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In-Situ Catalytic Pyrolysis of Spirulina platensis residue (SPR): Effect of Temperature and Amount of C12-4 Catalyst on Product Yield Siti Jamilatun; Ratih Mahardhika; Imelda Eka Nurshinta; Lukhi Mulia Sithopyta
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.60477

Currently, dependence on fossil energy, especially petroleum, is still high at 96% of the total consumption. One solution to overcome fossil energy consumption is processing alternative energy sources derived from microalgae biomass. This study aims to study the pyrolysis of microalgae with the addition of the C12-4 (Cr2O3+Fe2O3+C+CuO+promoter) catalyst. The biomass used in this study was Spirulina platensis residue (SPR). This study used a fixed bed reactor with an outer diameter of 44 mm, an inner diameter of 40 mm, and a total reactor height of 600 mm. The C12-4 was mixed fifty grams of SPR with a particle size of 100 mesh with a ratio variation of 5, 10, and 15 wt.%. The feed mixture was placed in the reactor (in-situ), and the reactor was tightly closed. The nickel-wire heater wrapped around the reactor wall was employed. The pyrolysis heating rate was 24.33 °C/min on average, and the temperatures were varied as 300, 400, 500, 550, and 600 °C. The research found that the optimum temperature conditions without and with the catalyst to produce bio-oil were different. The pyrolysis without any catalyst (500 ⁰C), with a catalyst of 5 wt.% (500 ⁰C), 10 wt.% (400 ⁰C), and 15 wt.% (550 ⁰C) produced the bio-oil yield of 15.00, 17.92, 16.78 and 16.54, respectively. The use of 5, 10, and 15 wt.% catalysts increased the water phase yield. The char yield was influenced by the amount of catalyst only at 300 ⁰C; i.e., the more catalysts, the less char yield. The pyrolysis without any catalysts produced the highest gas product. A catalyst significantly increased the pyrolysis conversion from 48.69 (without catalyst) to 62.46% (15. wt.% catalyst) at a temperature of 300 ⁰C. The optimum conditions for producing the best bio-oil were at 600 °C and 10 wt.% of catalysts, which resulted in an O/C ratio of 0.14.Keywords: C12-4 catalyst, in-situ catalytic pyrolysis, Spirulina platensis residue, yield bio-oilA B S T R A KKetergantungan terhadap energi fosil khususnya minyak bumi, saat ini masih tinggi yaitu mencapai 96% dari total konsumsi. Salah satu solusi untuk mengatasi ketergantungan energi fosil adalah dengan mengolah sumber energi yang berasal dari biomassa mikroalga. Penelitian ini bertujuan untuk pirolisis mikroalga dengan penambahan katalis C12-4 (Cr2O3 + Fe2O3 + C + CuO + promotor). Sampel yang digunakan adalah residu Spirulina platensis (SPR). Penelitian ini menggunakan reaktor unggun tetap dengan diameter luar 44 mm, diameter dalam 40 mm, dan tinggi reaktor 600 mm. Spirulina platensis dengan ukuran partikel 100 mesh sebanyak 50 gram dicampur dengan katalis C12-4 dengan variasi 5, 10, dan 15 wt.%. Campuran umpan (in-situ) dimasukkan ke dalam reaktor dan ditutup rapat. Pemanas menggunakan arus listrik melalui kawat nikel yang dililitkan pada dinding reaktor. Laju pemanasan pirolisis rata-rata 24,33 °C/menit, variasi suhu 300, 400, 500, 550, dan 600 °C. Kondisi optimum tanpa dan dengan katalis untuk menghasilkan bio-oil memiliki nilai yang berbeda yaitu pirolisis tanpa katalis (500 ⁰C), dengan katalis 5 wt.% (500 ⁰C), 10 wt.% (400 ⁰C) dan 15 wt.% (550 ⁰C) menghasilkan bio-oil 15,00; 17,92; 16,78; dan 16,54. Penggunaan katalis 5, 10, dan 15 wt.% berat dapat meningkatkan fasa air hasil. Yield char dipengaruhi oleh jumlah katalis hanya pada 300 ⁰C, semakin banyak katalis maka yield char semakin menurun. Pirolisis tanpa katalis menghasilkan produk gas tertinggi. Penggunaan katalis sangat signifikan dalam meningkatkan konversi pirolisis dari 48,69 (tanpa katalis) menjadi 62,46% (katalis 15 wt.%) pada suhu 300 ⁰C. Kondisi optimum untuk menghasilkan minyak nabati terbaik adalah pada 600 °C dengan katalis 10% berat, menghasilkan rasio O/C sebesar 0,14.Kata kunci: C12-4 catalyst, in-situ catalytic pyrolysis, Spirulina platensis residue, yield bio-oil

