Metrohm Petroleum Refinery Applications. Innovation to fuel profitability

Transcription

1 Metrohm Petroleum Refinery Applications Innovation to fuel profitability

2 Innovation to Fuel Profitability Impacting the Entire Refining Process Refineries are complex operations that convert crude oil into a range of products. Optimizing the production process to improve yield and maximize profitability is a key objective of any refinery. A recent study found that losses due to corrosion alone can approach $12 billion USD per year. Metrohm offers innovative analytical methodologies to improve process efficiency, protect against corrosion and maximize profitability. From crude oil to highly refined petroleum products, Metrohm offers solutions that deliver value across the refinery. The table on the following page demonstrates the utility of Metrohm products across the entire refining operation. This brochure connects the regulatory needs of the industry to our quality titration, ion chromatography, nearinfrared and process products. Whether it is simply running a standard method or implementing a customized process system, Metrohm is ready to partner with you to help drive productivity and profitability in your operation. Driving Global Standards Standard methods are more important than ever before because these industry validated solutions streamline testing, making it consistent in labs all over the world. ASTM, UOP, ISO, IP and other global standards are commonly used for product quality control testing as they facilitate global commerce and are the basis of sound economies. The testing of crude and refined oil products is demanding and requires precise and reliable analysis to meet regulatory demands. Metrohm is actively involved with ASTM and helps drive method development. We take on these challenges and deliver solutions that improve accuracy and efficiency. 1

3 PRODUCT PARAMETER TECHNOLOGY METHOD REFERENCE PAGE # Crude Oil Total acid number Thermometric titration ASTM D Total acid number Potentiometric titration ASTM D664 3 Water content KF volumetric titration ASTM D Water content KF coulometric titration ASTM D Salt content Potentiometric titration ASTM D Organic halides Potentiometric titration ASTM D Organic halides Combustion IC AN-CIC-14 4 Jet Fuel & Kerosene Acidity Potentiometric titration ASTM D Hydrogen sulfide and mercaptans Potentiometric titration ASTM D Organic halides and sulfur Combustion IC AN-CIC-14 4 Water content KF volumetric titration ASTM D Water content KF coulometric titration ASTM D Liquefied Petroleum Gas (LPG) Hydrogen sulfide Potentiometric titration ASTM D Water content KF coulometric titration AN-K Organic halides and sulfur Combustion IC AN-CIC Diesel & Biodiesel Blends Total acid number Potentiometric titration ASTM D664 6 Iodine number Potentiometric titration Water content KF coulometric titration Oxidation stability Oxidation stability EN15751(EN 14112) 6 Free and total glycerol content Ion chromatography ASTM D Antioxidant content Ion chromatography TA Sulfur content Combustion IC TA Fuel Ethanol & Gasoline Blends phe ph measurement ASTM D Total acid number and acidity Potentiometric titration ASTM D Water content KF volumetric titration ASTM E Water content KF coulometric titration ASTM E203 7 Inorganic chloride content Ion chromatography ASTM D7319 & ASTM D Total and potential inorganic sulfate content Ion chromatography ASTM D7319 & ASTM D PROCESS PARAMETER TECHNOLOGY METHOD REFERENCE PAGE # Crude Desalting Total acid number of crude oil Online titration AN-PAN Salt in crude oil Online titration AN-PAN Desalted water anlaysis Online and lab titration AN-T Mercaptans and hydrogen sulfide Online titration AN-PAN Salt content (salinity) Conductometric method ASTM D Alkylation Organically bound halides in feed, process and alkylates Combustion IC AN-CIC Acid strength Online titration AN-PAN Residual moisture in alkyate gas KF gas analyzer AN-K Sour Water Stripping Hydrogen sulfide and ammonia Online titration AN-PAN Anions, sulfide and ammonium in sour water Ion chromatography AW IC-US Amine Treatment Heat stable salts Ion chromatography AN-S Bicine Ion chromatography AW IC-US Amine strength Online titration AN-PAN Diesel & Gasoline Blending Monitoring Cetane number, density, FAME, flash point, pour point, viscosity, cloud point Online near-ir AN-NIR Ethylene Cracking Various parameters Online near-ir AN-NIR-US Water & Waste Water Analysis Various parameters Various technologies Various methods 13 Corrosion Monitoring Corrosion determination Electrochemistry Various methods 14

