Batteries have become a key contributor in the world’s energy transition and critical in the effort to slow climate change. As a result, battery manufacturing technologies and techniques are constantly evolving as producers look to remain competitive, increase storage capacity, and improve efficiency while decreasing battery size and weight. For instance, some producers are turning to a silicone-based anode material to increase battery output and reduce cost; others are exploring mining lithium from seawater to alleviate supply issues. When combined with an unprecedented increase in demand and subsequent production increases, it is fair to say that manufacturers are in a constant state of change. And it is not slowing down: some experts estimate the lithium-ion battery market alone will expand 18% by 2030. In short, we need more energy storage, in smaller batteries, at lower costs.
Lithium-ion batteries are considered the most energy-dense and longest-lasting rechargeable batteries currently available. The process of making them varies, but in general it consists of mixing raw materials followed by a series of coating, laminating, drying, cutting, winding, welding, sealing, forming, pre-charging, and degassing before a final test. However, when battery advancements occur, many of these existing production inputs and manufacturing practices need to change quickly. This can include raw material adjustments, production equipment modifications, or a change in coating techniques, just to name a few. The pollution control technologies employed at the battery manufacturing facilities are also affected by the upstream changes but are often an afterthought by plant personnel.
Regulated by most state and federal agencies, Volatile Organic Compounds, or VOCs, are pollutants generated in many manufacturing processes. The battery industry is accustomed to these harmful byproducts and the compliance hurdles that accompany them. The organic vapors are dangerous to humans when inhaled in quantities over an extended period. They also interrupt and destroy natural plant processes and play a significant role in the formation of ozone and smog. Hazardous Air Pollutants (HAPs) are a classification of VOCs with additional harmful properties, including potentially causing birth defects, nervous system damage, and even death in concentrated levels; HAPs are also a regulated pollutant from battery manufacturing.
One synthetic graphite anode powder manufacturer was modifying their furnaces to accommodate new products for lithium-ion battery manufacturing. Because their production facility was in a non-attainment area, per the United States Environmental Protection Agency (EPA), air quality standards required them to take special precautions. This meant a Title V permit would be required, as they have the potential to emit more than 100 tons per year (TPY) of VOCs, more than 10 TPY of any single HAP, or more than 25 TPY of any combination of HAPs.
This manufacturing plant in the United States produces high-performance anode material for lithium-ion batteries. A key component of lithium-ion batteries is the anode which stores and releases the lithium ions. Graphite is currently the most commonly used anode material. The process starts with a petroleum coke, which is formed into a synthetic graphite through graphitization. During operation, between 12 to 18 graphite furnaces, which are modular in construction and electrically heated utilizing local hydropower, are needed to meet the production demands.
This facility was no stranger to environmental stewardship. In years prior, they completed an Environmental Assessment to secure financial assistance from the Department of Energy and participate in the American Recovery and Reinvestment Act, which aims to accelerate the development and production of electric-drive vehicles systems to substantially reduce the United States’ consumption of petroleum. In fact, the site itself remains nearly 70% greenspace today.
In keeping with the company’s sustainability goals, they immediately began the search for an effective and efficient air pollution control system. As is the case with many manufacturing operations, process emissions are best destroyed using thermal and catalytic oxidation technologies where time, temperature, and turbulence convert VOCs and HAPs to heat, water vapor, and small amounts of carbon dioxide (CO2).
Widely considered the most energy-efficient oxidation technology, the Regenerative Thermal Oxidizer (RTO) uses these oxidation principles with a unique heat recovery component. Highly effective ceramic media within the oxidizer captures heat from emission combustion and reuses it to preheat incoming pollutants. The RTO also uses uniquely designed poppet valves to divert process air into and out of the oxidizer, properly balance emission loading, maintain destruction efficiency, and optimize heat recovery. Most RTOs are a two-bed design, but they can be designed in a multi-chamber configuration to accommodate larger airflows and achieve destruction efficiencies above 99.7%.
Given the emission loading and low process temperature, the company chose the RTO for its high destruction capability above 99%, and a preowned system was selected to meet their aggressive timeline for compliance. The refurbished, two-bed RTO from Anguil Environmental Systems was delivered, installed, and operational in less than ten weeks. It treats up to 5,000 standard cubic feet per minute (SCFM) of process flow containing methane, ethylene, acetylene, carbon monoxide (CO), benzene, aromatic hydrocarbons, and aliphatic organics from the electrically heated furnaces and corresponding collection hoods. Dilution air at each furnace was added to keep the overall lower explosive limit (LEL) in the duct system below 25%, per code.
The oxidizer can be operated in a bake-out mode to allow for the removal of organic build-up on the heat exchange media. At a reduced airflow, the outlet temperature is allowed to become elevated before the flow direction is switched, and this hot air vaporizes organic particulate that may have collected. Certain components of the RTO are insulated to prevent the temperature of the outer skin from increasing during bake-out.
Advanced programmable logic controls record vital oxidizer operating parameters for regulatory reporting and ethernet communications allow for remote diagnostics and service support. A variable frequency drive aids in minimizing operating cost by providing fan turn-down when only low airflow is required in the RTO.
Air pollution and greenhouse gas emissions from this facility remain extremely low due to the efficiency of the pollution control system and utilization of hydropower for the process furnaces. A preowned abatement system was selected to meet an aggressive timeline at this particular facility. However, battery manufacturers all over the world are employing various thermal oxidizer technologies to meet their unique process conditions. For instance, some silicone-based anode precursor manufacturers are utilizing direct-fired oxidizer technologies with downstream particulate control to handle silicon dioxide emissions and remain in compliance. Regardless of the process, oxidizer selection is application specific and should be based on emission constituents, process parameters, efficiency needs and regulatory requirements.
Ready-to-eat meals, freshly baked goods, and essential groceries draw loyal customers to a chain of convenience stores; they just also happen to sell gasoline. The chain’s nutritious food is locally sourced, processed, and packaged for distribution to almost 1,000 stores in the United States. This company is uniquely positioned as vertically integrated, whereas much of the supply chain is owned by a single corporation serving a common market and customer segment.
One such vertical operation is a commercial bakery that supplies the company stores with fresh bread, bagels, buns, doughnuts, muffins, and snacks. It is a state-of-the-art facility focused not only on quality, but operational energy efficiency and a low carbon footprint. When the company decided to increase capacity, they took a wholistic approach to the design and layout. New bread and bun ovens were purchased along with proofers which are large enclosures kept at elevated temperatures to help dough rise. Most commercial bakery ovens and the corresponding proofers rely heavily on natural gas or electric elements to generate heat for baking the products.
