I find David Burnett's stating that these companies that are doing water purification are ahead of their time a little odd. I found the following:
Currend R&D and Proposed Solution
In the past 10 years, the Texas A&M Desalination program has shown that produced water and frac Flowback brine can be treated and reused to replace otherwise additional fresh water resources. Now the program is seeking support to demonstrate that low cost, mobile units can be deployed in field operations to replace the more costly and environmentally questionable practices currently being employed in field operations.
The approach proposed is (1) to develop a portable pretreatment system to demonstrate effective water purification measure and (2) to create a mechanism for engagement of elected public officials, community leaders, and members of the general public to make them aware of produced water treatment technology and the potential benefit. Concomitantly with this “human dimension” portion of the A&M program, a systematic effort will be begun to identify potential market mechanisms and incentives that would encourage oil and gas producers to implement water treatment technology.
Demonstrations of pretreatment technology in field will be conducted using a trailer mounted platform that allows installations of multiple types of purification techniques. The pretreatment technology will be based on 10 years of experience by the prime contractor (Texas A&M University) in its produced water desalination program at GPRI - Siddiqui & Burnett, 2002 (7). The concept to be demonstrated will be that by removal of certain contaminants, a process stream can be used to provide “product water” of a specific concentration thereby recouping treatment costs. The concept is displayed in Figure 1. Total suspended solids (TSS) are removed first (including suspended oil). Handling this step separate from subsequent pre-treatment simplifies the separation process and allows disposal of the small volume of rejected material much less expensive. Treated water can then reused – the value of the “product water” serving to offset the cost of the purification treatment.
It is important to note that the pretreatment technologies are amenable to and in most instances required for ANY desalination process, be it thermal or membrane treatment. Several process techniques have favorable attributes desirable for mobile low cost process train systems. These pretreatment techniques are discussed below.
Solids Removal Techniques. Brines must be free of suspended solid material if subsequent re-use is planned. Recycled waters (including brines) should not be prone to precipitation, generally meaning low divalent ion concentrations, (Blauch 2009). Calcium and similar material often reduce the functionality of chemicals used for friction reduction, scale inhibition, and corrosion control. The A&M Separation Science Pilot Plant has identified methodology whereby undesirable ions can be removed using specialized membranes that do not require high pressure for separation. Test data collected in Pilot Plant experiments showed excellent rejection of Calcium from a high salinity feed water. Results from both laboratory prepared samples and field produced water showed 90% reduction in divalent ion concentration. Figure 2 shows test results with both synthetic produced water and actual produced water. Such separation allows a process “product water” stream to be created from high salinity brines (frac flowback & produced water).
Oil Removal Techniques. One of the prime reasons that traditional water treatment technology is ineffective in oil field operations is because of the hydrocarbon content in produced water. Experience has shown that oil removal before other pretreatment will improve water treatment efficiency and lower operating costs.
Laboratory tests have shown that experimental data for oil/water separation of controlled mixtures using packed columns with modified clay particles. The average oil loading capacity of these particles is better than activated carbon (over 60%). Both laboratory and field results indicate that packed beds can remove over 90% of the oil - Barrufet & Burnett, 2005 (8). One of the functional advantages of the newer forms of these material is the lessened contact time necessary of effect oil adsorption - Fabri, 2009 (9).
A particularly attractive technology is being licensed by Los Alamos National Laboratory. The process evaluated in field tests in the Farmington field in New Mexico - Kwon & Sullivan, 2008 (10) provides a means of regenerating the oil removal catalyst via biological treatment in packed beds. Such technology needs to be evaluated in longer duration tests with modified zeolitic catalysts according to LANL.
“Product Water” Techniques. The most practical way of handling waste brines is to reuse them in subsequent fracturing operations. However in the Marcellus Shale, the hyper salinity of the Flowback brines may preclude muc reuse unless the brines can be treated to remove offending ions that react with fracturing chemicals and cause precipitation when mixed with produced fluids
Undesirable ions can be removed using specialized membranes that do not require high pressure for separation. Data collected in the A&M Separation Science Pilot Plant showed excellent rejection of Calcium Chloride from a high salinity feed water. Both laboratory prepared samples and field produced water showed 90% reduction in divalent ion calculation - Olatubi, 2009 (11).
Field Unit Designs. As a first step, small-scale laboratory tests will be conducted using flowback water samples to demonstrate the performance of the pretreatment technologies, individually and in combination. These tests will show which combinations of technologies offer the best pollutant removals, and can give some early indications of the capital and operating costs, including the cost of disposal/management of any concentrated brines or sludge. Based on the results of the laboratory tests, one or more portable field units will be constructed for subsequent pilot tests in different shale formations and with different primary commercial flowback water technologies.
Field test demonstrations will be conducted on site at locations in the Marcellus Shale Play where frac water flowback operations are underway. The field demonstrations will evaluate a combination of the different techniques that are designed to sequentially remove contaminants from waste brine using equipment similar to the A&M Mobile unit for in the Permian Basin.
Concurrent with field testing, members of the team will work to address the Societal Issues portion of the project. As part of the program, researchers from team member Rensselaer Polytechnic Institute will conduct exploratory interviews with landowners and local government officials in northern PA to get a general sense of how issues such as industry secrecy and lack of access to scientific information are shaping local perceptions of the risks and benefits of natural gas development. – Kinchy (12). Researchers will identify pertinent regulatory agencies that have statutes applicable to oil and gas production and/or water quality issues within states located in the Marcellus Shale. Once these agencies are identified, researchers will contact by telephone selected key personnel within each agency. Face-to-face meetings then will be scheduled. A comprehensive program is also planned to communicate with stakeholders to inform them of the program and to offer opportunities to observe operations designed to minimize the impact on the environment
_displayNameOrEmail_ - _time_ - Remove_text_
Add comment.