The Effects of Quartic Term Mathematical Model on The Concentration Profile of Fixed Bed Gas Adsorber Ary Mauliva Hada Putri
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.61308

The need for a reliable mathematical model depicting the process inside a column adsorber has become a requisite in designing an effective gas adsorber. Even though this task can be done by using commercial software, it is still important to get an understanding of how the entire process happens. In this paper, we discuss a new way to approximate the concentration profile inside the porous solids. It is an extension of the work of Liaw et al., who adopted a parabolic (i.e., quadratic) profile, which is a function of pellet radius while retaining the spherical symmetry. We extend their work by adding the quartic term. The inclusion of this new term still preserves the form of linear driving force approximation with some correction to Glueckauf’s parameter (i.e., the effective diffusivity coefficient). The addition of the correction will affect the breakthrough curve so that it affects the saturation time. In the binary system of hydrogen/methane discussed in this study, we found that a negative correction to the diffusivity coefficient will make the saturation happen earlier compared to that of the parabolic case, and vice versa. This study may help us design an efficient gas purifier, in particular when we set out for the regeneration of the adsorbent.Keywords: activated carbon; effective diffusivity coefficient; hydrogen; linear driving force; methane; parabolic profile A B S T R A KKebutuhan model matematis yang dapat menggambarkan proses penyerapan dalam kolom adsorpsi telah menjadi kebutuhan yang tak terelakkan dewasa ini. Walaupun kini telah tersedia berbagai perangkat lunak komersial, namun tidak dapat dipungkiri bahwa memahami bagaimana proses tersebut terjadi tetap menjadi suatu hal yang berguna. Paper ini bertujuan untuk menampilkan cara baru dalam pemodelan konsentrasi adsorbat di dalam adsorben padat berpori. Kami memperluas metode yang dikembangkan Liaw et al. dengan menambahkan suku pangkat empat (kuartik). Penambahan ini akan mengoreksi koefisien difusivitas efektif dari persamaan linear driving force (LDF). Koreksi yang bernilai negatif, misalnya, akan mengurangi nilai koefisien difusivitas tersebut sehingga akan menghambat kemampuan adsorpsi. Hasil perhitungan kami pada sistem biner hidrogen/ metana menunjukkan bahwa suatu koreksi bernilai negatif dapat menyebabkan saturasi berlangsung lebih cepat dari kasus profil parabolik. Begitu pula sebaliknya, koreksi positif akan menambah daya adsorpsi sehingga saturasi dapat diperlambat. Studi ini kami harapkan dapat diterapkan untuk mendesain suatu kolom adsorpsi yang efisien, terutama dalam perencanaan proses regenerasi adsorben.Kata kunci: hidrogen; karbon aktif; koefisien difusivitas efektif; linear driving force; metana; profil parabolik

Studi Pengaruh Variabel Proses dan Kinetika Ekstraksi Nikel dari Bijih Nikel Laterit Menggunakan Larutan Asam Sulfat pada Tekanan Atmosferik Wahab Wahab; Erwin Anshari; Marwan Zam Mili; WD. Rizky Awaliah Nafiu; Muh. Nuzul Khaq; Daniyatno Daniyatno; Firdaus Firdaus; Yayat Iman Supriyatna
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.61533

