Controle do Processo TCPSD para Separação da Mistura Acetonitrila/Benzeno/Metanol

Visando uma maior economia em custos operacionais, a inclusão de correntes de reciclo e integrações térmicas são rotineiras nos processos químicos, gerando a necessidade de estruturas de controle mais robustas, capazes de impedir perdas devido a distúrbios rotineiros e proporcionar segurança operacional. A separação via Triple-Column Pressure-Swing Distillation (TCPSD) pode ser utilizada para separar diferentes solventes da indústria de química fina, e devido ao grande número de variáveis envolvidas, juntamente a integrações térmicas e correntes de reciclo, a definição de uma estrutura de controle eficaz se torna um problema complexo. Neste contexto, este trabalho tem como principal objetivo o desenvolvimento e avaliação de estruturas de controle plantwide para o processo TCPSD, utilizado para separação da mistura acetonitrila/benzeno/metanol. Utilizando os softwares Aspen Plus© e Aspen Plus Dynamics©, foram avaliadas duas estruturas de controle, nas quais as composições dos produtos são controladas por inferência, através do controle da temperatura de pratos sensíveis. A principal diferença entre as duas estruturas é que a Estrutura de Controle 1 possui uma malha de controle de soma dual de temperatura de pratos sensíveis na coluna de baixa pressão, manipulando a razão de refluxo. Ao avaliar os resultados das composições dos produtos ao atingir estado estacionário e valores de ISE, concluiu-se que ambas as estruturas são capazes de controlar distúrbios do tipo degrau na vazão e composição de alimentação do processo. Contudo, observaram-se melhores resultados na Estrutura de Controle 1.

Air column of pressure hydrocyclone with pneumatic regulator

A reliable non-contact pneumatic pressure regulator of a pressure hydrocyclone is offered. The regulator is installed in the area of ​​the sand nozzle. The pneumatic regulator of the standard pressure cylindrical-conical hydrocyclone provides non-contact thickening of the product in the area of ​​the sand nozzle. In the process of controlling the operation of the hydrocyclone along its axis, an air column is formed. Features of the regulator affect the formation of the air column of the hydrocyclone. The pressure in the air column is manometric. The task is to investigate the effect of pulp pressure at the inlet of the hydrocyclone, pulp thickening and air column pressure. Experimental studies were performed in the laboratory on a model of a standard industrial cylindrical-conical hydrocyclone HC360. The connection between the technological parameters of the hydrocyclone operation and the pressure in the air column has been studied. to establish possibilities of control of work of a hydrocyclone on pressure in an air column. The planning of the experiment in the laboratory on a hydrocyclone model was performed in the program Statgraphics Centurion XV. Experimental studies were performed for the optimal parameters of the angle and slit of the pneumatic regulator. The optimization criterion is chosen – the maximum effect of pulp thickening while minimizing local energy losses in the nozzle. In laboratory conditions, the change in pulp pressure and density at the inlet of the hydrocyclone over the entire operating range is simulated. The laboratory model of the hydrocyclone was made on a scale of M1:10. Flotation waste was used as pulp. Modeling of hydrocyclone operation as a part of water-sludge system at the concentrator is carried out. The density of the solid phase is 1500 kg/m3. The solids content at the inlet is 10 g/l. Samples were taken by volumetric measurement with a measuring vessel. A statistically significant relationship between the pressure in the air column of the hydrocyclone and the effect of pulp thickening in a standard cylindrical-conical hydrocyclone was established. The presence of the linear character of the dependence of the coefficient of thickening and pressure in the air column of the hydrocyclone with the pneumatic regulator is checked. The absence of a statistically significant effect of hydrocyclone supply pressure on the dependence of other selected factors was established. Experimental studies were carried out at the optimal design parameters of the pneumatic regulator according to the criteria of minimizing the loss of energy of air current in the nozzle and minimizing the volumetric flow of air.

