Liquid Natural Gas (LNG) Bunkering

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 and Remediation 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.

 

Pipeline Hydro Test – Water Treatment – West Coast

Portfolio Categories: Mobile Water Treatment.

Challenge

Envent Corporation was called upon to treat approximately 619,758 gallons of hydro-test water from two newly constructed pipelines on the west coast.  The newly constructed pipelines required hydro-static testing after they were installed to ensure there are no leaks and the pipelines are ready for full scale operation.  The challenge was what to do with all of the water once it has been used for the hydrostatic test?  Off hauling the water in tanker trucks to a treatment facility would be extremely cost prohibitive due to the remote location of the pipeline.

Solution

The solution was to have Envent acquire discharge permits, safely treat the water and discharge it on site.  After the pipeline testing was complete, a pig was ran through the line displacing the water into multiple temporary storage tanks while Envent simultaneously treated/discharged the hydro test water at ~400GPM to safe discharge specifications. The system included chemical injection, pH control, granular activated carbon, pumps, and filters. Envent obtained local discharge permits, created a treatment scheme based off the analytical, provided equipment and the manpower  to operate the onsite treatment system.

Benefit

The client was able to perform the necessary hydro-static testing of both lines with no delay to the project because Envent’s treatment system was designed to treat the water as fast it could be removed from the pipeline.  The water was safely, environmentally and economically treated then discharged to permit conditions. Additionally, the surrounding rural area was not subject to heavy hauling traffic and the treated water was returned to the environment where it came from, meaning no environmental impact.

Cost-effective turnaround for an Olefins Unit completed safely and on-time

Portfolio Categories: Vapor Control.

Challenge

During a turnaround for an Olefins Unit, a customer tasked Envent with providing a vapor control system to process stray hydrocarbon vapors while their normal vapor recovery system was down for maintenance. The customer’s unit superheaters were to be shut down for three months, and without a proper solution in place, the customer would release extraneous VOCs into the atmosphere violating emissions regulations. Therefore, it was important that an effective, low-cost solution would be able to continuously remove VOCs for the full duration of the project.

 

Solution

Envent implemented a two-stage system for this vapor control project. In the first stage, Envent used a scrubbing system that utilized a liquid media and activated carbon to target VOCs. This was designed to strip low concentrations of VOCs from the customer vapor streams. Envent utilized a downstream blower to pull vapor through the scrubbing system. Not only did the blower direct flow to the scrubbers, but it provided a slight vacuum on the customer system to prevent excess gas buildup and pressure release to atmosphere. Two trains of scrubbers were set up so that once media became spent, Envent could divert flow to a scrubber with fresh media. During this process, Envent utilized an FID monitor to keep track of VOC concentration levels entering and exiting the scrubbers. After the first stage of maintenance was completed by the customer, VOC concentration levels increased significantly. Therefore, Envent switched over to a thermal oxidizer system for the second stage of the project. The thermal oxidizer is designed to handle high concentrations of VOCs and combust them at a 99.9% destruction efficiency. With its built-in blower, Envent could pull significant vacuum on the customer system while handling the increased concentration of VOC from the customer side. Envent continued operation of this system until the customer maintenance was complete and the Olefins-1 Unit superheaters were back online.

 

Benefit

This customer benefited from Envent’s solution in a variety of ways. First, the customer was able to avoid releasing VOCs directly into the atmosphere. The significance of this allowed the customer to stay in compliance with emissions regulations and prevent environmental damages. Secondly, Envent’s experienced crew enabled the customer to focus efforts on completing the superheater maintenance in a timely manner rather than waste time and energy manning an additional set of tasks. Envent maintained and operated the implemented system for several weeks safely without issue. Lastly, Envent’s solution was both effective and low-cost. The equipment provided was designed to meet the functions of the project without over bidding materials. Additionally, the complete reduction of stray emissions saves the customer money by avoiding fines from violations. Overall, Envent’s simple solution proved to be highly efficient and cost-effective, and the Olefins Unit project was completed safely and on-time.

Engineered Solution for Gulf Coast Refinery

Portfolio Categories: Vapor Control.

Challenge

Due to the recent pandemic striking the world, a gulf coast refinery adjusted their refining process to allow them to continue production. They found a surplus of C4’s (n-butane, isobutane, etc) that typically sell with ease. During this process, multiple variations of C4’s are made from a single process. 1-3 Butadiene demand remained high, and had no problem selling. The remaining C4’s, however, had no demand at the time, and needed to be disposed of. This would allow their production to continue without delays.

Solution

This refinery reached out to Envent to engineer a solution. Based on their desired flow rates, Envent mobilized two of the largest (70MMBTU/HR) mobile thermal oxidizers available in the United States to meet the refinery’s requirements. Envent also custom designed a manifold to add safety features and pressure regulators to ensure consistent flow. The project is still running today as the country recuperates.