Leaching at atmospheric pressure is one of the leaching methods of concern because it has several advantages, namely that it can process low-level nickel ore, can operate at temperatures >100 ⁰C at atmospheric pressure, and can be used in saprolite and limonite ores. In this research, nickel extraction from nickel laterite ore was carried out using sulfuric acid solution (H2SO4) as a leaching agent. The variables that were varied in the leaching process were temperature (30, 60, and 90 ⁰C), sulfuric acid concentration (0.2, 0.5, and 0.8 molar) and leaching time (30, 60, and 90 minutes). In this study, a 3-factor analysis of variance (ANOVA) was used to see the significance of the variable effects and the order of the most influential variables. In addition, leaching kinetics was studied by shrinking core models to determine rate determining step. The results showed that the increase in temperature, sulfuric acid and leaching time produced a higher percentage of extracted nickel. Based on the 3-factor ANOVA, the order of the most influential variables was obtained, namely temperature, acid concentration and leaching time. The kinetics analysis showed that rate determining step of leaching ore nickel laterite with H2SO4 solution on atmospheric pressure is controlled by diffusion through solid layer product.Keywords: analysis of variance; leaching; saprolit; limonitA B S T R A KLeaching pada tekanan atmosfer adalah salah satu metode pelindian yang menjadi perhatian karena memiliki beberapa keuntungan yaitu dapat mengolah bijih nikel kadar rendah, dapat beroperasi pada temperatur >100 ⁰C pada tekanan atmosfer serta dapat digunakan pada bijih saprolit dan limonit. Dalam penelitian ini, dilakukan ekstraksi nikel dari bijih nikel laterit menggunakan larutan asam sulfat (H2SO4) sebagai agen pelindi. Variabel yang divariasikan dalam proses pelindian yaitu temperatur (30, 60, dan 90 ⁰C), konsentrasi asam sulfat (0,2; 0,5; dan 0,8 molar) dan waktu pelindian (30, 60, dan 90 menit). Dalam penelitian ini digunakan analysis of variance (ANOVA) 3 faktor untuk melihat signifikansi variabel dan urutan variabel yang paling berpengaruh. Selain itu, dilakukan studi kinetika pelindian menggunakan shrinking core model untuk mengetahui pengendali laju reaksi. Hasil penelitian menunjukkan bahwa peningkatan variabel temperatur, konsentrasi asam sulfat dan waktu pelindian menyebabkan meningkatnya persen ekstraksi nikel. Berdasarkan hasil ANOVA 3 faktor diperoleh urutan variabel yang paling berpengaruh yaitu temperatur, konsentrasi asam dan waktu pelindian. Hasil analisis kinetika menunjukkan bahwa pengendali laju reaksi pelindian bijih nikel laterit menggunakan larutan H2SO4 pada tekanan atmosfer yaitu difusi melalui lapisan produk padat.Kata kunci: analysis of variance; pelindian; limonit; saprolit

Eco-friendly Alkyd Resins Based on Vegetable Oil: Review Okta Amelia; Illah Sailah; Ika Amalia Kartika; Ono Suparno; Yazid Bindar
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.64143

The alkyd resin industry currently needs environmentally friendly raw materials, which emphasized the aspect of sustainability. Alkyd resin is a polymer product with oil as raw material which is widely used in the paint, coating, and other industries. The abundant demand for alkyd resin has led to a diversification of the raw material for alkyd resin from vegetable oils. The advantages of vegetable oil include being a renewable energy source for industry, sustainability, biodegradability, and being environmentally friendly as important considerations for the industry in recent times. This paper examines alkyd resins derived from several vegetable oils that are environmentally friendly. Alkyd resin is prepared by alcoholysis and esterification. Based on several studies of alkyd resins, there have been many modifications to the raw materials, technology, and catalysts used which can refer to an environmentally friendly and affordable industry.Keywords: alkyd resin; biodegradability; environmentally friendly; sustainability; vegetable oilA B S T R A KIndustri polimer pada masa ini membutuhkan bahan baku yang ramah lingkungan, yang menekankan pada keberlanjutan. Alkid resin adalah salah satu produk berbasis minyak yang banyak digunakan dalam industri cat, coating, dan industri lainnya. Keberlanjutan, biodegradabilitas, dan keramahan terhadap lingkungan menjadi pertimbangan signifikan bagi industri berbasis minyak nabati dalam beberapa waktu terakhir. Di dalam naskah ini, diulas beberapa minyak nabati yang digunakan untuk memproduksi alkid resin dengan cara alkoholisis dan esterifikasi. Berdasarkan berbagai studi yang telah dilakukan, masih terdapat modifikasi dari sisi material, teknologi dan katalis agar tercipta industri yang ramah lingkungan.Kata kunci: alkid resin; biodegradabilitas; keberlanjutan; minyak nabati; ramah lingkungan

