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The Situation A California refinery produces xylene for use as commercial product and a precursor for petrochemical manufacturing. A primary component to the production of xylene is the isolation and purification of the chemical from a complex mixture of petroleum hydrocarbons. Steam based heat exchangers are used to process the xylene. Inherent to the design and rough duty heat exchangers face during their operation, leaks can and do develop. When a heat exchanger leaks, xylene contaminates the steam and produces a number of problems ranging from loss of final product, contamination and fouling of steam transfer piping, and ultimately bio-fouling of cooling towers. Consistent and reliable monitoring for xylene or other petroleum hydrocarbons in cooling water or steam condensate can alleviate product loss and process equipment down time. The Problem The refinery routinely uses gas chromatography (GC) analysis of grab samples to detect leaks in steam condesate. This traditional approach is highly prone to missing upsets, time consuming and it carries the burden of recurring laboratory costs. (Contact Turner Designs Hydrocarbon Instruments for a copy of the continuous data log.)
The continuous on-line measurement and detection of petroleum hydrocarbons in water has been difficult. The difficulty lies in the need to detect low concentrations of hydrocarbons that are dissolved in water. Optical instruments called fluorometers can very easily detect and measure dissolved petroleum hydrocarbons in water, and at very low concentrations. The TD-4100 monitors xylene continuously over four consecutive weeks with a direct correlation coefficient of 0.9967 compared to GC grab sample analysis. The Solution Continuous uninterrupted leak detection of steam condensate requires continuous monitoring. The refinery chose the Turner Designs TD-4100 continuous on-line monitor to meet their monitoring needs for this study. The Turner Designs TD-4100 was installed to detect leaks from the heat exchanger. The TD-4100 continuous on-line monitor can measure and detect from ppb to ppm for both dissolved and dispersed aromatic hydrocarbons in water. The TD-4100 was configured with a BTEX optical filter kit which permits the detection and measurement of mono-aromatic hydrocarbons in water. In particular, the filter kit can measure benzene, toluene, ethylbenzene and xylene, as well as, phenol. The monitor provides continuous uninterrupted analysis of these chemicals in water. The TD-4100 was operated in the raw fluorescence mode, thereby functioning as an "upset" monitor. The monitor can be calibrated for direct reporting for ppb levels of xylene in the steam condensate. The TD-4100 served two functions at this facility; a leak detection tool to prompt mechanical repair of heat exchangers, and economic tool to protect fouling of cooling towers and other downstream processes. The Situation A municipal power plant in the southern United States operates more than 10 stationary power plant engines capable of producing 52 megawatts of electric power. The plant is part of a larger statewide power grid system. Within the grid, the municipality brokers the purchase or sale of power hourly, based on the needs of municipality and the market rate for power on the grid system. The power plant engines are fired-up on short notice to meet the needs of the dispatcher. The engines produce power ranging from two to 7.5 megawatts per engine. The engines operate on a blend of diesel fuel and natural gas. The cooling system for the power plant is a combination of closed and open loop cooling. The open loop cooling water comes from ground water wells and is circulated through the stationary power plant engines. The plant is permitted to discharge several million gallons of cooling water on a continuous basis per day into a canal system. The Problem
The municipal power plant had utilized a Dissolved Oil in Water (D.O.W.) monitor. The DOW utilized UV absorbance for oil detection and an articulated mechanical squeegee design to maintain flow cell cleanliness. This design proved to be very high maintenance and difficult to calibrate. Eventually, the articulated squeegee failed and scratched the optical flow cell windows. The power plant could not risk an undetected discharge of oil in cooling water with the DOW technology. The TD-4100 continuous on-line monitor verifies NPDES discharge compliance for oil and grease in power plant cooling water. The Solution The plant manager states, "the power plant decided to update the monitoring system with the latest monitoring technology. The Turner Designs TD-4100 was selected to reduce maintenance hassles and insure compliance with the NPDES discharge