Refinery Wastewater Treatment – Innovative Benzene Removal Solution

Refinery Wastewater Treatment – Innovative Benzene Removal Solution

Portfolio Categories: Case Studies, GHG Emission Control, Mobile Water Treatment, Vapor Control, and Vapor Scrubbing.

Challenge

A renowned US refinery faced a critical challenge regarding the removal of Benzene from wastewater. The wastewater contained several other constituents of lesser concern, posing a significant environmental and operational hurdle for the refinery.

Solution

Envent rose to the challenge and devised an ingenious solution to address the Benzene removal issue. The team designed, constructed, implemented, and operated a cutting-edge Nitrogen stripping tower system. This specialized system efficiently eliminated 93% of Benzene from the wastewater while allowing the other constituents to pass through unaffected. By integrating this solution, Envent ensured a seamless flow of Benzene-stripped wastewater back into the refinery system, continuing its journey towards the wastewater treatment plant. Moreover, the Nitrogen-stripped Benzene vapors were skillfully directed to a state-of-the-art Thermal Oxidizer, where they were destroyed with an impressive efficiency of 99.9%.

Benefit

The implemented system showcased remarkable advantages, revolutionizing the refinery’s wastewater treatment process. Notably, the system operated flawlessly, eliminating the need to open the towers for media replacement, debris clearing, or any internal servicing. This feature significantly enhanced the system’s reliability and minimized downtime, resulting in improved overall operational efficiency. Furthermore, the solution enabled the customer to conduct extensive parameter testing, fine-tuning the system for optimal performance. As a direct consequence, the  refinery successfully achieved a substantial reduction in Benzene emissions throughout its operations. This notable environmental benefit underscored Envent’s commitment to sustainability and responsible waste management practices.

By implementing this innovative wastewater treatment solution, Envent not only addressed the refinery’s immediate challenge of removing Benzene effectively but also showcased our expertise in designing and deploying advanced environmental technologies. Envent’s success in this project solidified our position as a trusted industry leader in providing tailored and sustainable solutions for complex environmental problems.

Flare Gas Scrubber System & Compliance

Portfolio Categories: Case Studies and Vapor Scrubbing.

Challenge

An Envent customer needed to perform maintenance on their distillation unit, SATS unit, and flare. For this project, the customer rented a temporary flare to combust VOCs while their main flare unit was serviced. The customer came to Envent requesting sour gas scrubbing. H2S levels up to 15,000 ppm were to be expected in their flare gas. Customer also requested that the H2S concentration be neutralized to remain in compliance with the EPA. In order to stay in compliance, H2S concentrations could not exceed 160 ppm at their temporary flare.

Solution

Envent proposed a customized scrubber system to neutralize the sour gas so that the customer could be in compliance with the EPA. Envent mobilized multiple pieces of equipment including three ESCRUB-2000s, three high pressure knockout pots, and two frac tanks. The three scrubbers and knockout pots were connected directly to the customer’s flare header in parallel in order to handle the highest flows and concentrations that were provided. The scrubber system was manned 24/7 by a team of two technicians and one crew lead to ensure operation and caustic change-outs were performed safely and efficiently.

Benefit

Envent provided an efficient setup which neutralized the H2S concentrations in the customer’s sour gas. The scrubber system was manned 24/7 to ensure equipment was fully functional and to keep the customer in compliance. Envent’s customer was satisfied with the professionalism and safe work practices when handling hazardous chemicals.

Hydrotreater Turnaround Vapor Control

Portfolio Categories: Case Studies, GHG Emission Control, Turnaround Services, Vapor Control, and Vapor Scrubbing.

Challenge

The customer needed to clear their hydrotreater of volatile vapors and product in order to allow manned entry for maintenance activities. During this process, there would be limited availability to use the flare or FGRU to purge vapors from the unit. Additionally, there were high concentrations of hydrogen gas and H2S that needed to be managed to make entry safe. Ultimately, the customer needed a supplemental system that could receive, scrub, and process excess unit vapors to maintain their project timeline.