Kinetics Study of Paracetamol Production from Para-Aminophenol and Acetic Anhydride Rifki Wahyu Kurnianto; Muhammad Fahrurrozi; Hilda Ismail; Raden Rara Endang Lukitaningsih; Indah Tri Nugraha; Pudjono Pudjono; Rochmadi Rochmadi; Ari Sudarmanto; Ratna Asmah Susidarti
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.64551

In the last decade, Indonesia intensifies the efforts to reduce pharmaceutical imports. One of the initiatives is establishing a paracetamol production facility to start operating in 2024. Kinetics study is needed as a basis to design the paracetamol reactor. This study investigated the optimal temperature, reactant mole ratio, and agitation speed in the reactor for paracetamol production. In this study, aqueous solution of para-aminophenol was reacted with acetic anhydride. The mole ratio of para-aminophenol to acetic anhydride was varied to 1:1, 1:1.2, 1:1.5, and 1:2 while the temperature was varied to 80 °C, 90 °C, and 110 °C. However, due to uncontrolled heat of the reaction and limitation of the mixture’s boiling point, the actual reaction temperatures were 86 °C, 90 °C, and 108 °C. In addition, the agitation speed of 250 RPM and 350 RPM were also studied. Thin layer chromatography (TLC) and densitometry were used to determine the concentration of paracetamol in the reacting mixture. The optimum temperature, reactant mole ratio, and agitation speed in this study were 108 °C, 1:1.5, and 350 RPM, respectively. In addition, a reaction performed under those operating parameters gave the reaction rate constant of 1.95 L mol-1 min-1.Keywords: acetic anhydride; kinetics; para-aminophenol; paracetamol; pharmaceutical industry A B S T R A KDalam sepuluh tahun terakhir ini, Indonesia bertekad mengurangi impor bahan baku farmasi. Salah satu upaya yang dilakukan adalah membangun fasilitas produksi parasetamol yang akan mulai beroperasi pada tahun 2024. Studi kinetika diperlukan sebagai dasar perancangan reaktor parasetamol. Oleh karena itu, penelitian ini mengkaji kondisi operasi optimal pada reaksi produksi parasetamol yang akan dibutuhkan sebagai dasar perancangan pabrik. Pada percobaan ini, para-aminofenol direaksikan dengan anhidrida asetat dengan media air. Rasio mol para-aminofenol terhadap asetat anhidrida divariasikan 1:1 1:1,2, 1:1,5, dan 1:2 sedangkan temperatur divariasikan 80 °C, 90 °C, dan 110 °C. Akan tetapi, karena panas reaksi yang tidak dikontrol dan batasan berupa titik didih dari campuran reaksi, temperatur aktual reaksi menjadi 86 °C, 90 °C, dan 108 °C. Selain itu, kecepatan putaran pengadukan juga divariasikan pada angka 250 RPM dan 350 RPM. Kromatografi lapis tipis (KLT) dan densitometri digunakan untuk menentukan konsentrasi parasetamol dalam campuran reaksi. Temperatur, rasio mol reaktan, dan kecepatan putaran pengadukan yang optimum pada penelitian ini masing-masing adalah 110 °C, 1:1,5, dan 350 RPM. Selain itu, reaksi yang dilakukan dengan kondisi operasi tersebut menghasilkan konstanta laju reaksi 1,95 L mol-1 menit-1.Kata kunci: anhidrida asetat, industri farmasi, kinetika, para-aminofenol, parasetamol

Kinerja Internal Reboiler Tipe Vertical Tubular Baffle pada Proses Distilasi Etanol secara Batch yuana susmiati; Bambang Purwantana; Nursigit Bintoro; Sri Rahayoe
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.65483

