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34 results on '"Yuliansyah, Ahmad Tawfiequrrahman"'

1. Furfural purification and production from prospective agricultural waste of oil palm empty fruit bunch: Simulation, design and economic assessments

Author

Muryanto, Handita, Fabio Carisma, Harahap, Andre Fahriz Perdana, Sahlan, Muhammad, Hermansyah, Heri, Darmawan, Muhammad Arif, Saputra, Hens, Murti, Sri Djangkung Sumbogo, Hartanto, Danang Tri, Yuliansyah, Ahmad Tawfiequrrahman, Putra, Meilana Dharma, Mirwan, Agus, Cognet, Patrick, Aroua, Mohamed Kheireddine, and Gozan, Misri

Published
2024
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4. On the influence of silica nanoparticles for enhanced oil recovery (EOR).

Author

Dampang, Sarah, Azis, Muhammad Mufti, Yuliansyah, Ahmad Tawfiequrrahman, and Purwono, Suryo

Subjects
ENHANCED oil recovery, SILICA nanoparticles, GAS industry, SURFACE tension, INTERFACIAL tension
Abstract

Utilization of nanoparticles in oil and gas sector has gained a significant interest. Silica nanoparticles is often considered as a promising chemical to improve the Enhanced Oil Recovery (EOR) process. The objective of this work was to provide a mini review to address the effect of silica nanoparticles addition in a chemical EOR. In this work, we have reviewed the influence of nanoparticles to reduce Interfacial Surface tension (IFT), to alter wettability, to reduce oil viscosity, to improve fluid rheology, and to alter structural disjoining pressure. We expect that this review may provide a useful guidelines for the development of silica nanoparticles in Indonesia. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Highly Efficient Modified Constructed Wetlands Using Waste Materials for Natural Acid Mine Drainage Treatment.

Author

Wibowo, Yudha Gusti, Wijaya, Candra, Yudhoyono, Aryo, Sudibyo, Yuliansyah, Ahmad Tawfiequrrahman, Safitri, Hana, Tsabitah, Natasya, Nur'ani, Herlina, Khairurrijal, Khairurrijal, and Petrus, Himawan Tri Bayu Murti

Abstract

Coal-mining activities have well-documented adverse effects on both the environment and human health. Acid mine drainage, a pivotal concern, necessitates effective interventions. This study introduces a novel solution: a modified constructed wetlands crafted exclusively from waste materials, ensuring cost-effectiveness. The innovation yielded exceptional results, achieving a noteworthy reduction of up to 99% in heavy metal concentrations, alongside swift pH normalization. What sets this study apart is its potential beyond the laboratory setting; the utilization of waste materials and low-cost methodologies underscores its scalability and practicality. This solution addresses immediate challenges and showcases promise for real-world implementation. Moreover, the results of the study extend to its insights, which offer a comprehensive examination of the method's reusability prospects, illuminating its sustained impacts; the recommendations for future action enhance its practical significance. This study marks a significant advancement in tackling acid mine drainage. The modified constructed wetlands, driven by cost-effective waste materials, embody scalable and sustainable potential. With its holistic outlook and strategic roadmap, this study holds the key to transforming acid mine drainage challenges, particularly in rural and developing regions. [ABSTRACT FROM AUTHOR]

Published
2023
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14. Kajian Kinerja Sistem Instalasi Pengolahan Air Limbah (IPAL) Komunal

Author

Kurnianingtyas, Erlina, Prasetya, Agus, Yuliansyah, Ahmad Tawfiequrrahman, Kurnianingtyas, Erlina, Prasetya, Agus, and Yuliansyah, Ahmad Tawfiequrrahman