4 Crude Oil Crude oil assays evaluate the physical and chemical composition of crude oil feedstock. Each type of crude oil has unique chemical characteristics that are important to refiners, oil traders and producers globally. Crude oil measurements can vary from a simple yield determination to a complex evaluation of the quality of the crude oil and all of its refined fractions. These evaluations are critical to control corrosion in the refinery and greatly impact the profitability of all refining operations given the potential for significant loss in crude investments and disruptions in the refining process that influence yield, quality, production and environment. Total Acid Number by ASTM D8045 Acid Number (AN) is a critical quality control parameter for crude oil and petroleum products. The accuracy of the AN results has significant influence on the commercial value of crude oil and the profitability of a refinery. Moreover, acidic compounds lead to corrosion in petroleum refining and transportation infrastructure, therefore accurate AN measurements are necessary for safe operation. Given the commercial and corrosion impact of acidic compounds monitored by AN titrations, new method ASTM D8045 is critical to quality control laboratories throughout the industry. Total Acid Number by ASTM D664 Even though it is not as effective or reliable as ASTM D8045, many laboratories still measure Acid Number using ASTM D664. Metrohm has proven potentiomentric systems that yield the most accurate results from D664 and provide a high level of automation for worry free analysis. Water Content by ASTM D4377 & D4928 The determination of the amount of water in crude oil and petroleum products has always been important. Karl Fischer (KF) titration is the best water determination method due to its excellent reproducibility and accuracy as well as its ease of use. For these reasons, KF is called out in numerous international standards. Water is not homogeneously distributed in these products, which means that the petroleum samples must be homogenized before analysis. Furthermore, crude and heavy oils contain tars that can contaminate electrodes and titration cells leading to frequent reagent exchange and titration cell ASTM D8045 uses thermometric titration and improves upon the traditional D664 analysis technique by utilizing a sensor that is unaffected by difficult matrices, requires lower solvent volumes, and completes sample analysis in often less than two minutes. 3

5 cleaning. These additional steps add time and complexity to these measurements. To ensure that the sample completely dissolves, solubility promoters are added to the methanol. Metrohm offers both volumetric and coulometric KF titrators for moisture determination in crude oil samples. Chloride by ASTM D6470 & D3227 Chlorides in crude oil form areas of salt accumulation in processing units. These salt accumulations corrode key equipment, especially those that run in low-temperature ranges where hydrogen chloride forms. Refineries constantly optimize the production process to improve the yield of high value products. They lose their profit due to the corrosion to the level of 1 billion per year. Protecting plants against the corrosion caused by sulfur, chloride and other organic acids is important in the context of safety and profitability. Chloride in crude oil is determined by potentiometric and conductometric methods in accordance with ASTM methods. Organic Chlorides by ASTM D4929 Organic chlorides in crude oil are known to cause severe corrosion in crude tower overhead systems, therefore, most refineries allow no more than 1 ppm (mg/l) organic chlorides in the crude charge. There are two alternative test methods for determination of organic chloride in washed naphtha fraction; sodium biphenyl reduction measured with potentiometry or combustion and evaluation by microcoulometry. Metrohm Combustion Ion Chromatography can be used instead of microcoulometry for this measurement. Organic Halides by Combustion IC Combustion IC enables the sulfur and halogen content in combustible solids, liquids, and gases to be determined by combining combustion digestion (pyrolysis) with subsequent ion chromatography. Combustion IC can detect of individual halides without the interference that is encountered in any of the competing detection methods for ASTM D4929 Jet Fuel & Kerosene Total Acid Number by ASTM D3242 The acid and base number may also be determined by photometric titration with color indication of the equivalence point. Metrohm offers a unique optical electrode called the Optrode, a new sensor for photometric titration. It is 100% solvent resistant thanks to its inert glass shaft. Another key advantage of the Optrode is its capacity for automation. Water Content in Jet Fuel by ASTM D4377 & D4928 Fuels contain mercaptans that are oxidized by iodine and can falsely indicate a high water content. The problem is addressed by adding N-ethylmaleimide, which causes the SH groups of the mercaptan to add to the double bond of N-ethylmaleimide. Normally the water content in fuels is determined by coulometric titration. With volumetric titration, a solubility promoter must be added to the methanol. Hydrogen Sulfide & Mercaptans by ASTM D3227 Sulfur compounds in petroleum products not only have an unpleasant odor, they are also environmentally damaging and promote corrosion. For determining hydrogen sulfide and mercaptans in gasoline, kerosene, naphtha, and similar distillates, the sample is titrated with a silver nitrate solution. In this titration silver sulfide (Ag 2 S) and silver mercaptide are produced and two pronounced potential jumps occur. The first endpoint corresponds to hydrogen sulfide (H 2 S), the second to the mercaptans. The indicator electrode for the titration is the Ag-Titrode with Ag 2 S coating. Since both H 2 S and mercaptans are oxidized by atmospheric oxygen and the arising oxidation products cannot be determined titrimetrically, work must be carried out under nitrogen atmosphere. 4