While working with local regulators to satisfy air pollution control requirements for the new lines, company engineers explored the utilization of waste heat from pollution control systems. Oven exhaust contains Volatile Organic Compounds (VOCs) like ethanol, as well as odors that must be treated to comply with national emission standards.
Like many other industries, food processors often find that the best available control technologies for emission and odor abatement are thermal and catalytic oxidizers. Oxidation systems use time, temperature, and turbulence to break down pollutants into Carbon Dioxide (CO2), heat, and water vapor. This bakery was particularly focused on minimizing the CO2 output from the planned oxidizer installation by utilizing the heat from combustion. It would not only save operating costs, but also keep with the company’s commitment to do right by customers and the community.
Anguil Environmental Systems was one of the first air pollution control system suppliers in the early 1990s to design and install oxidizers that met regulations limiting bakery oven emissions and odors. Three decades later, Anguil remains a leading supplier of both thermal and catalytic oxidizers to the baking industry. Regenerative Thermal Oxidizers, or RTOs, have been increasingly used on commercial ovens for their energy-efficiency operation. RTOs are typically 95% thermally efficient whereas catalytic oxidizers range from 60-80%. However, catalytic oxidizers are still widely applied at bakeries due to their lightweight construction which makes a rooftop installation more feasible, putting them near the ovens while eliminating costly duct runs.
This bakery was like many others in that regard; a roof installation made catalytic oxidation the most logical equipment selection. Two Anguil Model 50 (5,000 SCFM capacity) catalytic oxidizers would be installed, one for each oven, on dedicated roof platforms. During operation, ethanol-laden oven gases are pushed into a stainless-steel, shell-and-tube heat exchanger inside the oxidizers via a system fan. The contaminated airstream is progressively heated while traveling through the heat exchanger towards the combustion chamber. The cleanable, heat exchanger allows for self-sustaining operation with no auxiliary fuel usage at Lower Explosive Limits (LEL) levels of 8-12%. At the burner, the process gas is raised to the catalyst operating temperature. As the heated gas passes through the catalyst, an exothermic (heat releasing) reaction takes place as the pollutants are destroyed. The hot, purified air then passes through the opposite side of the internal heat exchanger and transfers thermal energy to preheat the incoming air.
This environmentally conscious bakery was interested in further reducing operating costs and energy consumption. Therefore, Anguil recommended and designed a secondary heat recovery system to capture additional waste heat from the two oxidizer stacks. Finned tube heat recovery coils with propylene glycol-heated fluid were installed to recover over 2.5 MMBtu/hr from the oxidizers and provide a heat source for the proofers.
The Anguil oxidizers achieve over 98% destruction efficiency of the ethanol emissions while reducing the carbon footprint of the bakery’s operations. The systems incorporate a self-cleaning ceramic filter, which prevents grease from plugging or fouling the catalyst. The Anguil design also ensured that the abatement devices would have no back pressure in the ductwork which could impact oven performance or product quality.
A family-owned manufacturer of metal wall and roofing systems in the Midwest was looking to expand their production capabilities while taking advantage of local utility rebate programs. Their existing operation contained three painting booths venting directly to atmosphere. As a part of the expansion, they planned to install two new paint booths, which would require them to install pollution abatement equipment.
Their application presented the following design challenges for the required emission control solution:
- The five paint booths represented a very large process stream containing volatile organic compounds (VOCs) including toluene, xylene, and ethylbenzene.
- The solution needed to process up to 90,000 SCFM of VOC-laden air with a minimum of 95% overall destruction efficiency.
- Space was also a major concern, as the equipment needed to fit in a tight space.
- They wanted to maximize energy rebates through their local utility provider, who offered prescriptive measures for the installation of pollution control equipment.
They solicited proposals from several air pollution control equipment suppliers including Anguil, another Midwestern family-owned business.
With such a large airflow from five paint booths, Anguil engineers quickly identified the emission concentrator system as the most cost-effective choice, proposing a 90,000 SCFM Rotary Zeolite Emission Concentrator Wheel combined with a 7,500 SCFM Regenerative Thermal Oxidizer (RTO).
Even though RTOs are extremely efficient and effective destruction devices, they rely on a steady stream of process emissions to fuel combustion of incoming contaminants. When coupled with a concentrator, the oxidizer consistently receives highly concentrated streams in a much smaller volume.
The selection of concentrator is easy to justify at this flowrate when compared to a standalone 90,000 SCFM RTO with similar footprint. While the capital cost of a concentrator and oxidizer combination is typically more expensive than the RTO without concentration, the proposed system would use dramatically less energy, which would reduce operating costs and greenhouse gas emissions. The reduction in natural gas and electricity usage would also make the manufacturer eligible for energy rebates in their state.
Their local utility company offers rebate program for customers that implement energy efficiency measures. Their current program has prescriptive measures for the installation of gas fired equipment like thermal and catalytic oxidizers. Under this program, the customer was eligible for a $37,500 rebate ($5.00/cfm for 2 shift operation x 7500 SCFM RTO).
Anguil’s local sales representative approached the utility company engineers with the possibility of doing a custom energy analysis since the concentrator system was even more efficient than a standard RTO. Anguil showed the energy consumption of the concentrator system and modeled it against a 90,000 SCFM RTO. This showed that the concentrator system would use 771,450 kWh/ year ($0.05/kWH incentive) and 51,393.82 MCF of natural gas/year ($3.50/MCF incentive). This calculated to a $218,000 rebate.
The utility company engineers brought the project to an external consulting company that provides oversight and regulatory compliance for the energy providers and their rebate programs. The consulting company agreed that the baseline should be a recuperative oxidizer, a less thermally efficient style of thermal oxidizer. This brought the energy savings up to 689,788 kWh electric and 209,094 MCF in natural gas savings for a total energy incentive of $766,319.00! However, there is a $300,000 cap per customer for natural gas payouts.
- With persistence and a strategic focus on maximizing the energy rebate program, Anguil was able to secure the project and increase the customer’s total project rebate from an initial $37,500 to $300,000 – that’s an additional $262,500 savings!
- The utility company determined to pay approximately half of the incentive for the program year 2020 and the balance in 2021 to better accommodate their savings goal and this also removed the payout cap so that the customer received the full amount through both program years.
- Since this was the customer’s first experience with emission control equipment, Anguil provided 10 days of start-up assistance and staff classroom training to ensure familiarity with their new state-of-the-art pollution control system.
Anguil has built upwards of 60 emission concentrator installations in the past five years and is well-regarded as an industry leader with this technology. Anguil’s extensive experience with emission concentrators and successful advocacy for a significant custom energy savings program gave the customer confidence in their selection for the project. In addition, Anguil’s similarity to the customer’s Midwestern, family-run business assured that they would be taken care of and would enjoy accessible communication and project transparency.