Abstract

IPAL Komunal Kalisong dibangun pada 2011 dengan menggabungkan sistem Anerobic Baffled Reactor (ABR) dan Anaerobic Filter (AF), namun belum dilakukan evaluasi kinerja IPAL Komunal. Pada operasional terdapat permasalahan seperti hasil efluent yang berwarna keruh dan masuknya limbah non domestik ke dalam instalasi IPAL. Penelitian ini bertujuan untuk mengkaji efisiensi pengurangan BOD, COD, TSS pada IPAL Komunal, mengidentifikasi dan mengkaji faktor teknis dan sosial penyebab penurunan kinerja IPAL. Analisis data mencangkup analisa kualitas efluent terhadap baku mutu, efisiensi unit pengolahan IPAL, dan kesesuaian bangunan dengan kriteria desain, sedangkan dari faktor sosial dilakukan wawancara kepada pengelola dan pengguna IPAL. Hasil kajian sosial menunjukkan pengelola dan pengguna IPAL belum melakukan pemeliharaan sesuai prosedur, sehingga berpengaruh terhadap performa IPAL. Pengguna IPAL mengalami penurunan dari 45 KK menjadi 21 KK, karena air limbah tidak mengalir. Debit air limbah 38,12 m3/hari, efluent yang dihasilkan dengan parameter pH 9,2, COD 180,99 mg/L dengan effisiensi 41,04 %, TSS 238,06 mg/L dengan effisiensi 71,55 %, dan BOD 87,09 mg/L dengan effisiensi 54,02 % yang belum sesuai dengan baku mutu. Nilai HRT eksisting dan HRT kriteria desain proses sedimentasi dan desain ABR masing-masing 8 jam serta 1,2-2 jam dan 22 jam serta > 8 jam. Pada AF nilai HRT eksisting dan kriteria desain yaitu 17 jam dan 24 – 48 jam. Penyebab IPAL Komunal tidak optimal adalah adanya limbah non domestik yang masuk, nilai HRT pada sedimentasi dan AF belum memenuhi kriteria desain dan kurangnya pemeliharaan oleh pengelola dan pengguna IPAL.

Published
2020

23. Mathematical Model for Water Flooding and HPAM Polymer Flooding in Enhanced Oil Recovery.

Author

Yuliansyah, Ahmad Tawfiequrrahman, Murachman, Bardi, and Purwono, Suryo

Subjects
*ENHANCED oil recovery, *MATHEMATICAL models, *POLYMER solutions, *POROUS materials, *POLYMERS, *PETROLEUM
Abstract

The need for energy, especially the petroleum-based one, is steadily increasing along with population growth and technological advancement. Meanwhile, oil exploitation from oil reservoirs using primary and secondary techniques can only obtain about 30%-50 % out of the original oil in place. Enhanced Oil Recovery (EOR) is a method for increasing oil recovery from a reservoir by injecting materials that are not found in the reservoir, such as surfactant, polymer, etc. This research aims to develop a mathematical model representing two-phase flow through porous media in the EOR process. This model was extended from mass balance and fluid flow in porous media equations. The reliability of the model was then validated by water flooding and polymer flooding experiment. A porous media, constituted by a silica sand pack, was saturated with 2 % brine and sequentially flooded with HPAM polymer solution at various concentrations (5,000-15,000 ppm). The volume of the oil coming out from the media at any time intervals was measured. Validation of the model was carried out by optimizing the model parameters to obtain the best curve-fitting on the plot of the percentage of cumulative recovered oil against time. The results showed that the proposed mathematical model was reliable enough to express both water and polymer-flooding processes. [ABSTRACT FROM AUTHOR]

Published
2021
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26. The Effect of Packing Media Addition on Biogas Production from Rubber Industrial Wastewater.

Author

El Mawaddah, Marisah, Purnomo, Chandra Wahyu, and Yuliansyah, Ahmad Tawfiequrrahman

Subjects
BIOGAS production, INDUSTRIAL wastes, SEWAGE, UPFLOW anaerobic sludge blanket reactors, PACKED bed reactors, RENEWABLE energy sources
Abstract

Latex is a yellowish colloidal liquid from rubber trees that can be used for natural rubber production. The latex processing creates quite large volume of wastewater that has very strong odor and high organic content which is suitable for biogas production in providing renewable energy resources. The purpose of this research is to study and optimize the biogas production from latex wastewater using 40 L packed bed anaerobic reactors with support media of bio-balls or called anaerobic filter reactor. Some key parameters of sCOD, pH, and methane gas composition have been observed. The reactor was operated batch for 36 days with or without packing media (bio-balls). The optimum results of sCOD removal was 81,73% and methane gas content of 55.089% using reactor with packing. The anaerobic filter column was used in continuous mode with 2L/day influent that can reach a steady condition within about 20 days and produce up to 95% COD removal. [ABSTRACT FROM AUTHOR]

Published
2019
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27. Pengaruh Jenis Limbah dan Rasio Umpan pada Biokonversi Limbah Domestik Menggunakan Larva Black Soldier Fly (Hermetia illucens)