6 Organic Halides and Sulfur by Combustion IC The burning of sulfur-containing fuel leads to the emission of air-polluting sulfur oxides into the atmosphere. Furthermore, high sulfur concentrations have an adverse effect on the ease of ignition of fuels and their stability during storage. Halogen concentrations in the refinery process must also be analyzed due to the corrosion risk. As a result, a fast and reliable method for determining the halogen and sulfur contents is required. The parameters that can be determined by NIR include: API gravity Density at 15 C Aromatic content Cetane index Boiling profiles at 10%, 20%, 50% and 90% recovery Flash point Freeze point Hydrogen content Viscosity at -20 C The Combustion IC method is captivating, not only due to its outstanding precision, but also because it has higher sample throughput. Jet Fuel Testing by Near-IR Spectroscopy Monitoring jet fuel properties is important because the fuel used in aircrafts must meet rigorous specifications. Near-infrared spectroscopy (NIR) is a fast method for fuel analysis. Metrohm developed a unique calibration solution for jet fuels testing in the laboratory. Liquefied Petroleum Gas (LPG) Water Content in Liquefied Gases Water is a contaminant in fuels and its concentration should be as low as possible. Water promotes corrosion and leads to undesired reactions in the fuel. In the case of liquefied petroleum gas, the challenge lies in the sample measurement and the associated phase transition from liquid to gas. In the sample cylinder, an equilibrium is reached between the liquid and gas phase. Depending on the sample, the water content in the gas phase can be several times higher than that of the liquid phase. Therefore, defined sampling is very important to ensure accurate and reproducible results. The 875 KF Gas Analyzer from Metrohm is a fully automated solution to determine trace levels of water in liquefied and permanent gases. Organic Halides and Sulfur in LPG by ASTM D7990 Fluorine, chlorine and sulfur contained in LPG can be harmful to many catalytic chemical processes, lead to corrosion and contribute to emissions pollutants. This test method can be used to determine total fluorine, chlorine and sulfur in processed and finished LPG products. The Combustion Module (Oven + LPG/GSS) is comprised of the combustion oven and the LPG/GSS module and enables sample digestion during the pyrolysis of liquefied gases and gases under pressure. 5