For any production facility, up-time is paramount. Machines churning and grinding equals profit, and the sound of silence is typically less desirable. For processes that generate dangerous Volatile Organic Compounds (VOCs) and Hazardous Air Pollutants (HAPs), uptime can be limited by both control of the emissions and safety considerations for your employees.
A tape manufacturer faced such a problem. They required emission control of solvent VOCs from their tape making process. They also wanted to provide a Permanent Total Enclosure (PTE) around their equipment to protect the health and safety of their facility, their employees and maintain a nuisance, odor-free environment.
As experts in the tape industry, they rightly reached out to a small, local engineering firm to design the PTE and size the VOC abatement device. Further, sensitive to their business needs, they approved the lowest cost solution using minimal ductwork and the purchase of a used oxidizer.
However, the decision to entrust their production uptime, worker safety and EPA compliance to an inexperienced consultant
resulted in undersized and malfunctioning equipment, which proved to be disastrous. It is never a best practice to let cost
be the only driver when selecting a technology which may impact production.
A Costly Low-Cost Decision
After having the PTE constructed and the used thermal oxidizer installed, the manufacturer ramped up production and rapidly became aware that the system was not working as sold. The number of air exchanges in the room was inadequate, requiring the employees to labor in gas masks. Moreover, though the used thermal oxidizer suffered from frequent shutdowns, the manufacturer would not support the equipment. More importantly, even when operating, the air pollution control (APC) device could not meet the Destruction Removal Efficiency (DRE) permit requirements, resulting in intermittent production uptime and ultimately a total facility shutdown coupled with the largest non-compliance fine ever levied by the state.
A Need For Trusted Expertise
To resolve the situation, the manufacturer brought a more established and experienced consulting firm on board, who immediately realized the capture and abatement system was woefully undersized. The Engineering, Procurement, and Construction (EPC) firm, after putting together new design specifications, reached out to Anguil to assess the abatement device. Anguil visited the site, spoke with the manufacturer concerning their project needs and determined that a Model 50 Regenerative Thermal Oxidizer (RTO) was the ideal solution.
In addition, in the interim prior to the new equipment install, Anguil was asked to try and get the used thermal oxidizer operational. However, it was found the fuel train did not contain the proper valves to control the burner. A plastic bottle cap had been installed in one pressure regulator in an effort to provide enough supplemental fuel. In addition, the wiring for the process damper had never been completed, rendering it inoperable. This last situation is a significant and potentially explosive safety concern.
Despite these challenges, Anguil was able to get the used competitor’s unit operating safely and sufficiently to meet most of their current tape orders. However, the manufacturer had to temporarily relocate production to their overseas facility to meet domestic demand during reconstruction of the PTE, ductwork and installation of the new
Anguil RTO, causing significant business implications including temporary assignment of domestic personnel overseas, increased shipping costs, uncertain lead times as well as all the headaches and hassles coming with coordination of the effort.
In order to meet the deadline established by the regulatory body to bring the facility back into compliance, Anguil was able to adjust their manufacturing schedule to complete the RTO with sufficient time to perform a full shop test prior to shipping. The unit was shipped, installed and brought up to temperature in a few hours during fresh air commissioning. As soon as process air was sent to the RTO, the Anguil unit met DRE expectations from day one, allowing the facility to ramp up production and provide the desired level of worker safety. Further, because the oxidizer was properly sized (with room for expansion), the manufacturer was able to keep production within normal operating hours and eliminate overtime costs.
If you have a critical production process where every minute of downtime costs you money, don’t use cost as the only decision making criteria. Rather, select a system which meets your production needs, has demonstrated reliability and long-term support from the supplier. If you value uptime, call Anguil today for your VOC and HAP emissions control needs. Sleep well at night knowing that your Anguil air pollution control device will keep you up and running.
As individuals and corporations continue to push towards smaller carbon footprints, the use of Lithium-Ion Batteries (LIB) has become increasingly prevalent. Specifically for individuals, the utilization of battery packs for all-electric automobiles and solar-powered home battery banks have continued to grow at a rapid rate. The manufacturing of these battery packs generates several air pollutants that must be treated prior to being released to atmosphere.
One large supplier of LIBs faced a unique set of challenges at their main production facility.
- Three identical abatement systems were required, capable of handling up to 35,000 SCFM of emission laden air each. Electrically heated air pollution control systems are typically much smaller.
- Fossil fuels (natural gas, propane, fuel oil, diesel, etc.) of any kind are not allowed in the factory.
- Process gases consist of both ambient and hot air streams, both with very low concentrations.
- All abatement systems were to be installed indoors on the third floor of the factory with very tight footprint and height constraints.
Manufacturing of complete LIBs requires several different processes and operations that produce Volatile Organic Compounds (VOCs) and Hazardous Air Pollutants (HAPs) at varying temperatures. For instance, making battery electrodes uses N-Methyl Pyrrolidone (NMP) which is a solvent the manufacturer can recover and reuse without treatment in a pollution control device. However, this supplier had additional module manufacturing lines and multiple e-coat paint lines with curing ovens where solvent recovery was not an option. This further complicated the compliance solution.
Anguil was tasked with developing a compliance solution to capture and treat 70,000 SCFM of emission laden air with the following requirements:
- Achieve a minimum 90% overall air pollutant reduction
- Any heating requirements must be achieved without the use of any fossil fuel
- Provide an n+1 arrangement for system redundancy during maintenance
- Minimize all utility consumption to the greatest extent possible
- Reduce overall system footprint, height, and weight to fit within facility restraints
Anguil is one of the few industrial air pollution control providers that offers a full line of thermal and catalytic oxidizer technologies that also includes emission concentrators. The diverse technology offering allowed Anguil to evaluate each option and its applicability for the demanding project objectives.
The first decision was to route all ambient process air sources to a zeolite concentrator wheel. The wheel uses a zeolite substrate to adsorb the VOCs and HAPs out of the process gases and onto the concentrator surface. A heated stream, approximately 10% the original volume, is used to desorb the pollutants from the wheel. The result is a highly concentrated stream that is one-tenth the original volume. This significantly reduces the size, capital and operating costs of the downstream oxidizers that are paired with the concentrator wheel.
Anguil engineers made the decision to utilize Regenerative Catalytic Oxidizers (RCO) with electric heating elements to treat both the hot process stream from their curing ovens and the concentrated air stream from the concentrator wheel. This technology combination is often referred to as an RCTO. Employing catalyst inside a thermal oxidizer allows emission destruction to occur at much lower temperatures; 600-800°F (315-427°C) versus 1,400-1,500 °F (760-816°C). The lower operating temperature also provides for a much more reliable and smaller (physical size and KW rating) electric heating element. The RCO uses ceramic blocks as the heat transfer media allowing for 97% Thermal Energy Recovery (TER) from combustion. The combination of lower operating temperature and 97% TER made the RCO the best choice for minimizing utility consumption and ensuring low maintenance operation.
