Perancangan Penangkap Debu (Wet ScrubberUntuk Penanganan Lanjut Debu Terbang Pabrik)Briket Arang "Aneka Sinendo" Ploso, Banguncipto,Sentolo, Kulonprogo,Daerah Istimewa Yogyakarta

ABSTRACT PT Aneka Sinendo produces charcoal briquette from wood mill saw. Fly ash coming from the dryer pollutes the environment, and then the effort to prevent this fly ash dispersion is needed. At the previous Vucer Program (Mindaryani, 1998), an additional cyclone has been constructed and 450 kg/day of fly ash can be recycled. Therefore the factory could save Rp 810.000,-/month to pay the electricity. As the pressure drop in the added equipment is very small while the fan is too big, the bin is needed to reduce the velocity into the extruder. From this evaluation, in order to trap all the dust out, a bag filter might be an alternative, as well as to use the excessive power of the fan. A bag filter has also been erected in the plant (Mindaryani, 2001) to solve this problem. As there was tar in the effluent gas, the filter was blocked. The filters should be changed every time, but the bag filter position is on the roof, so it is difficult to do this job. In order to solve this problem, a wet scrubber need to be constructed, this program would assist them in evaluating and design the equipment better, based on the engineering point of view. A wet scrubber system consists of a wet scrubber, pump and water circulation pond was also constructed in the plant. Wet scrubber construction next to the bag filter box reduced the fly ash and tar from the gas disposal and needs a little power for water circulation. The result of this activity is useful for the environment and especially for the factory worker. The partner from industry may apply this system and disseminate to other factories with the same problem to prevent the environmental pollution. Keywords:Penangkap Debu, environmental pollutio

Koefisien perpindahan massa volumetrik, padat - gas dalam kolom fluidisasl

ABSTRAK Data kecepatan perpindahan massa volumetrik antara padatan dengan gas dalam kolom fluidisasi diperlukan untuk perancangan berbagai alat-alat dalam industri kimia. Udara dialirkan dengan kecepatan tertentu ke alas, melalui tumpukan butir-butir kapur barus di dalam tabung yang berbentuk pipa tegak. Sebelum dan sesudah operasi, butir-butir kapur barus ditimbang untuk mengetahui massa yang dipindahkan ke fasa gas. Penelitian dijalankan dengan tinggi tumpukan kapur barus, diameter tabung, kecepatan aliran udara dan diameter kapur barus yang diubah-ubah. Hubungan koefisien perpindahan massa volumetrik antara zat padat dengan gas dalam kolom fluidisasi dengan peubah yang berpengaruh, jika dihitung secara bertahap Key words:masa volumetri

Optimasi proses metilasi brazilein hasil ekstrak kayu secang (caesalpinia sappan linn) sebagai bahan pewarna merah alami untuk tekstil

Salah satu upaya untuk mengurangi penggunaan pewarna sintesis yang berbahaya bagi manusia dan lingkungan adalah dengan menggunakan pewarna alami. Salah satu bahan pewarna alami yang potensial di Indonesia adalah kayu Secang (Caesalpina sappan L.). Kayu secang mengandung senyawa brazilein yang mampu menghasilkan warna merah. Namun, warna merah yang dihasilkan oleh brazilein sangat tidak stabil terhadap perubahan pH. Tujuan penelitian ini adalah meningkatkan kestabilan warna brazilein terhadap perubahan pH dengan menggunakan metode metilasi. Metilasi dilakukan dengan menggunakan dimetil karbonat (DMC) sebagai agen metilasi yang dikombinasikan dengan kalium iodide (KI) dan kalium karbonat (K2CO3). Metilasi dilakukan menggunakan metode reflux dengan variasi suhu (50, 60, dan 70 oC), waktu (3, 4, dan 5 jam), dan rasio pereaktan (1:5, 1:10, dan 1:15 g brazilein/mL DMC). Kestabilan warna dinyatakan sebagai nilai absorbansi yang diukur menggunakan spektrofotometer UV-Vis pada panjang gelombang 535,6 nm. Optimasi kondisi metilasi dilakukan menggunakan Response Surface Methodology (RSM). Hasil yang optimum didapatkan pada suhu 70 oC, waktu 3,46 jam, dan rasio pereaktan 0,12 g brazilein/mL DMC. Pada kondisi tersebut, penyimpangan nilai absorbansi asam sebesar 28,12% sedangkan penyimpangan nilai absorbansi basa sebesar 0,02%. Kestabilan warna brazilein berhasil ditingkatkan dengan melakukan metilasi pada kondisi optimum

Laju Reaksi Hidrolisis Herbisida Glifosat di Tanah Jenuh Air.

