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Effect of Devices and Driving Pressures on Energy Requirements and Mass Transfer Coefficient on Microalgae Lipid Extraction Assisted by Hydrodynamic Cavitation Setyawan, Martomo; Mulyono, Panut; Sutijan, Sutijan; Pradana, Yano Surya; Prasakti, Laras; Budiman, Arief
International Journal of Renewable Energy Development Vol 9, No 3 (2020): October 2020
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2020.26773

Previous studies of biodiesel production from microalgae have concluded that microalgal biodiesel is not profitable at an industrial scale due to its excessive energy consumption for lipid extraction. Hydrodynamic cavitation lipid extraction is one of the extraction methods which has lower energy consumption. Thismethod enables a fast extraction rate and low energy consumption for cell disruption. In order to achieve optimum process conditions, several influential parameters, which are cavitation generator geometry and driving pressure, need to be scrutinized. The experimental result showed that the maximum yield was obtained at 5 bar driving pressure. The lowest specific extraction energy was obtained at 4.167 bar driving pressure while using one side concave cavitation generator geometry with the ratio of the reduced cross-sectional area of 0.39. The value of the energy extraction requirement 17.79 kJoule/g lipids is less than the biodiesel heating value, and the value of the volumetric mass transfer coefficient is almost 20 times fold greater than the conventional extraction method, therefore this method is promising to be further developed.

The Effect of Biomass-Water Ratio on Bio-crude Oil Production from Botryococcus braunii using Hydrothermal Liquefaction Process Laras Prasakti; Rochmadi Rochmadi; Arief Budiman
Jurnal Rekayasa Proses Vol 13, No 2 (2019)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

The increasing demand of energy in Indonesia has led to the urgency to conduct research and development in renewable energy. Biomass is one of the largest renewable energy sources in Indonesia. For biomass to energy conversion, hydrothermal liquefaction (HTL) has been considered as one of the potential methods where biomass is processed using subcritical water to produce bio-oil, aqueous phase, gas, and solid product. In this research, the effect of biomass-water ratio on hydrothermal liquefaction (HTL) process of microalgae Botryococcus braunii has been investigated. The HTL was conducted using biomass/water ratio 1:10, 1:20 and 1:30 with various holding time for each ratio. The product was bio-crude oil with similar characteristics to crude oil. Experimental results showed that biomass-water ratio affected the distribution of bio-crude oil yields. For biomass-water ratio of 1:10 and 1:20, it was found that bio-crude oil yields reached a maximum at 20 minutes, while the highest bio-crude oil yield of 4% was obtained at biomass-water ratio of 1:10. On the other hand, with biomass-water ratio of 1:30, bio-crude oil yield was continuously increasing with holding time until it reached the maximum yield of 4% at 40 minutes of holding time. The aforementioned results indicated that the highest bio-crude oil yield was obtained using biomass-water ratio 1:10 and 20 minutes of HTL processing time. A B S T R A KPeruraian anaerobik merupakan salah satu bidang riset yang sangat menarik perhatian dalam era krisis energi. Biogas tidak hanya menyediakan energi alternatif, tetapi juga dapat mencegah pencemaran akibat limbah organik. Limbah lemak susu adalah substrat yang potensial untuk proses peruraian anaerobik karena memiliki potensi biogas teoritis yang tinggi akibat kandungan lemaknya yang tinggi. Namun, peruraian anaerobik dari limbah organik dengan kandungan lemak yang tinggi memiliki tantangan tersendiri. Hambatan utama dalam peruraian anaerobik dari limbah lemak susu adalah kecenderungan untuk membentuk lapisan padatan yang tidak larut dan mengapung di bagian atas fase cair. Fenomena ini menghambat akses bakteri hidrolisis terhadap substrat. Saponifikasi adalah salah satu cara untuk meningkatkan kelarutan lapisan padatan tersebut, sehingga meningkatkan ketersediaan substrat untuk bakteri. Saponifikasi akan mengubah kandungan lemak menjadi sabun yang memiliki gugus fungsi polar maupun non-polar. Gugus fungsi yang bersifat polar akan meningkatkan kelarutan substrat dalam air. Studi ini mengevaluasi pengaruh dari berbagai dosis larutan basa yang ditambahkan sebagai reaktan selama perlakuan awal saponifikasi terhadap peruraian anaerobik limbah lemak susu. Kinetika proses peruraian anaerobik dianalisis dengan menggunakan model matematika. Variasi dosis yang diamati pengaruhnya untuk perlakuan awal saponifikasi adalah 0,04 mol basa/g sCOD; 0,02 mol basa/g sCOD; dan nol (tanpa perlakuan awal saponifikasi). Dari penelitian ini, terbukti bahwa saponifikasi berhasil meningkatkan kelarutan limbah lemak susu dan juga ditunjukkan oleh nilai konstanta hidrolisis (kH) 0,00782/hari lebih tinggi dua puluh kali lipat dibandingkan dengan nilai kH 0,00032/hari pada reaktor tanpa saponifikasi. Akan tetapi, penelitian ini juga mengindikasikan bahwa bakteri asidogenik bawaan substrat terhambat kinerjanya oleh paparan pH yang tinggi selama perlakuan awal saponifikasi berlangsung sehingga hasil gas metan yang diperoleh lebih rendah daripada reaktor kontrol.