7 Sodium by Online Analysis The performance and life of combustion engines optimized for LPG can severely deteriorate with elevated sodium levels. Determining these levels at the downstream stage helps refineries adjust process conditions. Metrohm Process Analytics technologies use an ion-selective electrode and the dynamic standard addition technique to accurately measure sodium in LPG in the 0-2 ppm range. Process measurements overcome traditional, lab-based ICP or AAS, which cannot be implemented in the production area. Diesel & Biodiesel Blends Biodiesel is sold both as pure fuel and in blends with fossil fuels. The minimum requirements for biodiesel are set in the specifications of EN (pure fuel and blend stock) and ASTM D6751 (only blend stock). EN describes the minimum requirements for biodiesel used as heating oil. EN 590 applies to diesel fuels that contain up to 7% biodiesel and ASTM D7467 applies to those that contain between 6 and 20% biodiesel. Acid Number by ASTM D664 & EN The acid number is a sum parameter for all acidic components; at the same time it is a measure for the long-term stability and corrosiveness of the biofuel. The smaller the value, the higher the quality. Standard EN stipulates a non-aqueous potentiometric acid-base titration for determining the acid number. Moisture Determination The presence of water in biofuels reduces their calorific value and increases the corrosion rate. Some biodiesel fuels contain additives that can participate in side reactions during the direct coulometric Karl Fischer titration. In this case, Metrohm recommends that the biodiesel sample is not injected directly into the reaction solution. Instead, the water contained in the biodiesel should be driven off in a Karl Fischer oven. The water is driven off at 120 C and transported to the titration cell of the KF Coulometer in a stream of carrier gas (dry air or inert gas). This process can be completely automated with the 874 USB Oven Sample Processor. Iodine Number by EN Iodine number is a test for the number of double bonds in a sample. It is the amount of iodine (in g/100 g sample) that can be added to the sample under the given conditions. The determination of the iodine number in fatty acids or biodiesel is covered by European standard EN Oxidation Stability by EN & EN Fatty acid methyl esters are produced from a vegetable oil and usually obtained from oil seed by transesterification with methanol. Both feedstock and biodiesel have a relatively short storage life as they are slowly oxidized by atmospheric oxygen. The resulting oxidation products can damage vehicle engines. For this reason, the oxidation stability is an important quality criterion for biodiesel and vegetable oils and must therefore be checked regularly during manufacture and storage. The oxidation stability of fatty acid methyl esters is included as an essential parameter in EN & EN standards. Free & Total Glycerol Content by ASTM D7591 & EN The production of biodiesel from vegetable oils and animal fats leads to the formation of free and bound glycerol (monoglycerides and diglycerides) as by-products after transesterification of the triglycerides. Incomplete transesterification and/or separation of glycerol causes glycerol contamination in the biodiesel, which speeds up fuel aging and leads to deposits in the engine and blocked filters. To ensure engines operate properly, ASTM D6751 and EN limit the maximum total glycerol content (i.e., free and bound glycerol) to 0.24 and 0.25% (v/v), respectively. Free and bound glycerol is determined by ion chromatography with subsequent pulsed amperometric detection. Fuel Ethanol & Gasoline Blends The minimum requirements for fuel ethanol as a blend component in gasoline are documented in standards EN and ASTM D4806. ASTM D5798 relates to ethanolgasoline blends E75-E85. 6

8 phe Value of Fuel Ethanol by ASTM D6432 & EN A combined ph glass electrode with ground-joint diaphragm is recommended for measuring the ph value in organic solvents. Because phe determination according to ASTM D6423 and EN is time-controlled, it is essential that the sensor has a rapid response time. The Metrohm EtOH-Trode with a special membrane glass and the very precise fixed ground-joint diaphragm is particularly suitable for measuring the phe values of biofuels. Conductivity of Fuel Ethanol Electrical conductivity is an important analytical sum parameter for detecting and monitoring corrosive ionic constituents in ethanol and ethanol fuel. Due to the considerably lower conductivity in non-aqueous systems, very sensitive measuring systems are required. The stainless-steel conductivity measuring cell with Pt 1000 temperature sensor, in conjunction with the flexible 856 Conductivity Module, is ideally suited for this application in accordance with DIN Acidity by ASTM D7795 Fuel ethanol is mixed with gasoline in various ratios to reduce both the demand for gasoline and environmental pollution. Denatured fuel ethanol may contain additives such as corrosion inhibitors and detergents as well as contaminants from manufacturing that can affect the acidity of finished ethanol fuel. Very dilute aqueous solutions of low molecular mass organic acids, such as acetic acid, are highly corrosive to many metals, therefore, it is important to keep such acids at a very low level. Water Content by ASTM E1064 & ASTM E203 The ASTM E1064 and EN standards describe coulometric Karl Fischer titration for determining water content. For water content >2%, the recommended test method is volumetric titration as per ASTM E203. The volumetric KF titrators from Metrohm meet all the specifications required by the standards and are therefore extremely suitable for this application. Inorganic Chloride Content by ASTM D7179 & ASTM D7328 Bioethanol is either used in pure form as a fuel or blended with fossil fuels. Contaminants in the form of inorganic chloride and sulfate salts are corrosive and lead to deposits and blockages in the fuel filter and injection nozzles. The international ethanol specifications EN 15376, ASTM D4806, and ASTM D5798 regulate the sulfate and chloride content in bioethanol and bioethanol fuel blends. Total Potential Inorganic Sulfate Content in Fuel Ethanol & Gasoline Blend as per ASTM D7319 & ASTM D7328 According to ASTM D7319, the total content of inorganic chloride and sulfate is determined by direct injection of the ethanol sample, separation on an anion exchange column and measured using conductivity detection. If hydrogen peroxide is previously added, sulfur-containing species such as sulfites, sulfides, or thiosulfates can be oxidized to form sulfate and are quantified as potential sulfate content. 7

