|Left: KBR TRIG gasifier schematic. Right: TRIG gasifier demo unit, Wilsonville, AL. Source: http://www.kbr.com|
A recent post was about a patent issued to Bechtel for refueling natural gas combined cycle power plants with syngas derived from coal, and how it may be caught between market forces and a regulatory environment that could limit, if not preclude, its commercialization. This time, we’ll look at an invention from another international engineering, procurement, and construction company that pertains to syngas production.
KBR (NYSE:KBR), headquartered in Houston, TX, employs about 27,000 people worldwide in its various activities. The company, in addition to being a major defense contractor, is a major player in the energy, hydrocarbon, minerals, civil infrastructure, power and industrial markets. Started in 1901, the company claims milestones such as constructing the world’s first catalytic cracking facility in 1942 and creating a new ammonia process for fertilizer production in the 1960s, which had direct implications for improved global food and crop yields.
KBR’s intellectual property portfolio includes 170 issued US patents and applications (assigned to Kellogg Brown & Root). One of its more recent patents is US 7,955,403, issued under USPTO’s Green Technology Pilot Program. The '403 patent is the subject of today's post.
The ‘403 patent, ‘Systems and methods for producing substitute natural gas’, was invented by Siva Ariyapadi and Philip Shires and issued on June 7, 2011. The application was filed in May 2009, and assuming a 2–3 year lead time for R&D of the invention prior to filing, the genesis of this invention was probably in the 2005–2006 time frame - about the time that Bechtel was probably researching its refueling patent. See the Bechtel post for additional information on the natural gas market production and prices around that time and in the years since.
The inventors developed improvements to KBR’s synthetic natural gas system to provide coal gasification of low grade coal in a manner that reduces auxiliary power and process water requirements. Ariypadi and Shires teach that
[c]lean coal technology using gasification is a promising alternative to meet the global energy demand. Most existing coal gasification processes perform best on high rank (bituminous) coals and petroleum refinery waste products but are inefficient, less reliable and expensive to operate when processing low grade coal. These low grade coal reserves including low rank and high ash coal remain underutilized as energy sources despite being available in abundance. Coal gasification coupled with methanation and carbon dioxide management offers an environmentally sound energy source. Synthetic or substitute natural gas (“SNG”) can provide a reliable supply of fuel. SNG, with the right equipment, can be produced proximate to a coal source. SNG can be transported from a production location into an already existing natural gas pipeline infrastructure, which makes the production of SNG economical in areas where it would otherwise be too expensive to mine and transport low grade coal. Alternatively, in developing countries, the production and supply of clean efficient SNG to densely populated cities instead of the transport and use of low grade coal as an energy source in a multitude of inefficient and polluting facilities within the cities provides the means to effectively mitigate pollutants and carbon capture.
Their claim 1 states:
A method for producing synthetic natural gas, comprising:
gasifying a carbonaceous feedstock within a gasifier to provide a raw syngas;
cooling the raw syngas to provide a cooled raw syngas;
processing the cooled raw syngas within a purification system to provide treated syngas, wherein the purification system comprises a flash gas separator in fluid communication with the gasifier and a saturator;
converting the treated syngas to synthetic natural gas to provide steam, a methanation condensate, and a synthetic natural gas;
and introducing the methanation condensate to the flash gas separator.
The Technology and Its Use
The improvements memorialized in the ‘403 patent are a component of KBR’s TRIG™(Transport Integrated Gasification) technology which allows the gasification of inexpensive, low grade feedstock such as lignite, sub-bituminous, and high ash coal. KBR and Southern Company successfully demonstrated the system at USDOE’s Power Systems Development Facility in Wilsonville, Alabama. The companies are commercially deploying the TRIG system around the world. Major projects include two in China that will provide a retrofit to an integrated gasification combined cycle plant and a coal to chemicals facility, and an IGCC unit being installed for Mississippi Power in Kemper County, MS.
This technology, by allowing the efficient use of lower quality coal resources in a manner that reduces process energy requirements and water use, is an excellent example of truly clean technology.
Other examples may be found in other articles here on The Inkling, and in Way Better Patents’ USPTO Green Tech Pilot Program Discovery and Analysis Report.