The performance of ethanol distillation is determined by the type of reboiler used in the distillation column. This study aims to determine the effect of differences in diameter and height of internal reboiler tubes, as well as feed content on ethanol distillate concentration and distillation yield. The research was conducted on a batch ethanol distillation process using a rectified distillation device with an internal vertical tubular baffle reboiler using different diameters and tube height, namely 1.5, 1, and 0.5 inches of diameter, and 8, 6, and 4 cm of tube heights. Materials or feeds in this study were ethanol solutions with levels of 10%, 20%, and 30% v/v. The results showed that the highest ethanol distillate content of 97.17% v/v (average) was achieved in the distillation process using an internal reboiler with a diameter of 0.5”, a tube height of 8 cm, and a feed content of 10%. Geometry affected the heat transfer process in the internal reboiler of a distillation device so that it affected the distillation results.Keywords: distillation; ethanol; internal reboiler: performanceA B S T R A KKinerja alat distilasi etanol ditentukan oleh jenis reboiler yang digunakan pada kolom distilasi. Penelitian ini bertujuan untuk menentukan pengaruh perbedaan diameter dan tinggi tabung internal reboiler, serta kadar umpan terhadap kadar etanol distilat dan rendemen distilasi. Penelitian dilakukan pada proses distilasi etanol secara batch menggunakan alat distilasi rektifikasi dengan internal reboiler jenis Vertical Tubular Baffle yang berbeda ukuran diameter dan tinggi tabungnya, yaitu diameter 1,5, 1 dan 0,5 inci, serta tinggi tabung 8, 6 dan 4 cm. Bahan atau umpan pada penelitian ini adalah larutan etanol berkadar 10%, 20% dan 30% v/v. Hasil penelitian didapatkan kadar etanol distilat yang paling tinggi dengan kadar rata-rata 97,17% v/v dicapai pada proses distilasi dengan internal reboiler berukuran diameter 0,5 inci, dan tinggi tabung 8 cm dan kadar umpan 10%. Geometri berpengaruh pada proses perpindahan panas di dalam internal reboiler suatu alat distilasi sehingga berpengaruh terhadap hasil distilasi.Kata kunci: distilasi; etanol; internal reboiler; kinerja

Evaluasi Aspek Teknis dan Lingkungan Instalasi Pengolahan Air Limbah (IPAL) Komunal di Kabupaten Sleman Yogyakarta Dwi Saputri; Fajar Marendra; Ahmad Tawfiequrrahman Yuliansyah; Ir. Agus Agus Prasetya Prasetya
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.65833

As the producer of waste (both in solid form and wastewater), the increase of population creates a dominant effect on environmental problems. Escalation of the amount of domestic wastewater has led to greater sanitation problems. Indonesian government has carried out several programs for improving sanitation access and facilities. Community-based wastewater treatment plant (Communal WWTP) is one of the priority programs. Sleman Regency in Special Province of Yogyakarta owns 131 communal WWTP, where the oldest one had been built in 2006 while the newest one was installed in 2018. In this study, the techno-environmental assessment of communal WWTP in the District of Sleman, Yogyakarta was carried out. Sampling selection of communal WWTPs was undertaken using Stratified Random Sampling techniques. Data collection was executed by a combination of field surveys and in depth-interview of several relevant personnel. The study was done for 30 communal WTTP in various Districts in Sleman regency. Assessment was carried out based on the Likert scale of 4. The results showed that the average score for environment aspect was 2.94 (good), while that for technical aspect was 3.52 (very good). Overall, the techno-environmental score of communal WWTP in Sleman Regency, Yogyakarta was 3.23 out of 4, which was categorized as good.Keywords: communal WWTP; domestic wastewater; Likert scale sanitation; Sleman regency; stratified random samplingA B S T R A KSebagai produsen limbah (baik limbah padat maupun air limbah), peningkatan jumlah penduduk berpengaruh dominan terhadap masalah lingkungan. Eskalasi jumlah air limbah domestik berujung pada masalah sanitasi yang semakin besar. Pemerintah Indonesia sudah menjalankan beberapa program untuk meningkatkan fasilitas dan akses sanitasi. Instalasi pengolahan air limbah komunal (IPAL) menjadi salah satu program prioritas. Kabupaten Sleman memiliki 131 IPAL komunal, yang tertua dibangun tahun 2006 dan yang terbaru pada tahun 2018. Dalam penelitian ini, asesmen teknologi lingkungan (techno-environment) dilakukan terhadap IPAL komunal di Kabupaten Sleman, Yogyakarta. Pengumpulan data dikerjakan menggunakan kombinasi metode survei lapangan dan wawancara mendalam dengan pelaku IPAL komunal yang relevan. Pemilihan sampel IPAL komunal dipilih menggunakan teknik Sampling Acak Terstratifikasi (Stratified Random Sampling). Penelitian dilakukan terhadap 30 IPAL Komunal di berbagai Kecamatan di Kabupaten Sleman. Asesmen dilakukan berdasarkan skala Likert (4). Hasil penelitian menunjukkan bahwa aspek lingkungan memperoleh skor rata-rata 2,94 (baik) dan aspek teknis-teknologis 3,52 (sangat baik). Secara keseluruhan kategori teknologi-lingkungan (techno-environment) dari IPAL Komunal di Kabupaten Sleman Yogyakarta mempunyai skor rata-rata 3,23 dari nilai maksimal 4, dan dikategorikan sebagai baik.Kata kunci: air limbah domestic; IPAL komunal; Kabupaten Sleman; sanitasi; Sampling Acak Terstratifikasi; skala Likert