Penyisihan Kontaminan dari Air Limbah Hasil Daur Ulang Baterai LiFePO4 (LFP) Menggunakan Penukar Ion Resin Kation Amberlite HPR1100 Na dan Resin Anion Dowex Marathon A Satryo Dewanto Suryohendrasworo; Laras Prasakti; Sarah Nabila Salma; Agus Prasetya
Jurnal Rekayasa Proses Vol 15, No 2 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.69847

Pada tahun 2025, diperkirakan kebutuhan baterai Li-ion akan mencapai 400.000 ton. Upaya strategis diperlukan untuk mewujudkan pemakaian baterai Li-ion yang berkelanjutan. Setelah siklus pemakaian baterai Li-ion berakhir, baterai Li-ion akan diproses kembali untuk diambil kandungan logam-logam penting yang terkandung di dalam katoda, terutama litium. Secara umum, proses recycle tersebut dilakukan dengan metode hidrometalurgi yang terdiri atas rangkaian leaching dan presipitasi. Namun demikian, dalam proses pemurnian tersebut dihasilkan air limbah yang mengandung beragam logam dengan konsentrasi yang berbeda. Untuk baterai LFP, logam-logam tersebut berasal dari katoda yang mengandung Li, Na, Si, dan PO4. Proses pelindian dan pencucian serbuk katoda membutuhkan air dalam jumlah yang relatif besar. Pengolahan air limbah hasil proses daur ulang baterai diharapkan dapat secara signifikan meningkatkan efisiensi penggunaan air. Pada eksperimen ini, metode adsorpsi batch dengan ion-exchange resin kation Amberlite HPR1100 Na dan resin anion Dowex Marathon A digunakan untuk menghilangkan ion logam dari air limbah artifisial. Pengambilan sampel air limbah yang diolah diambil pada menit ke-3, 6, 10, 20, 30 dan hari ke-3. Berdasarkan pada hasil removal percentage, diperoleh bahwa pengolahan air limbah artifisial metode adsorpsi dengan menggunakan ion-exchange resin kation Amberlite HPR1100 Na dapat mengurangi kadar ion litium dan natrium sampai 100% pada menit ke-20 dengan variasi dosis adsorben 10 g/100 mL, sedangkan penggunaan ion-exchange resin anion Dowex Marathon A dapat mengurangi kadar ion fosfat sampai 100% pada menit ke-30 dengan dosis adsorben 10 g/100 mL. Dengan adsorpsi isotherm didapat model Langmuir lebih sesuai dengan data eksperimen dengan nilai parameter Qm dan KL untuk ion litium sebesar 1,16 mg/g dan 2,57 mg/g, ion natrium sebesar 74,62 mg/g dan 0,04 mg/gL/mg, dan ion fosfat sebesar 208,33 mg/g dan 0,06 mg/g. Selain itu, studi kinetika menunjukkan bahwa model pseudo second-order memiliki kesesuaian data yang lebih baik daripada pseudo first-order.

