Refinery Units Research Articles

Betung bamboo-based activated carbon bioadsorbent for the separation of hydrogen-methane gas mixture

Hydrogen recovery from off gas of hydrocracking and hydrotreating unit is one of the crucial processes in an oil and gas refinery unit as this process helps in lowering the expenses for operations. This study aims to obtain activated carbon that is made from Betung bamboo which can be used as the adsorbent in this process. The activated agents used are H3PO4 and K2CO3, respectively. Each activation lasts for 30 minutes. The results of the characterization test shows that the Iodine number of the activated carbon produced reaches 916.4 mg/g with BET surface area of 465.2 m2/g. SEM-EDX analysis shows that the carbon content is 74.83%. The activated carbon obtained is used to separate Hydrogen and Methane from its mixture at 10, 20 and 30oC with pressure variations of 1 - 6 bar. The results indicate that the maximum number of moles adsorbed from CH4(21.5%)/H2 gas mixture is 0.247 mmol/g, that has been carried out at 6 bar with temperature of 10oC. Methane has 2.2 times higher adsorption capacity than hydrogen, therefore, the Betung bamboo based activated carbon produced from this research can be applied as the adsorbent in the separation process of CH4/H2 mixture and it fits the Langmuir model.

Study on novel scheme for hydrodesulfurization of middle distillates using different types of catalyst

This study aimed to investigate the hydrodesulfurization (HDS) of a mixture of crude oil fractions (e.g., naphtha, kerosene, and gas oil) all in one time in a single reactor under various operating parameters such as temperature (T = 310–370 °C), pressure (P = 40–55 bar), weight hour space velocity (WHSV = 1.2–3.6 h−1), hydrogen-to- hydrocarbon ratio (150–300 vol/vol), and type of catalysts (di-metallic and tri-metallic). Experimental results showed that temperature and pressure have positive effects on process performance while weight hour space velocity gives a different trend. Results indicated that HDS efficiency was 95.8% at optimized operating parameters T = 350 °C, P = 50 bars, WHSV = 1.2 h−1, and (H2/HC) ratio = 200 vol/vol. and with NiCoMo/γ-Al2O3 catalyst which offered a higher HDS efficiency compared with other types of catalysts used. Kinetic analysis revealed that a pseudo-first order rate law is well expressing the HDS reaction of the operating system for all types of catalysts. Estimation of rate parameters over each type of catalyst was also presented. Study of mass transfer limitations revealed that surface reaction is the rate controlling step. Feasibility of the proposed technique may offer a large reduction in fixed and operating costs of the HDS unit in a modern petroleum refinery.

CORPORATE SOCIAL RESPONSIBILITY IN FAVOR OF IMPROVING EDUCATION IN SOCIETY (CASE OF PT PERTAMINA REFINERY UNIT VI BALONGAN)

Corporate Social Responsibility (CSR) is an external activity of a corporate undertaken for the benefit of society. It is expected to facilitate good relationship between the corporate and society. The purpose of this research is to describe Corporate Social Responsibility activity in favor of improving education in society. Research method was using an approach of qualitative descriptive in the case of PT. Pertamina Refinery Unit VI Balongan. Data was collected through conducting in-depth interview, observing, and implementing FGD. The results showed that CSR activity was very beneficial to local society as many of them were be able to continue higher education. Furthermore, local government also found out that CSR has a measurable good impact in local human development index. A long-term goal of CSR is to develop quality human resources to sustain a better life for all. Keywords: Corporate Social Responsibility, Society, Education

Comparison between Post- and Oxy-Combustion Systems in a Petroleum Refinery Unit Using Modeling and Optimization

Comparison between Post- and Oxy-Combustion Systems in a Petroleum Refinery Unit Using Modeling and Optimization

Comparison between Post- and Oxy-Combustion Systems in a Petroleum Refinery Unit Using Modeling and Optimization

Comparison between Post- and Oxy-Combustion Systems in a Petroleum Refinery Unit Using Modeling and Optimization

A new lumped kinetic model of an industrial hydrocracking process

Hydrocracking is a catalytic cracking process for the conversion of heavy oil fractions, such as vacuum gas oil (VGO), into valuable products with lower boiling point, such as diesel, kerosene and gasoline. Due to the flexibility of the process, high yields and good quality of liquid products, hydrocracking has become an important unit in modern refinery. However, the study of kinetic modelling towards hydrocracking reactor (HCR) is limited due to its complicated reaction mechanism. In this study, the reactor model is established based on a new six-lump model considering the velocity change along the reactor, different thermal effects and kinetic differences between hydrotreater (HT) and hydrocracker (HC). Compared with the previously reported lumped kinetic models, the fine-tuned model (calibrated by differential evolution algorithm) can predict products yields more accurately, in particular outlet temperature of each beds and the detailed yields and temperature distribution along with the reactor beds. The proposed lump based kinetic model can be applied to the optimization and control of industrial hydrocracking process.