Preparasi Katalis MgO/C dari Pirolisis Polimer Berbasis Magnesium Salisilat dan Aplikasinya untuk Reaksi Transesterifikasi Imam Prasetyo; Dwiana Ayu Kiranti Nur’aeni; Pandu Timur Bhaskara
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.65855

The objective of the study is to produce carbon-based magnesium oxide (MgO) solid base catalyst by pyrolysis of phenolic resin and to examine the material effectiveness as a catalyst for transesterification reaction. The phenolic resins were prepared by polymerization process of phenol, derivative salicylic acid (magnesium salicylate), and formaldehyde aqueous solution under acidic condition using H2SO4 as catalyst. The molar ratio of magnesium salicylate:phenol:formaldehyde was 0.33:0.67:2.80. Carbon-based magnesium oxide solid base catalyst (MgO/C) was produced from phenolic resins via physical activation process using steam at 850°C. Material was characterized using N2-sorption analysis, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Pyrolysis process for carbon formation resulted in 75% burn-off. The specific surface area of catalyst was 494 m2/g and the presence of MgO was confirmed by XRD diffraction pattern (2θ position of 36-43°, 61-63°, dan 74-78° according to JCPDS No.89-7746) and SEM image. Characteristic comparison of MgO/C with carbon produced from phenol formaldehyde resin (without magnesium salicylate) corroborate the finding that MgO/C was achieved. The catalyst was tested for transesterification reaction between palm oil and methanol. Conversion of 28.3% was achieved at temperature of 65 °C, reactant ratio of methanol: palm oil = 6:1 and reaction time of 2.5 hours. The activation energy of 6,444 cal/mol was obtained when evaluated in the range of 55-65 °C reaction temperature.Keywords: biodiesel; catalyst; magnesium oxide; phenolic resin; porous carbonA B S T R A KTujuan penelitian ini adalah membuat katalis magnesium oksida (MgO) yang teremban dalam karbon hasil dari proses pirolisis resin fenolik dan menguji efektivitasnya sebagai katalis reaksi transesterifikasi. Resin fenolik diperoleh melalui proses polimerisasi fenol, turunan asam salisilat (magnesium salisilat), dan formaldehid dalam kondisi asam menggunakan H2SO4 sebagai katalis. Rasio mol dari magnesium salisilat:fenol:formaldehid adalah 0,33:0,67:2,80. Katalis magnesium oksida teremban pada karbon (MgO/C) diperoleh dari pirolisis resin fenolik menggunakan steam pada suhu 850°C. Material dikarakterisasi dengan N2 adsorpsi-desorpsi isotherm, X-ray diffraction (XRD) dan scanning electron microscopy (SEM). Pirolisis untuk menghasilkan karbon memiliki burn-off sekitar 75%. Hasil penelitian menunjukkan bahwa katalis MgO/C memiliki luas permukaan sekitar 494 m2/g dan keberadaan MgO dikonfirmasi dari hasil pola difraksi XRD (posisi 2θ antara 36-43°, 61-63°, dan 74-78° sesuai dengan standar JCPDS No.89-7746) dan gambar SEM. Pembandingan karakteristik MgO/C dengan karbon hasil polimer fenol formaldehid (tanpa magnesium salisilat) memperkuat kesimpulan bahwa MgO/C dapat diperoleh. Katalis yang diperoleh digunakan sebagai katalis transesterifikasi antara minyak kelapa sawit dengan metanol. Konversi reaksi sebesar 28,3% didapatkan pada suhu 65 °C dan rasio reaktan metanol:minyak kelapa sawit = 6:1 dan waktu reaksi 2,5 jam. Energi aktivasi sebesar 6.444 kal/mol diperoleh pada rentang suhu reaksi 55-65 °C.Kata kunci: biodiesel; karbon berpori; katalis; magnesium oksida; resin fenolik