permit." The criteria used by the plant operators for finding the best available technology was accuracy, low maintenance, continuous monitoring, built-in alarm system and alarm relay system. The TD-4100 was the monitor of choice by the municipal power company. The TD-4100 utilizes a non-fouling, non-contact flow cell which requires little to no maintenance, and uses fluorescence technology to accurately detect oil in water from low ppb to high ppm. For this application, the TD-4100 monitors oil in water at 1 to 5 ppm and signals an operator with an alarm when the concentration exceeds the high alarm relay set-point. The key to routine, long term continuous monitoring is a non-fouling flow cell or detection system. The TD-4100 does not foul, even if high concentrations of oil were to pass through the monitor. Petroleum Hydrocarbons in Wastewater A wastewater treatment company established and operates an oil/water separation facility on a multi-acre industrial site in Northern California. Its purpose is to recycle oil products for profit while at the same time provide a wastewater treatment service for industries based in Northern California. The oily water mixes processed by the company are obtained from tanker bilges, contaminated rainwater runoff, truck spills, oil spills into waterways, crankcase drain oils, hydraulic oils and industrial lubricants, contaminated fuel oils and rinsate from fuel tanks. The water treatment system on this site is designed to treat the water which is separated from the "oily water mixes" before being discharged to the local publicly owned treatment works (POTW). The Problem
The economic advantage of continuous discharge can only be achieved at this location by meeting strict discharge limits for the level of hydrocarbons present in the discharged water. Local ordinances required continuous monitoring for continuous discharge of the company’s treated wastewater. Continuous hydrocarbon monitoring verifies removal of hydrocarbons from the water by the wastewater treatment system. The maximum discharge limit for hydrocarbons in water is 10 ppm for this application. "The local sewer authority would not issue a permit to continuously discharge treated water without verifying treatment with a continuous on-line monitor." The Solution Continuous discharge required continuous monitoring. The wastewater treater chose the Turner Designs TD-4100 continuous on-line monitor to meet their monitoring needs. The monitor was a mandatory component of their treatment system. In the words of the sewer authority; "Continuous monitoring of the discharge will let me sleep at night." The Turner Designs TD-4100 was installed to verify treatment of petroleum contaminated water. The treatment system consists of a dissolved air flotation system (DAF), solids centrifuge and three (3) 2000 lb carbon beds. The TD-4100 monitors treated water between carbon bed 1 and 2. The TD-4100 was configured with a mixed fuel filter kit which permits the detection and measurement of gasoline, diesel, jet fuel and lubricating oils in water. The monitor provides continuous uninterrupted analysis of their treated water. The TD-4100 is calibrated with gasoline to report concentration units and actuates a flashing light if fuel is detected in the treated water above 5 ppm. The TD-4100 serves two functions; a treatment verification tool to maintain discharge permit compliance, and a carbon break-thru tool to maximize the economics of carbon bed replacement. The oil and gas production industry generates produced water. Produced water is typically a mixture of formation and injection process water that contains oil, salts, chemicals, solids and trace metals. Produced water is the primary waste product resulting from the separation of oil, gas and water at production facilities. The discharge of produced water to the environment is regulated by the Environmental Protection Agency (EPA) in the United States. The EPA mandates that produced water discharge, as overboard water, must contain an oil and grease concentration less than 29 ppm and 42 ppm, respectively, for a 30 day average and daily maximum. Federal EPA Method 413.1 is mandated for regulatory compliance monitoring of oil and grease concentrations in produced water. Method 413.1 is a gravimetric method that utilizes solvent extraction (Freon 113) of oil and grease hydrocarbons followed by solvent evaporation and subsequent residue weight analysis. Regulatory compliance samples are typically taken at thirty day intervals and analyzed by EPA recognized laboratories. Method 413.1 analytical results are reportable to the Federal EPA. The Problem