Problem Solving of Isopropyl Alcohol – Water Azeotropic Characteristics Using Packed (Natural Zeolite) Bed Adsorber Laras Prasakti; Muhammad Hartono; Pandu Prabowo Jati; Muhammad Fajar Setiaji; Sang Kompiang Wirawan; Hanifrahmawan Sudibyo
ASEAN Journal on Science and Technology for Development Vol. 37 No. 1 (2020): Earth, Water & Fire
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29037/ajstd.611

The adsorption kinetics of water from an azeotropic mixture of isopropyl alcohol and water using chemically activated natural zeolites with and without a binder (starch) was investigated. In addition, an investigation of the compressive strength of zeolite pellets was conducted to ascertain the performance of the adsorbent for long-term operation. Three parameters were applied in the zeolite-making process: the particle size of zeolite (20, 30, 50, and 80 mesh), the sintering temperature (550, 750, and 1,000°C), the compaction pressure (2, 4, and 6 tonnes), and the starch-to-zeolite weight ratio (0, 1:3, 1:5, and 1:7). Initial screenings indicated that the strongest zeolite pellet was 80-mesh zeolite powder (without starch addition) that was compacted using 6 tonnes pressure and was sintered at 750°C. The adsorption tests using the strongest zeolite were conducted in a packed-bed column for three cycles, followed by compressive strength tests on the zeolite pellets after each cycle. According to the experimental data, zeolite pellets made without the addition of starch could adsorb up to 98.4% of the initial water in the mixture. From the four models proposed to describe the kinetics of adsorption of water from the mixture, the Freundlich model turned out to be the best model.

The Effect of Biomass-Water Ratio on Bio-crude Oil Production from Botryococcus braunii using Hydrothermal Liquefaction Process Laras Prasakti; Rochmadi Rochmadi; Arief Budiman
Jurnal Rekayasa Proses Vol 13, No 2 (2019)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

The increasing demand of energy in Indonesia has led to the urgency to conduct research and development in renewable energy. Biomass is one of the largest renewable energy sources in Indonesia. For biomass to energy conversion, hydrothermal liquefaction (HTL) has been considered as one of the potential methods where biomass is processed using subcritical water to produce bio-oil, aqueous phase, gas, and solid product. In this research, the effect of biomass-water ratio on hydrothermal liquefaction (HTL) process of microalgae Botryococcus braunii has been investigated. The HTL was conducted using biomass/water ratio 1:10, 1:20 and 1:30 with various holding time for each ratio. The product was bio-crude oil with similar characteristics to crude oil. Experimental results showed that biomass-water ratio affected the distribution of bio-crude oil yields. For biomass-water ratio of 1:10 and 1:20, it was found that bio-crude oil yields reached a maximum at 20 minutes, while the highest bio-crude oil yield of 4% was obtained at biomass-water ratio of 1:10. On the other hand, with biomass-water ratio of 1:30, bio-crude oil yield was continuously increasing with holding time until it reached the maximum yield of 4% at 40 minutes of holding time. The aforementioned results indicated that the highest bio-crude oil yield was obtained using biomass-water ratio 1:10 and 20 minutes of HTL processing time. A B S T R A KPeruraian anaerobik merupakan salah satu bidang riset yang sangat menarik perhatian dalam era krisis energi. Biogas tidak hanya menyediakan energi alternatif, tetapi juga dapat mencegah pencemaran akibat limbah organik. Limbah lemak susu adalah substrat yang potensial untuk proses peruraian anaerobik karena memiliki potensi biogas teoritis yang tinggi akibat kandungan lemaknya yang tinggi. Namun, peruraian anaerobik dari limbah organik dengan kandungan lemak yang tinggi memiliki tantangan tersendiri. Hambatan utama dalam peruraian anaerobik dari limbah lemak susu adalah kecenderungan untuk membentuk lapisan padatan yang tidak larut dan mengapung di bagian atas fase cair. Fenomena ini menghambat akses bakteri hidrolisis terhadap substrat. Saponifikasi adalah salah satu cara untuk meningkatkan kelarutan lapisan padatan tersebut, sehingga meningkatkan ketersediaan substrat untuk bakteri. Saponifikasi akan mengubah kandungan lemak menjadi sabun yang memiliki gugus fungsi polar maupun non-polar. Gugus fungsi yang bersifat polar akan meningkatkan kelarutan substrat dalam air. Studi ini mengevaluasi pengaruh dari berbagai dosis larutan basa yang ditambahkan sebagai reaktan selama perlakuan awal saponifikasi terhadap peruraian anaerobik limbah lemak susu. Kinetika proses peruraian anaerobik dianalisis dengan menggunakan model matematika. Variasi dosis yang diamati pengaruhnya untuk perlakuan awal saponifikasi adalah 0,04 mol basa/g sCOD; 0,02 mol basa/g sCOD; dan nol (tanpa perlakuan awal saponifikasi). Dari penelitian ini, terbukti bahwa saponifikasi berhasil meningkatkan kelarutan limbah lemak susu dan juga ditunjukkan oleh nilai konstanta hidrolisis (kH) 0,00782/hari lebih tinggi dua puluh kali lipat dibandingkan dengan nilai kH 0,00032/hari pada reaktor tanpa saponifikasi. Akan tetapi, penelitian ini juga mengindikasikan bahwa bakteri asidogenik bawaan substrat terhambat kinerjanya oleh paparan pH yang tinggi selama perlakuan awal saponifikasi berlangsung sehingga hasil gas metan yang diperoleh lebih rendah daripada reaktor kontrol.

