KINETIKA REAKSI KHROM DAN KAPUR PADAM PADA PENGOLAHAN LIMBAH PENYAMAKAN KULIT SECARA BATCH

Kulit merupakan bahan baku untuk produk-produk kerajinan. Sebelum digunakan, kulit melalui proses penyamakan. Sebagaian besar industri penyamakan kulit menggunakan khrom sebagai bahan penyamak. Untuk limbah penyamakan kulit yang mengandung khrom, kadar maksimum yang diperbolehkan sebesar 2,0 mg/L. limbah yang dihasilkan perlu ditangani agar tidak menimbulkan masalah lingkungan. Pemungutan khrom dari limbah cair penyamakan kulit dapat dilakukan dengan mereaksikan dengan kapur padam. Namun kondisi dan kinetika reaksinya belum diketahui secara baik, khususnya reaksi dalam reaktor batch, sehingga perlu dipelajari. Reaksi pemungutan khrom dengan kapur padam dapat dilakukan dalam reaktor slurry tangki berpengaduk secara batch. Mula-mula limbah penyamakan kulit dimasukan kedalam reaktor kemudian diaduk dengan kecepatan tertentu pada suhu kamar. Pada kondisi reaktor telah tercapai kemudian dimasukan kapur padam. Cuplikan diambil setiap selang waktu 3 menit selama 24 menit..Analisis konsentrasi khrom yang tertinggal dijalankan dengan Atomic Absorrption Spectrofhotometer (AAS). Variable yang dipelajari adalah variasi kecepatan pengaduk pada kisaran 140-200 rpm, suhu 30 –60 C, dan perbandingan mol kapur padam dengan mol khrom 1 – 3. Hasil penelitian menunjukkan bahwa reaksi antara kapur padam dengan khrom secara keseluruhan dikendalikan oleh perpindahan massa pada lapisan film cair dan lapisan hasil. Pada suhu 30 – 60 C, konstanta kecepatan reaksi mengikuti persamaan Arrhenius. Kenaikan suhu pada rentang tersebut tidak berpengaruh besar pada nilai difusivitas pada lapisan hasil. Perbandingan mol kapur padam dengan khrom tidak mempengaruhi konstanta perpindahan massa pada lapisan film cair, difusivitas pada lapisan hasil maupun konstanta kecepatan reaksi. Kata kunci: limbah, penyamakan, kulit, khrom, kapur padam, kinetika, reaks

Continuous Bioethanol Production Using Uncontrolled Process in a Laboratory Scale of Integrated Aerobic–Anaerobic Baffled Reactor

The expensiveness of bioethanol has made it unattractive and uncompetitive for alternative energy sources. Therefore, several ways to reduce the production cost of bioethanol become interesting topics, e.g. increasing its productivity. This research investigated the performance sensitivity of a laboratory scale of integrated aerobic–anaerobic baffled reactor (IAABR) towards the residence time. The ethanol productivity was monitored to know the optimum residence time. The difference residence times were varied between at 19.2 h and 26.7 h by using difference volume of fermenters i.e. 10 and 100 l, respectively. Molasses as a medium was fed into a reactor containing one compartment of aerobic fermentation and three compartments of anaerobic fermentation. Total sugar and bioethanol concentration were measured for each compartment to determine the production yield to sugar consumption and bioethanol productivity. The fermentation process was conducted at 30 °C, medium pH (4-5), and feed sugar concentration of 170 g/l. The results showed that the optimum residence time in this investigation range is 19.2 h. The ethanol productivity was recorded at 4.63 g/l.h and the production yield to sugar was obtained at 46 % (equivalent to 86 % of theoretical yield) with average feeding of molasses at 0.52 l/h

Steady-State and Dynamic Simulation Study of Reactive Distillation for FFA Esterification in Biodiesel Synthesis

Reactive distillation (RD) holds promise for process intensification in biodiesel production since it integrates reaction and separation. It simplifies the process and enhances the conversion of the equilibrium limited reactions. To ensure the stability in RD operation, sensitivity study and process control simulation are necessary. In this work, RD was employed for free fatty acid (FFA) esterification of mixed non edible oils in biodiesel synthesis. Non edible oils used were waste cooking oil, crude jatropha oil, and crude nyamplung oil (Calophyllum inophyllum L). Simulation was conducted using ASPEN Plus V8.8. Sensitivity study was carried out to determine the effects of the operating condition alteration. A dynamic simulation was performed as a Proportional-Integral-Derivative (PID) controller tuning. It was revealed that the highest FFA conversion was 85%, achieved at the feed stage of 7, distillate rate of 0.22 kmol/hr, and oil to methanol molar ratio of 1:5. Level, pressure and temperature controls were installed in RD. Then, a dynamic simulation was applied as a PID controller tuning. Three different controller tuning methods, viz. Ziegler-Nichols, Cohen-Coon, and Internal Model Control, were studied. The best PID parameter was obtained by using Cohen-Coon method which provided fastest rise time, lowest settling time and lowest overshoot