All three oxidizer systems and the concentrator wheel were to be installed inside on the 3rd floor of a building still under construction under an existing mezzanine that provided only 15’ of overhead clearance. Anguil designed all individual pieces so they could be lifted three stories using an external elevator and fit through a narrow overhead door. All three units were installed inline and connected via common inlet and outlet manifolds to reduce installation costs.
Once installation was complete, Anguil’s start-up technicians arrived onsite to complete final commissioning. Anguil’s technicians conducted operator training consisting of both “on skid” and classroom sessions. Test data has shown each of the systems is achieving greater than 90% overall emission removal and 97% TER.
- Anguil was able to listen to the customer’s needs and the unique requirements of an oxidizer system that can process up to 70,000 SCFM of VOC-laden air without the use of fossil fuels.
- The zeolite concentrator wheel was applied to the ambient temperature sources, greatly reducing the size of the downstream oxidizers and the associated utility requirements.
- Selecting an electrically heated RCO eliminates the need for a fossil fuel fired burner, a customer requirement. The use of catalyst allows the oxidizer to operate at a much lower temperature than a thermal oxidizer, minimizing the size of the electric heating element. The RCO was also designed with 97% TER, further reducing the utility requirements and the size of the heating element.
- The hot source from the cure oven was sent directly to the RCO inlet, having no negative impact on the operation and efficiency of the concentrator wheel.
- Supplying three identical systems each sized to process 35,000 SCFM allows the customer to process up to 70,000 SCFM of VOC-laden air while operating in the required n+1 arrangement.
- Each system was designed to minimize the footprint and height to the greatest extent possible, saving on valuable floor space inside the facility.
- The system efficiency and effectiveness have exceeded the design specifications.
Our planet is getting warmer. At what rate it is occurring or how much human activity has to do with the increasing temperatures is a heated debate. One thing we do know for sure is that Carbon Dioxide (CO2) is a contributing factor in global warming and humans are responsible for a large portion of these emissions. These days, many individuals and businesses alike are trying to reduce their environmental impact and GHG (Green House Gas) emissions. What the average person does not realize is that they have two types of footprints, a primary and secondary. The primary footprint is a measure of our direct emissions of CO2 from the burning of fossil fuels including domestic energy consumption and transportation, e.g. car and plane. The secondary footprint is a measure of indirect CO2 emissions from the whole lifecycle of products we use, those associated with their manufacturing and eventual breakdown. To put it simply: the more we buy, the more emissions will be caused on our behalf.
Thankfully companies like Corus, a subsidiary of Tata Steel, are doing their part to reduce the world’s secondary footprint by improving the energy efficiency of their manufacturing processes. Corus is Europe’s second largest steel producer and comprises three operating divisions: Strip Products, Long Products, and Distribution and Building Systems. Corus Colors as part of the Strip Products Division is an international business manufacturing pre-finished steel for the building envelope, domestic appliances and manufactured goods markets.
Corus Colors Shotton Works, located at Deeside, North Wales, produces organic paint coated prefinished steel principally for cladding, composite walling and roofing applications within the building and construction sector both in the UK and overseas. There are two manufacturing processes at Shotton Works for coating steel strips with paint. They use a series of driven roller coaters and industrial curing ovens, controlled within a continuous process line, that are capable of applying protective and decorative high quality finishes to the galvanized flat steel strip substrate. The No1 Colorcoat Line process is capable of coating strip widths up to 1400mm with a thickness up to 1.6mm, giving a weekly throughput capability of up to 4000 tonnes subject to product type and dimensions.
This manufacturing process requires large amounts of natural gas to ensure proper application and fast curing time in the ovens, which, in turn generates a substantial amount of CO2 and NOX (Nitrous Oxides). In addition to these emissions, the solvent-based coatings release HAPs (Hazardous Air Pollutants) and VOCs (Volatile Organic Compounds) during the drying process that need to be treated by an air pollution control device such as an oxidiser. New oxidiser systems are capable of destroying over 99% of the HAPs and VOCs through the process of high temperature destruction with very little fuel consumption. However older technologies can be a source of CO2 and NOX as well as the requirement for high maintenance and large operating expenditures.
Pollution control initiatives are nothing new to Corus, the company has been monitoring and controlling their oven emissions at the Shotton Works, North Wales facility, since the 1970’s. Their first oxidiser/incinerator was installed on the paint coating processes for abating exhaust gases and solvents. Even then, the company was thinking green by utilizing waste heat from these older oxidisers/incinerators to preheat the ovens and to supply their manufacturing facility with additional process steam. However, as environmental regulations tightened, energy prices increased and new technologies emerged, the company decided to re-evaluate their entire system as part of their manufacturing efficiency improvements as well as the wider Corporate Responsibility Program for energy usage reduction. The objective was to reduce the gas consumption by at least 45% and increase processing speeds on certain products but they quickly realised another benefit to their sustainable energy plans…a much smaller carbon footprint.
Looking for a sustainable energy solution, they turned to Spooner Industries in the United Kingdom who have worked closely with Corus on a number of projects over the past 30 years. Oven technology and safety regulations had changed dramatically since the line was first installed, but Spooner was able to successfully complete several upgrades that brought the system up to current standards and increased its flexibility.
- Each zone was retrofitted with a special low NOX burner to reduce emissions.
- Variable frequency drives or inverters on every oven fan were incorporated into the control system to make each section more efficient and reduce electrical consumption.
- The ductwork was changed to bring hot air into the system quickly, reducing maintenance issues.
- New thermocouples (temperature measurement), pressure transmitters, pressure switches and flow measurement systems were installed in the ovens to bring the equipment up to today’s technology standards, allowing for remote monitoring and fine-tuning.
- A new computer controlled system was integrated with the SCADA (System Control and Data Acquisition) program. The proper PLC (Programmable Logic Controller) allows the central Corus system to communicate with the ovens so they can be set up for different production runs, eliminating errors and decreasing setup time.
The oven alterations brought this production line from the least efficient in the Corus group to the most, meeting one of the two objectives for the company. While some of these improvements reduced the company’s environmental footprint and gas consumption, the increased throughput would further complicate their environmental responsibilities. Two existing, inefficient oxidisers for the Prime and Finish Ovens were being used to control VOC and HAP emissions at the North Wales facility. To achieve proper destruction the systems required large amounts of natural gas which affected operating expenses and contributed to CO2 and NOX emissions. Furthermore, breakdowns and maintenance problems were not only costing the company money to repair but also revenue in lost production. Because the oven and oxidiser are so vital to each other, Corus wanted a solution provider with experience and knowledge on both. In addition, they were looking for a system with low operating costs and heat recovery capabilities that could achieve 99.5% DRE (Destruction Removal Efficiency) which was well above their permit requirements.