9 Increase Your Profit Through Internal Process Improvement. Petroleum refineries are large and complex production facilities. Once the crude oil price is fixed the profitability can only be improved through process optimization. In plant operation, plant integrity and safety, production rate, product quality, and costs are primary considerations. These all depend on comprehensive process control through online and near-real-time monitoring of key process variables, often in explosive, dusty, corrosive, and hostile environments. Metrohm provides online analyzers specifically tailored to your process needs. In addition to dedicated analyzers, we specialize in suitable sample preconditioning systems that allow you to implement a reliable online solution. Explosion proof analyzers are available in a stainless- steel version for Zone I or Zone II according to the European explosive atmosphere directives (ATEX). Crude Desalting Salt Content by ASTM D3230 Excessive amounts of chloride salts in crude oil result in higher corrosion rates in refining units and have a detrimental effect on catalysts. Desalting techniques are well established, but continuous monitoring of the salt content is needed for process control and cost reduction. Salt in crude oil is determined by titration using ASTM D6470 or by conductometric measurement with ASTM D3230. Water Content by ASTM D4347 & ASTM D4928 Crude oil that comes in contact with water carries some residual water. If the level of water in crude oil exceeds 0.1 to 0.5%, the distillation column will over pressurize. This creates unnecessary wear on the column and a potential safety issue. Water content in crude oil is monitored using ASTM D4347 and ASTM D4928 Mercaptans & Hydrogen Sulfide Raw oil contains several percent by weight of sulfur compounds. These compounds not only have an unpleasant smell, they are also environmentally harmful and corrosive which is why they must be largely removed during refining. The 2045TI Ex Proof Analyzer with a flexible sample pretreatment system is found in a very wide variety of refinery applications. It monitors mercaptan and H 2 S content in accordance with ASTM D3227 and UOP163 and can also be used for the determination of ammonia, halogen and phenol content as well as for the bromide index, saponification and acid number. The analyzer fulfills EU Directive 94/9/EC (ATEX95) and is certified for Zones 1 and 2. Chloride Monitoring in Crude Desalting Monitoring of the chloride in crude and after desalting is needed to check the desalting process efficiency and to overcome corrosion problems in downstream processes. The analytical measuring method is ASTM D3230 by conductivity detection. Since the sample take off point is typically in a hazardous environment the ADI 2045 Ex Proof Process Analyzer is designed and equipped to meet directives 94/9EC (ATEX95). Desalting Water Analysis A large portion of the water used in the crude desalting process is recycled. The source of wash water for the desalters varies widely; in some cases stripped phonic sour water is used as wash water. Metrohm provides dedicated online solutions for important water analysis parameters such as: Sulfide, Ammonia, Phenol, ph, Alkalinity, Hardness, Conductivity. 8

10 the amount of organic fluorides in the alkylate product elevates as acid is consumed and exits with the alkylate. Metrohm provides easy to use solutions for the residual organically bound fluoride and sulfur in iso-butane and olefin feeds by CIC with a gas box that can withstand pressure up to 400 psi. Residual Moisture Content The alkylate is blended to make gasoline with specific Research Octane Number (RON) values and residual water content in the alkylate can induce corrosion. For finished product quality assurance the moisture content determination in the alkylate product is important. Alkylation Isobutane and olefin are feeds into the alkylation unit which combines the olefin with butane to increase octane and lower the vapor pressure of the product for blending. Alkylation is used in combination with fractional distillation, catalytic cracking and isomerization to increase the yield of automotive gasoline. Either sulfuric or hydrofluoric acid is used as the catalyst for the alkylation reaction. Both catalysts operate at low temperatures and high isobutane-to-olefin ratios to reduce the side reactions and catalyst consumption. Sulfuric acid is a liquid under normal operation conditions, while hydrofluoric acid is a gas. Produced alkylates are passed through caustic to remove residual acids. Online Acid Strength Determination Acid acts as a catalyst in a refinery alkylation reaction, therefore, a minimal amount of acid is required to enable the reaction to occur. As acid strength declines, undesirable side reactions increase and can cascade in a runaway manner that consumes all of the acid in the unit. This can lead to undesirable polymer formation or oily sample formation depending on the type of acid used. In the hazardous environment, rugged online analyzers monitor the concentration of acid used in the alklyation process. Alkali concentration can be measured using a similar online analyzer. Monitoring Alkylation by CIC Insufficient acid strength in the HF Alkylation unit can lead to flurobutane formation. In an acid runaway situation, The 875 KF Gas Analyzer from Metrohm provides predefined methods for water content determination in liquefied and permanent gases. Sour Water Stripping Sour water is condensed waste water produced during many downstream refining processes containing hydrogen sulfide, ammonia and other contaminating compounds. It is often acidic in nature and can cause corrosion problems within the refinery s pipework so it must be treated before it can be reused or disposed to the waste water treatment plant. Sour water is treated in the Sour Water Stripper (SWS) which uses a steam stripping process to remove sulfides and ammonia as gases. At optimum ph the sour water mixes with steam and the ammonia and hydrogen sulphide gas vent to the top of the stripper column to the Sulfur Recovery Unit (SRU). The stripped water is either used to produce steam in the reboiler or pumped within control limits to the waste water treatment plant for further processing 9

