《数据、模拟与决策》案例二报告Word格式文档下载.doc

1、17920091150764罗志锐 学号：17920091150767王晋军 学号：17920091150811许冰 学号：17920091150856Case 2： Exxons Response to the Regulations As a result of several major studies conducted by the Environmental Protection Agency, the federal government has issued regulations mandating a gradual phase out of tetraethyl lead

2、 （TEL） for gasoline sold in the United States. Separate legislation developed by the state of California provided even stiffer limits for the TEL content of gasoline. For years refiners had used TEL as an addition to gasoline as a cheap and convenient way to improve the octane rating of the gasoline

3、, thus reducing the potential for harm to motor vehicle engines. In the absence of TEL, a refinery must reprocess some of the low-octane components of gasoline to increase their octane ratings. This can be accomplished either by breaking apart the hydrocarbon chains, through processes known in the t

4、rade as “cat cracking” or “hydrocracking,” or by rearranging the bonding in the chains through processes called reforming or alkylation. All four processes are very costly and efficient but provide more variability in results than the simple addition of TEL to improve the octane rating of a blend. F

5、aced with the dual impact of federal regulations on TEL and the more stringent California limits, officials at Exxons Benicia, California, refinery initiated a crash program to determine the most efficient means of addressing the new requirements. Experiments were undertaken using each of the four k

6、nown methods of increasing octane ratings without exceeding mandated limits on the use of TEL. In their study gasoline from Exxons Benicia refinery was reprocessed in a way such that costs were equalized by using each experimental procedure. The data in the table show the octane ratings resulting fr

7、om the application of the four reprocessing procedures to gasoline derived from each of eight storage tanks. StorageOctane Rating When Reprocessing byTankCat CrackingHydrocrackingReformingAlkylation189.488.695.589.6288.391.394.090.2387.288.286.790.0489.889.087.588.9590.190.7687.788.894.892.5784.686.

8、087.387.1889.191.592.01. Do these data suggest that a difference exists in the ability of the four reprocessing procedures to increase octane ratings? 2. Does a difference exist between the octane efficiency of processes that break apart the hydrocarbon chains （cat cracking and hydrocracking） and pr

9、ocesses that rearrange the bonding in chains （reforming and alkylation）?3. If you were advising Exxon, which reprocessing procedure would you recommend for increasing octane ratings? （Hint: Consider the variability of octane rating when using each reprocessing procedure.） 案例2： 埃克森对新政策的回应根据美国环境保护局（EP

10、A）的研究结果，联邦政府出台了一系列关于逐步限定国内所销汽油中四乙基铅（TEL）含量的政策。其中，加州颁布的关于限制汽油含铅量的立法更加严格。多年来，炼油厂普遍采用一种成本低廉且便捷的方法，即在汽油中添加四乙基铅来提高油品的辛烷值，从而减少对机动车引擎的潜在危险。如果不添加四乙基铅，炼油厂则须对低辛烷值的原油组分进行再加工才能增加汽油中的辛烷值。再加工的方式可以通过以下两种途径的任意一种完成。一种是通过“催化裂化”或“氢化裂解”的方法分离烃链，另一种是通过“催化重整”或“烃烷基化”的方法重排。以上四种方法成本较高并且有效，但与单纯添加四乙基铅（TEL）提高辛烷值的方法相比，其产出结果的不确定因

11、素更多。面对来自联邦政策及限制更严的加州法规的双重压力，埃克森加州贝尼西亚炼油厂的管理层启动了紧急预案，商讨符合最新规定的最有效方式的决策，并用上述四种已知的实验方法进行提高辛烷值的试验，其中TEL的使用量均不超过法规限定的含量。在研究中，分别采用四种方法对埃克森贝尼西亚炼油厂的原油进行再加工，并调控使得这四种方法的成本相等。下表数据表示分别采用四种方法对八桶原油进行再加工所得到的辛烷值。通过不同再加工方式获取的辛烷值桶催化裂化氢化裂解催化重整烃烷基化1. 以上数据是否表明上述四种再加工方法对于提高辛烷值的效果存在明显差别？2. 两类增加辛烷值的方法，裂解（“催化裂化 ”和“氢化裂解”）和重排

12、（“催化重整”和“烃烷基化”）是否存在明显差别？3. 你会跟埃克森推荐采用哪种再加工方法来提高辛烷值？（提示：须考虑采用不种方法时辛烷值的变异性。）案例埃克森对于新政策的回应第小组案例分析报告摘要：为了检验四种再加工方式对提高汽油辛烷值的能力差异，在现行的质量随机实验数据的基础上，考虑各种检验方法的适用性和简便性，可以通过配合使用方差分析和两总体均值差的假设检验的办法，科学分析其中潜在的差异：包括提高辛烷值的能力，及生产的稳定性。关键字：方差分析，两总体均值差的假设检验，正态性检测，方差齐性检测Abstract：Considering the applicability and conveni

13、ence of the test method, we can use ANOVA and Difference between Two Population Means test to distinguish the difference and stabilization in the ability of four reprocessing procedures to increase octane ratings. Key words: ANOVA, Difference between two population means, Normal distribution, Equal

14、population variance一 问题的提出为了应对联邦政府和加州政府出台的限制汽油铅含量的政策，埃克森加州贝尼西亚炼油厂须在四乙基铅（TEL）含量不超标的情况下，对低辛烷值的原油组分进行再加工以提高汽油的辛烷值。该炼油厂分别运用四种提高辛烷值的实验方法对该厂的原油进行再加工，实验中其TEL的使用量均不超过法规限定的含量，并且通过调控使得这四种方法的成本相等。在通过实验获得的数据基础上，本文将探讨四种再加工方法对于提高辛烷值的效果是否存在明显差异；两种增加辛烷值的方式：裂解（“催化裂化”和“氢化裂解”）和重排（“催化重整”和“烃烷基化”）是否存在明显差别；以及最终推断出哪种方法具备最好和最稳定的效果。四种再加工方法的实验室数据和相关信息如下：表1：源数据