Spooner, having recently partnered with Anguil Environmental Systems in The United States to fabricate and install their oxidiser designs on applications throughout Europe, was confident that it could be done. After consulting with the engineers at both Spooner Industries and Anguil Environmental Systems, Corus made the decision to replace their multiple air pollution control systems with one, RTO (Regenerative Thermal Oxidiser) from Spooner Anguil. It would give them the desired efficiency and single-source solution they were looking for. The system has the following features and benefits:
- The oxidiser is a 3-chamber design that processes 83,000 Nm3/hr (55,000 SCFM) of air, achieving 99%+ DRE without visible emissions and 85%+ heat recovery for energy-efficient operation.
- The RTO self-sustains at low solvent-loading conditions, meaning that once the oxidiser is at operating temperature and receiving process airflow it requires no additional fuel for emission destruction, releasing very little CO2 and NOX.
- A secondary heat exchanger sends waste heat directly back to the ovens, reducing the amount of natural gas required for product curing.
- Stainless-steel components throughout the system prevent corrosion and allow for high temperature process streams.
- A hot-gas bypass on the RTO is used during high loading situations to avoid overheating the oxidiser.
- An intelligent bake-out feature cleans the RTO of condensable organics without internal fires or safety concerns.
- The control panel has a large operator screen with a built-in maintenance manual and troubleshooting guide which makes for ease of use.
- Corus has made a significant investment for the new equipment, upgrades and implementation of this energy reduction project. It has dropped their cost, per ton of steel produced, considerably and they estimate the payback will be less than one year.
The reduction in carbon emissions and energy consumption from this facility is dramatic. Their gas usage has dropped by more than 60%, an average reduction of 522 m³/hr (or 5742 kW) per hour – saving over £1million a year. At 181 grams of CO2 produced per KWH used, Corus is preventing 1 tonne of carbon from reaching our atmosphere each hour, nearly 8,000 tonnes per year.
With innovation and continuous improvement at the heart of its business, the company is already planning for similar modifications at other Corus plants. A spokesperson from Corus commented: “We are committed to minimizing the environmental impact of our operations and our products through the adoption of sustainable practices and continuous improvement in environmental performance.”
The worldwide energy sector has accelerated the development of its unconventional oil and gas resources through increased use of horizontal drilling and hydraulic fracturing practices. Water is an essential element in the fracturing process and the recycling or reuse of spent water can dramatically reduce costs. The volume of water required to fracture a well varies, but it generally ranges from one million gallons to five million gallons. Operators face difficult challenges securing water sources for their operations, especially already dry regions. Furthermore, the management of waste water associated with hydraulic fracturing has an environmental impact and associated cost.
The development of technology to recycle and reuse this water is now becoming critical and Anguil has integrated solutions to help. We have developed an effective water recycling system that allows well operators to safely reuse water without jeopardizing well output.
WATER RECYCLE AND REUSE
Water generated during drilling, well completion, and production is categorized either as flowback or produced water. Flowback water is the initial fluid produced after hydraulic fracturing and is typically recovered during the first six weeks of well production. The flowback water characteristics stem from the initial source water, the natural formation brine, fracturing fluid additives, proppants, and drilling fluids. Generally, 20-40% of the fracturing fluid volume is recovered as flowback. Produced water is the water which naturally exists within shale formation and is recovered concurrently with oil and gas. After the initial flowback period, produced water resembles the characteristics of the formation brine. The volume recovery rate of produced water is lower in comparison to the flowback, but occurs over the decades of a well’s lifetime. Currently, the majority of flowback and produced water is disposed of in salt water disposal wells.
Recycling and reuse of flowback and/or produced water reduces fresh water demand and the associated costs of water purchase, transportation, and disposal. In contrast to the usual practice of complete disposal, a portion of the flowback is treated for reuse either onsite or at an adjacent well. The primary economic benefit from recycling is a significant reduction in the number of truck loads required to ship fresh water to the well site and the flowback water offsite. Environmental benefits include reduced reliance on and competition for fresh water sources, a reduced carbon footprint from trucking, and less stress on the local infrastructure.
Treatment requirements for flowback and produced water are normally established by the company performing the well completion. Knowledge of the fracture fluid employed is required when considering the recycling methodology in order to identify the required treatment characteristics. Two common fracturing fluids are slick water and gels. Slickwater is normally used for natural gas production, whereas gels are often deployed for oil field development.
ANGUIL’S FRAC WATER REUSE SYSTEM
Since there is a wide variation in flowback and produced water quality in oil and gas fields, Anguil Aqua Systems is presently focused on the treatment of flowback and/or produced water from natural gas wells.
Previously, the high levels of Total Dissolved Solids (TDS) in produced water were thought to render it unusable. However, well service companies have demonstrated that moderate TDS levels in recycled water do not impact well production capacity. Hence our solution is to focus on the minimization of Total Suspended Solids (TSS) and, overall reduction of bacteria and other contaminants affecting the fracturing fluid additives.
Of the many approaches to the minimization of TSS, the Anguil solution is a ballasted flocculation system. Similar systems have been successfully employed to treat drinking water as well as municipal and industrial waste waters containing many of the same contaminants found in flowback and produced waters.
The diagram below depicts the flow pattern for the clarification process. In the first tank, the raw water or influent is combined with a coagulant, commonly ferrous sulfate, ferric sulfate, ferric chloride, or alum. The coagulated influent then passes into the flocculation tank where a polymer and a ballast material such as microsand, iron oxides, or chemically enhanced sludge is added. Coagulation and sedimentation times are reduced by the addition of chemical additives and the ballast material. After ballast and polymer additions, the flocculated water then proceeds to the third tank where additional mixing occurs, allowing the floc to coalesce into larger precipitates. The matured, flocculated water proceeds to the clarification tank where the floc is separated from the water by passing through plate or tube settlers. Clarified water then exits from the top of the system.
Settled floc and ballast material are collected and pumped to the ballast recovery unit where the ballast is separated from the waste solids. The waste solids are sent to disposal and the recovered ballast is returned to the first flocculation tank. We can provide treatment systems which help improve injection facilities operations and maintenance, reducing injection pressures and minimizing acid jobs by keeping your wells from fouling. Furthermore, our solutions include treatment options to enhance your oil recovery and treat for hydrogen sulfide control.