OUTDOOR CULTIVATION OF Scenedesmus obliquus BR003 IN STIRRED TANKS BY AIRLIFT

ABSTRACT: The use of microalgae as a source of raw material for biofuel production has been highly targeted. Compared to other biological options for the capture and use of CO2, microalgae crops have the following advantages: high productivity, lack of competition with feed and food-based products, use of unproductive and non-arable land, and allowance of the use of wastewater for its cultivation. The use of wastewater from industrial, agricultural, and domestic sewage has been indicated as an alternative means to reduce the cost of crops, since such waste is generally released into the environment without previous treatment. This work addresses the use of petrochemical wastewater (ARP) from effluent produced at the Gabriel Passos Refinery (Petrobras refinery unit) for the cultivation of a strain of Scenedesmus obliquus BR003. Twelve experimental units of 20 L each were constructed in the experimental area of the Biofuel Laboratory of the Federal University of Vicosa, Minas Gerais, Brazil in an uncontrolled environment, and the cultures were evaluated by quantification of total carbohydrates, total lipids, dry biomass, and growth evaluated by absorbance. The results showed that the wastewater from petrochemical effluent is an efficient growth medium for the growth of Scenedesmus obliquus BR003 microalgae for large-scale cultivation on land that is not suitable for other agricultural crops.

Maximisation of an oil refinery profit with products quality and NO2 constraints

Today science and engineering are concerned with maximising profit while maintaining minimum air emissions from chemical plants such as oil refineries. Air emissions, such as NO2, when exists in large amounts, it could cause different types of serious diseases and illnesses. This research focuses on studying NO2 emissions from oil refineries while maintaining a maximum profit and the desired final products quality such as sulphur contents in fuel or octane number for gasoline. This paper aims to analyse the cost-profit of an oil refinery with the inclusion of Visbreaker unit. Visbreaker unit contribution to the revenue of oil refinery was not included in previous literature. The Economic power of Visbreaking unit in an oil refinery is given a good chance, for the first time in research work; to be evaluated economically and show its strength and money return to the plant with other product and NO2 constraints. The objectives of visbreaking are to reduce the viscosity of the feed stream, reduce the amount of residual fuel oil produced by a refinery and increase the proportion of middle distillates in the refinery output. In addition, the aim of the study is to find how to reduce NO2 emissions from oil refineries using different technologies while maintaining profit at maximum possible level using mathematical modeling approach. The three methods being used for NO2 reduction are; balancing, fuel switching and use of technology for NO2 reduction. NO2 emissions will be reduced by using the above three methods to reach different reduction percentage ranging from 20% to 80%. The profit of the oil refinery for each reduction target of NO2 was analysed and looked at closely. For example, at the 20% of NO2 reduction target, profits were $720 million. At the 80% reduction target, profits dropped down to $701 million. The contribution of Visbreaker to final products was calculated. For example, Visbreaker was responsible for adding 60,000 bbl of light and heavy naphtha to final products with total sales of around $6.0 million per year for this contribution. The model is mixed integer nonlinear (MINLP) and GAMS package is used to run a case study to validate the developed model. In addition to maximising profits, maintaining good quality products, reducing NO2 emissions and focus on Visbreaker products contributions is investigated deeply.

Fitness for service assessment of a pressure vessel subjected to fire damage in a refinery unit

Abstract The fire-damaged pressure vessel reactor, evaluated in this study, was a cylindrical vessel with design conditions of 460 psig (3.17 MPa) at 413 °C. The fitness for service (FFS) of the fire-damaged pressure vessel was assessed according to API 579-1/ASME FFS-1. First, the maximum temperature during the fire accident was determined based on deterioration of outer protective layer. Then, the possible damage was examined by hardness test, in-situ field metallography and metallographic replicas. Grain growth and spheroidized pearlite were observed in the base metal at the inner surface of the vessel. Outer surface of the vessel showed ferritic microstructure with smaller grain size as compared to the inner surface. Decarburizing and carbide formation were also visible at the outer surface. The lower hardness of the base metal at both sides of the vessel was compared to the standard value and related to the microstructure evolution during high temperature/fire exposure condition. The results of the FFS evaluation indicated that the vessel is not suitable for the current design conditions, and therefore a new maximum allowable working pressure was determined.