IR instrument response is calibrated and allows production chemists to determine oil and grease concentrations in produced water. The modified Method 413.2 is classified as a "non-report" method whose analytical results are not reportable to the EPA. The oil and gas industry is now challenged with developing an alternative analytical method for use by production chemists to measure oil and grease without using Freon 113. Recent amendments to the Clean Air Act of 1990 and the Montreal Protocol force the phase out of Class I chlorofluorocarbons (CFC’s) by January 1, 1996. This presents a dilemma for all analytical methods using Freon 113 as an extraction solvent for oil and grease measurements. The EPA has issued Method 1664 to replace Method 413.1 with the primary objective to substitute Freon 113 with n-hexane as the extraction solvent. The American Petroleum Institute (API) is currently evaluating alternative methodology to support oil and grease measurements in produced water by oil and gas production facilities. The new EPA solvent, n-hexane, cannot be used as a replacement solvent for Freon 113 in the Freon/IR modified 431.2 method. The flammable solvent, n-hexane, strongly absorbs IR wavelengths and interferes with the oil and grease measurement. The TD-4100 continuous on-line monitor demonstrates high correlation to Freon/IR grab sample measurements. The Solution Yielding to produced water discharge regulations and the phase-out of CFC’s, the oil and gas industry is consistently asked to invest in analytical methods that demonstrate the effectiveness of process control for oil/water separation systems. Protecting regulatory compliance for produced water discharge translates directly to effective management of process control systems that treat produced water. Continuous treatment verification for discharge compliance is only achieved by continuous on-line oil in water monitoring. Until recently, viable continuous on-line oil in produced water monitoring systems were absent from the oil and gas industry. Recent advances in the development of a continuous on-line monitor, the TD-4100, provide the oil and gas industry with a viable complement to grab sample measurement for oil and grease measurements in produced water. The TD-4100 makes a positive impact on the effectiveness and costs associated with managing treatment and discharge compliance for produced water. Continuous oil in produced water monitoring benefits the growth of unmanned production facilities, and need to monitor the purity of re-injection water. Data generated by the Turner Designs TD-4100 compared with the Method 413.2 Freon/IR techinque demonstrate strong correlation between continuous monitoring and grab sample measurements for overboard discharge (Figure 1). These data provide strong support for utilizing continuous monitoring for verifying treatment of produced water either for discharge compliance, process control applications or re-injection. The Situation Various processes onboard ships, such as machinery wash-down, maintenance, and leakage generate oily wastewater. This contaminated water flow collects in the bilge of the ship. Marine diesel, lubricating oils, grease, as well as garbage may be present in bilge water. The bilge water is discharged overboard, with oil and grease concentrations in the discharged water limited by national and international regulations. In the United States territorial waters, the U.S. Coast Guard (USCG) limits the discharge of oil and grease in bilge water to 15 ppm, measured by the U.S. Environmental Protection Agency (EPA) oil and grease measurement method. The USCG further limits bilge water and oily discharges that cause a visible sheen on the water. In Canadian inland waters, the Canadian Coast Guard limits the discharge of oil and grease in bilge water to 5 ppm. Bilge water discharges in international waters are limited to 15 ppm by the International Maritime Organization (IMO). Ship operators who violate the discharge limits are subject to large fines by the jurisdictional authority. Recently, cruise ship lines have incurred record fines for discharge violations. The Problem The maritime industry needs an effective and accurate analyzer to monitor the oil concentration in the bilge water before discharge. On-line analyzers manufactured by several companies have been employed for this application, yet to date, none of these analyzers have been effective or accurate. Most analyzer’s monitor oil in water by using a contact flowcell through which the bilge water flows. The flowcell is regularly fouled by oil and other material. Even mechanical wipers cannot keep the flowcell free of fouling. Most analyzers require considerable maintenance for proper operation or measure the oil concentration indirectly by turbidity, which is subject to interference by solid material present in bilge water.