Author

Muhayyat, Mahfudl Sidiq, Yuliansyah, Ahmad Tawfiequrrahman, and Prasetya, Agus

Subjects
domestic waste, bioconversion, Hermetia illucens larvae
Abstract

The high content of protein is the main reason for domestic waste to be potentially processed by bioconversion using Hermetia illucens larvae. Hermetia illucens larva can accumulate protein content as high as 45-50% and fat which reaches 24-30%, so that it becomes a good source of highly nutritious feed. This research studied the production of Hermetia illucens larvae through bioconversion process on rice waste, cassava leaf, and mixed rice-cassava leaf (with the weight ratio of 1: 1), by varying the feed rate of 60, 80, and 100 mg/larva/day. The experiment was conducted for 21 days. Samples were taken periodically to be analyzed for their weight, substrate consumption, and waste reduction index. Proximate analysis was conducted on raw material and larvae media. The results of this study indicated that the optimum waste for larvae was the mixed rice-cassava leaf waste with feed rate of 60 mg/larva/day or total weight of 10.00 grams per feeding. At this condition, the optimal waste reduction in the bioconversion process was observed as substrate consumption of 65.82% and the waste reduction index of 18.02%. ABSTRAKTingginya kandungan protein membuat limbah domestik berpotensi untuk diproses secara biokonversi dengan menggunakan larva Hermetia illucens. Larva Hermetia illucens memiliki kandungan nutrisi protein yang mencapai 45-50% dan lemak yang mencapai 24-30%, sehingga dapat dijadikan sumber pakan bernutrisi tinggi. Penelitian ini mempelajari produksi larva Hermetia illucens melalui proses biokonversi pada limbah nasi, daun singkong dan campuran nasi-daun singkong (1:1), dengan memvariasikan feed rate sebesar 60, 80, 100 mg/larva/hari. Penelitian dilakukan selama 21 hari, dengan menganalisis berat larva, substrate consumption, dan waste reduction index. Analisis proksimat dilakukan pada media pakan dan larva. Hasil penelitian ini menunjukan bahwa limbah yang paling optimal memproduksi larva dalam proses ini adalah limbah campuran nasi-daun singkong dengan feed rate 60 mg/larva/hari atau dengan berat total 10,00 gram per feeding. Reduksi limbah paling optimal pada proses biokonversi teramati sebagai nilai konsumsi substrat sebesar 65,82% dan waste reduction index sebesar 18,02%.