Solution

Envent provided (2) EMECS thermal oxidizer units to combust process vapors at a 99.9% destruction rate efficiency. Additionally, Envent’s system included (4) ESCRUB recirculating scrubbers that neutralized H2S in the streams, (2) heat exchangers to cool and condense vapors, and a collection system to move condensates back to a designated containment. Lastly, additional safety measures were implemented on the thermal oxidizer to allow for safe combustion of up to 100% hydrogen streams.

Benefit

Envent’s system aided the customer by providing an additional avenue to process unit vapors, thereby allowing the customer to purge their system more quickly. The recirculating scrubbers were able to neutralize all H2S vapors in the vapor stream, eliminating any chance of hazardous SOx emissions from being formed. Additionally, the high thermal capacity of each EMECS allowed Envent to process heavily hydrocarbon-ladened vapors without compromising on flow rates. Nitrogen purge capacity was also increased due to Envent’s presence by providing the customer’s FGRU with additional capacity to manage an inert stream. Overall, the system provided by Envent reduced the customer expected turnaround timeline by ~2 days, thereby saving the end user several million dollars!

Envent’s solution to landfills logistical and regulatory challenges

Portfolio Categories: Case Studies, GHG Emission Control, Odor Control, Soil Vapor Extraction & Mitigation Systems, and Vapor Control.

Challenge

The challenge of this project is to provide supplemental soil vapor extraction (SVE) and vapor control to the plants existing vapor recovery system. Additional soil vapor extraction wells were installed on the periphery of the plant due to the expansion of the landfill. The plants SVE blowers are unable to provide sufficient vacuum and the flares lacked the thermal capacity to maintain regulatory compliance. Envent was tasked with designing and implementing a system that could maintain a vacuum of 50 inches of water column on the new SVE header and provide vapor destruction of the extracted Methane gas. SVE and processing of landfill gas has inherent problems; the extracted vapor is entrained with moisture, solids and is highly combustible. An Engineered solution is necessary to separate the moisture and solids while maintaining an inert process stream to allow safe processing.

Solution

Envent Engineered the following system to solve these challenges. The system includes a SVE blower capable of maintaining a vacuum of 60 INWC and a 2500 CFM flow rate. The blower is equipped with a spark resistant housing and fan blade with an explosion proof electrical panel. An EMECS 70 was selected as the vapor destruction unit due to its large thermal capacity of 70 MMBTU/HR, as well as its advanced safety features. The EMECS 70 is a direct fired thermal oxidizer with no addition of dilution air which is well suited for the pressurized and inert process stream coming from the SVE blower. The challenge of moisture and solids entrained in the gas was solved by adding inline liquid knock out pots as well as solid separating filters. An automatic liquid drain system was also installed that allow the liquids to be pumped out of the KO pots and filters without the need to shut down the process system. Envent has operators onsite 24/7, to ensure the equipment is operating at peak performance and to log all compliance data to meet and exceed all regulatory standards.

Benefit

Envent’s solution to this logistical and regulatory challenge provided immense benefit to the landfill by allowing the facility to maintain environmental compliance and continue operating at full capacity. The system enabled the plant to avoid all environmental violations and maintains a safe working environment for its employees and the public.

 

Mobile Multi/Dual Phase Extraction Pilot Test

Portfolio Categories: All, Case Studies, GHG Emission Control, Soil Vapor Extraction & Mitigation Systems, and Vapor Control.

Challenge

There was a large plume of MTBE below grade near a waterway strait. Envent had been collecting ground water and treating it from this site for approximately 10 years but due to multiple years of drought ground water was no longer mobilizing large concentrations of MTBE for removal.

Solution

Envent was asked to provide a multi-phase or dual phase extraction system to target the heart of the plum since we were already onsite providing groundwater treatment services. We brought is a full vacuum DVT blower with a 300 gallons KO pot, automatic pump on level control, and a thermal oxidizer for destruction of the vapor phase MTBE/GRO gases.

Benefit

We were able to target the heart of the plum with soil vapor extraction, while still managing the water that came from the extraction wells. It was a great way to keep the clean up/remediation efforts moving forward when the amount of groundwater slowed down due to draught.

Duct Removal NOx Vapor Control – Richmond, CA

Portfolio Categories: Case Studies, GHG Emission Control, Vapor Control, and Vapor Scrubbing.