Perbandingan Performa Refrigeran Propana dan Amonia pada Siklus Refrigerasi Dew Point Control Unit (DPCU) Mochammad Syahrir Isdiawan; Aditya Nurfebriartanto; Rafitri Rusmala
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.65973

Natural gas, that has been processed and met certain specifications, is sent to consumers through pipeline. Gas condensation within the pipeline should be avoided because it has negative impacts. Hydrocarbon dew point is a measure of the easiness of gas condensation. To meet the hydrocarbon dew point, heavy hydrocarbon should be extracted in dew point control unit (DPCU). The extraction is done by gas cooling in gas chiller followed by separating the liquid formed in low temperature separator (LTS). The gas chiller functions as an evaporator in the DPCU refrigeration cycle. Propane is a common refrigerant in the DPCU. In addition, ammonia is also a potential refrigerant due to its normal boiling point being close to the hydrocarbon dew point. Refrigeration cycle performance depends on evaporator temperature, condensor temperature, and the inherent pressure-enthalpy (PH) characteristic of the selected refrigerant. This study aimed to compare the performance from ammonia and propane against the change of evaporator and condenser temperature. This study was a dry research using Aspen Hysys V11.0 simulation software (academic license). The refrigeration cycle was a simple cycle with fixed variables in the form of evaporator load, saturated liquid at outlet condenser, and saturated vapour at outlet evaporator. This study indicated that at the same evaporator load, evaporator temperature, and condenser temperature, ammonia refrigeration cycle was better than the propane because coefficient of performance (COP) of ammonia was higher than propane. This study also modeled COP changes of propane and ammonia as mathematical equation. Quantitatively, it appeared that COP of propane was more sensitive than ammonia against both evaporator and condenser temperature changes.Keywords: ammonia; condenser; evaporator; propane; refrigeration cycle; simulationA B S T R A KGas alam yang telah diolah dan sesuai spesifikasinya dikirim ke konsumen melalui pipa. Kondensasi gas dalam pipa harus dihindari karena menimbulkan dampak negatif. Titik embun hidrokarbon menjadi ukuran kemudahan proses kondensasi gas. Untuk mencapai titik embun hidrokarbon yang diinginkan, maka hidrokarbon berat harus diekstraksi di dew point control unit (DPCU). Ekstraksi dilakukan dengan cara mendinginkan gas di gas chiller lalu memisahkan cairan yang terbentuk di low temperature separator (LTS). Gas chiller tersebut berfungsi sebagai evaporator pada siklus refrigerasi DPCU. Propana adalah refrigeran yang umum digunakan di DPCU. Selain itu, amonia juga menjadi refrigeran yang potensial karena kedekatan titik didih normalnya terhadap titik embun hidrokarbon yang diinginkan. Performa siklus refrigerasi dipengaruhi oleh temperatur evaporator, temperatur kondensor, dan karakteristik tekanan-entalpi (PH) yang melekat pada refrigeran yang dipilih. Penelitian ini bertujuan untuk membandingkan performa siklus refrigerasi propana dan amonia terhadap perubahan temperatur evaporator dan kondensor. Penelitian ini merupakan penelitian kering yang menggunakan perangkat lunak simulasi Aspen Hysys V11.0 (lisensi akademik). Siklus refrigerasi yang digunakan adalah simple cycle dengan variabel tetap berupa beban evaporator, kondisi cair jenuh outlet kondensor, dan kondisi uap jenuh outlet evaporator. Hasil penelitian ini menunjukkan bahwa pada beban evaporator, temperatur evaporator, dan temperatur kondensor yang sama, maka siklus refrigerasi amonia lebih baik dari propana karena COP amonia lebih tinggi dari propana. Penelitian ini juga memodelkan nilai COP propana dan amonia sebagai persamaan matematika. Secara kuantitatif, terlihat bahwa COP amonia lebih stabil dari propana terhadap perubahan temperatur evaporator dan kondensor.Kata kunci: amonia; evaporator; kondensor; propana; siklus refrigerasi; simulasi

