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All Journal Jurnal Rekayasa Proses Reaktor International Journal of Renewable Energy Development Jurnal Bahan Alam Terbarukan Jurnal Pengabdian Kepada Masyarakat Sakai Sambayan Prosiding Semnastek PROSIDING SEMINAR NASIONAL CENDEKIAWAN Jurnal Rekayasa Proses ASEAN Journal of Chemical Engineering Abdimas Singkerru Prosiding Seminar Nasional Hasil Penelitian Sains, Teknik dan Aplikasi Industri Fakultas Teknik Universitas Lampung Medic Nutricia : Jurnal Ilmu Kesehatan International Journal of Renewable Energy Development Jurnal Rekayasa Proses JURNAL REKAYASA KIMIA & LINGKUNGAN Jurnal Bahan Alam Terbarukan Nemui Nyimah
Heri Rustamaji
Teknik Kimia, Universitas Lampung
Agriculture, Biological Sciences & Forestry Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering Environmental Science Health Professions Industrial & Manufacturing Engineering Languange, Linguistic, Communication & Media Materials Science & Nanotechnology Medicine & Pharmacology Neuroscience Nursing Public Health Social Sciences Veterinary Other

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Synthesis and Characterization of Hydrochar and Bio-oil from Hydrothermal Carbonization of Sargassum sp. using Choline Chloride (ChCl) Catalyst Heri Rustamaji; Tirto Prakoso; Jenny Rizkiana; Hary Devianto; Pramujo Widiatmoko; Guoqing Guan
International Journal of Renewable Energy Development Vol 11, No 2 (2022): May 2022
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2022.42595

Abstract

The purpose of this study is to alter the biomass of Sargassum sp. into elective fills and high valuable biomaterials in a hydrothermal process at 200oC for 90 minutes, using ZnCl2 and CaCl2 activating agents, withChClas a catalyst. This method generatedthree primaryoutputs: hydrochar, bio-oil, and gasproducts. ChCl to water ratio varies from 1:3, 1:1, and 3:1. The hydrochar yield improved when the catalyst ratio was increased, but the bio-oil and gas yield declined. The highest hydrochar yields were 76.95, 63.25, and 44.16 percent in ZnCl2, CaCl2, and no activating agent samples, respectively.The porosity analysis observed mesopore structures with the most pore diameters between 3.9-5.2 nm with a surface area between 44.71-55.2. The attribute of interaction between activator and catalyst plays a role in pore formation. The hydrochar products with CaCl2 showed the best thermal stability. From the whole experiment, the optimum hydrochar yield (76.95%), optimum surface area (55.42 m2 g-1), and the increase in carbon content from 21.11 to 37.8% were achieved at the ratio of ChCl to water was three, and the activating agent of ZnCl2. The predominant bio-oil components were hexadecane, hexadecanoic, and 9-octadecenoic acids, with a composition of 51.65, 21.44, and 9.87%, respectively the remaining contained aromatic alkanes and other fatty acids. The findings of this study reported that adding activating agents and catalysts improve hydrochar yield and characteristics of hydrochar and bio-oil products, suggesting the potential of hydrochar as a solid fuel or biomaterial and bio-oil as liquid biofuel
Synthesis of ZSM-5 From Natural Zeolite Lampung (ZAL) and Rice Husk by Seeding Method using Microwaves Ginting, Simparmin Br; Putri, Erisha; Miranda, Thalya; Darni, Yuli; Utami, Herti; Wardono, Herry; Darmansyah, Darmansyah; Rustamaji, Heri
Jurnal Bahan Alam Terbarukan Vol 13, No 1 (2024): June 2024 [Nationally Accredited Sinta 2]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v13i1.49738