Challenge

A customer removed 50′ of 60″ ducting which contained NOx. The facility is located next to a major highway and bridge in the California Bay Area. Envent provided vapor control on the NOx so it did not produce a toxic orange cloud over the heavily populated area while the customer was removing the ducting.

Solution

Envent connected a 2,000 cfm blower to the 8″ flange connection on top of the ducting provided by the facility. 8″ connections were provided at multiple locations. Envent provided (3) re-circulation liquid scrubbers, ESCRUB 6000’s, in order to mitigate the NOx in the vapor stream. The first ESCRUB’s were filled with a sulfamic acid solution. The second was filled with a caustic solution. And the third was provided as a back-up unit on standby to be used if need with the sulfamic acid for NOx. Lastly, the cut pieces of ducting were forklifted to a hooch for storage while they were cleaned and prepared for disposal. Envent connected to the hooch via a fitting provided by our customer to scrub vapors while the ducting was cleaned.

Benefit

The facility remained in compliance with the BAAQMD due to Envent’s engineered solutions safely removing the NOx from the ducting. The heavily populated area remained safe while the ducting was removed, cleaned and disposed.

 

 

Gulf Coast Refinery Changing Focus

Portfolio Categories: Case Studies, GHG Emission Control, Marine Vapor Recovery, and Vapor Control.

Challenge

A gulf coast refinery was recently the target of a large hurricane: a storm that caused them significant damages. It was at this point, the refinery decided to change their model from a refinery into a storage terminal facility. During this process, the facility found value in selling their current product via marine vessels. When loading vessels with certain hydrocarbon products, the US Coast Guard mandates the use of a Dock Safety Unit (DSU) or MVR (Marine Vapor Recovery) system as an added safety feature to prevent the possibility of a flame. Unfortunately, however, the facility’s MVR had been destroyed in the storm.

Solution

The facility reached out to Envent with their problem, and Envent responded with a BACT (Best Available Control Technology) solution. Envent maintains and operates their own MVR; the EDSU. The Envent Dock Safety Unit (EDSU) is a portable equivalent to many facilities’ permanent MVR installations. This, paired with Envent’s EMECS style thermal oxidizer, saved the facility from having no means to transport this product from their facility via marine vessels.

Benefit

The facility benefited from utilizing Envent’s mobile equipment at time they needed it most. The facility was able to quickly move product without spending a significant amount of resources (time and money) repairing the fixed MVR system on site. Envent earned a deserved trust with this facility, and this opportunity has led to future growth between Envent and this company, which is one of the country’s largest refining companies.

 

 

Liquid Natural Gas (LNG) Bunkering

Portfolio Categories: Case Studies, GHG Emission Control, Marine Vapor Recovery, and Vapor Control.

Challenge

A customer of ours has two cargo ships that constantly transfer cargo up and down the west coast. These ships are always sailing back or forth with commerce and are on extremely tight schedules. Envent Corporation was challenged with assisting in the commissioning a new LNG fuel system on one of these cargo ships, while minimizing downtime. LNG Bunkering requires cooling in steps with nitrogen to cryogenic temperatures of ≤-156 °C or ≤-250°F in order to prepare the fuel system materials to receive liquid natural gas (LNG) at -260°F. Once the fuel system is cooled, liquid natural gas is introduced, but the system cannot be utilized until all N2 has been removed.

Solution

The customer will set up a liquid nitrogen pumper to cool the fuel system in prep for LNG. Envent Corporation will set up ambient air vaporizers and an EMECS 70 thermal oxidizer to receive N2 and natural gas from the commissioning process, until all N2 has been removed. The cryogenic gases will be transported through ss braided hose from the ships fuel system to our ambient air vaporizers, bringing the gas temperature up above minimum allowable working temperatures. The gas mix will then continue to be safely oxidized by our EMECS 70.

Benefit

Envent Corporation’s engineering, equipment selection, and expertise allows us to take this dangerous cryogenic/explosive fuel from the bunkering process and quickly/safely combust it in a controlled burn. Thus allowing, our customer to safely convert their cargo ship into a clean burning fuel vessel without emitting large volumes of greenhouse gases in the process.

 

 

Envent Vapor Control Assisting with COVID 19 Vaccine

Portfolio Categories: Vapor Scrubbing.