11 Online Monitoring of Hydrogen Sulfide and Ammonia Online analysis of ammonia and sulfides increases the efficiency of the SWS which leads to significant steam reduction and increased energy savings. Effectively stripping and monitoring H 2 S and NH 3 is an essential operation in the overall pollution reduction program of refineries. The Process Analyzer 2045TI can analyze H 2 S and NH 3 simultaneously with automatic cleaning and calibration using absolute wet chemical techniques. Fast and accurate results are continuously transmitted for process control. Online Monitoring of Amine Strength Determination of free amine is an important parameter to ensure acid gas removal. The alkalinity of gas washing solutions containing alkanolamines is measured by potentiometric titration with sulphuric acid using a combined glass electrode. Other contaminants that increase the sour water corrosiveness like phenol and cyanide can also be analyzed with Metrohm Process Analyzers. Determination of Anions, Sulfide, and Ammonium by Ion Chromatography Determination of sulfide and other sulfur species is critical for strict SWS process monitoring. While titration is a suitable technique for the sulfide content, the other corrosive sulfur species can be determined by ion chromatography. The degradation products of sulfide, such as sulfite, sulfate, thiosulfate and thiocyanate can be monitored by suppressed ion chromatography. Sulfide content in sour water can be monitored with UV detection while ammonia content can be monitored by cation exchange chromatography. Sample preparation steps such as ultrafiltration and dilution can be automated. Amine Treatment An amine treating unit captures hydrogen sulfide and other acidic gases from the refinery gas streams and concentrates them into an amine solution. It is also used to capture acidic gases from raw or sour natural gasses. Amine gas sweetening is a proven technology that removes H 2 S and CO 2 from natural gas and liquid hydrocarbon streams through absorption and chemical reaction. The entire process is very energy intensive and results in high operating costs. Optimizing the amine activity and usage by online analysis is a critical step in reducing overall costs and measuring the efficiency of the CO 2 capture at the same time. A single online analyzer can monitor several sample streams and determine the binding capacity of several amine scrubbers in succession. By implementing Metrohm s fully automated online monitoring solution for this process, it is possible to optimize the amine activity and measure the efficiency of the acidic gas capture, reducing overall costs while ensuring environmental compliance. Monitoring Heat Stable Salt Formation by Ion Chromatography Heat stable salts are a product of the neutralization reaction between the alkaline amine and an organic or inorganic acid (the neutralizing agent). Amine solutions extract other contaminants that form salts of organic acids and sulfur species such as oxalic acid, formic acid, thiosulfate and thiocyanate. The accumulation of heat-stable salts not only causes a reduction in CO 2 absorption capacity, but also causes a significant increase in the system corrosiveness. Metrohm provides a simple to use Isocractic IC method to determine heat stable salts. Bicine Determination by Ion Chromatography During degradation of these amines they form various products, especially bicine which is corrosive. It is extremely important to determine the accurate amount of bicine in order to control corrosion and cost. Bicine can be determined using cation exchange chromatography with electrochemical detection. 10

