA medium resulted the highest total butanol concentrations by N1-4 (12g/L), 8052 (11 g/L), and 824 (15 g/L) and the highest partition coefficient (3.7) among the three media with Ve/Vb ratiosat 0.5. N1-4 yielded the highest increment of total butanol production (22 g/L) in the extractive fermentation with highcell density. Low butanol concentration of 0.8 g/L butanol in broth was maintained with the extractant to broth volumeratio (Ve/Vb), which was much lower than 4.4 g/L with the ratio of 0.5. Ve/Vb ratio of 10 provided 2-fold higher totalbutanol concentration (28 g/L) than that 11 g/L obtained with Ve/Vb ratio of 0.5. These results indicated that largervolume of extractant to broth improved total butanol concentration by reducing butanol toxicity and led to high mediumbasedbutanol yield in fermentation using high cell density.

Jember memiliki komoditas tembakau yang cukup melimpah, salah satu daerah penghasil tembakau adalah di kawasan Wuluhan. Program Pengabdian Masyarakat Fakultas Teknik, Universitas Jember dengan mitra yaitu Kelompok Tani Karunia Tembakau yang terletak di Desa Tamansari, bertujuan untuk mengatasi permasalahan mitra. Bagian tembakau yang laku dijual para petani adalah daun tembakau, sedangkan batang tembakau tidak dimanfaatkan dan menumpuk menjadi limbah. Upaya mengurangi limbah batang tembakau dan menambah nilai guna dapat dilakukan dengan memanfaatkan batang tembakau menjadi pewarna alami batik. Penggunaan pewarna alami pada kain batik juga berkontribusi dalam mengurangi pencemaran lingkungan yang disebabkan oleh penggunaan pewarna sintetis pada industri batik. Pewarna alami dari batang tembakau dapat dimanfaatkan oleh pengrajin batik yang ada di wilayah Jember dan sekitarnya. Pemberdayaan masyarakat dalam pengolahan batang tembakau menjadi pewarna alami batik diharapkan mampu meningkatkan ekonomi Kelompok Tani Karunia Tembakau di Desa Tamansari. Penyelesaian masalah dari mitra dilakukan dalam skema pengabdian masyarakat dengan tahapan pemberian sosialisasi tentang pengelolaan dan pengolahan limbah batang tembakau menjadi pewarna alami batik, menginisiasi dan memberikan bantuan kepada masyarakat contoh satu set alat produksi pewarna alami dalam skala rumah tangga, pemberian sosialisasi terkait proses pengemasan dan pemasaran produk, serta menginisiasi proses pemasaran produk dengan mengundang distributor dan konsumen potensial. Hasil dari program pengabdian masyarakat ini adalah diharapkan Kelompok Tani Karunia Tembakau Desa Tamansari mampu mengolah limbah batang tembakau menjadi pewarna alami batik secara mandiri dan kontinyu. Kata kunci: Batang tembakau, Pewarna alami batik, Desa Tamansari

Beluntas (Pluchea Indica L.) yang biasa digunakan sebagai astringent dan antipiretik memiliki potensi yang tinggi sebagai bahan baku produksi minyak atsiri. Tujuan dari penelitian ini adalah untuk mengoptimalkan solvent-free microwave extraction (SFME) dari daun beluntas menggunakan response surface metodology (RSM). Desain Box-Behnken dengan variasi waktu ekstraksi (60-120 menit), rasio bahan/labu distilat (0,06-0,1 g/ml), dan daya pemanas (150-450 Watt) digunakan untuk mengoptimalkan produksi minyak atsiri. Faktor rasio bahan/penyuling memiliki pengaruh signifikan paling tinggi terhadap rendemen minyak atsiri (P<0,05). Rendemen minyak atsiri meningkat seiring dengan meningkatnya daya pemanasan minyak dan waktu ekstraksi, dan sebaliknya. Di sisi lain, peningkatan rasio bahan/labu distilat memberikan dampak negatif terhadap rendemen minyak atsiri. Hasil minyak atsiri maksimum menggunakan metode SFME sebesar 0,2728 b/b% diperoleh untuk kondisi optimal waktu ekstraksi 90 menit, daya pemanasan 450 W, dan rasio bahan/labu distilat 0,06.Beluntas (Pluchea Indica L.) which commonly used as astringent and antipyretic has a high potential for the feedstock of essential oil production. The objective of this work is to optimize solvent-free microwave extraction (SFME) of Beluntas leaves by using response surface methodology (RSM). Box-Behnken Design with the variations of extraction time (60-120 min), feed/distiller ratio (0.06-0.1 g/ml), and heating power (150-450 W) was utilized to optimize essential oil yield. The feed/distiller ratio factor had the highest significant effect on the essential oil yield (P<0.05). Essential oil yield increased as the increase of oil heating power and time extraction, and vice versa. On the other hand, the increase in the feed/distiller ratio gave a negative impact on the essential oil yield. The maximum essential oil yield using SFME method of 0.2728 b/b% was obtained for the optimized condition of extraction time of 90 min, microwave heating power of 450 W, and feed/distiller ratio of 0.06.

Bioethanol can be used for biosolvents and antiseptics material in the pharmaceutical industry. With the abundance of tobacco production in Jember, East Java, Indonesia, tobacco stalks become a promising biomass raw material for bioethanol. The purpose of this study was to determine the effect of temperature on the pretreatment process of bioethanol production. Settings and Design of this study using Conventional pretreatment with batch system. The materials used in this study include industrial tobacco waste, HCl, H2SO4, aquadest, filter paper, and aluminum foil. The pretreatment method used is chemical methods. The effect of pretreatment temperature was analyzed on the pretreatment process for the optimization of bioethanol production. Statistical analysis used a percentage frequency distribution. The test results of cellulose with H2SO4 solvents are 6.99 % at temperature 100 °C, 6.60 % at temperature 120 °C, and 4.47 % at temperature 140 °C. The test results of cellulose with HCl solvents are 6.00 % at temperature 100 °C, 6.23 % at temperature 120 °C, and 5.66 % at temperature 140 °C. Conclusions of this study, the optimum temperature in the pretreatment process with H2SO4 for the temperature range 100 °C to 140 °C is 100 °C, with the cellulose content produced as much as 6.99 %. The optimum temperature in the pretreatment process with HCl for the temperature range 100 °C to 140 °C is 120 °C, with the cellulose content produced as much as 6.23 %.

The challenges faced by the Indonesian state are increasing greenhouse gases, climate change, and depleting fossil fuel reserves. This requires the exploration of alternative energy that is environmentally friendly and sustainable. Algae biomass, especially Ulva sp. is one of the resources that have the potential for bioethanol production as an alternative energy producer. The purpose of this study is to determine the potential of Ulva sp. as raw material for bioethanol and to determine the effect of particle size, solvent concentration, and power on the hydrolysis process. This study used Ulva sp. as raw material. hydrolyzed with HCl solvent using the microwave assisted hydrolysis method. Hydrolysis with HCl concentrations of 0.1 N, 1 N, 2 N, variations of microwave power 150 watts, 300 watts, 450 watts, and particle sizes of 60 mesh, 80 mesh, and 100 mesh. Measurement of reducing sugar levels was carried out using the dinitro salicylic acid (DNS) method. The results showed that the best conditions for hydrolysis were when the HCl concentration was 0.1 N, the microwave power was 450 watts, and the particle size was 80 mesh which resulted in a reducing sugar content of 20.751 mg/mL.