Published
2016

29. Pemanfaatan Cangkang Biji Pala sebagai Briket dengan Proses Pirolisis

Author

Rukmana, Purwono, Suryo, and Yuliansyah, Ahmad Tawfiequrrahman

Abstract

The abundance of nutmeg seed shells in Tidore is the reason to study the possibility to produce charcoal briquettes. The use of charcoal briquettes was expected to reduce waste of nutmeg seed shell and can be an alternative energy source with a high economic value. This study aims to investigate the effect of pyrolysis temperature and composition of tapioca adhesive to resulting quality of briquettes. The first step of the research was the preparation of nutmeg seed shells consisted of drying and size reduction into less than 20 mesh size. Afterward, the powder was put into furnace and heated to 350°C, 400°C, and 450°C for 90 minutes. During the process, volume of gas and liquids were measured every 15 minutes, while gas was sampled at 60-minute reaction. When pyrolysis was finished, about 20 g of charcoal was mixed with tapioca adhesive. The compositions of adhesive were 10%, 15%, 20%, 25%, and 30%. Finally, composite was formed in a cylindrical shape and compressed with hydraulic press at f 3 tons weight for a minute. The briquettes were then dried and analyzed with proximate analysis test. The results show that the highest calorific value was 6717.74 cal/g for material pyrolyzed at 450oC and 20% adhesive. The effect of adhesive on shatter index test showed that increasing composition of adhesive makes a better briquette quality as shown by a lower shatter index. In this study, the minimum weight loss was obtained by the addition of 30% adhesive. Keywords: briquettes, nutmeg seed shells, pyrolysis Ketersediaan cangkang biji pala yang melimpah di kota Tidore menjadi dasar dilakukannya penelitian mengenai pemanfaatan cangkang biji pala menjadi briket arang. Penggunaan briket arang diharapkan dapat mengurangi limbah cangkang biji pala dan sebagai sumber energi alternatif ramah lingkungan yang memiliki nilai ekonomi tinggi. Penelitian ini bertujuan untuk mempelajari pengaruh suhu pirolisis dan komposisi campuran perekat dengan arang cangkang biji pala terhadap kualitas briket. Tahap pertama dalam penelitian ini adalah penyiapan bahan baku berupa pengeringan dan penyesuaian ukuran cangkang biji pala sebesar 20 mesh. Tahap kedua yaitu proses pirolisis dengan cara memasukkan bubuk cangkang biji pala ke dalam tungku pirolisis (pirolisis selama 90 menit dengan variasi suhu 350oC, 400oC dan 450oC). Selama proses pirolisis berlangsung, volume gas dan cairan diukur setiap 15 menit, sedangkan pengambilan sampel gas dilakukan setelah pirolisis mencapai waktu 60 menit. Setelah dipirolisis, arang cangkang biji pala ditimbang seberat 20 gram kemudian bahan ini dicampurkan dengan perekat tapioka dengan variasi komposisi sebesar 10%, 15%, 20%, 25%, dan 30%. Setelah itu, arang cangkang biji pala dicetak dalam bentuk silinder dan dikempa dengan alat kempa hidrolik dengan berat 3 ton selama 1 menit. Briket kemudian dikeringkan dan dianalisis uji proksimat. Hasil uji proksimat menunjukkan bahwa nilai kalor yang tertinggi sebesar 6717,74 kal/g dimiliki oleh bahan hasil pirolisis suhu 450oC dengan campuran perekat 20%. Pengaruh perekat terhadap uji shatter index menunjukkan bahwa semakin tinggi kandungan perekat dalam briket maka semakin baik shatter index dari briket. Pada penelitian ini diketahui bahwa briket dengan penambahan perekat sebesar 30% mengalami kehilangan berat yang paling sedikit. Kata kunci: briket, cangkang biji pala, pirolisis

Published
2015

30. Karakterisasi Larutan Polimer KYPAM HPAM untuk Bahan Injeksi dalam Enhanced Oil Recovery (EOR)

Author

Wicaksono, Harimurti, Sutijan, and Yuliansyah, Ahmad Tawfiequrrahman

Abstract

Polymer injection is one method of Enhanced Oil Recovery (EOR), where the polymer is dissolved in water, usually the formation water. Hydrolyzed polyacrylamide (HPAM) polymer types are most commonly used. This study aims to investigate the effect of KYPAM HPAM polymer concentration and operating conditions upon the water injection in order to determine the optimal injection system. Viscosity of polyacrylamide solution was measured with a Brookfield viscometer. Variation in salinity is carried out by mixing formation water with distilled water, whereas for high salinity of formation water using evaporation method. Shear rate was varied in the range of 145 s-1, while solution temperature was varied in the range of 70  87°C , and the effect of H2S gas in the solution was conducted by saturating the solution using natural gas which has concentration of H2S as 100 ppm. The results show that the effect of salinity solution has the greatest influence on the decrease in viscosity of the solution when compared to the other factors. Decrease in viscosity was due to agglomeration process resulting precipitate of polyacrylamide in the form of vaterite and aragonite morphology. The result also show that an increase in shear rate resulting lower viscosity. The increase in temperature causes the viscosity of the solution decreases. Meanwhile, the presence of H2S in the solution reduces the viscosity of the solution due to chemical degradation. Keywords: EOR, formation water, polymer injection, hydrolyzed polyacrylamide, salinity, polymer concentration. Injeksi polimer merupakan salah satu metode dalam Enhanced Oil Recovery (EOR). Dalam hal ini, polimer terlebih dulu dilarutkan dalam air, biasanya air formasi. Poliakrilamida terhidrolisis (HPAM) merupakan salah satu jenis polimer yang paling sering digunakan. Penelitian ini bertujuan untuk mengetahui pengaruh konsentrasi polimer KYPAM HPAM dan kondisi operasi pada injeksi air untuk menentukan sistem injeksi yang optimal. Larutan poliakrilamida diukur viskositasnya dengan viskometer Brookfield. Variasi salinitas dilakukan dengan mencampur air formasi dan aquades, sedangkan untuk salinitas tinggi dari air formasi dengan menggunakan metode penguapan.Variasi shear rate dilakukan pada kisaran 145 s-1, sedangkan suhu larutan divariasikan di kisaran 7087°C. Pengaruh gas H2S dalam larutan dilakukan dengan menjenuhkan larutan menggunakan gas alam yang memiliki konsentrasi H2S 100 ppm. Hasil penelitian menunjukkan bahwa salinitas memiliki pengaruh terbesar pada penurunan viskositas larutan bila dibandingkan dengan faktor-faktor lain. Penurunan viskositas disebabkan aglomerasi menghasilkan endapan poliakrilamida dalam bentuk vaterite dan morfologi aragonit. Hasil percobaan juga menunjukkan bahwa peningkatan shear rate, mengakibatkan viskositas larutan terukur rendah. Peningkatan suhu menyebabkan viskositas larutan turun, sedangkan kehadiran H2S dalam larutan mengurangi viskositas larutan karena terjadi degradasi kimia pada polimer. Kata kunci: EOR, air formasi, injeksi polimer, hydrolyzed polyacrylamide, salinitas, konsentrasi polimer