12 Diesel & Gasoline Blending Monitoring Gasoline Blends API Alcohols & ether (MTBE, etc.) Alkene content Aromatic content Benzene content Density Motor octane number (MON) Octane index number Research octane number (RON) Reid vapor pressure Diesel Blends Boiling Point Cetane number Cloud point Color Cold filter plugging point (CFPP) Density FAME content Flash point Pour point Specific weight Viscosity During the blending process, different fractions of the crude oil distillation are mixed together to produce ready-to-sell diesel or gasoline. This process is the most economical when it is carried out in automated process systems that work online. The endpoint of the blending process is reached when the required fuel specifications are achieved. Key characteristics, which indicate the progress of the blending process, are the cetane number for diesel blends and the octane rating for gasoline blends. Near-infrared spectroscopy (NIR) sensors located directly in the process enable the entire process to be controlled and ensure a high-quality end product. Parameters that can be monitored in parallel and inline are listed in the table above. Advantages of NIR Analysis in Petrochemistry Near-infrared spectroscopy has been successfully used in oil refineries for years. NIR detects numerous parameters in a single measurement in less than a minute. The cost savings are enormous. Further advantages are: short response times and fast quality control improved product quality and process optimization reduced investment, analysis, and maintenance costs accurate and precise measuring results. Real Time Blending Process Monitoring by NIR Monitoring the blending of a range of fuels is a direct example of the success of NIR in the refinery. NIR detects numerous parameters in a single measurement in less than a minute. Metrohm manufactures dedicated lab and process NIR analyzers for diesel and gasoline analysis and blend monitoring. These dedicated analyzers are provided with start-up calibration that eliminates time-consuming calibration development. 11

13 Ethylene Cracking Approaching 150 million tons per year, ethylene is the largest volume industrially produced organic material. Feedstock, typically naphtha or light gases (e.g., ethane, propane), is first heated to high temperatures to break down the feed into small hydrocarbon molecules. After being cooled, the products are then sent through a variety of separation processes with high purity ethylene being one product stream among many. Process optimization focuses on maximizing the output of ethylene and other profitable products. Typically, a Process GC is utilized for monitoring the cracking process. However, these measurements are time-consuming and maintenance-heavy. Near-IR with multicomponent analysis capability can be used for real-time cracking process monitoring. NIR process analysis is a key component of process optimization, because it provides process control with realtime gas concentrations at various points in the process. The use of fiber optics enables real-time sequential measurements of up to 9 positions (e.g., feed, recycle streams, product streams) with a single instrument. This allows for rapid adjustments of the process to account for changes such as differences in feed or temperature. The net results of incorporating NIR into the process are increased capacity, improved process reproducibility and product quality. Further, the amount of process testing can be shortened while enhancing plant safety. In combination with a high pressure cell, NIR spectroscopy can also be used as a tool for online, real-time analysis of industrial gases. 12

14 Water & Waste Water Monitoring Many of the processes in a petroleum refinery use water in large quantities. Refineries also generate a significant amount of waste water that has been in contact with hydrocarbons. In addition, most organic and inorganic compounds found in the refinery accumulate in this process water. To sustain this resource, refineries treat the waste water and reuse it for various process applications. This requires treatment utilizing reliable analyses that monitor the composition of the water continuously. Raw water or source water for refineries could come from lakes, rivers, ground water or sea water. Due to the specific requirements of process water in the refinery, all source water needs to be treated before being used for refinery applications. Waste water from refineries contains high levels of pollutants and is characterized by the presence of large quantities of oil products and other chemicals that are hard to degrade. With increasing regulatory limits and stringent monitoring requirements, most refineries are forced to use advanced water treatment, recovery and process monitoring technologies. Major waste water streams in refineries include desalter water, sour water, spent caustic formed in the extraction of acidic compounds from products, tank bottoms, and condensate blow down. Below is a table listing analytical parameters monitored in various water sources within the refinery. Water Source Parameters of Interest Technology Source water: Ground water, River water, Sea water, Rain water Process Water: Hydrocracking steam condensate Desalter waste water ph, Conductivity, Hardness, Alkalinity, Chloride, Sulfate, COD, Chloride, Sulfate, Nitrite, Nitrate, Phosphate & other anions Sodium, Potassium, Calcium, Magnesium, Ammonium, Barium ph, Conductivity, Hardness, Alkalinity, Chloride, Sulfate, COD Ammonia, Nitrite, Phosphate, Silica, Iron, Cobalt, Sulfide, Fluoride, Hypochlorite ph, Conductivity, Chloride, Sulfide, hardness, alkalinity Sulfide, Ammonia, Phenol ISE Measurement; Titration & Online Analyzer Ion Chromatography; Online IC Ion Chromatography; Online IC Titration Dedicated Online Analyzers ISE Measurement; Titration; Dedicated Online analyzer Dedicated Online Analyzers Sour water Ammonia, Sulfide, Chloride Dedicated Online analyzers; Ion Chromatography Cooling water & cooling tower blow down Calcium, Magnesium, Zinc, Phosphate, Silica Dedicated Online analyzers; Ion Chromatography Spent caustic Cyanide, Phenol, Sulfide, Ammonia, Dedicated Online analyzers; Titration; ISE Measurement Waste water treatment Ammonia, Sulfide, Cyanide, Phenol, Nitrite, Nitrate, Total Nitrogen, Sulfate, Calcium, Magnesium, Barium, COD, Phenol, Total Dedicated Online Analyzers phosphate ph, Conductivity, Alkalinity, Hardness, Chloride, Sulfate Measurement & Titration Fluoride, Chloride, Sulfate, Nitrite, Nitrate, Phosphate, organic acids, hexavalent chromium, Sodium, Ammonium, Potassium, Calcium, Magnesium and other amines, Cobalt, Zinc Ion Chromatography 13