Optimising of vacuum distillation units using surrogate models

Crude oil blending is an important step for the operation of crude distillation systems in the refinery to improve the yield and profitability of the products. The product’s yield and quality are strongly dependent on the properties of the crude oil. However, the products of crude distillation units, especially the vacuum distillation unit (VDU) need to satisfy the yield and quality requirements of the downstream process units in the refinery. Otherwise, the performance of downstream processes will be affected, and loss of profitability in the refinery. Hence, it is important to optimise the performance of the VDU to ensure the optimum operation of VDU. This work covers the process simulation of VDU, surrogate modelling and mathematical optimisation model. The objective of the developed optimisation model is to determine an optimal for maximum high vacuum gas oil (HVGO) yield and minimum total annualised cost (TAC) respectively. To do this, crude oil blending ratio, column temperature, column pressure, stripping steam flowrate, pump-around flowrate in the VDU are optimised. Based on the optimised result, the heavy-light crude blend achieves higher HVGO yield and lower TAC as compared to the heavy-medium crude blend and heavy-medium-light crude blend. The optimised results can provide insight into the optimal process conditions of VDU for the refiners. With this insight, effective operating strategies can be developed to overcome the limitations present in real VDU operations.

ANALISA PERFORMA KOLOM DISTILASI (105D4) DI FATTY ACID PLANT-1 PT. DOMAS AGROINTI PRIMA DENGAN SIMULASI ASPEN HYSYS

Fatty acid adalah salah satu bagian dari produk industri oleochemical. Salah satu industri hilir yang bergerak pada produksi fatty acid (asam lemak) adalah PT. Domas Agrointi Prima. Pada PT. Domas Agrointi Prima fatty acid diproduksi di fatty acid-1 plant. Untuk menghasilkan fatty acid yang sesuai spesifikasi pasar, maka perlu dilakukannya proses pemisahan dan pemurnian pada kolom distilasi/fraksinasi. Salah satu produk utama pada fatty acid-1 plant adalah fatty acid yang banyak mengandung asam oleat (C18:1) yang dipisahkan dan dimurnikan pada kolom distilasi 105D4. Penelitian ini menganalisa performa kolom distilasi 105D4 pada fatty acid-1 plant PT. Domas Agrointi Prima dengan mensimulasikan proses pemisahan dan pemurnian fatty acid ke dalam aspen hysys dengan mentuning variabel suhu top column, suhu side column, suhu bottom column, pressure top dan pressure bottom yang bermaksud untuk meninjau laju alir fatty acid yang berhasil dikeluarkan pada setiap aliran, yield fatty acid aliran destilat, dan konsentrasi asam oleat pada aliran destilat untuk mendapatkan performa yang paling optimal dari kinerja kolom distilasi 105D4 dalam proses pemisahan dan pemurnian fatty acid. Hasil yang diperoleh dari penelitian ini yield produk fatty acid pada distillate stream yang paling maksimal didapatkan pada run ke 6 yaitu sebesar 99,22%. Konsentrasi asam oleat pada produk yang keluar melalui distillate stream yang paling maksimal didapatkan pada run ke 6 yaitu sebesar 57,95%. Kondisi operasi kolom distilasi 105D4 yang paling optimal didapatkan pada simulasi run ke 6, dimana untuk suhu top column sebesar 189,35 oC , suhu side column sebesar 210,65 oC, suhu bottom column sebesar 223,69 oC, tekanan top column sebesar 9,58 mBar dan tekanan bottom column sebesar 11,87 mBar.

High-Throughput Griess Assay of Nitrite and Nitrate in Plasma and Red Blood Cells for Human Physiology Studies under Extreme Conditions

The metabolism of nitric oxide plays an increasingly interesting role in the physiological response of the human body to extreme environmental conditions, such as underwater, in an extremely cold climate, and at low oxygen concentrations. Field studies need the development of analytical methods to measure nitrite and nitrate in plasma and red blood cells with high requirements of accuracy, precision, and sensitivity. An optimized spectrophotometric Griess method for nitrite–nitrate affords sensitivity in the low millimolar range and precision within ±2 μM for both nitrite and nitrate, requiring 100 μL of scarcely available plasma sample or less than 50 μL of red blood cells. A scheduled time-efficient procedure affords measurement of as many as 80 blood samples, with combined nitrite and nitrate measurement in plasma and red blood cells. Performance and usefulness were tested in pilot studies that use blood fractions deriving from subjects who dwelt in an Antarctica scientific station and on breath-holding and scuba divers who performed training at sea and in a land-based deep pool facility. The method demonstrated adequate to measure low basal concentrations of nitrite and high production of nitrate as a consequence of water column pressure-triggered vasodilatation in deep-water divers.

