Penyingkiran Merkuri Dari Minyak Mentah Berat: Konversi Merkuri Ion ke Merkuri Metalik

The presence of mercury in crude oil creates problems in oil processing in refineries, both in terms of operations and health. The previous removal process of mercury has not yet optimally removed mercury in the product, due to ionic and metallic mercury species. In this study, to obtain optimum results, the process of removal of mercury begins with the process of converting ionic (non-metallic) mercury into metallic mercury thermally in the liquid phase, followed by the transfer of metallic mercury to the gas phase by instant evaporation (flashing) and reinforced by gas stripping using internal gas cone from the evaporation of an instant. The results of the optimization of the process carried out can eliminate mercury with an efficiency of more than 95%

Teknoekonomi Penyingkiran Senyawa Sulfur dari Kondensat Gas Alam dengan Metode Desulfurisasi Oksidatif-Ekstraktif

In the oil and gas production process, apart from hydrocarbons, a number of impurities are produced, including CO2 and sulfur in various concentrations, depending on the conditions and characteristics of the reservoir and the location where the oil and gas is located. To process sulfur removal from condensate, the common technology is HDS (Hydrodesulfurization). However, with process requirements such as high temperature, pressure, and intensive hydrogen consumption, an alternative technology is needed for this desulfurization. One of them is oxidative-extractive desulfurization. Technical and economic evaluations to determine the feasibility of applying on an industrial scale need to be studied further. The study of oxidative-extractive desulfurization process of sulfur compounds (represented as dibenzothiophene, DBT) was carried out using H2O2/formic acid as oxidizing agent and catalyst, as well as extraction with DMF. For a capacity of 1000 bpd of condensate with 1%-wt sulfur, desulfurization was successfully carried out with sulfur removal of 96.55% and condensate recovery of 99.41%. A processing fee of 9.14 USD/barrel is required, of which 84% is required for chemicals. The alternative process configuration for DMF recovery succeeded in reducing chemical costs by 35.5% and reducing total processing costs by 27.0% to 6.67 USD/barrel. In this alternative process configuration, 95.80% sulfur removal was achieved with condensate recovery of 99.21%

Mekanisme Teoritis Pembentukan Senyawa Siklik Hidrokarbon dari Reaksi C4H5 dan C4H2

Acetylene and polyyne are intermediates in the formation of Polycyclic Aromatic Hydrocarbons (PAHs) and soot in combustion or pyrolysis. PAH formation from acetylene is known as the most adopted pathway because it has a low reaction energy. Another mechanism for the formation of PAH is a mechanism that involves polyyne or known as a radical pathway, proposed by Krestinin. This pathway involves the reaction of alkyne + alkenes which results in the addition of radical sites to the molecular structure. In this study, the two reaction mechanisms will be compared. Electronic features and energy requirements of the reaction process will be evaluated using molecular computational studies based on electron density (DFT). In combustion conditions (high temperature), the formation of radical sites requires relatively little energy, with a range of 2-5 kcal/mol. This is very different when compared to the energy profile for the same reaction at room temperature. From this study, it can be concluded that the mechanism of radical growth has the potential to occur in combustion reactions.Polycyclic aromatic hydrocarbons, radical growth, combustion, polyyne

Analisis perilaku hidrodinamik kolom absorber pada laju alir gas umpan rendah terhadap perubahan laju alir pelarut dan wash water pada unit penghilangan senyawa sulfur

Metode absorpsi merupakan metode yang banyak digunakan dalam pemurnian gas alam dari senyawa pengasamnya. Unit pemisahan senyawa sulfur pada PT BCD dirancang untuk menurunkan konsentrasi H2S pada gas alam dari 9957 ppm menjadi kurang dari 10 ppm dengan laju alir gas umpan pada rated condition adalah 327,7 MMSCFD. Keseluruhan sistem pengolahan gas didesain dengan turndown ratio 40%. Karena alasan operasi, laju alir gas umpan perlu diturunkan hingga 20% kapasitas desain (65,54 MMSCFD). Analisis dilakukan untuk mengetahui perilaku hidrodinamik kolom absorber dan sistem pendukungnya pada pengoperasian di 20% kapasitas desain. Simulasi dilakukan menggunakan perangkat lunak ASPEN HYSYS V11 untuk mengetahui parameter operasi kolom absorber dan kondisi untuk mendukung pengoperasian di 20% kapasitas desain. Dengan desain operasi peralatan saat ini, weeping terjadi pada laju alir gas umpan 28% desain (91,59 MMSCFD). Pada laju alir gas umpan 28% desain, wash water pump sudah mencapai kapasitas minimum, yaitu 78 gpm. Semakin kecil laju alir gas umpan, maka laju sirkulasi wash water perlu dikurangi untuk menghindari weeping. Untuk dapat beroperasi di gas umpan 20% desain, kapasitas wash water pump perlu diturunkan hingga 25 gpm