15 Corrosion Monitoring Reliable Corrosion Measurements via Electrochemistry Refineries are complex systems of multiple operations that depend on the type of crude refined and the desired products. They constantly optimize the production process to improve the high value products yield that maximizes profitability. Refineries lose their profit due to the corrosion to the level of $1 billion per year. Protecting refinery plants against corrosion due to the sulfur, chloride and other organic acids is important in regard to safety and profitability. Metrohm offers innovative and improved analytical methodologies to improve process efficiency and to protect against corrosion to maximize profitability. Over the past three decades, several methods have been introduced to measure and monitor corrosion. While many of these traditional methods such as weight loss or spray test analysis are quick and cost-effective, they can only offer a qualitative overview of the process. In comparison, electrochemistry techniques are accurate, reproducible and often the only method to measure corrosion rates on a quantitative basis. Electrochemistry has not only made it easy and direct to measure the parameters governing the corrosion processes but has also helped greatly in the overall development of the novel corrosion resistant films and corrosion inhibitors. Depending on the nature of the application, different electrochemical techniques are needed to determine specific parameters of interest. Metrohm instruments and pre-programmed methods provide ready-to-use tools to determine these parameters. Metrohm offers fully customized corrosion analyzers to evaluate corrosion parameters for specific ASTM methods. A corrosion software package with pre-programmed protocols is provided with every analyzer at no charge. Corrosion parameters of interest and the relevant ASTM methods are summarized in the table below. Electrochemistry Techniques Parameters of Interest ASTM Reference Methods DC Techniques Linear sweep voltammetry Tafel slope analysis Potentio-dynamic polarization (LPR) AC Techniques Electrochemical impedance analysis (EIS) Chrono & other Techniques Electrochemical noise (ECN) Critical pitting technique (CPT) Hydrogen permeation study Cyclic potentiodynamic polarization Hydrodynamic linear sweep Polarization resistance (Rp) Corrosion rate (mm/year) Corrosion current Corrosion potential Film resistance & conductivity Charge-transfer resistance Solution resistance Polarization resistance Redox kinetics Pit initiation Crevice progression Hydrogen resistance Surface morphology ASTM G102 ASTM G59 ASTM G59 ASTM G106 ASTM G150 ASTM G148 ASTM G100 ASTM G61 ASTM F746 ASTM F

16 Partner with Metrohm for Profitability Petroleum refining is demanding and requires precise and reliable analysis. As a leading manufacturer of instruments for chemical analysis we are aware of these challenges. We work closely with the petroleum refineries and with the regulatory agencies such as ASTM and EPA to come up with new and improved analytical methods that improve overall product quality and profitability. Your partners at Metrohm are experienced professionals who help you with customized application support and service. Quality Service Metrohm Quality Service begins before you purchase your instrument and continues throughout its entire lifecycle. Instrument experts help you make the right decisions to satisfy your analytical and environmental requirements. Application chemists assist you in every technical aspect, from support in method development to troubleshooting and process optimization. Our certified service engineers are always on alert to provide emergency service in the shortest possible time wherever you are. Metrohm provides the same high standard of service all over the world by trained and certified service engineers based at local Metrohm offices. After all, who is better qualified to care for your instruments than the people who built them? For more information visit: C Metrohm USA / Belgium. Metrohm and design is a registered trademark of Metrohm Ltd.