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Abstrak :
Beragam kebutuhan industri, membuat jenis-jenis proses pada industri pengolahan menjadi beragam dengan berberapa parameter input dan output, salah satunya adalah proses thermal mixing yang menggunakan sistem multi input multi output. Thermal mixing atau continuous stirred-tank reactor mengendalikan 2 aliran dengan temperatur berbeda kedalam tanki pencampur sehingga mendapat temperatur dan ketinggian tangki sesuai yang diinginkan. pada penelitian ini telah dirancang sistem pengendali berbasis logika fuzzy pada pengendalian temperatur dan level. Penelitian ini sistem logika fuzzy menngunakan 2 input dan 1 output unutk masing-masing parameter pengendalian. 2 input fuzzy set menggunakan nilai error dan change of error. Setiap fuzzy set menngunakan 7 membership function yaitu negative big (NB), negative medium (NM), negative small (NS), zero (Z), positive small (PS), positive medium (PM), dan positive big (PB). Sistem dapat melakukan pengendalian temperatur dan level sesuai yang diinginkan. Sistem ini menggunakan simulasi berbasis aplikasi MATLAB Simulink. Berdasarkan hasil simulasi, dapat disumpulkan bahwa pengendalian menggunakan fuzzy logic controller lebih baik dibandingkan pengendalian PID. Hasil pengendalian fuzzy memiliki rata-rata rise time dan settling time yang lebih cepat dan tidak memiliki overshoot.

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A variety of industrial needs, making the types of processes in the processing industry to be diverse with several input and output parameters, one of which is a thermal mixing process that uses a multi-input multi output system. Thermal mixing or continuous stirred-tank reactor controls 2 streams with different temperatures into the mixing tank so that the temperature and height of the tank are as desired. In this research a fuzzy logic based controller system has been designed for controlling temperature and level. This study uses a fuzzy logic system using 2 inputs and 1 output for each control parameter. 2 fuzzy input sets use error and change of error values. Each fuzzy set uses 7 membership functions, namely negative big (NB), negative medium (NM), negative small (NS), zero (Z), positive small (PS), positive medium (PM), and positive big (PB). The system can control the temperature and level as desired. This system uses a simulation based on the MATLAB Simulink application. Based on the simulation results, it can be concluded that the control using fuzzy logic controller is better than PID control. Fuzzy control results have a faster average rise time and settling time and do not have overshoot.

Abstrak :
Bioreaktor tipe Continuous Sfrirred Tank Reactor (CSTR) merupakan salah satu jenis reaktor yang banyak digunakan dalam pengolahan limbah cair pada industri-industri-besar maupun kecil. Penelitian ini bertujuan untuk membuat suatu prototipe reaktor CSTR pengolah limbah cair industri resin sintetik. Prototipe reaktor ini nantinya dapat dimanfaatkan tidak hanya untuk keperluan perancangan bioreaktor dan optimasi pada industri resin sintetik, namun juga untuk berbagai keperluan seperti pemodelan, perancangan, scaling-up, maupun untuk keperluan pendidikan sebagai alat peraga dalam mata kuliah Perancangan Reaktor atau keperluan riset para mahasiswa maupun staf pengajar. Di dalam penelitian ini dilakukan perhitungan perancangan bioreaktor beserta kolam pengendapan (settling tank). Sebagai produknya adalah sebuah prototipe bioreaktor lengkap dengan kolam pengendapan, alat pengatur kecepatan pengadukan serta alat kendali suhu. Pengujian prototipe akan dilakukan dengan menggunakan limbah industri resin sintetik yang memiliki BOD 2000 mg/L, Mikroorganisme yang akan digunakan berasal dan penggayaan mikroba (enrichment) dari sekitar lokasi pabrik di kawasan Cimanggis, Bogor. Produk air bersih diharapkan hanya mengandung BOD 5 ma. Lumpur yang terendapkan pada settling tank akan diuji kadar BOD-nya serta kandungan Nitrogen dan Phosphatnya dan diharapkan dapat menjadi pupuk setelah melalui proses stabilisasi. Dengan demikian hal ini memberi nilai tambah bagi produsen resin sintetik sekaligus dorongan untuk melakukan perlindungan terhadap lingkungannya.