The TD-4100 On-line Oil in Water Monitor eliminates the problems associated with other bilge water monitors. The TD-4100 uses a non-fouling, non-contact flowcell to monitor the hydrocarbon concentration by fluorescence which is directly proportional to the oil concentration. The non-fouling, non-contact flowcell eliminates contact between the water and optical windows, thereby preventing fouling. The TD-4100 can be calibrated with a CheckPoint™ solid standard, which allows quick calibration checks and re-calibration of the analyzer without the need for preparing hydrocarbon solutions. Bilge water monitors require certification. The TD-4100 and TD-4100XD are certified by the USCG as a Oil Content Meter – 15 ppm bilge alarm according to Regulation 16(5) of Annex I to Marpol 73/78. The solid-state alarm relays of both instruments can activate control devices and/or alert operators. The TD-4100XD received approval by the American Bureau of Shipping (ABS) for use on ABS classed vessels. The USCG presently uses a Turner Designs Model 10-AU instrument for monitoring and tracking oil spills. The TD-4100 and TD-4100XD utilize the same fluorescence technology as the model 10-AU. The TD-4100 is certified by the Canadian Coast Guard as a 5 ppm bilge water alarm and is currently being deployed onboard Canadian naval vessels. The TD-4100 is also certified to meet the Canadian Coast Guard’s inland waters requirement of 5 ppm bilge water alarm. The Situation A major pipeline company has large storage tank farms throughout the Western States. The pipeline company transports, stores, blends additives, and distributes gasoline, diesel and jet fuel to retail service stations and airports. Due to the quantity and movement of fuel at these facilities, there is always the potential for fuel spills. These facilities prevent out of compliance discharge by capturing all stormwater in storm drains which is then sent to treatment systems prior to discharge. At some sites, groundwater from on-going remediation is mixed with stormwater at the treatment system prior to local discharge. The Problem
Previous continuous on-line measurement and detection of fuel in water has been difficult. The difficulty was the need to detect fuel in water at 1 ppm for discharge compliance at these facilities. Fuel at or below concentrations of 1 ppm is, physically, fully dissolved in the water. Turbidity, ultra-sonic and light scatter oil-in-water monitors cannot detect dissolved hydrocarbons water. Optical instruments called fluorometers can "see" dissolved petroleum hydrocarbons in water, and at very low concentrations. The TD-4100 continuous on-line monitor can measure and detect ppb to ppm for both dissolved and dispersed aromatic hydrocarbons in water. The TD-4100 is a fluorometer based monitor "Turbidity, ultra-sonic and light scatter oil-in-water monitors cannot detect dissolved hydrocarbons in water." The Solution Continuous discharge requires continuous monitoring. The pipeline facility chose the Turner Designs TD-4100 continuous on-line monitor to meet their monitoring needs. The Turner Designs TD-4100 was installed to verify treatment of contaminated stormwater run-off. Although the technology used at each site is unique, a typical treatment system utilizes large tanks for primary fuel/water separation. The water from the storage tanks is then treated with two activated carbon beds and a "polish" or cleaning is performed with an ozone treatment system. The TD-4100 typically monitors treated water between carbon beds 1 and 2. The TD-4100 was configured with a mixed fuel filter kit which permits the detection and measurement of gasoline, diesel and jet fuel in water. The monitor provides continuous uninterrupted analysis of their treated water. The TD-4100 is calibrated to report concentration units for fuel at a high alarm level of 1 ppm. The TD-4100 serves two functions; a treatment verification tool to maintain discharge permit compliance. Monitoring Phenol in Water The Situation A plant located in the eastern United States manufactures phenolic resin for applications in plastics molding. This plant uses well water for cooling its reaction process and then discharges the water into a local creek. A leak in the reactor and associated cooling equipment would cause phenol and phenolic compounds to contaminate the cooling water. Such a leak could result in a discharge violation. The local regulators frequently inspected the plant’s discharge to ensure compliance with the discharge permit.
