Chinese Refinery Research Articles

Data-driven prediction of product yields and control framework of hydrocracking unit

In this study, the relationship between the operating conditions and the product yields and a control framework of the hydrocracking process was developed. The data were collected from a hydrocracking unit in a Chinese refinery. Principal component analysis was used to decrease the number of input variables. Then support vector machine, Gaussian process regression (GPR), and decision tree regression models were developed to establish the relationship above. The best model is GPR, whose Pearson correlation coefficient between the prediction value and the actual value is greater than 0.97 for all the product yields. Shapley additive explanations were performed to interpret the results of the GPR models. A control framework of the hydrocracking unit was then proposed based on the results above. The results show that the machine learning method is a valuable tool for predicting the yield of hydrocracking products, and the control framework proposed helps optimize hydrocracking product yields.

Cobalt: corporate concentration 1975–2018

The world’s dependency on cobalt mines in Congo and cobalt refineries in China is seen as serious security issues with potentially dangerous implications for the energy transition. However, Chinese refineries have a similar supply security issue as most of its cobalt concentrates are imported. Most supply security studies take a country perspective on market concentration and supply risks. However, control of the mines and refineries lies with the producing companies, not the governments of the countries where they are located. This paper analyses the corporate structure of the cobalt industry at the mine and the refinery stages over a longer time period to establish changes in the level of corporate concentration and to put the situation in 2018 in perspective. The level of corporate concentration at the mine stage is low and does not raise concerns for market failures or a lack of competitiveness. Corporate concentration of refined cobalt depends on the Chinese government’s influence over Chinese production: if the state control over individual refineries is assumed to be strong, the corporate concentration is high. Mine stage supply security could be strengthened by improving the general political stability in the DRC to make the country more attractive for investors other than the present ones. Increased local beneficiation would strongly benefit Congo and reduce China’s influence. This is a long and complicated process and its success is not at all certain. At the refinery stage, the solution is much easier: reliability of supply could be improved by constructing refineries in countries outside China.

Kamapim gutpela man: Papua New Guinean and Chinese refinery workers' changing understandings of becoming a good man

ABSTRACTThis article adds to research on emerging masculinities in the Pacific by analysing how Papua New Guinean and Chinese male employees' intercultural work experiences impact their perceptions of becoming a good man. The idea of a good man acts as a benchmark for assessing the adaptability of Papua New Guinean employees to new work environments and determining if Chinese colleagues are their desired partners. I illustrate this point by first considering ‘becoming’ as an alternate framework to the binary framework reflected in earlier research. I next describe how Papua New Guinean workers impress their Chinese supervisors through negotiations and concessions about industrial and subsistence farming time, as well as how working with Papua New Guinean workers alters Chinese employees' perceptions of work. Finally, I demonstrate how employment practices foster Papua New Guinean workers' evolving perspectives on becoming agutpela man(‘good man’) and Chinese employees' evolving perspectives on becoming a good person, a vital route to becoming achenggongman (‘successful man’). This article proposes characterizing emerging masculinities as hybrid identities that are context‐dependent, interculturally exchanged and temporal by presenting two parties' new thoughts on becoming a good man. This article demonstrates modulatory power dynamics in the Chinese refinery based on a two‐way narrative as opposed to portraying Chinese management as the dominating force.

Global tellurium supply potential from electrolytic copper refining

The transition towards renewable energy requires increasing quantities of nonfuel mineral commodities, including tellurium used in certain photovoltaics. While demand for tellurium may increase markedly, the potential to increase tellurium supply is not well-understood. In this analysis, we estimate the quantity of tellurium contained in anode slimes generated by electrolytic copper refining by country between 1986 and 2018, including uncertainties. For 2018, the results indicate that 1930 (1500-2700, 95% confidence interval) metric tons of tellurium were contained in anode slimes globally. This is nearly quadruple the reported tellurium production for that year. China has the greatest potential to increase tellurium supplies. However, most of the tellurium potentially recoverable by Chinese refineries appears to come from copper mined elsewhere. Further research into the business decisions associated with tellurium recovery may help translate the physical availability of tellurium into economic availability. The methodology presented here can be applied to other byproduct elements.