Penyisihan Kontaminan dari Air Limbah Hasil Daur Ulang Baterai LiFePO4 (LFP) Menggunakan Penukar Ion Resin Kation Amberlite HPR1100 Na dan Resin Anion Dowex Marathon A Satryo Dewanto Suryohendrasworo; Laras Prasakti; Sarah Nabila Salma; Agus Prasetya
Jurnal Rekayasa Proses Vol 15, No 2 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.69847

Pada tahun 2025, diperkirakan kebutuhan baterai Li-ion akan mencapai 400.000 ton. Upaya strategis diperlukan untuk mewujudkan pemakaian baterai Li-ion yang berkelanjutan. Setelah siklus pemakaian baterai Li-ion berakhir, baterai Li-ion akan diproses kembali untuk diambil kandungan logam-logam penting yang terkandung di dalam katoda, terutama litium. Secara umum, proses recycle tersebut dilakukan dengan metode hidrometalurgi yang terdiri atas rangkaian leaching dan presipitasi. Namun demikian, dalam proses pemurnian tersebut dihasilkan air limbah yang mengandung beragam logam dengan konsentrasi yang berbeda. Untuk baterai LFP, logam-logam tersebut berasal dari katoda yang mengandung Li, Na, Si, dan PO4. Proses pelindian dan pencucian serbuk katoda membutuhkan air dalam jumlah yang relatif besar. Pengolahan air limbah hasil proses daur ulang baterai diharapkan dapat secara signifikan meningkatkan efisiensi penggunaan air. Pada eksperimen ini, metode adsorpsi batch dengan ion-exchange resin kation Amberlite HPR1100 Na dan resin anion Dowex Marathon A digunakan untuk menghilangkan ion logam dari air limbah artifisial. Pengambilan sampel air limbah yang diolah diambil pada menit ke-3, 6, 10, 20, 30 dan hari ke-3. Berdasarkan pada hasil removal percentage, diperoleh bahwa pengolahan air limbah artifisial metode adsorpsi dengan menggunakan ion-exchange resin kation Amberlite HPR1100 Na dapat mengurangi kadar ion litium dan natrium sampai 100% pada menit ke-20 dengan variasi dosis adsorben 10 g/100 mL, sedangkan penggunaan ion-exchange resin anion Dowex Marathon A dapat mengurangi kadar ion fosfat sampai 100% pada menit ke-30 dengan dosis adsorben 10 g/100 mL. Dengan adsorpsi isotherm didapat model Langmuir lebih sesuai dengan data eksperimen dengan nilai parameter Qm dan KL untuk ion litium sebesar 1,16 mg/g dan 2,57 mg/g, ion natrium sebesar 74,62 mg/g dan 0,04 mg/gL/mg, dan ion fosfat sebesar 208,33 mg/g dan 0,06 mg/g. Selain itu, studi kinetika menunjukkan bahwa model pseudo second-order memiliki kesesuaian data yang lebih baik daripada pseudo first-order.

Effect of salt concentration on the properties of electrolyzed reducing water (ERW) and electrolyzed oxidizing water (EOW): an empirical correlation study Laras Prasakti; Billy Dion Yogihaz; Lukman Subekti; Anton Sujarwo; Agus Prasetya
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.69673

This research aimed to examine the effect of NaCl concentration on the pH and Oxidation Reduction Potential (ORP) values of both EOW and ERW products. The experiment was conducted using distilled water. The electrolysis apparatus consisted of anode and cathode chambers. The chambers were connected by a tube filled with a cotton (or a fabric). Both electrodes (anode and cathode) were made of titanium and formed as a spiral. Electrolysis was performed for 780 minutes, and the pH and ORP values of both EOW and ERW were measured every time. Sodium chloride concentration was varied for 0, 100, and 200 ppm. Experimental results revealed that the higher the NaCl concentration, the higher ERW’s pH rise and the lower the EOW’s pH. Similar results were found for ORP. ERW’s ORP was lowered while EOW’s ORP rose with the increase in NaCl concentration. This study could also generate a mathematical model that correlates pH and time during the electrolysis process. The model was developed by connecting with a simple polynomial. A similar approach was used to develop the model that correlates pH and ORP value.