Abstract

ZSM-5 can be synthesized from Lampung Natural Zeolite (ZAL) and rice husks as a source of additional silica. To speed up the synthesis time, ZSM-5 was synthesized using microwaves. Based on this, the synthesis of ZSM-5 was carried out using microwaves at a temperature of 140 oC with a power of 540 watts with time variations of 10, 15 and 30 minutes with the seeding method as a template replacement of 20%. Amorphous silica with a SiO2 content of 95.324% was extracted from rice husks with a suitable alkali solution. The influence of synthesis time on the formation of ZSM-5 has been carried out. The resulting product was characterized using X-ray Diffraction (XRD), and FTIR (Fourier-Transform-Infrared), Scanning Electron Microscopy (SEM) and BET (Brunaur, Emmet and Teller). The results of the analysis show that the results of the research show that the synthesis of ZSM-5 has been successfully carried out by changing the amorphous phase from natural Lampung zeolite and rice husks into ZSM-5 crystals using microwaves which can shorten the synthesis time 216 - 72 times faster than with heating. conventional, produces high crystallinity, provides small particle sizes with larger surface area, pore volume and pore diameter, and microwave radiation does not damage the Si-O bonds. The best sample was obtained at a synthesis time of 30 minutes with a crystallinity percentage of 96.76% and a specific surface area of 138.616 m2 /g.
Bahan bakar padat dari biomassa bambu dengan proses torefaksi dan densifikasi Azhar Azhar; Heri Rustamaji
Jurnal Rekayasa Proses Vol 3 No 2 (2009): Volume 3, Number 2, 2009
Publisher : Jurnal Rekayasa Proses

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.563

Abstract

Bamboo can be utililized as biomass through torrefaction and densification processes and be used as solid fuel. In the present work, bamboo was cut into pieces followed by torrefaction process in a furnace. The product of the torrefaction process was then milled or ground to produce smooth powder which was then pressed to form briquettes. The resulting briquettes were characterized by determining their calorific value, proximate analysis, ultimate analysis and burning rate. The torrefaction process was successfully carried out in a temperature range of 200-300°C to obtain charcoal that had following properties: brittle, hydrophobic with decreasing moisture content. The experimental results showed that the calorific value was influenced by bamboo briquette density. Greater the density higher the calorific value of the resulting brequettes. In addition, the rate of burning was also determined by the density. The briquettes that had higher density had lower burning rate. The results showed that torrefaction and densification processes could increase carbon content and calorific value of the bamboo brequttes by 19-20% in a temperature range of 200 – 300°C.
Pemodelan dan simulasi kinetika reaksi alkoholisis minyak Jarak pagar (Jatropha curcas) dengan katalisator zirkonia tersulfatasi Heri Rustamaji; Hary Sulistyo; Arief Budiman
Jurnal Rekayasa Proses Vol 4 No 1 (2010): Volume 4, Number 1, 2010
Publisher : Jurnal Rekayasa Proses

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.571

Abstract

Jatropha oil is a very potential source of biodiesel fuel that can be processed through alcoholysis. In the present work, a study on alcoholysis of Jatropha oil with the use of solid acid catalyst was conducted in a wellmixed batch reactor. The study involved varying reaction temperatures of 100°C to 140°C, ethanol-oil molar ratio of 9, agitation speed of 1000 rpm and catalyst loading of 3% with respect to the oil. The reaction was carried out for 120 minutes; meanwhile samples were taken from the reactor every 15 minutes for glycerol analysis. In order to predict kinetics parameter of the alcoholysis reaction, a mathematical model of consecutive reactions was developed. The Matlab software was used to solve the simultaneous differential equations. Over the range of variables used in the experiment, the mathematical model was able to fit the experimental data quite well. The calculation results showed that the values of collision frequency factor for the consecutive reactions are 5.13 x 103; 5.682 x 103, and 2.534 x 103 (cm3/mgek) (cm3/g.cat/min). Meanwhile, the activation energies for the consecutive reaction are 4,176; 4,310 and 6,019 cal/mol.
The Study of Hydrothermal Carbonization and Activation Factors' Effect on Mesoporous Activated Carbon Production From Sargassum sp. Using a Multilevel Factorial Design Prakoso, Tirto; Rustamaji, Heri; Yonathan, Daniel; Devianto, Hary; Widiatmoko, Pramujo; Rizkiana, Jenny; Guan, Guoqing
Reaktor Volume 22 No.2 August 2022
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.22.2.59-69

