Mercury Chemicals in Fuels and Scrubbers was the Hot Topic Hour April 10
Suppliers, consultants, and utilities were well represented in a discussion of chemicals and their role in reducing mercury. The meeting started with an explanation of a new website which is aggregating the information on mercury reduction Mercury Removal - Continuous Analyses.
Anyone with valuable information to share can send it to the McIlvaine Company for evaluation and posting. In anticipation of the meeting there were a number of additional papers received and uploaded. So if it has been a week or two since you visited the site, you may want to revisit now.
Lesley Sloss of IEA joined the discussion and explained the activities of an important UN group which is coordinating mercury reduction activities globally. The group is aiming for a commitment by the nations of the world to promulgate regulations for both new and existing sources. There is the realization that the poorer nations may not want to adopt expensive solutions. They will be looking for ways to obtain modest reductions using the existing equipment. So one of the tasks is to identify the options and determine the cost. In this regard, there are ongoing meetings including one this month.
The Mercury Emissions from Coal - 10th workshop will be held at the Sand Key Sheraton Hotel, Clearwater, Florida, USA from April 23 to 25, 2014. http://mec10.coalconferences.org/ibis/MEC10/home
Chemtura (Great Lakes Solutions) will be one of the sponsors of the workshop. Jon Lehmkuhler will be on site and has agreed to provide some of the coordination between the McIlvaine effort and the workshop. The free McIlvaine site will be one of the tools available to the attendees.
UNEP is striving to demonstrate the cost effectiveness of mercury technologies with the case histories and more specific performance information. The discussion yesterday ranged from very efficient to low efficiency options. There was even discussion of the use of the unburned carbon in the flyash as a way to provide inexpensive mercury capture.
There will be Chinese representatives at the meeting. McIlvaine had earlier reported that China is now moving beyond the recently promulgated but lenient limits and is targeting 70 percent reduction. There are likely to be 15 installations made in the near future to demonstrate the cost effectiveness of technologies. This would then be the first step in moving forward with reduction technologies.
The webinar was conducted as a discussion but there were some designated discussion leaders.
John Grocki, [Materials/Corrosion Expert] Industeel/private consultant
Jonathan (Jon) Allen, Allen Analytics, LLC
Jon D. Lehmkuhler, Commercial Manager, Brominated Products, Chemtura Corp., Brominated Performance Products, Great Lakes Solutions
Dan Cicero, Industry Development Manager, Power Group, Nalco
Bruce A. Keiser, PhD, Research Fellow, Air Protection Technologies and Nanotechnologies, Nalco
The bulk of the discussion was around material submitted and posted by the leaders. Here is how it appears on the site.
Information regarding Mercury Abatement, FGD Liquors and Dissolved Metals Concentrations in FGD Wastewater. There is a big difference in selenium and mercury concentration in the scrubbing liquor which has to be process rather than fuel related.
Treatment Chemical Case Studies by Bruce Keiser, Nalco - Hot Topic Hour April 10, 2014
Nalco offers chemicals to solve the mercury emission problem for coal-fired boilers. One chemical is designed to inject in the boiler, another is injected in the scrubber and a third in the wastewater. The chemical quantities can be varied in order to compensate for process variables. For example the SCR does a better job of oxidizing mercury when the catalyst is new than later in the campaign. As the oxidation potential deteriorates the quantity of chemicals can be increased.
Bromine can accumulate in the scrubber recycle, Confirmation of the accumulation was determined in a study at Lower Colorado River Authority (LCRA). John Grocki advised the attendees that there are big variations even between units at the same plant. There is a range of concentrations which can be of concern. Bromine and Chlorine cannot be treated the same and the combination has a different impact than either one independently. So whether there will be corrosion and which material is best to protect against it is based on the concentrations of both halogens. In addition to the scrubber itself, the injection of halogens in the fuel can have impacts on the air heater and ductwork.
Chemtura can supply bromine as calcium bromide or in many other forms. The company works with clients from inception through continuing operational support. Setting up calcium bromide systems is relatively easy but there is no reason to over-design and invest more than necessary or to under-design and create operational problems. Chemtura is conducting tests which show the impact of bromine in the gas and scrubbing liquor on the materials with which it may come in contact. The quantity of bromine added can vary to compensate for changes in the process e.g., changes in fuels or deterioration of the catalyst. Since activated carbon is quite expensive it makes sense to utilize bromine with the fuel to supplement the carbon under upset conditions.