Effect of salt concentration on the properties of electrolyzed reducing water (ERW) and electrolyzed oxidizing water (EOW): an empirical correlation study Laras Prasakti; Billy Dion Yogihaz; Lukman Subekti; Anton Sujarwo; Agus Prasetya
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.69673

This research aimed to examine the effect of NaCl concentration on the pH and Oxidation Reduction Potential (ORP) values of both EOW and ERW products. The experiment was conducted using distilled water. The electrolysis apparatus consisted of anode and cathode chambers. The chambers were connected by a tube filled with a cotton (or a fabric). Both electrodes (anode and cathode) were made of titanium and formed as a spiral. Electrolysis was performed for 780 minutes, and the pH and ORP values of both EOW and ERW were measured every time. Sodium chloride concentration was varied for 0, 100, and 200 ppm. Experimental results revealed that the higher the NaCl concentration, the higher ERW’s pH rise and the lower the EOW’s pH. Similar results were found for ORP. ERW’s ORP was lowered while EOW’s ORP rose with the increase in NaCl concentration. This study could also generate a mathematical model that correlates pH and time during the electrolysis process. The model was developed by connecting with a simple polynomial. A similar approach was used to develop the model that correlates pH and ORP value.

Effect of Devices and Driving Pressures on Energy Requirements and Mass Transfer Coefficient on Microalgae Lipid Extraction Assisted by Hydrodynamic Cavitation Martomo Setyawan; Panut Mulyono; Sutijan Sutijan; Yano Surya Pradana; Laras Prasakti; Arief Budiman
International Journal of Renewable Energy Development Vol 9, No 3 (2020): October 2020
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2020.26773

Previous studies of biodiesel production from microalgae have concluded that microalgal biodiesel is not profitable at an industrial scale due to its excessive energy consumption for lipid extraction. Hydrodynamic cavitation lipid extraction is one of the extraction methods which has lower energy consumption. Thismethod enables a fast extraction rate and low energy consumption for cell disruption. In order to achieve optimum process conditions, several influential parameters, which are cavitation generator geometry and driving pressure, need to be scrutinized. The experimental result showed that the maximum yield was obtained at 5 bar driving pressure. The lowest specific extraction energy was obtained at 4.167 bar driving pressure while using one side concave cavitation generator geometry with the ratio of the reduced cross-sectional area of 0.39. The value of the energy extraction requirement 17.79 kJoule/g lipids is less than the biodiesel heating value, and the value of the volumetric mass transfer coefficient is almost 20 times fold greater than the conventional extraction method, therefore this method is promising to be further developed.

Comparative Study of Maceration and Ultrasonic Techniques in Coffee Oil Extraction Based on Energy Evaluation and Mass Transfer Value Mustikaningrum, Mega; Yulianto, Mohamad Endy; Prasakti, Laras
CHEESA: Chemical Engineering Research Articles Vol. 7 No. 1 (2024)
Publisher : Universitas PGRI Madiun

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25273/cheesa.v7i1.19326.47-56

Coffee is a significant commodity trend, with numerous coffee shops rapidly established in Indonesia. The development of this industry has led to an increased discharge of coffee grounds into the environment. The discarded grounds contain oil which can be optimized using various methods and serve as a raw material for biodiesel. Therefore, this study aimed to compare the maceration and ultrasonic methods of extracting coffee grounds. The comparison focused on yield, mass transfer value (diffusivity), and extraction speed constant based on the proposed mathematical model. The results showed a yield of 12.1% and 16%, for the maceration and ultrasonic methods, respectively. Diffusivity value was registered at 9.99 x 10-11 m2/min and 9.8 x 10-10 m2/min, while extraction speed constant values were discovered to be 0.2 m/min and 1.798 m/min, respectively. Additionally, the energy evaluation of ultrasonic extraction produced a Gibbs energy value of -3765.72 Joules.

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