Abstract

Seaweeds are large-scale multicellular marine algae categorized based on color as Chlorophyceae, Rhodophyceae, and Phaeophyceae. No information has been provided on the conditions affecting the production of mesoporous activated carbon from one member of the described aquatic plants, namely Sargassum sp. Therefore, this study aimed to determine the impact of the main factors and their interactions on Sargassum sp.-derived activated carbon manufactured (SAC) by hydrothermal carbonization and CO2 activation methods. A mathematical approach was employed using a multilevel factorial design with the main factors being the activator type (ZnCl2, CaCl2, & KOH), hydrothermal temperature (200, 225, & 250oC), and activator ratios (2 & 4). Meanwhile, the response variables were yield and BET surface area (SBET) of SAC. Morphological, functional, crystallographic, and porosity characterization was carried out on the samples. The SAC-Ca-200-2 sample had the highest yield, with the value being 26.5 percent of weight. The activators having the highest specific surface area (SBET) were SAC-Zn-250-4, SAC-Ca-225-2, and SAC-K-250-2, with 1552, 1368, and 1799 m2/g, respectively. The pore size distribution in SAC products ranged from 2.16 to 10 nm in diameter. The analysis conducted indicated the activator type and interaction with its ratio substantially impacted the SAC yield value; besides, only the activator type affects the formation of high surface area pores.
Synthesis of rubber seed shell-derived porous activated carbons for promising supercapacitor application Rustamaji, Heri; Prakoso, Tirto; Devianto, Hary; Widiatmoko, Pramujo; Febriyanto, Pramahadi; Ginting, Simparmin br; Darmansyah, Darmansyah
International Journal of Renewable Energy Development Vol 14, No 2 (2025): March 2025
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2025.60869

Abstract

This work investigates synthesizing activated carbon obtained from rubber seed shells utilizing several activating agents (KOH, CaCl2, and ZnCl2) for supercapacitor applications. Activated carbon was produced from a rubber seed shell using hydrothermal carbonization at 275 °C for 60 minutes and a 120-minute activation treatment at 800 °C. Various activating agents pronounced impacted the pore architecture, surface area, crystallinity, and level of graphitization, which collectively determined the electrochemical characteristics of the resulting materials. Incorporating activation agents enhances the specific surface area and influences the extent of graphitization of activated carbon. The specific surface area of activated carbon products ranges from 367 to 735.2 m² g⁻¹. Further investigation through electrochemical analysis, conducted with a carefully engineered two-electrode system, demonstrated a peak electrode capacitance value of 246 F g-1 at 50 mA g-1 for an ACZn-based supercapacitor. Supercapacitor cells’ energy and power densities reached significant levels, measuring 5.47 Wh kg-1 and 246 W kg-1, respectively. The RSS-derived activated carbon-based supercapacitor exhibited remarkable longevity in a 5000-cycle test, with consistent capacitance retention and coulombic efficiency of 100.11% and 100%, respectively. This work presents a sustainable pathway for producing activated carbon electrodes, contributing to the global circular economy and demonstrating considerable industrial potential.
HUBUNGAN PEMENUHAN KEBUTUHAN SPIRITUAL DENGAN TINGKAT KECEMASAN PASIEN PRE OPERASI ELEKTIF DI RSUD BUNG KARNO KOTA SURAKARTA Heri Rustamaji; Vitri Dyah Herawati; Indriyati, Indriyati
Medic Nutricia : Jurnal Ilmu Kesehatan Vol. 14 No. 1 (2025): Medic Nutricia : Jurnal Ilmu Kesehatan
Publisher : Cahaya Ilmu Bangsa Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5455/nutricia.v14i1.11640

Abstract

Latar belakang :Pada umumnya kecemasan pasien pre operasi dimulai ketika dokter menyatakan akan dilakukan operasi, tindakan pembedahan sering menimbulkan dampak yang luas dan pengaruh psikologis terhadap pasien pre operasi (Smeltzer & Bare, 2016). Kebutuhan spiritual merupakan kebutuhan dasar yang dibutuhkan oleh setiap manusia. Apabila seseorang dalam keadaan sakit, maka hubungan dengan tuhan pun semakin dekat, mengingat seseorang dalam kondisi sakit menjadi lemah dalam segala hal, tidak ada yang mampu membangkitkannya dari kesembuhan, kecuali Sang Pencipta. Dalam pelayanan kesehatan, perawat sebagai petugas kesehatan harus memiliki peran utama dalam memenuhi kebutuhan spiritual (Hasnidar, 2020).Tujuan : untuk mengetahui hubungan antara hubungan pemenuhan kebutuhan spiritual dengan tingkat kecemasan pasien pre operasi di RSUD Bung Karno Kota Surakarta.Metode : Jenis penelitian ini adalah penelitian deskriptif analitik korelasi dengan pendekatan kuantitatif, desain penelitian cross sectional.Penelitian ini dilakukan bulan November – Desember 2024 dengan sampel 55 responden. Hasil penelitian : Hubungan pemenuhan kebutuhan spiritual dengan kecemasan pasien pre operasi di RSUD Bung Karno Surakarta menggunakan uji korelasi Chi Square di dapatkan nilai Sig 0.001 yang artinya terdapat hubungan yang signifikan. Kesimpulan : Ada hubungan pemenuhan kebutuhan spiritual dengan kecemasan pasien pre operasi.
Hidrolisis Ampas Tebu dengan Katalisator Asam Asetat untuk Memproduksi Furfural menggunakan Metode Steam Stripping Listiani, Nita; Iryani, Dewi Agustina; Rustamaji, Heri
Jurnal Rekayasa Kimia & Lingkungan Vol 11, No 2 (2016): Jurnal Rekayasa Kimia & Lingkungan
Publisher : Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23955/rkl.v11i2.4983