The objectives of the research were to find out the parameters of the hydrolysis reaction rate (k,,) and partition coefficien (Kr) of glyphosate herbicide in saturated soil system, to identify the variables affecting those parameters, and to develop the empirical equations corelating those parameters to the pertinent variables. The experimental work or physical simulation in laboratory was conducted in a batch reactor. The sterilized soil 5 gram put into a 1000 cm3 of Erlenmeyer glass and 500 cm3 of glyphosate solution with 8 g/1 concentration was added. The Erlenmeyer mouth was covered with plastic film and the entire Erlenmeyer surface was covered with aluminium foil to minimize vaporization and photolysis reaction. The solution was mixed continuously with magnetic stirrer. At the initial time and selected time intervals, 5 cm3 of the samples were taken with syringe. The samples were centrifuged and filtered, 1 cm3 of the filtrate were analyzed its glyphosate concentration with UV- VIS. The experiments were conducted for various soil types, and the empirical correlation between the hydrolysis reaction rate (k,,) and partition coefficien (Kr) with the affecting variables can be developed. Based on the laboratory data and the simulation of mathematical model, it could be concluded that the empirical correlation between the Kr and kh values with the affecting variables could be represented in the equations: Kr =11.035 (%organic matter) + 0.25 (%clay mineral) mL gram kh =1.0810 (%organic matter) + 1.5310-5 (%clay mineral) min-1 Keywords: glyphosate herbicide, rate constants of hydrolysis reaction, partition coefficient, unsaturated soil system

Konduktivitas panas berbagai jenis kayu dan koefisien perpindahan panaskayu dan udara dalam kolom fluidisasi.

Thermal conductivities (k) of various woods and solid â gas heat transfer coefficient (h) in fluidized bed were measured in this study, using low temperature air. The air with constant humidity and temperature (around 500C) was flown through the bed of spherical wood (dp = 1 cm) until fluidization takes place. The effluent temperature were measured regularly until constant. Thermal conductivity and solid â gas heat transfer coefficient were estimated from the temperature data obtainde using the Hooke-Jeeves optimization method. Experiments were conducted at various air velocities. The conductivitiy of teakwood (jaa) is = 0.468 J/(K.m.â¤), of mahagony (mahoni) is = 0.413 J/(K.m.â¤), of sonokeling is = 0.389 J/(K.m.â¤), of mranti is = 0.486 J/(K.m.â¤), and of kamper is = 0.458 J/(K.m.â¤). For 9178 < Re < 13193, the range of solid â gas heat transfer coefficient (h) is 359 â 475 J/(Km2.â¤), and its correlation is given by .⢠lid,, k I f 9.3 p f J id v 0.343 with the average error of 2.14%

Evaluation of the Effect of Operating Parameters on the Performance of Orifice/Porous Pipe Type Micro-bubble Generator

The micro-bubble generator (MBG) is a novel aeration technology utilizing the concept of fluid flow through an orifice, where air is sucked into the internal chamber of the MBG by the pressure difference created by the orifice and immediately pushed by the high-velocity flow of the fluid. This mechanism creates micro-size bubbles with a high dissolution rate. This study focused on studying the effect on the oxygen dissolution rate of the two most important operating parameters, i.e. the volumetric flow rate of the liquid (QL) and the volumetric flow rate of the air (QG). Various combinations of values for QL and QG were systematically compared by means of the oxygen mass transfer coefficient (kLa). The experiment was carried out in a transparent container of 2.8 m x 0.6 m x 0.4 m filled with tap water that was aerated using an orifice/porous-pipe type MBG. The dissolved oxygen (DO) values were measured at distances of 60 cm, 120 cm, and 180 cm from the MBG outlet. The experiment was designed with five different values for QL and QG respectively. The results showed that the value of kLa, which is proportional to the oxygen dissolution rate, increased asymptotically with increasing QL value, while the QG values did not significantly affect the kLa value

Decreasing COD in Sugarcane Vinasse Using the Fenton Reaction: The Effect of Processing Parameters

An experiment on Fenton degradation of sugarcane vinasse was carried out to determine its effect on the wastewater characteristics. Vinasse, a by-product of distillation in the bioethanol industry, contains high organic matter, as the value of chemical oxygen demand (COD) is >100,000 mg/L and BOD5 is 31,250 mg/L. The Fenton reaction is one of the advanced oxidation process (AOP) methods which has been widely applied for the treatment of wastewater containing organic pollutants and contaminants. This method utilizes hydroxyl radical (•OH) produced from the catalyzing reaction between Fe2+ or Fe3+ and hydrogen peroxide. The effect of pH, the ratio of [H2O2] and [COD], and the ratio of [H2O2] to [Fe3+] were studied in this research to evaluate the Fenton reaction. Results from this experiment showed that treatment of vinasse using the Fenton reaction decreased the COD value to 48.10%, and its biodegradability enhanced almost two times at a pH value of 3.8, a ratio of [H2O2] to [COD] of 0.62, and a ratio of [H2O2] to [Fe3+] of 50 (g/g), which demonstrated that the Fenton treatment was effective to reduce organic matter of sugarcane vinasse. Three kinetic models (first order, second order, and Behnajad–Modirshahla–Ghanbery (BMG) kinetic model) were used to evaluate the degradation of the COD value. On the basis of the value of R2 (coefficient of determination), we suggested that BMG represented the best kinetic model. This study finds that the Fenton treatment is able to mitigate the environmental impacts of sugarcane vinasse