Challenge

Due to the COVID-19 pandemic the Biomedical Advanced Research and Development Authority (BARDA) and contract development and manufacturing organization (CDMO) network were created. Our customer was approved to join and manufacture COVID vaccines and needed to start production quickly. They requested an automated system to control vapors from their process units.

Solution

Envent’s engineers modified a thermal oxidizer to automatically regulate the inlet valve position and record temperature. An alarm cell phone and signal to the control room were also added in case of any shutdowns. Envent’s supervisors and engineers were present for set up, safety meetings, and operator training.

Benefit

Envent’s custom engineered solution allowed our customer to safely manufacture the COVID-19 vaccine. The automation Envent engineered saved the customer hundreds of thousands of dollars in manpower. Additionally, Envent was able to mobilize and be fully operational within ten days.

Envent provides a customized Noise Emission Control System

Portfolio Categories: All, GHG Emission Control, and Vapor Control.

Challenge

A customer in the Midwest needed to reduce noise coming from a natural gas pipeline blowdown. Pipeline blowdown operations can be very loud have the potential to disrupt the immediate area. The gaseous contents of the pipeline are at high pressure and when that pressure is under controlled release, creates an unpleasant rushing sound. ENVENT was called upon to assist with the noise emissions.

Solution

ENVENT engineers developed a portable pipeline silencer and constructed it in-house. This silencer was designed to lower noise emissions while allowing for a quick de-pressure of the pipeline. We also used our pipeline liquid/gas separator upstream of the silencer to capture any condensate or residual product in the pipeline during de-pressure and subsequent pigging.

Benefit

The customer was very pleased with the performance of the silencer, allowing for a faster blowdown with no complaints from the adjacent neighborhood. Moreover, the pipeline liquid/gas separator ensured there was no risk of any liquids touching the ground. ENVENT provided a noise emissions control system that doubled as a spill prevention system.

 

Envent Finds Themselves Inside Another Houston Refinery

Portfolio Categories: Turnaround Services, Vapor Control, and Vapor Scrubbing.

Challenge 

A Houston refinery reaches out to Envent to submit a competitive proposal amongst many other thermal oxidizing companies to assist in the cleaning and degassing an API Seperator. This tank is an underground-rectangular tank with an extrernal-floating roof. This tank has taken years of waste-water products from all over the refinery, which creates a potentially unknown mix of hydrocarbons. The reports state it contains 5-6 feet of Sludge.

Solution

The refinery utilized frac tanks, a pump, a centrifuge, and a manway cannon to complete this cleaning, and Envent provided vapor control every step of the way. A centrifuge separates sludge from water, and delivers the two parts into frac tanks. When filling frac tanks with hydrocarbon liquids, a vapor space is displaced, and vapor control is needed. Envent utilizes their EMTOS thermal oxidizer to receive those vapors. Once the tank was cleaned, Envent Utilized their thermal oxidizer to finish the degas.

Benefit

By utilizing Envent’s thermal oxidizer, the refinery was able to complete the tank cleaning safely, and compliantly. Envent and the refinery kept constant communication throughout the entire process, and built a strong working relationship. This was Envent’s first major project within this refinery, and upon perfect execution, created an everlasting impression with them.

Downtown Soil Vapor Extraction

Portfolio Categories: Soil Vapor Extraction & Mitigation Systems, Vapor Control, and Vapor Scrubbing.

Challenge

Extremely high levels of Methane and over 10,000ppm of H2S in the soil under downtown Los Angeles near the La Brea Tarpits was making the path for a large tunnel boring machine very difficult. To get through the worst sections they knew they were going to need a solution to keep the levels in a safe range to keep the crew and equipment underground safe and avoid costly evacuations and subsequent delays due to hazardous gasses.

Solution

Envent provided equipment over a three-year span ranging from small carbon vessels all the way up to our 42 MMBTU/H EMECS42 Thermal Oxidizer along with three other Smaller thermal oxidizers. All of these are working in parallel with recirculating scrubbers to process the high levels of H2S and destroy the methane.

Benefit

Alternative solutions were estimated to be 4-5 times as costly and had major safety concerns. The Envent solution left almost no long term underground infrastructure and required very little disturbance aboveground besides the traffic control for the work area.

 

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