通过使用简单强大的在线分析仪技术，优化炼油厂催化改革单元

This article uses the example of the catalytic reforming unit generally found in a refinery in order to illustrate the options presently available for using simple, robust on-line analyzers to deliver useful timely and available process stream quality data in advanced process control.

炼油厂

测量变得容易

本文首先考虑了背景：为什么优化refinery process unitsis so necessary and so common, and what analytical tools exist to help. The main problem in refining is that, although crude oil refining is a continuous and high-volume process with extremely vital raw-material and energy costs, it is not steady-state.

原油原料在质量，成本和可用性方面持续不断差异 - 与此同时，炼油厂产品及其市场在需求，价格和规格方面非常动态。这导致使用相对复杂的全额线线性编程（LP）模型来管理这些更改。在这些模型下，单个流程单元高级过程控制（APC）软件包需要将单位保持在目标上（即使这些目标将改变）并在控制之下。

带有CCR和集成的石化单元的炼油厂石脑油综合体

Considering one specific area within the refinery — the naphtha complex, or naphtha conversion area — it is possible to see the interaction between many different process units and streams. Key to these process units and streams is the Catalytic Reformer (CCR) unit. This unit is responsible for taking low-value heavy naphtha from the CDU and converts it, after hydro-treating, into a higher-value high-aromatics, high-octane feedstock.

Note:在本文中，CCR被用作通用，以指示催化重整单元。提出的论点主要适用于连续的催化再生改革者，但是，它们也可以应用于固定床单。问题是 - Naphtha处理或CCR Naphtha feed的来源可能还有哪些替代方法，而不同的单位产品存在哪些替代用途？

成本，容量，质量，价值和需求不断变化。

上图试图展示这些场景的简化和理想化的观点。例如，CCR的重新构造产品通常被引导到汽油混合池作为有用的高辛烷值混合物成分，但是重新质量的高辛烷值源自高芳香族剂（BTX）含量。这具有替代用途，并且根据混合汽油产品和芳香族单元之间的价格中断，可以确定作为芳香族单位饲料的转移。同样，CDU的直线发光体（通常用作CCR饲料）可以更好地用作Naphtha Steam Cracker烯烃单元的原材料，再次基于芳香族，汽油和烯烃产品的相对瞬时盈利能力。

Measurement at some level is essential to process optimization. Measurement yields information which permits the possibility of control. What form this measurement takes is a somewhat more open question, and one subject to considerable debate between those (chiefly engineers) who like statistics and dislike analyzers, and those (chiefly chemists) who do not trust anything which is not considered to be a directly traceable analytical result.

这导致了APC的不同方法：

APC based on inferential models

• 使用许多基本的质量流，温度和压力发射器
• 需要实验室测试数据，以校准和维护推论质量估计器
• 需要单元的化学工程模型

APC based on physical analyzers

• 使用许多单期物理分析仪进行直接测量
• Needs extensive maintenance, training, calibration and spares stockholding

基于高级分析仪的APC

• Use of a smaller number of multi-stream multi-property analyzers
• Generally offers significant improvement in precision, speed and reliability
• 需要校准或校准模型开发

APC based on actual process stream quality measurements from real analyzers is considered to be superficially attractive but fraught with risk.

Historically this approach was hindered by:

• 高资本成本
• High life-cycle costs, limited reliability
• 复杂的操作要求（验证，校准）
• 安装的大型基础设施要求

技术进步已导致：

• More robust, simpler, lower cost analyzers
• Extensive range of available technologies
• Significantly reduced operational and installation demands

The article considers two examples of modern, robust analyzer technologies that have enabled more reliable and easier implementation of APC strategies based on real-time process analytical measurement. Long maintenance intervals, low lifecycle costs Fourier-Transform Near IR (FT-NIR) analyzers have offered one route in order to deal with part of the problem. Chosen wisely, they provide space technology levels of reliability and uptime (quite literally since the technology is normally used in climate sensing satellites).

On-line FT-NIR analyzers presently have an established track record in reliable hydrocarbon stream property measurement (in this case RON and BTX in reformate product and PINA in heavy naphtha feed). The second technology refers to a solid-state electrochemical sensor-based method for observing the hydrogen recycle/net gas stream also critical in CCR operation.

ABB Process FT-NIR analyzer TALYS ASP400-Ex.

ABB Process Hydrogen Analyzer HP30.

典型的UOP CCR平台过程单元。

Thus, the Catalytic Reforming Unit, whether a CCR, as shown here, or a fixed-bed type, takes a heavy naphtha feed and, by catalytic conversion at reasonably high temperatures but fairly low operating pressure, transforms the naphthenes and paraffins to mainly aromatics.