Life cycle assessment of petroleum refining process: A case study in China

Climate change mainly caused by transportation fuel consumption has attracted global concern. In life cycle environmental burdens generated from transportation fuel production, petroleum refining stage is the hotspot. However, the in-depth environmental analysis of petroleum refining is very limited. China is the second largest petroleum refining country, so it is very essential to break petroleum refining stage into specific unit to analyze how Chinese refinery can be improved in environment performance. To achieve this goal, a systematic life cycle analysis of the environmental burden generated from petroleum refining process was conducted to identify the control emphasis and seek potential improvement measures. Sensitive analysis and volatile organic compounds (VOCs) emission characteristics were additional discussed to improve the accuracy of results. The significant burdens generated from petroleum refining process were freshwater ecotoxicity and climate change. Crude oil extraction and transport dominated most environmental categories, which indicated that the environmental problem exist in upstream supply chain. Catalytic cracking, feedstock and product handling, catalytic reforming, crude oil distillation, cooling water system and diesel hydrotreating were the major control units due to their direct emissions and electricity consumption. VOCs (e.g., acrolein and chlorofluorocarbons) produced from refinery fugitive emissions were the main substances for refinery to reduce human toxicity, ozone depletion and photochemical oxidant formation influences. 14% of Climate change were derived from organic chemicals emission in this study, which suggested that VOCs-related carbon emission should be involved in current carbon accounting work or greenhouse gases (GHGs) studies on the petroleum refining industry. The identified control emphasis included equipment leaks from core refining units, storage tank emissions control, energy structure optimization and catalysts consumption intensity reduction. Some feasible and useful reduction measures targeted the control emphasis were proposed for policy makers and refinery managers to formulate reduction strategies and improve the sustainability of the petrochemical industry.

Comments: Reshaping Energy Markets

Editor's column The US shale sector continues to disrupt global oil markets. Soaring US crude production and the resulting exports to Asia and Europe, are transforming worldwide trade flows and changing how consumer countries price crude. The US has overtaken Saudi Arabia as the world’s largest exporter, the International Energy Agency (IEA) reported in September, as its crude oil exports rose to more than 3 million•B/D and its total exports of crude and products reached almost 9 million B/D. Saudi Arabia was the globe’s top exporter for part of the third quarter as hurricanes and the US-China trade dispute affected US exports but that appeared to be temporary. In the past decade, US has more than doubled oil production, to 12.3 million B/D, becoming the world’s largest producer. “Since the last in-depth (IEA) review 5 years ago, the United States has reshaped energy markets both domestically and around the world,” said Fatih Birol, the IEA’s executive director, The US’ new role was underscored last month when a drone strike knocked out a large portion of Saudi Arabian production. In previous years, oil markets would have panicked, but traders quickly looked to the US to make up much of the difference. The US lifted its ban on exporting oil in 2015—put in place after the oil embargoes of the late 1970s—and, in December 2015 exported its first oil cargo in 40 years. That shipment of Eagle Ford light oil to the Mediterranean ushered in a new age and, within 2 years, the US was exporting more than 1 million B/D. Exports of unconventional crude from the Permian, Bakken, Niobrara, and Eagle Ford joined output from Gulf of Mexico fields such as Mars and Thunderhorse headed abroad. The impact on trade flows has been significant. Just a few years ago, Nigeria sold the US more than 1 million B/D of crude annually, but that volume has been replaced by the similar light, sweet crude produced in the Permian Basin. US crude has flowed to European refineries, which have seen declines in North Sea output, and to Asia, principally China. Since the US-China trade dispute began, Chinese refineries have cut back on US imports significantly, but consumption in India, Indonesia, and Taiwan has risen sharply at the same time. Asia has accounted for 45% of all US crude exports so far in 2019. That shift is changing how crude oil is bought and sold. The US Gulf Coast is quickly becoming a benchmark center for the worldwide oil market, with oil priced in relation to West Texas Intermediate’s value at the coast. Global exports to Asia previously were priced against North Sea Brent crude, but output there has been in decline, or Dubai crude, which is dominated by only a few participants. As new infrastructure is built in the US, carrying more crude to the coast, WTI priced at the Gulf of Mexico will only grow in stature as a pricing•benchmark.• Many analysts believe the shale boom is moderating because of the decline in oil prices since the start of the fourth quarter of 2018, and that the deceleration might continue through the rest of this year and into 2020. But production from the Permian Basin in particular has swamped available pipeline capacity to bring the oil to market, and several pipeline projects are scheduled to be completed this year and next, which should allow for even higher exports.

