August 2002
Volume 44 Number 8

LETTERS: Hullabaloo over carbon
by Laurence G. D’Alberti   Pages: 

The following is a letter and author's response WC&P received following publication of the article mentioned below:

Dear Editor:

In reference to WC&P's August 2002 issue, pg. 28 "The Great Activated Carbon Dilemma":

UMI-2000 is a supplier of both "off-shore" and domestic activated carbon, as well as a producer of USA-made adsorption filter vessels for liquid and vapor phase applications since 1996. We are preparing a formal rebuttal of this article and will present it to you soon with our company product literature. How you expected to have an objective, impartial and unbiased report on Calgon reagglomerated activated carbon, (written and contributed to by Calgon employees and their customers), without any cross reference or input from other carbon companies or end users—well, this article cannot be taken seriously by water treatment or pollution engineering professionals.

Allow us to explain: Back in 1995, Calgon bought about 500,000 pounds of "off-shore" (synonym for Chinese), direct activated virgin bituminous coal-based GAC from the carbon company I worked for at the time (Norinco - China North Industries). They were so impressed with the product and price, that they proceeded to renege on our verbal supplier agreement, cut us out and went straight to the factory in China, to order direct, without using us as their import broker anymore! At that time, before we started going after Municipal WTP [water treatment plant] projects in the USA, and winning them incidentally with China [sic] carbon, Calgon was charging about two to three times the price it is now. So in terms of improving the productivity, pricing and performance of activated carbon here in the USA, we have a lot to thank these "off-shore" factories for. Calgon remains the largest importer of China activated carbon in the USA to this day. They recently christened their own factory in China and have now reached an all time low in carbon pricing with this imported product for one of the largest GAC filter plants in the USA (Riverside, Calif.). The carbon factory in Datong China that we represent is ISO-9002 QMS registered, certified to NSF Standard 61and a supplier to Calgon. See the following URL for a news report of Calgon's alliance with the Datong factory:
Calgon Carbon
Asia Business Trade

Currently our factory is in the development phase of producing a briquetted or "re-agglomerated" GAC for Calgon. We must remark that factories in China have been manufacturing this product since 1956 and, by now, are experts in the production if EAC (extruded activated carbon) from which reagglomerated GAC is ground. This article makes no mention of Calgon's new China carbon factory while at the same time continuously slams "off-shore" product. Neither does this article state if the carbon manufactured and imported by Calgon from China is direct activated or reagglomerated product or where their "off-shore" product is going to here in the USA. Off-shore activated carbon must be good for something if Calgon is manufacturing and importing so much of it!

Also, very important, no mention is made of the adsorbates that the reagglomerated carbon adsorbed better than lignite and direct-activated carbons. Concentrations, temperatures, flow rates, pH, competing adsorbates, etc., are curiously absent from mention—and yet from reading this article one could come away with the impression that Calgon carbon is the best carbon for all municipal WTP flow conditions and applications. There are many applications (e.g., MTBE, low molecular weight trace organics, removal of color bodies, heavy metals abatement and odor control) for which alternate activated carbon base materials (e.g., coconut shell, lignite, anthracite, wood, domestic nut and bio-mass) are superior to reagglomerated carbons. We find this exclusion of important information concerning the performance claims of Calgon carbon to be suspect. The article also makes no mention of any of the negative qualities of reagglomerated activated carbon which may cause a WTP professional to reconsider using this product without independent review (we will outline the undesirable qualities of reagglomerated carbon in our formal rebuttal). Also, some of the specification claims and other technical information are just plain misleading.

For example, the claim that offshore carbons have 14 percent ash is rubbish. Our highest ash carbon has 12 percent ash maximum, and we routinely produce acid-washed carbons of 5 percent maximum ash content. If our customers specify low ash carbon, we supply acid-washed GAC for not a lot more in price. The fines content of our carbons are routinely reduced prior to packaging and shipping by water washing. (Our coconut shell GAC has less than 4 percent ash content without any secondary treatment or washing.) More important than the total ash content specification (when concern is for leachables) is the water soluble ash content, which is specified by the AWWA Standard B604 to be no more than 4 percent. Practically any activated carbon will give a water soluble ash specification of very much less than 1 percent. Perhaps Calgon would like to re-write the AWWA standards as well?!