Figure 1: Measured phenol concentration swing corresponds to reactor pressurization swing, thus the TD-4100 detected a leak. (click image to see full sized). " The TD-4100 detected a leak in the reactor before the discharge limit had been exceeded." The Problem The company requires on-line monitoring of the cooling water to detect a leak and prevent a discharge violation. Previously the company employed a Technicon analyzer, which used wet chemistry techniques to continuously monitor the phenol in the water. The Technicon analyzer required considerable maintenance due to the wet chemistry method. A replacement monitor was necessary to replace the aging Technicon, which was no longer manufactured nor supported. The replacement analyzer had to be capable of reliably detecting phenol in water below the discharge threshold of 150 ppb. Given the direct discharge of the cooling water into a stream, the local regulators as well as the plant were concerned about the potential discharge of phenol, a toxic compound. The Solution The company chose the Turner Designs Hydrocarbon Instruments TD-4100 as a replacement for the Technicon analyzer. Phenol is an extremely fluorescent compound, therefore the fluorescence-technology TD-4100 was capable of detecting phenol much lower then the required alarm limit of 150 ppb. The actual detection limit of phenol for this application was determined to be between 12.5 to 25 ppb in the cooling water. A potential company concern was the baseline noise of the TD-4100 compared to the old Technicon analyzer, yet this concern was eliminated since both instruments exhibited similar background noise. The instrument drift of the TD-4100 proved to be less than the replaced Technicon. The company was pleased with the instrument performance, yet the true performance test was verified when the TD-4100 detected a regularly occurring phenol concentration swing in the cooling water. Company personnel initially suspected a problem with the TD-4100, yet the period of the concentration swings identically matched the pressurization cycle of the reactor. Figure 1 shows the regular phenol concentration swing corresponding to the reactor pressurization cycle. The TD-4100 detected a leak in the reactor before the discharge limit had been exceeded. Thus, the TD-4100 prevented a costly discharge violation by allowing the company to detect a small leak before a catastrophic failure. back to topTD-4100 Oil in Water Monitors for Hydroelectric Dam Sumps
The pictures below are from a recent visit at the US Army Corps of Engineers dams on the Columbia River in Oregon. At this time they have one TD-4100 installed on “The Dalles” dam and one on order for the Bonneville Dam. We also have instruments installed with BC Hydro in Vancouver, City of Mt. Holyoke, MA Hydro Plant, Danube Hydro in Austria and many others worldwide.
©2007 Turner Designs Hydrocarbon Instruments |
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The success of this municipal power plant relies on its ability to provide economical and uninterrupted power to its clientele. A primary component to keeping the economics favorable is the plant’s ability to continuously discharge uncontaminated cooling water into the canal system. As part of a NPDES permit renewal in the early 1990’s, the power plant added a cement lined pond containing a slant rib separator to effect the mechanical separation of any oil present in the cooling water that is caused by a leak from a power plant engine. The permit also maintained the requirement that a continuous monitor verify that the discharged water was free of oil. 
The success of this facility as a profitable enterprise depends on its economical operation. This company chose to avoid the cost of large storage tanks, the associated land mass and more costly equipment used for "batch" treatment and discharge. A significant component to the company’s success is its dependence on continuously discharging treated wastewater to the local sewer authority. 
The oil and gas production industry typically monitors oil and grease concentrations in produced water at production facilities on a daily basis to manage oil/water separation processes and discharge compliance. The industry utilizes a modified Method 413.2 which relies on Infra-Red (IR) measurement of the Freon 113 extract for oil and grease concentrations versus residue weight (gravimetric analysis). 
The Solution
The challenge requires developing a system or program for continuous uninterreupted pollution prevention and environmental discharge compliance. Traditional grab or batch sample analysis is not a viable option for continuous discharge programs. It only provides snapshot status of a treatment system’s performance, it is highly prone to missing upsets and it carries the burden of recurring laboratory costs. 
