Martin A. Taylor is
a Sulfur Technologist for Bechtel Hydrocarbon Technology Solutions, Inc. (BHTS)
based in Houston, TX, USA. His experience includes design, troubleshooting,
consulting, commissioning, and start-up of Sulphur-related units. Martin has
patents and patents pending for technologies in and around the Sulphur
industry. He recently participated in ASIA-TECH 2016: Asia Downstream
Technology Forum held in Bangkok from 11 to 12
October 2016.
You were among our
respected speakers at the ASIA-TECH 2016 which has been recently held in
Bangkok. What were the main issues you addressed in your presentation at the
event?
At the recent ASIA-TECH 2016, I discussed latest
improvements in the Waste Water Treatment (WWT) technology that have resulted
in 4 patents pending, addressing capex, opex and ammonia product quality.
Could you outline the
main features of WWT technology?
WWT is the original
two-tower Sour Water Stripping (SWS)
technology invented by Chevron in the 1960’s and now licensed by BHTS. It allows recovery of salable ammonia from
refinery or gasifier sour water, while simultaneously expanding the Claus
sulfur recovery unit. It does this at a
fraction of the capex required for a new Sulphur Recovery Unit (SRU) train and
does not require an air permit.
In your presentation
you are advising to take the Sour Water Stripper Acid Gas Stream (SWSAG) as the starting point rather than the sour water. What is the advantage
of this?
Starting with the SWSAG results in a more
concentrated sour water feed to the WWT unit, which in turn reduces capital and
operational expenditures.
According to your
presentation, WWT does not require new air permit. Could you elaborate on this?
Does this mean it is more eco-friendly?
The air permit question and eco-friendly
question have the
same explanation, and the answer is yes. When burnt in the Claus SRU, the resulting
combustion products (nitrogen and water) continue to float through the system
through the various reactors, condensers, and reheaters. The water is condensed
in the Quench Tower (aka Contact Condenser) in a reduction-amine type Tail Gas
Treating Unit (TGTU), and the nitrogen continues to the Thermal
Oxidizer (aka Incinerator). There, the
nitrogen must be heated with the other processes gases to ~650-815 C by using
fuel gas or natural gas. All such
burners generate a degree of CO and NOx as byproducts, so removing ammonia from
the SRU feed makes WWT an eco-friendly technology, as does recovering a popular
fertilizer (ammonia). If ammonia is
recovered as anhydrous or aqueous ammonia, nothing is incinerated, so NOx and
CO emissions are reduced.
Alternately, a new SRU would result in more
fuel gas firing in the Incinerator, resulting in more CO and NOx. Thus, the need for a new air permit.
How does Bechtel / BHTS
contribute to the sustainable development of our industry?
We approach sustainability holistically. It is
not any single activity but rather the totality of our efforts to execute
projects with excellence. By improving the sustainability in the equipment,
materials, and services we procure, we are improving the quality of our
projects while at the same time helping to protect people and the environment,
promote economic development, and partner with communities and society.
We also require our suppliers and contractors
to comply with all applicable national legislation, export-import rules, regulatory
requirements, and project-specific sustainability requirements established by
our customers.
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