As a member of the Gas Processors Suppliers Association, Anguil is heavily invested in industry’s success and future. Countless air pollution control installations at natural gas processing and petroleum refining sites gives us the necessary knowledge to address your water treatment needs safely, effectively and within your demanding production schedules.
- Reuse of Flowback and Produced Water: Physical and chemical treatment system that reduces suspended solids to acceptable reuse standards for hydraulic fracturing.
- Mobile Precipitation: A system easily deployed on site, allowing treatment for multi-well completions, or transport to a nearby well.
- High Contaminant Removal: Total Suspended Solids (TSS), turbidity, oil/grease, color, and bacteria.
- Chemical Coagulation: A wide range of available coagulants and polymers allows customization to site specific needs.
- Automated Chemical Feed System: Treatment begins with proper dosing of chemicals to precipitate dissolved contaminants. The Frac Water Reuse System incorporates chemical metering pumps, day tanks and pH instrumentation to ensure treatment objectives are being achieved.
- Lower Costs: Ballasted clarification allows for smaller equipment footprint, reduced power consumption, and reasonable chemical use. Recovery and reuse of ballast material lowers consumable costs.
- Short Term Lease Agreements: Flexibility to only pay for water recycling system during peak water demand.
- Customized Service and Project Management Contracts: Anguil personnel can be contracted to provide continuous service and/or operation of the entire water recycling system.
Food production has always been a demanding and competitive process. Executives are constantly challenged by slow product development cycles, competition from healthier alternatives and even food fraud. In today’s climate, producers now worry they can be perceived as environmentally and socially irresponsible, resulting in some retail chains refusing to stock their brands until they make often intensive and expensive changes.
Many producers are being hit by a second blow to their profit margins due to failing and overcapacity Publicly Operated Treatment Works (POTWs). Wastewater previously discharged with little care may now be subject to volume and contaminant surcharges as POTWs repair infrastructure and struggle to meet increased EPA discharge regulations.
Finally, treatment system operators with decades of experience are retiring and their tribal knowledge of how to run their antiquated treatment system retires with them. This leaves owners and executives wondering how to replace that knowledge base and ensure they remain in compliance.
In the face of increased regulatory control and rising environmental concerns about wastewater, food producers are looking for cost-effective ways to stay in compliance while keeping operating costs low. Anguil’s four-step approach to industrial wastewater treatment challenges can help producers address economical, operational and compliance challenges.
NAILING DOWN THE REQUIREMENTS
Anguil Environmental provides highly engineered environmental equipment and service solutions that solve complex industrial air and water challenges. When we are aiding companies with water projects, we follow a very simple but effective process to deliver systems tailored to each customer’s specific needs.
The first step is to understand the business case.
We collaborate with the client to understand their challenges, and determine the project needs and objectives. We gather benchmark data to assist with alignment of solutions that offer the best return on investment (ROI), then work with the customer to understand their decision process and criteria to ensure we can check all their boxes. For example, is our customer willing to spend more on controls and automation to minimize operator involvement or to better deploy staff in other areas of the facility?
In this case, a client was looking at TSS surcharge costs of $40,000 per quarter and a surcharge of $20,000 per quarter for acidic discharge waters. The client was essentially looking at $240,000 in increased operating costs per year. BOD did not receive a surcharge, and overall water volume costs were negligible.
The second step is to explore and validate all treatment and operational processes in the Anguil lab.
Anguil validates all potential treatment and process options that align with the customer objectives. A client wanted to determine a solution for TSS removal below discharge requirements. We started by asking the client to send a wastewater sample to our inhouse wet lab to validate potential treatment protocols. We determined pH / polymer protocol resulted in TSS removals well below the discharge requirements. Hence, we determined a simple scheme could meet the customer’s goals.
After bench-testing provided us with a viable treatment option, we generated a simple Process Flow Diagram (PFD) to illustrate the primary equipment integrated into the treatment train. This train included the appropriate equalization and buffer tanks, pump logistics, clarifier, and a filter press for solids handling. In our discussion with the client, we offered additional options including:
- Ballasted flocculation versus straight clarification to lessen the overall footprint
- A rotary vacuum drum for dewatering instead of a filter press to lessen the burden on facility personnel and lower the liquid content (weight) of solids being shipped off site
Even though the customer appreciated the pros of each option, after reviewing the capital cost increase, the client decided to remain with the original approach.
The third step is a pilot system onsite to test waters in-situ:
With the client satisfied with our lab trials, we asked if they required a pilot system to validate the treatment approach insitu. When asked for our opinion on the value added, we stated we were confident with the treatment approach and market proven technologies. In this case a pilot study would not bring a great deal of value.
PUTTING IT ALL TOGETHER
The final step in the process is the Commercial Deployment.
After completion of lab testing, discussion of various equipment options and testing against the business case, Anguil provided a firm proposal for a treatment system which would meet the treatment efficacy and business needs of the customer. The proposal contained detailed nuts and bolts information on the treatment system, estimated operational costs and options for installation, start-up and commissioning. The flexible approach allowed the customer to choose the package that best suited their needs. Anguil provided installation supervision while their local mechanical and electrical partners were contracted directly by the customer to install the equipment. Anguil performed a 3-day start-up and training. Anguil provided final “as-built” drawings within 2-weeks of startup and shipped spare parts the client requested. Additionally, Anguil’s Aftermarket and Service group was proactively in touch, ready to provide long term system and parts support.
Anguil followed a better approach to solving complex water challenges, which started with listening to the client’s needs and business case. Anguil advocated an efficient process that would provide the client with the information they wanted to make an informed decision.
- TSS surcharges had risen 3x what they experienced 3 years prior
- Without reduction, operational costs and compliance could prove negative to business growth and profitability
- The lab trials at Anguil quickly validated the most cost-effective approach to reduce Total Suspended Solids (TSS)
- 5-gallon sample sent to Anguil wet-lab for testing was ideal to determine equipment sizing and validate capital costs of the equipment
- Lab trials allowed Anguil to optimize the chemistry and extrapolate an operational expense for the entire water treatment system
- Anguil leveraged a Process Flow Diagram (PFD) to illustrate the equipment in the primary approach, while also showing options to increase automation, lower resources for solids handling, minimize moisture content in solids, and reduce overall footprint.
- General Arrangement (GA) drawing allowed client to understand process flow
- GA allowed Anguil to offer different options to client, such as Rotary Vacuum Drum vs. Filter Press for solids handling
- Offering options allowed the client to make an informed decision on the system capabilities and system price point based on their decision criteria.
- Anguil Project Manager (PM) led internal Project Launch and engineering completed necessary drawings within two weeks for customer to review and sign-off on.