Dynamic Evaluation: Centrifugal Compressor’s Operation in Determining Anti-Surge Controller

Anti surging is developed for a compressor system consisting of a booster compressor and a high-pressure compressor in a serial circuit.  This evaluation presented 6 options of anti-surge systems with variations of the number of Anti Surge Valve (ASV) and its combination with the addition of Hot Gas Bypass Valve (HGBV) and Cold Gas Bypass Valve (CGBV).  From the model evaluation, the option that involves a special ASV (dedicated) for each compressor and coupled with a dedicated CGBV or HGBV is the best because the compressor can be back to normal in less than 1 second (maximum time to return to normal condition is 3 seconds.  Referring to these options, dedicated ASV for each compressor provides more benefits to the security of compressor operation.  However, the most appropriate option in the field will return to the issue of cost or ease of modification.  For facilities that are running (brownfield), the use of tools which already exist in the field and do a little modification is the most appropriate option, while for the new facility (grassroots project), the single ASV for a compressor circuit is the most optimum as it only involves minimum equipment and configuration as simple as possible piping/instrumentation.Anti-surging is developed for a compressor system consisting of a booster compressor and a high-pressure compressor in a serial circuit.  This evaluation presented 6 options of anti-surge systems with variations of the number of Anti-surge Valve (ASV) and its combination with the addition of a Hot Gas Bypass Valve (HGBV) and Cold Gas Bypass Valve (CGBV).  From the model evaluation, the option that involves a special ASV (dedicated) for each compressor and coupled with a dedicated CGBV or HGBV is the best because the compressor can be back to normal in less than 1 second (maximum time to return to normal condition is 3 seconds.  Referring to these options, a dedicated ASV for each compressor provides more benefits to the security of compressor operation. However, the most appropriate option in the field will return to the issue of cost or ease of modification.  For facilities that are running (brownfield), the use of tools that already exist in the field and do a little modification is the most appropriate option, while for the new facility (grassroots project), the single ASV for a compressor circuit is the most optimum as it only involves minimum equipment and configuration as simple as possible piping/instrumentation

Selective H2S Absorption Using the Mixture of NaOH-NaHCO3-Na2CO3 Buffer Solvent Solution

Acid gas enrichment unit (AGEU) involves selective separation of H2S from acid gas mixture, for example using absorption with an NaOH solvent solution. Sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) buffer addition to NaOH solution suppresses CO2 absorption, thereby increasing the selectivity of H2S absorption. This study evaluated the effect of buffer addition to increase H2S absorption selectivity using an NaOH solution. It was shown that both buffer addition and L/G ratio decrease could increase H2S selectivity by limiting CO2 absorption. Based on the simulation results, in the 0.006 to 0.030 L/G ratio range and NaOH solvent concentration greater than 2%-mass, the addition of NaHCO3 with mass ratio greater than 1.5:1 to NaOH and the addition of Na2CO3 at 1.26 times NaHCO3’s mass increased H2S absorption selectivity up to 17.3%. The combination of an L/G ratio of 0.006 and solvent with a composition of 5%-mass NaOH, 15%-mass NaHCO3, and 18.9%-mass Na2CO3 produced the highest H2S selectivity of 23.1 (379.7% H2S selectivity increase)

Selective H2S Absorption Using the Mixture of NaOH-NaHCO3-Na2CO3 Buffer Solvent Solution