Abstrak :
Bio-oil produced by biomass pyrolysis contains high oxygenates, namely, carboxylic acids, alcohols, and ketones resulting in low calorific fuel, and therefore bio-oil requires upgrading to sequester these oxygenates. By conducting the co-pyrolysis of biomass and plastic feed blend, the donation of hydrogen by plastic free radicals to the oxygen of biomass free radicals may sufficiently reduce oxygenate compounds in the bio-oil and increase its yield. Therefore, the synergetic effects are functional. Currently, co-pyrolysis reactors have high aspect ratios (ratio of height to diameter) of 4 or more and small diameters (maximum 40 mm), in which the heat transfer from the furnace to the feed blend is immaterial even though the plastic material has low thermal conductivity. However, in large-scale reactors, such a design restricts the bio-oil’s capacity due to the heat transfer constraint. To resolve the latter and to improve bio-oil quality, in the present work, the co-pyrolysis of corn cobs and polypropylene (PP) is conducted in a stirred-tank reactor with a low aspect ratio (2). PP composition in the feed blend was varied from 0-100% weight with a 12.5% weight interval, heating rate of 5oC/min, and final temperature of 500oC. The results show that by increasing the PP composition in the feed blend from 37.5% to 87.5%, the bio-oil yield increased from 25.8% to 67.2% feed weight. An analysis of bio-oil quality shows that there was a favorably abrupt increase of non-oxygenate composition in the bio-oil from less than 5% to more than 70% as the PP composition in the feed blend was increased from 37.5% to 50% and more.

Abstrak :
Flex matala biofilter dengan luas permukaan 365 m2/m3 (M365) dan 190 m2/m3 (M190) digunakan sebagai carrier bkteri dalam produksi biohidrogen menggunakan reaktor CSTR. Reaktor CSTR yang dilengkapi dengan biofilter (CSTR-PBF) didesain dan dioperasikan untuk memproduksi gas biohidrogen dengan bahan baku limbah pabrik minuman sebagai substrat pada konsentrasi 10 ? 30 g total glukosa/L dan waktu tinggal 8 jam ? 0,5 jam. Carrier atau biofilter dipasang pada bagian tengah fermentor (60 mm dari dasar fermentor) yang berfungsi untuk menghindari washout. Hasil menunjukkan bahwa konsentrasi substrat 15 ? 20 g/L memberikan yield dan Laju produksi gas biohidrogen (LPH) yang tinggi. Biofilter M365 memberikan kinerja produksi hidrogen yang lebih baik dibanding dengan biofilter M190. HRT 0,5 jam memberikan LPH yang paling tinggi, yakni 124,87 L H2/L/hari, namun yieldnya 1,17 mol H2/mol glukosa. Di sisi lain, kondisi yang memberikan yield tertinggi dicapai pada waktu tinggal 4 jam dengan LPH sebesar 13,74 L H2/L/hari dan yield sebesar 1,82 mol H2/mol glukosa. Kondisi operasi yang direkomendasikan adalah waktu tinggal 1 jam dan konsentrasi substrat 20 g glukosa/L dengan LPH 88,69 L H2/L/hari, konversi substrat, 91,85 % dan yield 1,42 mol H2/mol glukosa. Pada waktu tinggal yang rendah, yakni 1 jam dan 0,5 jam terdapat perbedaan distribusi konsentrasi biomassa pada bagian atas, tengah dan bawah reaktor. Produk cair terbesar adalah asam butirat dan asam asetat dengan rasio 1,41 mol asam butirat/mol asam asetat sampai dengan 5,66 mol asam butirat/mol asam asetat. ......A flex-matala packed biofilter with specific surface area M365 m2/m3 (M365) and 190 m2/m3 (M190) were used as a bacteria carrier in a Continuous Stirred Tank Reactor (CSTR) in this study. The continuous stirred tank reactor with packed biofilter (CSTR-PBF) was designed and operated under sugary wastewater substrate at concentration of 10 g total sugar/L ? 30 g total glukosa/L and hydraulic retention time (HRT) 8 h - 0.5 h to assess the biohydrogen producing ability. Biofilter was installed at 60 mm height from the bottom of bioreactor (middle of the bioreactor). The biofilter played a role in avoiding biomass washout. It was found that substrat concentration of 15 ? 20 g glucose/L lead the hydrogen production performa. Biofilter M365 produced the higher hydrogen production rate and yield. The condition producing the higher hydrogen production rate was at HRT 0.5 h with hydrogen production rate (HPR) of 124.87L H2/L/d, and yield of 1.17 mol H2/mol glucose. On the other hand, the condition producing the higher yield obtained when the fermentor operated at HRT 4 h, which hydrogen production rate and yield were 13.74 H2/L/d, and yield of 1.42 mol H2/mol glucose. Operation condition suggested for hydrogen production was HRT 1 h and 20 g total glucose/L which HPR, susbtrate conversion and yield were 88.69 H2/L/d; 91.85 % and 1.42 mol H2/mol glucose. There was difference distribution of biomassa on top, middle and bottom part of the bioreactor observed at HRT 1 h to 0,5 h. Butyric acid and acetic acid were the main liquid product that the ratio was 5.66 mol butyric/mol acetic. A flex packed biofilter used in CSTR system is a better approach to accumulate biomass concentration in bioreactor for enhancing biohydrogen production rate comparison with other kinds of bioreactor.