- PM launched internal kick-off meeting within 48 hours of receipt of PO
- Nine people from nine departments attended to define and own their respective responsibilities
- Anguil provided Installation Supervision over local contractors, who were responsible for installing equipment and handling electrical wiring to panel, equipment and pump skids.
- Anguil provided engineering drawings to local contractors familiar with the client site to bid on mechanical, electrical
and piping/plumbing of system.
- All Anguil skids were self-contained, including all electrical and piping, so connection could come to a j-box or single inlet/outlet on skid
The final treatment system offered an ROI in line with management’s criteria. The system was also designed with additional treatment capacity to handle 30% growth in business and the resulting impact that would have on the treatment system. Although we did not pursue BOD in our treatment approach, we did discuss how we would determine viable treatment technologies to address it.
A packaging company who had traditionally manufactured steel cans decided to diversify by adding aluminum aerosol cans to their product portfolio. Due to the extensive project scope and a significant capital investment in new equipment including air and water pollution control, the packager stipulated that the successful vendor had to single source the entire project. Since the can making equipment manufacturer who ultimately won the project was not an expert in air and water treatment, they in turn searched for a partner with the ability to single source all pollution control aspects. Anguil, a single source air and water treatment system provider, was selected to be that partner.
NAILING DOWN THE REQUIREMENTS
The aluminum can making process requires water to remove oils and post-forming debris as well as chemical surface conditioning of the cans to prep for coating. To accomplish cleaning and conditioning, the cans are passed through a large multi-stage washer, which requires clean, consistent input water. Concurrently, the dirty rinse water needs to be pretreated before it can be discharged to the local Publicly Operated Treatment Works (POTW). Since this was a new line for the equipment manufacturer, Anguil assisted the manufacturer with developing specifications for:
- Input water quality (conductivity < 10 micro Siemens)
- Average input flow (30 GPM)
- Required washer input pressure
- The need for a “fast fill” mode to quickly refill the washer after maintenance activities
- The requirement for maximal equipment up time
With customer input, Anguil selected a dual train Reverse Osmosis (RO) system to meet the washer’s influent requirements.
On the wastewater side, where the exact water chemistry was unknown, Anguil again worked with the can manufacturer to determine an expected range of water contaminants to select candidate treatment technologies which could handle the variable chemistry. Expecting a pH of 2-5, high TSS loading, significant amounts of sulfuric and hydrofluoric acids, oils and greases as well as possible surfactants, Anguil proposed a form of enhanced clarification called Ballasted Flocculation (BF). With a BF system, the pH could be adjusted as needed, fluoride and other metals precipitated, and oils broken out of suspension chemically using caustic addition, coagulants and polymers. With the addition of sand to flocculated species, the settling rate increases dramatically, leading to a smaller overall equipment footprint, important since this wastewater treatment system was to be housed inside the production facility. Extra space was left in the system design to allow the addition of water polishing equipment if after start-up, it was deemed necessary.
Because Anguil is an air and water treatment supplier, Anguil was able to evaluate solutions for both treatment needs, ultimately proposing a solution that did not require air pollution control equipment. Again, this fits into Anguil being a technology agnostic solution provider always on the look-out for the customer’s bottom line.
PUTTING IT ALL TOGETHER
After determining the flow and treatment requirements for the Process Water Conditioning System (PWCS) and the Wastewater Treatment System (WWTS), Anguil proceeded to determine the required logistics equipment and controls to operate both systems in automatic mode with the least operator involvement possible.
For example, inlet water buffer and RO permeate storage tanks were selected to supply some onsite storage, ensuring back-up capacity should the city water supply fail and to provide constant, even flow to the varying washer demands. Non-metallic AODD pumps were selected to lift and convey the high solids content and corrosive waste water to the treatment system. An equalization tank and an emergency dump tank were included to buffer flow through the WWTS while providing emergency capacity if the washer needed to be dumped for maintenance reasons, and to collect additional waste water sources from sludge dewatering and secondary containment floor sumps.
In addition to the mechanical components of both the PWCS and WWTS, Anguil’s control engineers worked to integrate both the larger sub-systems (RO, ballasted floc, Rotary Vacuum Drum) into the treatment plant. More importantly, they also worked directly with the canning equipment manufacturer to seamlessly integrate the disparate washer/water treatment systems to minimize production downtime and product loss in the event of failures with the PWCS, washer system or the WWTS.
GETTING THE SYSTEM UP AND RUNNING
After obtaining customer approval of the system design, Anguil ordered the long lead-time items, namely the tanks and large third-party vendor skids. Once these items were on order, Anguil coordinated the purchase and delivery of all the parts (pumps, valves, instrumentation, etc) to be shipped loose for field installation or to be assembled on Anguil pump skids.
Since the canning equipment manufacturer had already obtained the services of installation contractors, Anguil was not engaged for a turn-key installation. However, based on our installation experience with similar systems, Anguil received, labeled each part with its PID drawing tag number, and then “kitted” all the parts into boxes to aid the installation process. For example, all the instruments, valves and piping fittings associated with a given storage tank or sub-assembly were placed in their own box. Kitting parts in this way acted as a quality control step, ensuring the correct parts and amounts were delivered, and greatly assisted the install crew as they knew exactly where and how many parts to install on each tank.
Even though Anguil was not asked to perform installation work, Anguil was hired to provide an install supervisor to interface with contractors, provide guidance where necessary, troubleshoot issues, expedite defective part replacement, communicate the project schedule and handle changing project requirements. One direct benefit of Anguil’s install supervision was the ability to respond rapidly to changing site conditions and requirements. For example, prior to processing cans, the washer system required a “passivation” step consisting of treating the washer interior with caustic and acidic waters. This requirement was not originally intended to be included in Anguil’s scope in any way. However, to assist the customer, Anguil reorganized the installation effort to enable the RO system to be run in manual mode to feed the washer and the wastewater treatment system to be run in manual mode to allow discharge and pH neutralization of the passivation water.
Special site supervision and controls workarounds were required since the equipment had not been fully commissioned and installed at the time passivation was to occur. However, Anguil’s ability to accommodate the project needs saved the customer $100,000s in disposal and transport costs of the passivation water. After can making equipment was brought online, Anguil brought in their commissioning crew to ensure that the control program was operating correctly – especially with communications between the PWCS, WWTS and washer system. This included confirming that chemical protocol was validated and optimized and ensuring that any issues discovered during the initial start-up and shake-down were addressed quickly and efficiently. Ultimately, after training the site personnel on the system operation, troubleshooting of general issues and becoming familiar with system operation, both the PWCS and WWTS were able to support the washer’s input and waste water needs with minimal operator involvement and get the packager back to what they do best—making cans.