The assertion that imported GAC has widely varying specifications is grossly misleading and entirely incorrect. Poor product quality of China GAC may have been a problem for certain low-price, mass production factories years ago. Largely through the efforts and considerable investment of companies like UMI-2000, Norinco, Westfield Industries and now Calgon, factories in China are certified and registered for the production of GAC and PAC exceeding the requirements of NSF and AWWA. No shipment of our activated carbon is put into a container until it passes QC [quality control] tests both at the factory, at a certified U.S. lab and in some cases by a third party elected by the customer to test the carbon. The statement that China carbon is of poor quality is science fiction!

Neal Megonnell can claim Calgon has a superior and more cost effective carbon than other carbon companies, but recently (August 2002) Calgon was not the low bid for the city of Los Angeles WTP carbon change-out services contract. Typically, it is the carbon buyer or municipality that specifies the base material of the carbon they want—not the supplier. Calgon has tried and succeeded for many years to get their name, model numbers and specifications written into municipal carbon bids to their obvious advantage. It is up to the supplier, however, to meet the specifications and base material as asked for by the municipal WTP officer at the time of bid, not the other way around. Also, to imply that Calgon is the only company that can supply reagglomerated carbon is doing the water treatment industry a disservice by re-enforcing the myth that Calgon will ever attain a U.S. monopoly in activated carbon supply. Maybe that was the intent of Neal Megonnell's article. If Calgon were to achieve a monopoly, then the price would double or triple as competition is stifled dishonestly. We could tell Neal about how we have built a carbon business on top of the customers in California that were fed up with the poor level of service they got from Calgon after their reagglomerated carbon was delivered and installed, but we don't use our customers to promote ourselves unless asked to.

We still appreciate any articles written about activated carbon, even if they are a little lop-sided like this one was! As mentioned, we will send you our formal rebuttal as soon as we get input from the other "off-shore" and "domestic" factories.

Laurence G. D'Alberti - ChE
Red Bluff, Calif.

Author's reply: While we do not wish to debate every argument made by Mr. D’Alberti in his letter, we will address several points. For the past several years, users of granular activated carbon products have been confronted with a vast array of product choices at their disposal. In particular, the debate over reagglomerated carbons versus direct activated carbons has been especially strong over this time. As the number of suppliers and available products has multiplied, customers have had difficulty assessing which carbon is best for their application. The point of our article was to make end users understand that not all activated carbons are the same, and that customers should do their homework before selecting the proper product for their specific case.

Calgon Carbon has performed significant evaluations at laboratory, pilot, and full-scale operation over the last several years to separate fact from fiction with regard to the true life-cycle costs of reagglomerated carbons as compared to direct activated materials. Our article was a qualitative discussion of several cases in the drinking water industry where, once testing was conducted and overall performance was included in the equation, reagglomerated carbons were the superior choice.

The intent of our article was not to say that direct activated materials are poor in all applications. Offshore direct activated carbons are in fact quite suitable for many applications, provided that they are properly selected and applied in these applications. With hundreds of activated carbon manufacturing plants in China, the variability in product quality and performance in direct activated materials is considerable; but by having a proper understanding of the manufacturing process, as well as proper quality controls in place within China, this variability can be reduced and good performing carbons can be provided for certain applications. As one of the world’s largest importers of direct activated carbons from Asia, and as the world’s leading technical and application resource on activated carbon technologies, Calgon Carbon is well positioned to explain the differences between these manufacturing processes, and their technical and economic impact on specific applications.

We agree with Mr. D’Alberti’s statement that, in the end, it is the customer’s right to specify the type of carbon that they desire for their application. Each customer’s needs are unique. That is why we have supplied and will continue to supply both reagglomerated carbons and direct activated materials, as warranted in each individual case. The intent of our article was to help current and potential users of activated carbon begin to understand the differences between the variety of products available to them, and to help them solve their purification problems in the most cost-effective manner.

Neal Megonnell
Calgon Carbon Corp.
Pittsburgh, Pa.