Petrochemical

CCPIT Sub-Council of Petrochemical Industry,established in August 1988, is a non-governmental foreign trade organization with 73 members including SINOPEC and other Chinese petroleum and petrochemical enterprises and organizations.

A Hybrid Model Predictive Control for Handling Infeasibility and Constraint Prioritization

A hybrid approach using MLD (mixed logical dynamical) framework to handle infeasibility and constraint prioritization issues in MPC (model predictive control) based on input-output model is introduced. By expressing constraint priorities as propositional logics and by transforming the propositional logics into inequalities,the infeasibility and constraint prioritization issues are solved in the MPC. Constraints with higher priorities are met first, and then these with lower priorities are satisfied as much as possible. This new approach is illustrated in the control of a heavy oil fractionator-Shell column. The overall control performance has been significantly improved through the infeasibility and control priorities handling.

Simulation of hydrocarbons pyrolysis in a fast-mixing reactor

Currently, thermal decomposition of hydrocarbons for the production of basic petrochemicals(ethylene, propylene) is carried out in steam-cracking processes. Aside from the conventional method, under consideration are alternative ways purposed for process intensification. In the context of these activities, the method of hightemperature pyrolysis of hydrocarbons in a heat-carrier flow is studied, which differs from previous ones and is based on the ability of an ultra-short time of feedstock/heat-carrier mixing. This enables to study the pyrolysis process at high temperature(up to 1500 K) at the reactor inlet. A set of model experiments is conducted on the lab scale facility. Liquefied petroleum gas(LPG) and naphtha are used as a feedstock. The detailed data are obtained on temperature and product distributions within a wide range of the residence time. A theoretical model based on the detailed kinetics of the process is developed, too. The effect of governing parameters on the pyrolysis process is analyzed by the results of the simulation and experiments. In particular, the optimal temperature is detected which corresponds to the maximum ethylene yield. Product yields in our experiments are compared with the similar ones in the conventional pyrolysis method. In both cases(LPG and naphtha), ethylene selectivity in the fast-mixing reactor is substantially higher than in current technology.

Commercial Application of Novel FDFCC Grid Packing Type Stripper

The novel FDFCC grid packing stripper is used to raise the stripping efficiency of the equipment. This technology aims to increase the gas-solid contact area and improve the gas-solid contact efficiency. This technology has been applied in the revamped 1.05 Mt/a No. 1 FCC unit at the SINOPEC Changling Branch Company. The outcome on application of this equipment has revealed that the fluidization of the stripper was stable coupled with smooth operation. At a steam stripping load of less than 50% of the design value the spent catalyst had a lower H/C ratio, and the hydrogen content in the coke after revamp of the FCC unit decreased by 8.1% compared to the case before the equipment revamp. The spent catalyst had higher activity with the dry gas and coke yields reduced by over 0.5%, resulting in goodeconomic benefits.

Research and Commercial Application of CPP Technology for Producing Light Olefins from Heavy Oil

Catalytic pyrolysis process(CPP)producing ethylene and propylene from paraffin base atmospheric residue was developed by RIPP and its first in the world unit was put into commercial operation successfully.The results of performance test showed that the yield of ethylene and propylene reached 14.84% and 22.21% ,respectively,at a reaction temperature of610℃by using Daqing atmospheric residue as the feedstock under an operation mode of producing ethylene and propylene at the same time,and the aromatic content of cracked naphtha reached 82.46% .The successful operation of this unit has opened a novel route for producing light olefins and aromatics from heavy oil,which is also a good example symbolizing the integration of refining technology with petrochemical process.

Application of Olefin-Reducing Catalyst in FCC Unit at Daqing Petrochemical Company

This article refers to the application of DOCO olefin-reducing catalyst developed by RIPP and manufactured by the Catalyst Factory of Changling Refining and Chemical Company in the 1.4 Mt/a RFCCU at Daqing Petrochemical Company. Results of operation over two months had revealed that this catalyst had good olefin-reducing ability and heavy oil converting ability adapted to paraffinic feedstock. The gasoline olefin yield had been reduced to 36.1 v% from 54.2 v% with gasoline RON rating decreased by 1.4 units. The induction period of gasoline had significantly increased to 952 mm, while the coke yield was increased by 0.05 percentage point with light oil yield dropping by only 0.02 percentage point. The FCC product distribution is favorable.

Increasing Liquid Yield and Diesel Fraction in Delayed Coking Process: Mechanism of Liquid Formation

The thermal upgrading of two residual oils tory-scale continuous delayed coking unit. The goal with different characteristics was studied in a labora- was to investigate the influence of the process vari- ables such as temperature, reaction time and additive on liquid yield and products distribution. A maximum liquid yield of 73% was achieved compared to 69% with the commercial unit. This yield was even increased to 75% under the effect of an additive. The fractionation of liquid oil by simulated vacuum distillation showed a high yield of diesel （46.9%）, compared to 28% for the commercial unit.

Development of RSDS-III Technology for Ultra-Low-Sulfur Gasoline Production

The 3rd generation catalytic cracking naphtha selective hydrodesulfurization(RSDS-III) technology developed by RIPP included the catalysts selective adjusting(RSAT) technology, the development of new catalysts and optimized process conditions. The pilot plant test results showed that the RSDS-III technology could be adapted to different feedstocks. The sulfur content dropped from 600 μg/g and 631 μg/g to 7 μg/g and 9 μg/g, respectively, by RSDS-III technology when feed A and feed B were processed to meet China national V gasoline standard, with the RON loss of products equating to 0.9 units and 1.0 unit, respectively. While the feed C with a medium sulfur content was processed according to the full-range naphtha hydrotreating technology, the sulfur content dropped from 357 μg/g in the feed to 10 μg/g in gasoline, with the RON loss of product decreased by only 0.6 units. Thanks to the high HDS activity and good selectivity of RSDS-III technology, the ultra-low-sulfur gasoline meeting China V standard could be produced by the RSDS-III technology with little RON loss.

茂名石化

总经理余夕志:事争第一,追求卓越,建设人民满意、高度负责任、高度受尊敬的世界一流炼化企业。茂名石化,创建于1955年,是我国最大的炼化一体化企业之一。原油加工能力2000万吨/年,乙烯生产能力110万吨/年,同时拥有完善的动力、港口、铁路运输、原油和成品油输送管道以及30万吨级单点系泊海上原油接卸等配套系统。余夕志总经理(左)

Impact of crude distillation unit model accuracy on refinery production planning

In this work, we examine the impact of crude distillation unit(CDU) model errors on the results of refinery-wide optimization for production planning or feedstock selection. We compare the swing cut + bias CDU model with a recently developed hybrid CDU model(Fu et al., 2016). The hybrid CDU model computes material and energy balances, as well as product true boiling point(TBP) curves and bulk properties(e.g., sulfur% and cetane index, and other properties). Product TBP curves are predicted with an average error of 0.5% against rigorous simulation curves. Case studies of optimal operation computed using a planning model that is based on the swing cut + bias CDU model and using a planning model that incorporates the hybrid CDU model are presented. Our results show that significant economic benefits can be obtained using accurate CDU models in refinery production planning.