- Anguil was able to walk the customer through a collaborative treatment technology selection process resulting in systems (waste and process) that the customer was comfortable with and had high confidence would meet the desired treatment efficacy.
- Anguil’s approach of sticking to our core competency of engineering and integration led to the selection of technologies and vendors which resulted in a successful water treatment system.
- Anguil’s single source approach enabled streamlined communication when problems arouse. Instead of the customer calling multiple vendors, trying to figure out who owned the problem, they would call Anguil and Anguil led the charge as necessary. One call did it all.
- Anguil’s ability to provide both air and water treatment solutions allowed our engineering experts to explore all possible solutions and design the best fit treatment train — which ultimately removed the need for air pollution control—and lowered the total cost of ownership of the treatment system.
- Even though the customer had already contracted with installation contractors for this project, Anguil’s experience with turn-key installations made it apparent that the logistics of kitting equipment was necessary to ensure project success—all conducted within the original contract price.
- Because of the amount of pre-work done scoping the customer’s needs for both the PWCS and WWTS, no change orders were issued to complete the work—except for those items requested by the customer at a later date.
- Anguil’s customer-focused philosophy enabled us to maintain a flexible schedule to accommodate rapidly changing site demands without significant added costs to the customer.
Anguil Environmental Systems was asked to supply an oxidizer and packed tower air stripper to treat a 65 gallon per minute water stream containing significant concentrations of Diesel Range Organics (DRO), Volatile Organic Compounds (VOCs) and Total Suspended Solids (TSS). The customer was sending the wastewater stream through a cooling tower which was continually fouling from the DRO present in the water. Significant maintenance costs and production downtime were incurred every time the tower was being brought out of service for cleaning. In addition, the customer was trying to achieve zero VOC emissions from their facility.
Application engineers at Anguil determined that a Regenerative Thermal Oxidizer (RTO) would meet the customer’s needs but were skeptical that the air stripper would function properly given the customer supplied water characteristics. Anguil was engaged to evaluate the water stream for the air stripping application. Review of the supplied water analysis indicated that concentrations of the heavier Diesel Range Organics (naphthalene and higher) were beyond their solubility limits. Hence, the presence of free product in this water stream would quickly cause any air stripper to foul, detrimentally impacting stripping performance and potentially creating a safety hazard. Anguil recommended that the customer evaluate oil/water separation and emulsion breaking to remove and potentially recover the free product prior to entering the air stripper.
Using water samples obtained from the customer, an initial bench evaluation of oil/water separation was conducted. Upon receiving the samples, Anguil realized that either the customer-supplied water analysis was incorrect or that the water samples received were not representative of the customer’s process water since the presence of free product was not observed. The emulsion breaking tests were performed anyway, predictably meeting with little success. In addition to the emulsion breaking tests, Anguil attempted to coagulate the water to determine if this approach would be suitable, determining this method had merit.
Based on results from the initial separation study, Anguil recommended two courses of action. First, the customer would redo their analytical water analysis using suggested test methods to improve confidence in the treatment design requirements. Based on the results of the second round of analytical tests, Anguil suggested that a two stage pilot study be conducted. For Stage 1, Anguil representatives would perform treatability studies on site via jar testing. Based on the results obtained from Stage 1, Anguil engineers would perform a full scale, onsite pilot with the appropriate equipment for Stage 2.
Stage 1: Anguil representatives traveled to the site and performed jar tests directly with the process water in question. Since the process water was at a temperature of 110-120 oF, it was advantageous to work with the process directly rather than trying to ship samples off site possibly compromising their integrity from cooling, biological action or chemical reactions from long hold times. After a number of trials, they successfully determined that the water could be coagulated by raising the pH from 4 to 8.5, utilizing a poly aluminum chloride (PAC) based coagulant blend and a standard polymer. After coagulation and filtration, color, turbidity and solids content were reduced. Anguil then sent the untreated and treated water for third part lab analysis to determine the overall effectiveness of the process. The results were promising and the customer elected to move forward with Stage 2 of the pilot study.
Stage 2: Based on the site constraints and treatment goals, Anguil modified its pilot clarification system to perform the second stage of the study. Equipment arrived onsite,was unloaded and placed within the facility. A generator was rented since the facility could not easily supply the required power. Anguil then proceeded to unpack and plumb the pilot system into the existing process piping.
Once everything was set-up, pumps primed and running, the operator filled the tank with process water and began processing using the chemical formula determined in Stage 1: Raise pH > 8.5 using 50% caustic solution, add 300 ppm coagulant, add 1 ppm polymer. As expected, the clarifier influent demonstrated a good floc which quickly began to settle to the bottom of the clarification tank. With continued processing, clarity improvements in the clarification tank became noticeable as submerged parts of the tank became visible as the initial dirty water was displaced by the coagulated and clarified water. Water samples pulled from the clarifier effluent were obviously cleaner than the raw process water, and with continued processing acceptable clarity was achieved.
After successfully demonstrating the clarification process, treated samples were pulled and tested using the same test protocol used in Stage 1. In addition, a sludge sample was sent for benzene analysis in order to determine if the sludge would be considered hazardous. Sludge production rates were quantified by coagulating, flocculating and filtering specific volumes of process water. Filtered samples were wrung dry and air dried for several days. Wet and dried samples were weighed.
The qualitative and quantitative results met the customer’s expectations and treatment goals. The chemical coagulation protocol and clarifier in this pilot work were able achieve a DRO reduction of 85% or greater and an 80% reduction in TSS. Since Anguil was proposing a ballasted floc system for the final treatment system to handle the design flow rate of 65 GPM, another set of samples was taken for ballasted floc testing which achieved similar DRO removal rates but improved on the TSS reduction to less than 1 NTU. After reviewing the sludge production rates and potential hazardous classification for the sludge, the customer asked Anguil to recommend a sludge dewatering system. Further, after reviewing the treatment system capabilities and facility requirements, Anguil recommended removing the air stripper and oxidizer from the scope of supply as it was determined that removing the heaviest organics would solve the facilities heat exchanger fouling problems, and the limited VOC loading did not justify the use of an oxidizer.
Anguil was able to guide the customer through the equipment design and selection process by identifying and rectifying shortcomings in the analytical data, avoiding time and cost specifying and designing equipment which would not address the customer’s project goals. Ultimately, the main benefit of Anguil was determining a solution which did meet the customer’s objectives despite the fact that the selected solution differed greatly from the original request. Onsite jar and pilot tests allowed the customer to become educated and familiar with the treatment process while understanding the benefits, capabilities and trade-offs of the proposed system. Further, being on site allowed Anguil to really understand the customer’s needs and process, allowing them to identify customer process variables which could potentially affect treatment system performance and provide seamless integration of the new treatment system into the existing process.