Abstract

Proses hidrolisis ampas tebu menggunakan asam asetat sebagai katalis dengan metode satu tahap (steam stripping) telah dilakukan. Ampas tebu sebanyak 50 gram dihidrolisis dalam 500 ml akuades yang mengandung katalis asam asetat sebesar 2 - 6% dengan variabel waktu selama 1 - 3 jam dan temperatur hidrolisis 110 - 120oC menggunakan metode steam stripping. Metode konvensional dilakukan dalam dua tahap yaitu pemasakan dan pemisahan dalam waktu tinggal tertentu, sehingga dapat menyebabkan degradasi furfural. Selain itu, energi yang digunakan sangat besar karena ada energi yang terbuang saat pendinginan produk. Maka peneliti mengembangkan proses hidrolisis hemiselulosa menjadi furfural sekaligus juga proses pemisahan yang dilakukan secara serempak dalam satu tahap yaitu dengan menggunakan metode distilasi steam stripping. Penelitian ini ditujukan untuk melihat apakah metode steam stripping dengan menggunakan katalis asam asetat efektif untuk digunakan dalam memproduksi furfural. Dalam studi ini juga dipelajari pengaruh waktu hidrolisis, konsentrasi katalis, dan temperatur terhadap konsentrasi furfural. Hasil uji menggunakan Response Surface Methodology (RSM) menunjukkan bahwa variabel yang paling berpengaruh untuk perolehan furfural adalah konsentrasi katalis dan temperatur. Hasil penelitian menunjukkan optimum dengan perolehan konsentrasi furfural tertinggi (6,038 mg/ml) di peroleh pada waktu 3 jam, temperatur 120C, dan konsentrasi katalis 6%. Hasil penelitian menunjukkan bahwa metode ini efektif untuk digunakan dalam produksi furfural.
Kajian Tekno Ekonomi Produksi Gliserol Karbonat dari Gliserol dan Urea Rustamaji, Heri; Martinus; Erfani, S; Djanna, M; Febrianti, A; Hillary, S
Prosiding Seminar Nasional Ilmu Teknik Dan Aplikasi Industri Fakultas Teknik Universitas Lampung Vol. 7 (2024): Prosiding Seminar Nasional Ilmu Teknik dan Aplikasi Industi (SINTA) 2024
Publisher : Fakultas Teknik Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Limbah gliserol mentah dari produksi biodiesel dapat digunakan sebagai bahan baku untuk produk dengan nilai tambah seperti gliserol karbonat yang menjadi produk berkualitas di sektor medis dan kecantikan, sebagai pembawa pada baterai litium dan litium-ion, pelarut, komposisi deterjen, surfaktan, perantara kimia, polimer, dan bahan untuk membangun material eko-komposit. Tujuan dari penelitian ini adalah untuk menilai aspek teknis dan ekonomis dari proses produksi gliserol karbonat melalui simulasi. Simulasi dilakukan dengan perangkat lunak yang melibatkan beberapa unit operasi dan unit rekasi. Kemurnian produk gliserol karbonat tinggi sebesar 99,99% dan performa kimia yang baik dengan konversi gliserol 93,20% dan hasil gliserol karbonat sebesar 93,13% berhasil diperoleh. Nilai bersih sekarang (NPV), periode pengembalian (PP), dan tingkat pengembalian internal (IRR) adalah masing-masing 5.480.000 USD, 5,69 tahun, dan 20,9%. Analisis sensitivitas menunjukkan bahwa biaya bahan baku dan harga produk utama memiliki dampak signifikan terhadap NPV dan PP. Untuk meningkatkan keuntungan proses ini, harga gliserol mentah harus kurang dari 0,44 USD/kg dan harga gliserol karbonat harus lebih dari 3,15 USD/kg. Temuan ini menunjukkan bahwa penggunaan gliserol mentah sebagai produk samping dari sintesis biodiesel merupakan pilihan yang sangat baik untuk mengembangkan produk baru dengan nilai lebih tinggi, serta berkontribusi signifikan terhadap prinsip zero-waste dan ekonomi sirkular.
Glukoamilase amobil pada silika mesostructured cellular foam (mcf) magnetik untuk hidrolisis pati kentang Agustian, Joni; Hermida, Lilis; Rustamaji, Heri; Haviz, Muhammad
Prosiding Seminar Nasional Ilmu Teknik Dan Aplikasi Industri Fakultas Teknik Universitas Lampung Vol. 7 (2024): Prosiding Seminar Nasional Ilmu Teknik dan Aplikasi Industi (SINTA) 2024
Publisher : Fakultas Teknik Universitas Lampung