Honeywell UOP's Isoalky technology chosen for Sinochem Hongrun's Chinese refinery

Honeywell UOP's Isoalky technology chosen for Sinochem Hongrun's Chinese refinery

Aramco inks MoU to purchase interest in Zhejiang's Chinese refinery project

Aramco inks MoU to purchase interest in Zhejiang's Chinese refinery project

Hazards of Organic Chloride to Petroleum Processing in Chinese Refineries and Industrial Countermeasures

Hazards of Organic Chloride to Petroleum Processing in Chinese Refineries and Industrial Countermeasures

Industrial delayed coking process optimization on the basis of lumped kinetic model

ABSTRACTDelayed coking is an economic and practical technic for the conversion of residua to naphtha and diesel. In this work, a 10-lumped reaction scheme is applied to investigate the industrial delayed coking process. The feed is decomposed to four lumps, including saturate, aromatics, resin and asphaltenes, and the products are decomposed to six lumps according to the boiling points. Industrial data from a Chinese petroleum refinery are used to validate the model. It is shown that the proposed kinetic model is able to predict yields of delayed coking products at a wide range of feedstock properties. On the basis of this model, the feed distribution and reaction temperature of an industrial delayed coking process are optimized, which significantly increases the economic benefits.

Improvement potential analysis for integrated fractionating and heat exchange processes in delayed coking units

A novel diagram-based representation approach is developed to analyze the thermodynamic efficiency and identify quickly the promising energy-use improvement for integrated fractionating and heat exchange processes in delayed coking units. For considering temperature dependence of heat capacity and integrating fractionating and heat exchange processes, an advanced energy level composite curve is constructed by using the simulation results and a stepwise procedure. More accurate results of exergy analysis are obtained and the interaction between different components of the integrated system can be properly revealed in an integrated figure. Then the exergy calculation is performed to validate the performance of processes and to define the targets for improvement. The avoidable exergy destruction is also analyzed by applying the concepts of avoidable and unavoidable exergy destructions for the integrated system. In a case study for a Chinese refinery, the results reveal that the heat exchange between gas oil and deethanization gasoline is the most inefficient process with the highest retrofitting potential, and the lowest exergy efficiency of component in the integration system is only 29.4%. The improvement potential and exergy efficiency for the fractionator are 38.1% and 97.3%, respectively. It is obvious that the fractionator is not the most promising component for improvement.

Model Optimization for an Industrial Fluid Catalytic Cracking Riser-regenerator Unit by Differential Evolution Algorithm

A differential evolution (DE) algorithm for determining 16 advanced turning model parameters of a 1.2 million industrial fluid catalytic cracking (FCC) unit modeling by HYSYS 8.4 is presented. Industrial data from a Chinese petroleum refinery were used to develop, train and check the model. Due to FCC complexity, the proposed model is capable of predicting the yield of products based on main operating conditions. The optimized FCC model is used for further optimized analysis of the FCC unit operating conditions based on the maximum of economic benefits. Prediction of the economic benefit of FCC unit increases 917 yuan/h at the optimized operating conditions.

Refining the prize: Chinese oil refineries and its energy security

Since China became a net oil importer in 1993, oil refineries have played integral roles in China's quest for oil security. And yet, the capacity, security, and configurations of refineries were rarely featured in the discussions about China's oil policy. To fill this gap, this paper explains the basics of refinery economics and technology, and details the development in China's refining industry since the early 1990s. By taking refineries into consideration, it then revisits and reassesses the existing literature regarding the motives and drivers behind China's foreign oil policy, its effectiveness, and the political interactions between China and crude oil producers.

Optimization of CO2 separation technologies for Chinese refineries based on a fuzzy comprehensive evaluation model

This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristics of flue gas from Chinese refineries, three feasible CO2 separation technologies are selected. These are pressure swing adsorption (PSA), chemical absorption (CA), and membrane absorption (MA). Secondly, an economic assessment of these three techniques is carried out in accordance with cash flow analysis. The results show that these three techniques all have economic feasibility and the PSA technique is the best. Finally, to further optimize the three techniques, a two-level fuzzy comprehensive evaluation model is established, including economic, technological, and environmental factors. Considering all the factors, PSA is optimal for Chinese refineries, followed by CA and MA. Therefore, to reduce Chinese refineries carbon emission, it is suggested that CO2 should be captured from off-gases using PSA.

Preface for the special issue of the 1st Saudi–Chinese Oil Refinery Forum (1st SCORF 2013)

Preface for the special issue of the 1st Saudi–Chinese Oil Refinery Forum (1st SCORF 2013)

Sources of Polycyclic Aromatic Hydrocarbons in Soybean Oil and its Dynamic Changes Refining Processing

In order to understand the sources of Polycyclic Aromatic Hydrocarbons (PAHs) and the influence of the refining steps for soybean oils, soybeans, solvents and samples of the crude soybean oils and the corresponding neutralized, bleached and deodorized oil were collected online in a Chinese oil refinery and then analyzed for 12 different PAHs. PAHs are environmental carcinogenic compounds that may contaminate soybean oils due to contaminated soybeans and extraction solvents and their levels can be reduced by refining. The changes in PAH content in soybean oils at the various refining stages were investigated using a method based on HPLC with fluorescence detection. Soybeans, solvents and the crude soybean oils contained various amounts of PAHs. The PAH levels in the refined oils were considerably lower than those in the corresponding crude oils. An evident decrease in PAH content was observed during extraction, neutralization, bleaching and deodorization.