Simultaneous valorization and biocatalytic upgrading of heavy vacuum gas oil by the biosurfactant-producing Pseudomonas aeruginosa AK6U.

SummaryHeavy vacuum gas oil (HVGO) is a complex and viscous hydrocarbon stream that is produced as the bottom side product from the vacuum distillation units in petroleum refineries. HVGO is conventionally treated with thermochemical process, which is costly and environmentally polluting. Here, we investigate two petroleum biotechnology applications, namely valorization and bioupgrading, as green approaches for valorization and upgrading of HVGO. The Pseudomonas aeruginosa AK6U strain grew on 20% v/v of HVGO as a sole carbon and sulfur source. It produced rhamnolipid biosurfactants in a growth‐associated mode with a maximum crude biosurfactants yield of 10.1 g l−1, which reduced the surface tension of the cell‐free culture supernatant to 30.6 mN m−1 within 1 week of incubation. The rarely occurring dirhamnolipid Rha–Rha–C12–C12 dominated the congeners’ profile of the biosurfactants produced from HVGO. Heavy vacuum gas oil was recovered from the cultures and abiotic controls and the maltene fraction was extracted for further analysis. Fractional distillation (SimDist) of the biotreated maltene fraction showed a relative decrease in the high‐boiling heavy fuel fraction (BP 426–565 °C) concomitant with increase in the lighter distillate diesel fraction (BP 315–426 °C). Analysis of the maltene fraction revealed compositional changes. The number‐average (Mn) and weight‐average (Mw) molecular weights, as well as the absolute number of hydrocarbons and sulfur heterocycles were higher in the biotreated maltene fraction of HVGO. These findings suggest that HVGO can be potentially exploited as a carbon‐rich substrate for production of the high‐value biosurfactants by P. aeruginosa AK6U and to concomitantly improve/upgrade its chemical composition.

Performance Monitoring via Disturbance Characterization in Refinery Control Loops

This study is motivated by the fact that minimum variance control (MVC) benchmark can be insufficient in case of deterministic process inputs, since stochasticty is assumed. Therefore, it is crucial to know the type of disturbance while assessment. In this paper, a new approach is proposed to extend MVC via characterization of disturbance, which require only routine closed loop data and is easy-to-use online. The method can also detect oscillations properly in noisy process measurements. Suggested method uses a decision tree to combine controller performance index (CPI) with correlation coefficient which identifies the type of disturbance. The algorithm is applied into a refinery unit where the root causes of poorly performing loops are known. The results are discussed in the scope of performance monitoring.

Optimal design and operation of an industrial fluidized catalytic cracking reactor

Fluidized catalytic cracking (FCC) is regarded one of the most significant operations in the oil refining industries to convert feedstock (mainly vacuum gasoil) to valuable products (namely gasoline and diesel). The behavior of the fluidized catalytic cracking process is playing a main part on the overall benefits of refinery units and improving in process or control of fluidized catalytic cracking plants will result in exciting benefits economically. According to these highlights, this study is aimed to develop a new mathematical model for the FCC process taking into account the complex hydrodynamics of the reactor regenerator system with a new six lumps kinetic model for the riser. The mathematical model, simulation and optimization have done utilizing vacuum gas oil (VGO) as a feedstock and zeolite as a catalyst under the following operating conditions: temperature (733K, 783K, and 813K), weight hourly space velocity (5, 20 and 30h−1) and catalyst to oil ratio (4, 7 and 10). The best kinetic parameters of the relevant reactions are estimated using the optimization technique based on the experimental results taken from literature. The effect of operating condition (mainly, reaction temp (T), catalyst to oil ratio (CTO) and weight hourly space velocity (WHSV) on the product composition has also been discussed. The optimal kinetic parameters obtained from the pilot plant scale have been employed to develop an industrial FCC process, where optimal operating condition based on maximum conversion of VGO with minimum cost in addition to maximizing the octane number of gasoline (GLN), have been studied. Minimum coke content deposition the catalyst within the regenerator is also investigated here. New results (the highest conversion and octane number, and the lowest coke content) have obtained in comparison with those reported in the literature.