Published
2015

31. Preparation of Supercritical Fluid Extraction Using Dry Ice and Exploration of Equation of State to Predict The Operating Conditions.

Author

Kwartiningsih, Endang, Sediawan, Wahyudi Budi, Hidayat, Muslikhin, and Yuliansyah, Ahmad Tawfiequrrahman

Subjects
SUPERCRITICAL fluid extraction, SUPERCRITICAL fluids, SOLVENTS, SUPERCRITICAL carbon dioxide, DRY ice, EQUATIONS of state
Abstract

Supercritical Fluid Extraction (SFE) is the process of separating a soluble material from an insoluble residue using the supercritical fluid as the extracting solvent. This extraction is the most effective and efficient way to extract valuable constituent in botanicals. Supercritical carbon dioxide is a fluid state of carbon dioxide that is held above its critical temperature (Tc=31.1 °C) and critical pressure (Pc=73.8 bar). It is a natural solvent and has been widely used in practical applications because of its non-toxic, non-flammable, plentiful, inexpensive and tunable of solvent properties by just adjusting temperature and pressure. Due to carbon dioxide's relatively low critical temperature, it is especially suitable for processing thermo-labile compounds, such as pharmaceutical and nutraceutical compounds. Nevertheless, the cost of SFE equipment is outside the range of most of our finances. A high-pressure intensifier pump is used to achieve the required pressure. In this research, the supercritical CO2 condition was achieved by other alternative using dry ice. It is a solid phase of CO2 when frozen. At standard temperature and pressure (STP), CO2 usually behaves as a gas. If dry ice is put in an enclosed vessel, it will sublimate to become a gas and the pressure will increase depending on the mass of dry ice until the desired pressure (supercritical pressure) is achieved. By supercritical CO2 from dry ice, the equipment of SFE will be simpler and cheaper. It is also suitable for batch operation to get equilibrium data of supercritical fluid extraction. Exploration of Equation of State, such as Ideal Gas, van der Waals, Redlich Kwong, Soave-Redlich Kwong and Peng Robinson, was done to predict the operating condition (supercritical pressure and temperature). In this research, by comparing the calculated and the experimental data, Peng Robinson is considered as the most appropriate Equation of State. [ABSTRACT FROM AUTHOR]

Published
2018
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34. Solid Biofuel Production from Meranti (Shorea Sp.) Sawdust Using Hydrothermal Treatment

Author

Mappapa, Indah Astieningsih and Yuliansyah, Ahmad Tawfiequrrahman

Abstract

In the context of industrialization, wood industry plays an important role as one of thepillar components in building Indonesia industry where 76.36% is supported by Meranti (Shorea Sp.).However, the increase of wood processing industries produces waste biomass in the form of largeamount sawdust. Hydrothermal treatment is an environmentally clean technology of convertingbiomass into coal-like solid called hydrochar using subcritical water. The purpose of this research isto determine the effect of temperature and water to biomass (b/w) ratio in the formation of hydrocharfrom Meranti sawdust. This research was carried out using a 250 mL hydrothermal reactor where amixture of Meranti sawdust and water heated at temperature variation of 240 and 300oC; b/w ratio1:20, 2:20, 3:20; initial pressure of 1.0 Mpa and holding time for 30 minutes. Hydrochar were thencharacterized in terms of yield, caloric value, proximate and ultimate analysis. Based on experimentalresult, 39-78% raw materials were converted into hydrochar where the highest yield was found ontemperature operation of 240oC and b/w ratio 2:20.

Published
2018
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