Economic Evaluation of CO<sub>2</sub> Separation Technologies in Chinese Refineries

With the clear emission reduction target of China for 2020, the refining industry as a large emission source inevitably plays a significant role. The paper confirmed and assessed three commercially available CO2separation technologies for refineries, vacuum swing adsorption (VSA), monoethanolamine (MEA) and membrane absorption (MA). The economic results indicate that the capital cost of constructing a CO2capture unit is 35.996 M¥, 34.418 M¥, 37.502 M¥, respectively. And the corresponding cost of avoided is 379.8 ¥/tCO2, 249.6 ¥/tCO2and 376.5 ¥/tCO2. Sensitivity analyses are also performed examining the effect of CO2price on economic feasibility, as well as improvements of regeneration energy demand and CO2capture system on the CO2avoided cost. The regeneration energy demand impacts the avoided cost significantly, whereas CO2capture system demonstrates insensitivity. Though the CO2avoided cost for MEA case is highest, MEA has been commercially the most available processe so far for existing refineries. However, MA will be the most promising alternative to chemical absorption in the future, provided that membrane performance is further improved. In addition, the CO2avoided cost of VSA is close to that of MEA, but other economic indicators are optimal due to a large amount of H2recovered. Currently, without any incentive and a major technological break-through, CO2capture from the source of hydrogen production units at Chinese refineries is the most attractive opportunity.

Procurement models under purchase price uncertainty for Chinese oil refineries

This paper examines the crude oil procurement practices of Chinese oil refineries to suggest improved procurement policies that can reduce the cost associated with fluctuating oil prices in the international spot market. In the industrial environment, the purchase price of crude oil is based on the spot price at the time of delivery rather than that at the time of ordering. Therefore, the purpose of this paper is to develop a procurement model that factors in the spot prices at both the time of ordering and the time of delivery so that the total procurement cost can be minimised over the planning horizon. First, the shortcomings of the current procurement policy of a typical Chinese refinery are presented. A model to address these shortcomings is then developed and embellished by incorporating market information dynamics through Bayesian learning. The effectiveness of the proposed models is compared with the current practice using the historical spot price data of crude oil from two representative spot markets; this comparison verifies that the model with Bayesian sampling performs well empirically and can result in considerable cost savings.

A Novel Strategy for Simulating the Main Fractionator of Delayed Cokers by Separating the De-superheating Process

Delayed coking is an important process in refinery to convert heavy residue oils from crude distillation units (CDUs) and fluid catalytic cracking units (FCCUs) into dry gas, liquefied petroleum gas (LPG), gasoline, diesel, gas oils and cokes. The main fractionator, separating superheating reaction vapors from the coke drums into lighter oil products, involves a de-superheating section and a rectifying section, and couldn't be simulated as a whole column directly because of non-equilibrium in the de-superheating section. It is very important to correctly simulate the main fractionator for operational parameter and energy-use optimization of delayed cokers. This paper discusses the principle of de-superheating processes, and then proposes a new simulation strategy. Some key issues such as composition prediction of the reaction vapors, selection of thermodynamic methods, estimation of tray efficiency, etc. are discussed. The proposed simulation approach is applied to two industrial delayed cokers with typical technological processes in a Chinese refinery by using PRO/II. The simulation results obtained are well consistent with the actual operation data, which indicates that the presented approach is suitable to simulate the main fractionators of delayed cokers or other distillation columns consisting of de-superheating sections and rectifying sections.

Simultaneous optimization of energy and materials based on heat exchanger network simulation for diesel hydrotreating units

A multi-period nonlinear programming (NLP) formulation is presented in this paper. This is intended to optimize energy and materials simultaneously for diesel hydrotreating units in order to minimize the total costs which include product income, material cost, energy cost, and other fixed operating costs. The heat exchanger network (HEN) is integrated into the model to address the energy consumption changes with the stream flow and temperature of different production modes. Some process models are regressed from production data or are supplied by refinery engineers, similar to the models for steam turbines and compressors, and distillation towers. An iterative algorithm is developed to solve the complex mathematical model based on HEN simulation. An industrial diesel hydrotreating unit is provided by the Chinese Refinery Complex and is used to demonstrate the performance of the formulated model and algorithm. It is found that the optimized results from the simultaneous consideration of the energy and materials are more profitable than those obtained from other methods that individually optimized the energy or materials.