最终的产品是芳香剂丰富的重新溪流，并且在单元内产生氢净气体并部分回收。

该单元的操作存在哪些选择和问题？如前所述，CCR unit被认为不仅是汽油混合物的潜在混合储备。这是标准的关键产品，但是具有不同的市场，并且具有更复杂的炼油厂，并具有广泛的重油上转换，而先前被视为CCR副产品现在已成为至关重要的，假设的经济选择。

改革将重型石脑油转变为：

• 用于汽油混合的高辛烷值原料
• High-aromatics (BTX) feed for petrochemicals
• High-purity hydrogen suitable for use as hydrocracker make-up gas

CCR unit operation provides a surprisingly huge number of degrees of freedom including severity vs. pressure vs. selectivity, which can all be traded off to:

• Run for maximum Net Gas
• 运行最大的催化剂寿命
• Run for minimum energy usage
• Run for maximum octane barrels
• 运行以最大的BTX收率

The key operating parameters for the unit will be pressure, severity, catalyst bed temperatures and profiles, which are interlinked and simultaneously affect octane number, aromatics content, yield and BTX spread along with net hydrogen make.

Example operating parameter trade-offs in CCR operation.

校准数据集，1^st罗恩的导数和PLS回归图。

On-line FT-NIR vs Lab Test Method RON

示例验证图（系列1）与实验室测试样本（系列2）的验证图。

最标准的测量是重新构造产品流的辛烷值监测（通常是RON），是反应器严重程度的标志，对此测量可以轻松地整合化学成分参数，例如总芳香族％，或离散的成分，例如甲苯，苯％，苯％％和Xylenes％。

为了进行说明，ABB显示了典型的RON和芳香学建模数据集，以及由此产生的RON校准模型。

Note that the model accuracy (vs lab test) at about 0.2 RON @ 1 sigma is better than the ASTM standard technique reproducibility (R) because of good site laboratory precision. Thus, the on-line FTIR does a better job than an online CFR engine, which would in any case be considerably more expensive on the whole.

这是用于过程流质量分析的高级光学或固态设备的主要优点：更好，更快，更便宜的数据。

第二个流分析可以使用与重新格式产品相同的FTIR单元进行测量，这是沉重的Naphtha Feed。在这里，极大地影响CCR单位产量和选择性的目标特性是蒸馏和PITA。

在石脑油饲料中的PIONA的PLS回归校准图。

Naphtha quality differences can arise from variable CDU feedstocks and operation, but also from substitute naphtha feed sources. Where CCR units are operated to have excess catalyst regeneration capacity, then sub-optimum heavy naphtha feeds (for example – from the FCC unit) can be run or mixed with conventional straight-run naphtha, resulting in a lot more dynamic unit envelope.

For the final measurement in this set of real-time on-line process analyzes for unit enhancement, ABB looks at the net gas/ hydrogen recycle stream. Here, the main parameter is just H₂mol％，但必须在混合光碳氢化合物含量的背景下进行测量。显然，净气体回收流不是纯氢。它与在分离器/恢复阶段中回收的其他轻质气体混合

对于传统技术（例如热导率检测（TCD））等传统技术，这是一个值得注意的挑战，该技术只能处理有限数量的干扰组件（不超过两个）。固态传感器对氢的响应是特异₂S, and CO by a diffusion membrane, therefore allowing quick hydrogen transport but blocking larger contaminant species.

概括

在本文中，ABB审查了强大而简单而高级的流程分析仪技术的使用，尤其是FT-NIR以及基于固态传感器的氢检测，到催化重整单元中最关键的过程单元流。ABB已经看到，可以使用这些相对直接的分析技术进行辛烷，芳香族剂，PITA和氢测量，并且该数据是在几乎实时的（一分钟的流周期时间）中报告的，从而可以与单位高级过程控制密切集成。这可以改善单位运营参数的管理，以改善高质量重新质量和净气体/氢的生产，其产量和成分与整体炼油厂和产品市场需求更好。

参考

1. Mohaddecy，S.R.S；Sadighi，S。；Bahmani，M。；“在德黑兰炼油厂的催化石脑油改革者中优化催化剂分布”，石油和煤炭50（2），60–68，2008

2. Taskar, M.U.; “Modelling and Optimization of a Catalytic Naphtha Reformer” PhD Dissertation, Texas Tech University, USA, May 1996

3. K. Kavousi；Mokhtarian，n。“使用Petrosim软件模拟ISFAHAN炼油厂CCR单位”，国际科学与调查杂志4（3），14-33，2015亚博老虎机网登录

4. Poparad, A.; Ellis, B.; Glover, B.; Metro, S.; “Reforming Solutions for Improved Profits in an Up-Down World”, UOP LLC, a Honeywell Company, Des Plaines, Illinois, USA, 2011

5. Robert A. Meyers, Handbook of Petroleum Refining Processes, Third Edition, 2004

6. Chapter 4.1 – UOP Platforming Process

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