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Abstract

Inovasi dan studi silika mesopori magnetik untuk penyangga imobilisasi enzim glukoamilase untuk hidrolisis pati kentang belum dilakukan karena penyangga magnetik hanya dikaitkan dengan bahan partikel nano baik murni maupun komposit. Proses imobilisasi enzim glukoamilase pada penyangga dengan kondisi operasi proses divariasikan untuk diketahui pengaruhnya terhadap proses dimana hasil akhir adalah tingkat imobilisasi enzim yang cukup besar yang disimpulkan dari hasil analisis kandungan protein (metode Bradford), FTIR dan SEM-EDX. Bahan partikel nano magnetik berhasil diinkorporasi pada permukaan silika MCF (9.2T-3D) dengan tingkat imobilisasi optimum enzim glukoamilase bebas adalah sekitar 89,46% yang didapatkan pada kondisi operasi optimum pH larutan buffer 5,0, suhu operasi 35°C, kecepatan pengadukan 120 rpm,dan konsentrasi enzim suplai sebesar 5,5%. Walaupun unit aktivitas enzim amylase amobil adalah lebih rendah daripada enzim amylase bebas, enzim amobil tetap dapat digunakan untuk menghidrolisis susbtrat larut dalam air. Poses hidrolisis pati kentang dengan enzim tersebut menghasilkan nilai DE optimum 26,93% pada suhu 70°C, kecepatan pengadukan 170 rpm, pH buffer asetat 0,1 M 4,6, dan konsentrasi enzim 1500 U/mg.
Co-Authors Ade Okta Viani Agustian, Joni Ari Wibowo Arief Budiman Arief Budiman Aviati S., Yuniar Azhar Azhar Azhar Daniel Yonathan, Daniel Darmansyah DARMANSYAH . Devianto, Hary Dewi Agustina Iryani Dewi Agustina Iryani, Dewi Agustina Djana, Miftahul Djanna, M Donny Lesmana Erfani, S Erisha Putri Erlangga, Sona Febrianti, A Febriyanto, Pramahadi Ghea Maulidaco Anandati Ginting, Simparmin Boru Guan, Guoqing Guoqing Guan Hary Devianto Hary Devianto Hary Sulistyo Hary Sulistyo Hermida, Lilis Herry Wardono Herti Utami Herti Utami Hillary, S Indriyati Indriyati Isdiriayani Nurdin Jenny Rizkiana Joni Agustian Lilis Hermida Lismeri, Lia Listiani, Nita M. Haviz Martinus Miranda, Thalya Nandi Haerudin Nita Listiani Panca Nugrahini Febriningrum Pramujo Widiatmoko Pramujo Widiatmoko Pramujo Widiatmoko Putri, Erisha Rizkiana, Jenny Rustamaji, Galuh S Septi Qomah Simparmin br Ginting Solly Aryza Sri Ismiyati Damayanti Sumanjaya, Erlan - Thalya Miranda Tirto Prakoso Tirto Prakoso Tirto Prakoso Utami, Heri Vitri Dyah Herawati Widiatmoko, Pramujo Wijaya, Muhammad Niki Yuli Darni Yuli Darni Zulfa Fauziyyah