Acid gas enrichment unit (AGEU) involves selective separation of H2S from acid gas mixture, for example using absorption with an NaOH solvent solution. Sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) buffer addition to NaOH solution suppresses CO2 absorption, thereby increasing the selectivity of H2S absorption. This study evaluated the effect of buffer addition to increase H2S absorption selectivity using an NaOH solution. It was shown that both buffer addition and L/G ratio decrease could increase H2S selectivity by limiting CO2 absorption. Based on the simulation results, in the 0.006 to 0.030 L/G ratio range and NaOH solvent concentration greater than 2%-mass, the addition of NaHCO3 with mass ratio greater than 1.5:1 to NaOH and the addition of Na2CO3 at 1.26 times NaHCO3’s mass increased H2S absorption selectivity up to 17.3%. The combination of an L/G ratio of 0.006 and solvent with a composition of 5%-mass NaOH, 15%-mass NaHCO3, and 18.9%-mass Na2CO3 produced the highest H2S selectivity of 23.1 (379.7% H2S selectivity increase)

Simulasi Dinamik Pengoperasian Kompresor Sentrifugal Multitahap untuk Mengatasi Penurunan Tekanan Sumur Gas

Currently, the utilization of natural gas as an energy source needs to be optimized due to its increasing demand. The utilization of natural gas to produce LNG requires a high-pressure operating system of 1000 psig. The installation of a multistage centrifugal compressor unit is essential to maintain the operating pressure when there is a decrease in the feed gas pressure from natural gas wells. This study aims to predict the performance of the compressor that would be used and optimize the compressor operating conditions to satisfy the specifications of the gas selling pressure. In this study, simulations were conducted on how to maintain the stability of the feed operating pressure in the case of a drop in the gas source pressure from 1000 psig to 200 psig over a period of 15 years. Herein, the gas flow rate under normal conditions is 80 MMSCFD with a gas flow rate variation under surge (minimum) and maximum conditions of 110% × normal flow rate. By using the compressor map prediction curve and Hysys simulation under dynamic conditions, the compressor performance can be analyzed and then used for process requirements in the field.Dewasa ini pemanfaatan gas alam sebagai sumber energi perlu dioptimalkan karena kebutuhannya yang meningkat. Pemanfaatan gas alam untuk memproduksi LNG memerlukan sistem operasi bertekanan tinggi yaitu 1000 psig. Pemasangan unit kompresor sentrifugal multitahap mutlak diperlukan untuk dapat menjaga tekanan operasi saat terjadi penurunan tekanan gas umpan pada sumur-sumur gas alam. Penelitian ini bertujuan untuk memprediksi kinerja kompresor yang akan digunakan serta mengoptimasi kondisi operasi kompresor agar memenuhi spesifikasi tekanan gas jual. Dalam kajian ini, dilakukan simulasi bagaimana mempertahankan kestabilan tekanan operasi umpan untuk kasus penurunan tekanan sumber gas dari 1000 psig hingga 200 psig dalam kurun waktu 15 tahun. Laju alir gas pada kondisi normal adalah 80 MMSCFD dengan variasi laju gas pada kondisi surge (minimum) dan kondisi maksimum sebesar 110% × laju alir normal. Dengan menggunakan kurva prediksi peta kompresi dan simulasi Hysys pada kondisi dinamik, kinerja kompresor dapat dianalisis dan kemudian dapat digunakan untuk kebutuhan proses di lapangan

Calcium soap from palm fatty acid distillate for ruminant feed: Calcium oxide particles size

High production of crude palm oil has led Indonesia to become one of the countries that have a large number of palm fatty acid distillate (PFAD) in the world. As a source of fatty acid, PFAD has wide range of uses, including as a fat supplement in the ruminant feed when reacted with a calcium source such as calcium oxide (CaO). At the working temperature above PFAD’s melting point, those reactants form a homogeneous phase with the help of intensive stirring. By the presence of a small amount of water, the mixture will be saponified and become the calcium soap. This research studied how different particles sizes of CaO could influence the reaction conversions based on the acid value of the product. The CaO solid particles were sieved and separated into the different fraction of sizes (<177 μm, 177-320 μm, and 320-640 μm). Smaller particle resulted in a lower acid value which indicates a high conversion of free fatty acid and lower moisture content which is preferable for the product