Benefit

The benefit of Envent providing this service is the refinery was able to continue creating 1-3 Butadiene that remains in high demand, and allow them to continue their income, stay in business, and provide jobs for their employees. Had the refinery needed to stop processing, the entire plant would shut down. Envent benefits in the same way, while also feeling a certain accomplishment being an essential business in the trying times of today.

West Coast Pipeline Purge Vapor Control

Portfolio Categories: Vapor Control and Vapor Scrubbing.

Challenge

A west coast pipeline company requested Envent to provide vapor control during a pipeline purging process. Normally large vessels with adsorption media were proposed for this kind of job. However, due to the high pressure operation, either expensive high pressure vessels should be used or some devices should be installed to protect the regular vessels which were supposed to be used under atmospheric pressure.

Solution

At the planning stage, several options were considered by the engineering team. Eventually a high flow carbon system integrated with high pressure devices was proposed. Based on an absorption model developed, a calculation was made to size the vessels. According to the estimation, the team determined to deploy one trailer-mounted BD 6000 scrubber system to control the vapor venting from the pipeline. A high pressure regulator was used to bring down the inlet vapor pressure while a high pressure knock out pot was added the scrubber system to remove the liquid generated during the purging process.

Benefit

By using Envent’s custom engineered solution, our customer was able to manage their pipeline purging project in a safe and economical way.

Envent provides turnaround support for emergency shutdown

Portfolio Categories: Turnaround Services and Vapor Control.

Challenge

A Gulf Coast Refinery was faced with an emergency shutdown on one of their reactors, the catalyst was spent and needed immediate replacement, and it needed to be completed in time for their Alkylation unit was to be brought back online. The reactor needed to be cleaned in three separate phases in order to neutralize the catalyst and prepare the system for maintenance. The system would be at high pressures (>200 PSIG), high temperatures (>320F) and would contain Hydrogen at 90%, along with inbound sweeps of Hot N2. The work needed to be scoped, planned and executed in around 7 days in order to meet the desired timelines.

Solution

Envent worked with the site’s Turnaround planners and engineering team to properly scope a system that would handle the critical parameters, as well as be able to handle and process the changing atmosphere within the reactor. Envent mobilized the EMECS 70, the largest mobile thermal oxidizer in the US, the EMECS along with heat exchangers, regulators, NFPA approved Hydrogen flame/detonation arrestors, and ASME rated pressure vessels ensured that all conditions and phases of the project were dealt with. Envent operated the entire project with Field Supervisors, Project engineers, and the best equipment operators in the industry.

Benefit

The project was completed safely and in a timely manner, the customer was able to meet the deadline set forth by it’s turnaround schedule. The reactor was verified to be gas-free and safe for entry and inspection. Envent’s ability to provide turnaround support at a very short notice allowed the site to bring up a major Unit’s components at the same time without any delays, saving them costly delays in labor and production.

Northern California Waste Water Treatment Solution

Portfolio Categories: Mobile Water Treatment and Vapor Scrubbing.

Challenge

On Christmas Eve 2019 the citizens of a Northern California city woke up to a terrible rotten egg smell. The General Manager of the water treatment facility made a call to Envent around 2:30 p.m. on December 24th, 2019. He said he had a terrible rotten egg smell coming out of one of the digesters. Envent’s engineering team quickly sprung into action.

Solution

The engineering team put together a solution which would mitigate the H2S coming out of the digester. Our technician went to the site and the H2S in the vapor stream venting to atmosphere was at 3,000 ppm. The Water Treatment plant is located in a centralized neighborhood of homes. You could smell the H2S for miles. The team mobilized an ESCRUB 2000-SS and two each 2,000 pound vapor media vessels containing DARCO Carbon. by 9:00 p.m. that evening the smell was gone and the citizens of the Northern California City were safe and enjoying the holiday.

Benefit

The system has been functioning at the Northern California Waste Water Treatment Plant for three months now and everyone is very satisfied. The General Manager said, “I am thankful to Envent for its expertise in engineering and being incredibly responsive”.

Long Term Vapor Control Project in Southern California

Portfolio Categories: Vapor Control.

Challenge 

We have a long term project located in Southern California where we are providing vapor control for tanker trucks being loaded with crude. We decided to use a TO as the carbon spend rate will be very high. The unit is always on hot standby. The challenge of this project comes from the inconsistency of vapor composition and loading schedule. When a truck begins to load, a flood of high BTU vapors are sent directly to our unit. This would cause the unit to reach very high temperatures before the fuel management system could adjust.

Solution

We designed and installed an automated valve solution. This involved a pressure sensor that would sense when a truck began to load. This signal was sent to a UDC programmed with a proportional delay. The UDC would then output the signal to slowly and proportionally open an inlet valve depending on the pressure coming from the truck.

Benefit

This solution allows the unit to adjust to changes in process conditions automatically. After verification and testing of the automated solution, the unit can now provide unmanned vapor control for all truck loading activities.

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