Inverted Decoupling 2DoF Internal Model Control for Mimo Processes

In general, the multiple-input-multiple-output (MIMO) system is the main method of process control in industry. However, the interaction between variables in the process is a challenge when designing controllers for the system. Strong interaction worsens system performance. Inverted decoupling plays an important role in reducing interaction in the process. Internal model control (IMC) is the controller used in this research. A one degree of freedom (1DoF) IMC controller is only able to provide a good response to set-point tracking, and has a slow response to disturbance rejection. Therefore, a controller that has a good response to set-point tracking and disturbance rejection is a two degrees of freedom (2DoF) IMC. The tuning method uses maximum peak gain margin (Mp-GM) stability criteria based on the uncertainty model. In this study, a reduction in interaction was realized by the addition of inverted decoupling to the 2DoF IMC control scheme. The Wardle & Wood and Wood & Berry column distillation models are given as illustrative examples to demonstrate the performance of the inverted decoupling 2DoF IMC control scheme. A comparison is made of the IAE values of 1DoF IMC, 2DoF IMC, decoupling 2DoF IMC, and inverted decoupling 2DoF IMC, with inverted decoupling 2DoF IMC showing the lowest IAE value

Modelling and simulation of lanthanum (La) and neodymium (Nd) leaching from monazite ore using METSTM

Digestion and leaching are known as part of the main processing pre-treatment method in the extraction of rare earth elements (REEs). This work aims to carry out the sensitivity analysis of the liquid–solid (L/S) ratio, the type of acids as well as the number of reactors for the recovery of REEs, namely lanthanum (La) and neodymium (Nd) from monazite concentrate through the leaching process. A model was developed and simulated by using METSIM, a software for modelling metallurgical processes. The process was modelled as a two-step process; the first is the digestion, followed by the leaching process to produce monazite leachate. The results show that the optimum L/S ratio was 8:1 to recover the highest amount of REEs, with HCl was found to perform better as a solvent for the recovery of REEs compared to H2SO4. In addition, the optimum recovery of REEs was achieved by using three reactors, which is in the range of 70-95%

High strength inert ceramic balls

To develop sintered inert ceramic (balls) from Malaysian clays to meet industrial requirement for Malaysian oil and gas industries, oleochemical, fertilizer, gas processing and acid separation

Formulation of Malaysian clay into inert ceramic balls : Effect of sintering temperature

Ceramic ball support bed materials are used in multiple industries with the aim of providing support for the catalytic materials and assisting the reaction. The majority of ceramic ball products used in Malaysia are either imported as finished products or domestically produced using an imported formulated powder. Besides, the characteristics of sintered ceramic balls depend on the specific powder metallurgy route, including the material composition, range of particle size, and sintering process. Thus, this study focuses on producing inert ceramic balls from local Malaysian raw materials and optimising the sintering temperature with the aim of fulfilling the Universal Oil Products (UOP) standard requirements. The research utilises local clay raw material originating from Trong, Perak, Malaysia. The formulation of each ball was formulated based on a mixture of kaolinite clay, potash feldspar, and silica sand. The sintering process was then varied between 1250 and 1350 °C to tune the character of the finished ceramic ball product. The characterization of the ceramic ball was carried out based on the UOP standard and complemented with X-ray Diffractometer (XRD), Scanning Electron Microscope – Energy Dispersive X-ray (SEM-EDX), and X-ray Fluorescence (XRF) analysis. All tested ceramic balls meet the requirements of the UOP standard. In fact, locally formulated samples had approximately twice the crushing strength of required standards. Different sintering temperatures affect the quartz phase, kaolinite dehydroxylation, mullite formation, and feldspar fusion, thus controlling the final physical–mechanical properties of ceramic balls. Overall, the sintering temperature of 1300 °C provides the most promising output in terms of the quality of ceramic balls and the cost consideration involving the high-temperature heating process