Densification process of Merbau (Intsia bijuga) and Matoa (Pometia pinnata J.R. Forster & J.G Forster) Sawdust Waste for Biomass Based Solid Fuel Source in West Papua Indonesia: Optimization using Response Surface Methodology (RSM) Agus Prasetya; Halomoan Siagian; Felix Arie Setiawan; Himawan Tri Bayu Murti Petrus, S.T., M.E, D.Eng.
Jurnal Rekayasa Proses Vol 15, No 1 (2021)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.66024

Merbau (Intsia bijuga) and matoa (Pometia pinnata J.R. Forster & J.G Forster) are two amongst many prominent biomass sources from West Papua, Indonesia. With their versatile characteristics, merbau and matoa wood are used in many industries such as furniture, music instrument, and many other specialty products. However, wood processing industries can emit up to 60% of the residue. In this study, the usage of both merbau and matoa sawdust wastes as solid fuel was studied using response surface methodology (RSM). merbau and matoa sawdust are sieved to get the desired particle size (-20+50 mesh). Two kinds of the sawdust are then mixed in various compositions (70, 50, and 30% merbau). The mixed sawdust is then mixed with varied sticky starch solutions (1, 5, and 10%) to be formed in pellets with various moulding compression force (50, 100, and 150 kg/cm²). The pellets are then analyzed for its characteristics such as ash, moisture contents, and calorific value to be compared with its initial conditions. A full three-level factorial design under RSM was applied to explain the correlation between independent and dependent variables. The results show that statistically, merbau content, binder content, and compressive force showed relatively significant effects on the studied responses (ash content, moisture content, and calorific value). In addition, ANOVA analysis proved that each variable has significant effects on the responses that are confirmed by practically zero P-value. The coefficient of determinations (R²) are all above 0.96 and the normal probability plots confirm that the proposed models adequate the experimental results.Keywords: biomass waste; densification; merbau; matoa; RSM A B S T R A KMerbau (Intsia bijuga) dan matoa (Pometia pinnata Forster) adalah dua di antara sumber biomassa potensial yang berasal dari Papua Barat, Indonesia. Dengan karakteristiknya yang serbaguna, merbau dan matoa digunakan di banyak industri seperti furnitur, alat musik, dan banyak produk khusus lainnya. Namun, industri pengolahan kayu dapat menghasilkan hingga 60% residu. Di Pada penelitian ini, pemanfaatan limbah serbuk gergaji merbau dan matoa sebagai bahan bakar padat dipelajari dengan menggunakan response surface method (RSM). Serbuk gergaji merbau dan matoa diayak untuk mendapatkan ukuran partikel yang diinginkan (-20+50 mesh). Dua jenis serbuk gergaji kemudian dicampur dalam berbagai komposisi (70, 50, dan 30% merbau). Serbuk gergaji yang sudah tercampur kemudian dicampur dengan bahan perekat yang bervariasi larutan pati (1, 5, dan 10%) untuk dibentuk dalam pelet dengan berbagai gaya tekan cetakan (50, 100, dan 150 kg/cm²). Pelet kemudian dianalisis karakteristiknya seperti abu, kadar air, dan nilai kalor untuk dibandingkan dengan kondisi awalnya. Sebuah desain RSM tiga faktorial penuh diterapkan untuk menjelaskan korelasi antara variabel independen dan variabel terikat. Secara statistik, hasil penelitian menunjukkan bahwa kadar merbau, kadar pengikat, dan gaya tekan menunjukkan efek yang relatif signifikan pada respons yang dipelajari (abu kadar air, kadar air, dan nilai kalor). Selain itu, analisis ANOVA membuktikan bahwa masing-masing variabel memiliki efek signifikan pada tanggapan yang dikonfirmasi oleh nilai P yang mendekati nol. Koefisien determinasi (R²) seluruhnya berada di atas 0,96 dan grafik probabilitas normal mengonfirmasi bahwa model yang diusulkan cukup sesuai dengan hasil eksperimen.Kata kunci: limbah biomassa; densifikasi; merbau; matoa; RSM

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INDONESIA