Wellhead Design Enables Offline Cementing and a Shift in Operational Efficiency

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 202439, “Pushing Malaysia’s Drilling Industry Into a New Frontier: How a Distinctive Wellhead Design Enabled Implementation of a Fully Offline Well Cementing Resulting in a Significant Shift in Operational Efficiency,” by Fauzi Abbas and Azrynizam M. Nor, Vestigo, and Daryl Chang, Cameron, a Schlumberger Company, prepared for the 2020 SPE Asia Pacific Oil and Gas Conference and Exhibition, originally scheduled to be held in Perth, Australia, 20–22 October. The paper has not been peer reviewed. Traditionally, rigs are positioned over a well from the moment the surface casing is drilled until the installation of the wellhead tree. This results in the loss of precious time as the rig idles during online cementing. However, in mature Field A offshore Terengganu, Malaysia, a new approach eliminated such inefficiency dramatically. Operational Planning With oil production in Field A initiated in October 2015, historical data on well lithology, formation pressure, and potential issues during drilling were available and were studied to ensure that wells would not experience lost circulation. This preplanning is crucial to ensure that the offline cementing activity meets the operator’s barrier requirements. Petronas Procedures and Guidelines for Upstream Activities (PPGUA 4.0) was used for the development of five subject wells in Field A. In this standard, two well barriers are required during all well activities, including for suspended wells, to prevent uncontrolled outflow from the well to the external environment. For Field A, two barrier types, mechanical and fluid, allowed by PPGUA 4.0 were selected to complement the field’s geological conditions. As defined in PPGUA 4.0, the fluid barrier is the hydrostatic column pressure, which exceeds the flow zone pore pressure, while the mechanical barrier is an element that achieves sealing in the wellbore, such as plugs. The fluid barrier was used because the wells in Field A were not known to have circulation losses. For the development of Field A, the selected rig featured a light-duty crane to assist with equipment spotting on the platform. Once barriers and rig selection are finalized, planning out the drill sequence for rig skidding is imperative. Space required by drillers, cementers, and equipment are among the considerations that affect rig-skid sequence, as well as the necessity of increased manpower. Offline Cementing Equipment and Application In Field A, the casing program was 9⅝×7×3½ in. with a slimhole well design. The wellhead used was a monobore wellhead system with quick connectors. The standard 11-in. nominal wellhead design was used for the wells with no modifications required. All three sections of the casing program were offline cemented. They were the 9⅝-in. surface casing, 7-in. production casing, and 3½-in. tubing. The 9⅝-in. surface casing is threaded to the wellhead housing and was run and landed with the last casing joint. Subsequent wellhead 7-in. casing hangers and a 3½-in. tubing hanger then were run and landed into the compact housing.

Non-contact measurement system for hot water drilled ice boreholes

A programmable borehole measurement system was deployed in hot water drilled ice holes during the ‘Bed Access and Monitoring of Ice Sheet History’ (BEAMISH) project to drill to the bed of the Rutford Ice Stream in West Antarctica. This system operates autonomously (no live data) after deployment, and records borehole diameter (non-contact measurement), water column pressure, heading and inclination. Three cameras, two sideways looking and one vertical, are also included for visual inspection of hole integrity and sediments. The system is small, lightweight (~35.5 kg) and low power using only 6 ‘D’ cell sized lithium batteries, making it ideal for transport and use in remote field sites. The system is 2.81 m long and 165 mm in diameter, and can be deployed attached to the drill hose for measurements during drilling or on its own deployment line afterwards. The full system is discussed in detail, highlighting design strengths and weaknesses. Data from the BEAMISH project are also presented in the form of camera images showing hole integrity, and sensor data used to calculate borehole diameter through the full length of the hole. These data are used to show confidence in hole verticality and subsurface cavity development and connection.