Design and operation of multivessel batch distillation

Distillation processes in chemical industries have shown significant roles for separating valuable compounds from a mixture. In a specific separation process like separation of perfumes, essential oils, and pharmaceutical products, batch distillation is somehow preferable than continuous one. Batch distillation, however, in these separation processes is advantageous, particularly in the flexibility of fluctuating concentration of feed and products, and in changing production capacity based on market demand. In addition, the separation can be performed in only single batch distillation column for all the changing conditions. Due to the dynamic behavior of the operation of batch distillation that leads to more difficult operation, such efforts have been done to attain the desired specifications and, at the same time, to increase the operability. The efforts include both the design and operation of batch distillation. This research focuses on the investigation of separation behavior of multivessel batch distillation for multicomponent mixtures. The distillation unit used in this research consists of two columns with a vessel between the columns, a reflux vessel on the top of the column, and a reboiler (still pot). The experimental data are validated by simulation. Several cases of separation processes are represented by case studies as follows: Top product recovery, removal of light and heavy impurities, and removal of middle boiling component. By using an ideal ternary mixture consisting of ethanol, 1-propanol, and n-butanol, the case studies were used to investigate the separation behavior. It is found that for the case of top product recovery, increasing the vessel holdup of the middle vessel did not make a significant effect to the increase of ethanol purity in top vessel. However, an increase of ethanol purity in top vessel was obtained by simultaneously increasing the middle vessel holdup and reducing the holdup of top vessel. In this case, reducing the top vessel holdup of 50% results in the maximum achievable ethanol purity in top vessel of 96%. For the case of removal of light and heavy impurities, the concern was on the trade-off between product purity and product recovery. An agreement was found to have 91% purity of 1-propanol in the middle vessel with recovery of 74%. However, if it is desired to produce high purity product with suffering on the product recovery, reprocessing the top and bottom product can be carried out to recover the middle component in another batch. In addition, for the case of removing a middle boiling component from a mixture, increasing the middle vessel holdup did not give significant effect to the ethanol purity in top vessel. This may, therefore, be uneconomical to carry out since it leads to more losses of ethanol in middle vessel. An additional investigation on an introduction of slop vessels in the operation of multivessel batch distillation was also discussed in this thesis through simulation works. For the case studies discussed, it is found that slop vessel holdup and slop vessel position simultaneously give significant effects on the product purity of respective vessels

KINETIKA REAKSI KHROM DAN KAPUR PADAM PADA PENGOLAHAN LIMBAH PENYAMAKAN KULIT SECARA BATCH

Kulit merupakan bahan baku untuk produk-produk kerajinan. Sebelum digunakan, kulit melalui proses penyamakan. Sebagaian besar industri penyamakan kulit menggunakan khrom sebagai bahan penyamak. Untuk limbah penyamakan kulit yang mengandung khrom, kadar maksimum yang diperbolehkan sebesar 2,0 mg/L. limbah yang dihasilkan perlu ditangani agar tidak menimbulkan masalah lingkungan. Pemungutan khrom dari limbah cair penyamakan kulit dapat dilakukan dengan mereaksikan dengan kapur padam. Namun kondisi dan kinetika reaksinya belum diketahui secara baik, khususnya reaksi dalam reaktor batch, sehingga perlu dipelajari. Reaksi pemungutan khrom dengan kapur padam dapat dilakukan dalam reaktor slurry tangki berpengaduk secara batch. Mula-mula limbah penyamakan kulit dimasukan kedalam reaktor kemudian diaduk dengan kecepatan tertentu pada suhu kamar. Pada kondisi reaktor telah tercapai kemudian dimasukan kapur padam. Cuplikan diambil setiap selang waktu 3 menit selama 24 menit..Analisis konsentrasi khrom yang tertinggal dijalankan dengan Atomic Absorrption Spectrofhotometer (AAS). Variable yang dipelajari adalah variasi kecepatan pengaduk pada kisaran 140-200 rpm, suhu 30 –60 C, dan perbandingan mol kapur padam dengan mol khrom 1 – 3. Hasil penelitian menunjukkan bahwa reaksi antara kapur padam dengan khrom secara keseluruhan dikendalikan oleh perpindahan massa pada lapisan film cair dan lapisan hasil. Pada suhu 30 – 60 C, konstanta kecepatan reaksi mengikuti persamaan Arrhenius. Kenaikan suhu pada rentang tersebut tidak berpengaruh besar pada nilai difusivitas pada lapisan hasil. Perbandingan mol kapur padam dengan khrom tidak mempengaruhi konstanta perpindahan massa pada lapisan film cair, difusivitas pada lapisan hasil maupun konstanta kecepatan reaksi

Responsible Mineral Resource Development: The Way Forward

This paper provides an insight to a responsible mining, whereby it is an effective application of sustainability concepts to the full mining life cycle. Responsible mining refers to advocacy to reform mining activity, as well as to a marketing strategy used by mining companies to promote their operations as environmentally or socially sound. The author explains the ASEAN principles of responsible mineral resource development, the reporting mechanism and criteria in ASEAN countries responsible mining framework