BCCK’s NRU technology is engineered to deliver optimal methane recovery with the minimum environmental impact. The tower measures almost 37 metres in height.
BCCK, an engineering, procurement, fabrication and field construction services specialist based in Texas, is at the forefront of designing and manufacturing Nitrogen Rejection Units (NRU) for the oil & gas industry. To delve deeper into this innovative technology, Stainless Steel World spoke to Fraser McDowell, a seasoned professional with a wealth of expertise in this field.
By Joanne McIntyre, Stainless Steel World
BCCK has blazed a trail in the nitrogen rejection sector for over 40 years, tracing its origins to the oil and gas sector where some gas fields exhibit nitrogen levels, which affect the calorific value of the gas, referred to as BTU value or Wobbe index.
“Pipeline operators require the gas to meet a minimum BTU content to meet their customer’s specifications and thus require the nitrogen removal,” explains Fraser. “We believe our NiTech® NRUs to be the most efficient nitrogen reduction process, using cryogenic distillation and the Joules Thompson (JT) effect to condense nitrogen out of the methane-rich stream.”
The company specializes in full EPC projects, including concept, engineering, design, fabrication, manufacturing, and construction services. In addition to its NRU technology and cryogenic plants utilizing C2R-Flex, RSV, GSP and Score technologies, BCCK is a solution provider for helium recovery, and oxygen and CO2 removal. It has grown to be the world’s largest cryogenic NRU provider for Landfill gas (LFG) applications.
From the North Sea to Texas
Today, Fraser is Director of Strategy and Business Development (Renewables) at BCCK, but his career started in the North Sea, where he was involved in the commissioning and pre-commissioning offshore platforms, subsea pipelines, and tieback systems.
“I transferred to the United States in 2003 when the Gulf of Mexico was being developed for its deepwater reserves. I was Global VP for Weatherford in their Process & Pipelines services division, with over 20 locations around the world. In the last ten years, I have been involved with designing and manufacturing specialist cryogenic technologies from LNG, PDH (Propane Dehydrogenation) and BDH’s (Butane Dehydrogenation and Nitrogen rejection units). In my current role, I’m responsible for the development of strategy for BCCK’s renewable business, which includes renewable natural gas (RNG) and landfill gas (LFG).”
“The material selector for this technology is critical.”
“The material selector for this technology is critical.”Fraser McDowell, Director of Strategy and Business Development
Minimal environmental impact
BCCK’s NiTech® NRU technology is engineered to deliver optimal methane recovery while minimizing the environmental impact. The proprietary cryogenic technology features a flexible design with minimal equipment and requires low power consumption.
“The material selection for this technology is critical, as we are dealing with very low temperatures that are classified as cryogenic,” explains Fraser. “Austenitic stainless steels have been used extensively for subzero applications to -269°C (-452°F). These steels contain enough nickel and manganese to depress the acceptable design into the subzero range. Thus, they retain face-centered cubic crystal structures when cooling from hot working or annealing temperatures. The tensile strengths of chromium-nickel austenitic stainless steels increase markedly with decreasing temperature; yield strengths also increase but to a lesser degree. Therefore, we specify stainless grade 304 due to its proven history in cryogenic services.”
Strategic Partnership
BCCK recently established a strategic partnership with Vision RNG, a full-service developer of landfill gas (LFG) infrastructure, to deliver its NiTech® Single Tower Nitrogen Rejection Units (NRU) and amine systems to Vision RNG’s LFG worksites in Ohio.
BCCK is providing two NiTech® Single Tower NRUs and amine systems to two landfill gas processing sites — one in Seneca County, Ohio, and one in Perry County, Ohio. Both sites are owned by WIN Waste Innovations, a sustainable waste services and disposal provider that has contracted Vision RNG to develop gas conversion capabilities at both sites.
BCCK’s partnership with Vision RNG will aid their efforts to reduce their environmental impact by providing clean, sustainable energy for customers. The NiTech® technology will provide efficient methane recovery with very low operating and maintenance costs, yielding improved revenue streams while reducing greenhouse gas emissions.
Robust design
The field of NRU requires robust technology, and the BCCK team have a long track record of successful applications.
“Our design has been proven successful in over 44 locations and offers a low capex solution through its proprietary tower design. Additionally, it requires very little horsepower or other externally supplied energy, as it has no rotating or moving parts and relies on pressure and temperature. These attributes result in low operating and maintenance costs, high reliability, and superior methane recovery.” The towers themselves are similar to most towers, other than the proprietary design, but incorporate heads, shells, internals (packing or trays) and other proprietary components.
In-house design
BCCK’s mechanical engineering department is well-versed in material selection for each design case. It ensures that all relevant codes are being adhered to, such as ASME Section VIII for pressure vessels and ASME B31.3 for piping. “Most fabrication is done in-house at our Midland, Texas facility, which is an ASME U and R coded shop and is certified to the ISO 9000 quality standard,” continues Fraser. “Corrosion isn’t a real concern in this application, as all contaminants are removed upstream of our NRU. We also provide Deoxygenation systems for the landfill gas sector, and in those applications, we have selected stainless steel 304H due to the high temperatures and 316L in the caustic wash piping associated with these systems.”
“BCCK is also active in the hydrogen market, and for this sector, we have leaned on manufacturers for their knowledge and insight”.
Nitech® benefits
- Low capital cost
- Flexible design
- Low power consumption
- Simple process design requiring minimal operator attention
- Small footprint
- Low compression horsepower
- High CO2 tolerance
- Nitrogen contents from 3 – 90% reduced as low as 1%
- High efficiency – 99% hydrocarbon recovery
- Environmentally friendly – emits no non-methane VOCs
About this Featured Story
Appearing in the August 2024 issue of Stainless Steel World Magazine, this Featured Story is just one of many insightful articles we publish. Subscribe today to receive 10 issues a year, available monthly in print and digital formats. – SUBSCRIPTIONS TO OUR DIGITAL VERSION ARE NOW FREE.
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