The competitive reactions of lignocellulose hydrolysis and monosaccharide degradation in the subcritical water (SCW) hydrolysis of coconut husk were investigated to optimize the reducing sugar yield. Optimization analysis was performed by response surface methodology (RSM) and kinetics studies. Parameters of process optimization were varied at 130-170 °C for 15-45 min. The reducing sugars were measured using the Dinitro salicylic acid method. The sugar yield increased when the temperature increased from 130 °C to 170 °C. The highest reduction sugar yield of 4.946 g/L was obtained at 183.6 °C for 4.8 min and 23.4 liquid/solid ratio (LSR). Kinetics studies were carried out at temperature variations of 150, 170, and 190 °C and pressures of 60, 80, and 100 bar for 5 to 60 min. The yield of reducing sugar decreased with increasing temperature. The kinetic model 2B is the best method to explain the competitive reaction kinetics of coconut husk hydrolysis. This research is an innovation to increase the reducing sugar to make the process more commercially viable. Copyright © 2022 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).

<p class="E-JOURNALAbstractBodyEnglish">Previous reports showed that there has been a continuous increase in the annual production of onion in Indonesia, and it is inversely proportional to the market price. The price drop is often caused by the high water content, which makes it easy to rot. Preservation of onions through a tray dryer is a good preservation method because it is effective and does not require much energy. Therefore, this study aims to determine the effect of variations in time, material thickness, and air velocity on the drying rate of onions. The samples were sliced to a size of 2 - 5 mm, followed by drying for 60 min using a tray dryer with different air rates between 4 - 7 m/s, and the rate of the process was observed every 15 min. The results showed that the drying time reduced the humidity in the chamber. The highest rate of 0.525 g/min was obtained at the peak air rate of 7 m/s. ANOVA results revealed that variations in time, onion thickness, and flow rate have a significant effect on increasing the drying rate of onions. This indicates that the method can be an effective and efficient solution to optimize the drying of the commodity.</p>

No abstract

PT. Industri Gula Glenmore (PT. IGG) setiap tahunnya memproduksi 14.300 ton abu ampas tebu (AAT) sebagai hasil samping pembakaran boiler yang belum dimanfaatkan secara maksimal. Menariknya, AAT memiliki kandungan silika tinggi yaitu 68,5% yang dapat ditingkatkan nilainya sebagai substitusi parsial semen dalam pembuatan bata beton. Oleh karena itu, pada penelitian ini komposisi dan ukuran partikel AAT dioptimalkan dalam pembuatan bata beton. Optimasi dilakukan dengan menggunakan Response Surface Methodology (RSM) untuk memahami perilaku faktor-faktor signifikan yang mempengaruhi kuat tekan bata beton. RSM ditentukan dengan menggunakan software Design-Expert V11. Bata beton dibuat dengan perbandingan semen dan pasir menggunakan perbandingan 1:6 dengan variasi AAT 5% sampai 25% dari berat normal semen. Hasil pengujian di Workshop menunjukkan bahwa penggunaan Fly Ash dan kapur sebagai bahan pengikat untuk menggantikan sebagian semen dengan variasi 23, 26, 28, 30, dan 33% menghasilkan kuat tekan berturut-turut sebesar 56, 52, 49, 40, dan 34 kg/cm2. Dengan demikian, bata beton pada penelitian ini termasuk dalam mutu tingkat 3 berdasarkan SNI 03-0349-1989. Inovasi ini merupakan solusi untuk meningkatkan nilai tambah AAT dan menjadi peluang bisnis baru bagi PT. IGG di masa depan.PT. The Glenmore Sugar Industry (PT. IGG) annually produces 14,300 tons of Sugarcane Bagasse Ash (SCBA) as a by-product of boiler combustion that has not been fully utilized. Interestingly, SCBA has a high silica content of 68.5% which can be valorized as a partial substitution of cement in the manufacture of concrete bricks. Therefore, in this study, the composition and particle size of SCBA were optimized in the manufacture of concrete bricks. Optimation was carried out by using Response Surface Methodology (RSM) to understand the behavior of significant factors affecting the compressive strength of concrete bricks. RSM was determined using the Design-Expert V11 software. Concrete bricks were made with a ratio of cement and sand using a ratio of 1:6 with a variation of bagasse ash 5% to 25% of the normal weight of the cement. The test results showed that the use of fly ash and lime as a binder to replace some cement with variations of 23%, 26%, 28%, 30%, and 33% resulted in a compressive strength of 56 kg/cm2, 52 kg/cm2, 49 kg/cm2, 40 kg/cm2, and 34 kg/cm2. Thus the concrete brick in this study was included in the quality level 3 based on SNI 03-0349-1989. This innovation is a solution to increase SCBA's added value and a new business opportunity for PT. IGG in the future.

The noodles in the market are dry noodles with 8-10% water content. Dried noodles have a longer shelf life because they are less prone to mold growth. Drying noodles with the help of the sun and tray dryers are currently an option because they are efficient and do not require a lot of energy. Reduction of water content is also optimized by soaking wet noodles in salt water. This study aims to determine the effect of soaking noodles in salt water and the flow rate to decrease the water content of noodles. The study began with soaking wet noodles in a salt solution with a variation of 50-150 g/L, then dried for 1 hour using a hybrid method and tray dryer with a flow rate variation of 1.2-3.3 m/s. Observations were made at intervals of 0-1 hour. The results showed that the time and speed of the flow rate can reduce the humidity in the drying chamber of the tray dryer. The lowest water content reduction of up to 11% was obtained when soaking wet noodles in 150 g/L salt solution and at the highest flow rate of 3.3 m/s. The ANOVA results show that the drying method with tray dryer is more optimal than hybrid drying. Thus, this method can be a solution to optimize the noodle drying process quickly and efficiently.