Abstrak :
Previous research of thermal co-pyrolysis of biomass-plastics where plastics function as hydrogen donor to induce synergistic effect on non-oxygenated fraction of bio-oil has reached a condition that there was a difficulty of separating non-oxygenated compounds from oxygenated compounds either at low heating rate. It was suspected that the content of high molecular weight of compounds especially polyaromatic hydrocarbons (PAH) in bio-oil retarded this separation. At low heating rate, most of co-pyrolysis until recently have been conducted in fixed bed and auger reactors. The present work proposed a stirred tank reactor as the reactor alternative to avoid formation of PAH in bio-oil. A series of experiments of co-pyrolysis of corn cobs and polypropylene at low heating rate (5oC/min) with maximum temperature of 500oC has been conducted with the ultimate goal of producing non-oxygenated fraction of bio-oil similar to diesel fuel. The qualities of the fraction targeted were its viscosity, double bond content and branching number of carbon chains. The values of these properties in diesel fuel are 2.7 cStokes, 0%, 0.4, respectively. The experiments involved 3 different reactors, i.e. the first, a stirred tank reactor with its aspect ratio (the ratio of the height to the diameter) of 2.0, the second, a stirred tank reactor with aspect ratio of 1.35 and the third, a dispecement reactor. Nitrogen gas as a sweeping gas was predicted to generate local turbulence favouring convective heat transfer. The work has resulted in some important results, i.e. the first, there was phase separation between oxygenated and non-oxygenated fractions, the second, synergistic effects in copyrolysis have been achieved both in bio-oil and non-oxygenated fraction yields, the third, non-oxygenated fraction had viscosity of 2.03 + 6.47% cStokes, the fourth, nonoxygenated fraction contained only 6-7% double bonds, which eases the hydrogenation reaction in further processing for double bond saturation, the fifth, non-oxygenated fraction had average branching number of 0.57, slightly above that of diesel fuel, which is unfavourable to reach short ignition delay time in the combustion, the sixth, the aspect ratio of the reactor significantly affected the extent of biomass pyrolysis, but not polypropylene pyrolysis.

Abstrak :
Pengadukan dalam Anaerobic Digestion AD dapat dikontrol untuk meningkatkan kinerja proses AD. Penelitian ini bertujuan untuk mengetahui pengaruh intensitas pengadukan terhadap kinerja proses AD, transfer panas di dalam digester dan untuk menganalisis kesetimbangan energi. Penelitian dilakukan menggunakan Continuous Stirred Tank Reactor CSTR dengan volume terisi 400 L yang beroperasi pada suhu rata-rata 27,8 1,07oC. Penelitian operasi skenario pertama dilakukan dengan input substrat sampah makanan dengan Organic Loading Rate OLR 10 kg VS/m3 selama 43 hari dan diaduk menggunakan variasi intensitas pengadukan 30 rpm dan 60 rpm selama 4 jam/hari untuk melihat kinerja proses AD. Operasi skenario kedua dilakukan menggunakan substrat sampah makanan dan kotoran sapi banding limbah Fat Oil and Grease FOG sebesar 10:1 dengan OLR 10 kg VS/m?3 dan dilakukan variasi pengadukan berkala 30 rpm, 15 menit/1,5 jam dan kontinu 30 rpm, 4 jam/hari untuk melihat tansfer panas dalam digester. Hasil penelitian operasi skenario pertama menunjukkan terdapat perbedaan yang signifikan pada kedua intensitas pengadukan.

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Mixing in Anaerobic Digestion AD can be controlled to improve the performance of the AD process. This study aims to determine the effect of mixing intensity on the performance of the AD process, heat transfer in the digester and to analyze the energy balance. The study was conducted using a Continuous Stirred Tank Reactor CSTR with 400 L working volume which operates at an average temperature of 27,8 1,07 C. In the first scenario operation study, reactor was fed with food waste with Organic Loading Rate OLR 10 kg VS m3 for 43 days and mixed using variation of mixing intensity 30 rpm and 60 rpm for 4 hours day to see AD process performance. The second operation was carried out using food and cow dung with Fat Oil and Grease FOG waste ratio 10 1 and mixed intermittent 30 rpm, 15 min 1.5 hour and continuous 30 rpm, 4 hour day to see heat transfer in the digester. The results of the first scenario operation study showed that there was a significant difference in both mixing intensity p.