A molecular lump based model for simulation of industrial naphtha hydro treators

A detailed, molecule-based kinetic model has been developed to simulate industrial naphtha hydro treators. A feed characterization module has been developed to calculate the composition of pre-defined pure molecules representing the feed quality without any detailed experimental component analysis. Feed naphtha is represented by a pre-defined set of 95 pure molecules, from carbon numbers C5 to C11, and the proportion of these components is calculated using an optimization algorithm so as to match the physico-chemical properties of the mixture with those of naphtha, as measured in the laboratory. The output from this optimization model is used as a direct input to a model of a hydro treating reactor. The main reactions occurring in the hydro treator, such as hydro desulfurization reactions and olefin saturation reactions, are modeled. The kinetic parameters for these reactions have been estimated from a comprehensive set of experimental pilot plant data spanning a wide range of process conditions. The kinetic model quantitatively predicts the exit composition, temperature rise and pressure drop in the catalyst bed for a range of conditions for two industrial refinery units.

A study of cement Type II hydration partially substituted by Brazilian spent cracking catalyst fines

In fluidized catalytic cracking refinery units, two kinds of wastes are generated: the equilibrium catalyst, which is withdrawn continuously from the catalyst regenerator, and the catalyst fines (Epcat), which are dragged by the gas stream leaving the regenerator, being separated by cyclones or electrostatic precipitators. This work aims to study the early cement hydration stages of Type II Portland cement, when substituted partially by Epcat. For this purpose, pastes were prepared with water/(cementitious material) ratio (W/C) of 0.5 and substitution degrees up to 30 mass% of cement per Epcat, which were analyzed during the first 24 h of hydration by non-conventional differential thermal analysis. The results show that the higher is the substitution degree of cement by Epcat, the higher is the formation of ettringite and the higher is the acceleration effect of tricalcium silicate hydration reactions. The deconvolution of the NCDTA curves obtained for the early cement hydration stages indicates that, in the early hydration stages, ettringite and tobermorite have an inverse relationship formation as a function of the degree of substitution, which shows a linearly growing ettringite content, as tobermorite content decreases. The released accumulated energy, calculated from NCDTA curve data, shows that Epcat has pozzolanic activity, which increases with the degree of substitution, also shown from the respective curve deconvolution data.

Analysis of Petroleum Downstream Industry Potential in Riau Province

Petroleum downstream industry in Riau Province is still not optimal. The data shows that from 98,892,755 barrels lifting oil each year only 62,050,000 barrels could be processed in refinery unit II Dumai operated by PT Pertamina. There is a potential of 35-40% of downstream industry. Indonesian Government through The Ministry of Energy and Mineral Resources declared the construction of a mini refinery to boost oil processing output in the downstream sector. A feasibility study of development plan mini refinery is needed. The study includes production capacity analysis, product analysis, development & operational refinery analysis and economic analysis. The results obtained by the mini refinery capacity is planned to process crude oil 6000 BOPD with the products produced are gasoline, kerosene, diesel and oil. Investment cost consist of is capital cost US $ 104419784 and operating cost US $ 13766734 each year with net profit earned US $ 12330063/year and rate of return from investment 11.63%

Failure of 321 stainless steel heater tube in heavy crude oil

Failure investigation was done on a 321 stainless steel charge heater tube which failed in a refinery unit processing heavy crude oil. Crude oil was the charge in the radiant and convection sections; while saturated stripping steam is present in convection section. After a leak was detected, visual inspection revealed that nine convection tubes had black oil/coke deposits on their external surfaces. The deposits were seen on the first three rows of tubes. When one of the tubes was lightly ground at the black colored area, a circumferential crack was visually observed. The investigation revealed that long-term aging, coupled with localized deposition of salts and coke from the heavy crude led to sensitization of the tube surface layers. This in turn resulted in sulphidation of the internal surface grain boundaries, formation of grooves, and cracking of the material. Thus, cracking was intergranular in nature in the initial stage, but became transgranular at later stages. It was concluded that cracking was due to chloride stress corrosion cracking catalyzed by the presence of sulphur-bearing species. It was recommended that the desalter operation be improved and frequent decoking and scale removal be carried out, with emphasis on the convection section at the refinery.

Characterization of coke, or carbonaceous matter, formed on CoMo catalysts used in hydrodesulfurization unit in oil refinery

When a mixture of light gas oil (LGO) and light cycle oil is fed into an oil refinery’s hydrodesulfurization (HDS) unit to produce diesel fuel, the catalyst in the HDS unit is rapidly deactivated. By contrast, when the feed is LGO mixed with residue desulfurization gas oil, the catalyst is deactivated slowly. Hoping to understand why, the authors focused on the coke formed on the catalysts during the HDS reaction. The result of a comprehensive analysis of the coke suggested that the ways coke formed and grew on the catalysts may differ depending on the feeds used, which in turn could affect the deactivation behaviors of the catalysts.

Hazop Study and Fault Tree Analysis for Calculation Safety Integrity Level on Reactor-C.5-01, Oil Refinery Unit at Balikpapan-Indonesia

plat former reactors are reactors that are in the plat forming unit is designed for developing your specific hydrocarbon molecules that are used in catalytic engine fuel in boiling point range naphtha and fuel mixture to produce components with a higher octane value. Plat former reactor system failure may disrupt operations in the oil processing refinery unit. These circumstances will cause the supply plaformat as products of the plat forming unit valued high octane which is the main raw material of gasoline blending system is reduced. Resulting in decreased production consequency large losses. The failure of the reactor system can also be harmful to the operator, the environment and there is a possibility of reactor unit may explode. To avoid these risks we conducted studies identify hazards that occur in the process rector Hazard and operability (HAZOP) analysis and calculate the value of safety integrity level (SIL). In this study reviewed three nodes Overview consisting of node stage 1, stage 2 and stage 3. Based on the results of identification are thirteen instruments on the third node, which includes equipment; PC-193, FI-005, PC-194 and FI-010. Standards-based Service Oriented systems have Unacceptable risk criteria and the criteria of likelihood 4 Consequences worth three. As for the evaluation of SIL is known that C-5-01 reactor system has two safety Integrity Function (SIS) located in the path of fuel gas and pilot gas lines of the reactor heater. Both SIS has a vote = 1oo3 architecture with similar characteristics, and a review of the SIS has a security level SIL = 2 with a value of PFD = 0.00103.

Integration strategies of hydrogen network in a refinery based on operational optimization of hydrotreating units

Abstract Inferior crude oil and fuel oil upgrading lead to escalating increase of hydrogen consumption in refineries. It is imperative to reduce the hydrogen consumption for energy-saving operations of refineries. An integration strategy of hydrogen network and an operational optimization model of hydrotreating (HDT) units are proposed based on the characteristics of reaction kinetics of HDT units. By solving the proposed model, the operating conditions of HDT units are optimized, and the parameters of hydrogen sinks are determined by coupling hydrodesulfurization (HDS), hydrodenitrification (HDN) and aromatic hydrogenation (HDA) kinetics. An example case of a refinery with annual processing capacity of eight million tons is adopted to demonstrate the feasibility of the proposed optimization strategies and the model. Results show that HDS, HDN and HDA reactions are the major source of hydrogen consumption in the refinery. The total hydrogen consumption can be reduced by 18.9% by applying conventional hydrogen network optimization model. When the hydrogen network is optimized after the operational optimization of HDT units is performed, the hydrogen consumption is reduced by 28.2%. When the benefit of the fuel gas recovery is further considered, the total annual cost of hydrogen network can be reduced by 3.21 × 107 CNY·a− 1, decreased by 11.9%. Therefore, the operational optimization of the HDT units in refineries should be imposed to determine the parameters of hydrogen sinks base on the characteristics of reaction kinetics of the hydrogenation processes before the optimization of the hydrogen network is performed through the source-sink matching methods.

Transient natural convection and conduction heat transfers on hot box of a coke drum in Pre-heating stage

In an oil refinery unit, coke drum is subjected cyclic thermal stress and mechanical loads due to cyclic heating and cooling loads. Thus, the useful life of a coke drum is much shorter than other equipment. One of the most severe locations due to thermal stress is shell to skirt junction. Here, a hot box is proposed. In this study effectiveness of a hot box will be analyzed numerically. The addition of hot box (triangular cavity) was expected to generate natural convection, which will enhance heat transfer. As for the result show that heat flux conduction and natural convection have the same trend. The peak of conduction heat flux is 122 W/m2 and for natural convection is 12 W/m2. In the heating stage of coke drum cycle it found that the natural convection only provide approximately 10 % of heat transfer compare to conduction heat transfer. In this study it was proved that in the heating stage, the addition of triangular enclosure is less effective to enhance the heat transfer than previously thought.