Carbon, Carbon, My Kingdom for some Carbon!

By Ken Schaeffer

The activated carbon industry is experiencing turbulent times and may be heading for more product shortages due to a “perfect storm” related to several factors:

• New high anti-dumping duty on Chinese carbon imports (approx. 70%);
• Repeal of the Chinese 13% VAT rebate system for activated carbon exports.
• General metallurgical coal shortage in China due to increased coal needs of dozens of new power plants and the closing of many mines due to safety and environmental reasons.
• Higher Chinese carbon prices also due to increased energy and labor costs, ocean freight and currency exchange rates.
• Higher domestic carbon prices due to higher production costs and price protection by the new anti-dumping duty.
• Some carbon companies are getting out of coal carbon business and others are cutting back inventory as the high duty on imports can add $8,000 - $15,000 per container upfront costs.

One also has to consider the approaching new very large potential carbon market for PAC (powder activated carbon) in mercury removal from flue gas applications that could require between 400 – 900 million additional lbs. of carbon per year phased in over the next decade as tighter mercury emission limits become reality (30% to 70% reduction in mercury between 2010 and 2018). The entire U.S. carbon production capacity is only 400 million-lbs. now. Domestic manufacturers will expand production and/or convert some GAC (granular activated carbon) production to PAC production to meet the needs of power plants in North America. This could reduce even more the supply of GAC. There has been talk of new players entering the activated carbon manufacturing arena, but no ground breaking has happened yet.

One effort to meet increasing carbon demand is to determine the carbon need one has and what carbon will work most economically to obtain desired results. Maybe one can replace coal carbon with a coconut shell carbon as many coconut carbon products are now actually less expensive than coal carbon and that has never been the case until this year. Some applications may be able to use a reactivated carbon instead of a higher priced virgin carbon. There are some non-Chinese imported coal base carbons available that are not subject to anti-dumping duty. In some cases if a system has used a particular mesh-size carbon, it might perform better if a smaller mesh size is used for better adsorption kinetics if pressure drop allows. There has never been a better time to really get to know your carbon supplier and get expert assistance.

COCONUT SHELL ACTIVATED CARBON AN ALTERNATIVE TO BITUMINOUS

By Robert Potwora

With the recent price increases on bituminous coal based activated carbons this year due to new tariff rates, many users are switching to coconut shell based activated carbons.  Carbon Resources has always offered coconut shell based activated carbon.  Carbon Resources offers many different types of activated carbons, including our “C” series, coconut shell based and “B” series, bituminous coal based activated carbon.

The starting raw material used to produce the activated carbon has a major impact upon the activated carbon’s characteristics.  Each has its own advantages.  Below the characteristics of coconut shell based activated carbons are reviewed along with their best application uses.

“C” Series

“C” series is our coconut shell based activated carbon.  It is the hardest activated carbon available.  Hardness numbers greater than 95 are typical.  Because of this it has very low attrition and very low dust levels.  A new charge of virgin coconut granular activated carbon will require less backwashing compared to bituminous based activated carbon and clear up much faster.  Therefore, it’s preferred for point of entry (POE) and point of use (POU) water treatment applications.

Coconut shell is a better raw material for the generation of micropores (diameters less than 20 angstroms) than bituminous coal.  Therefore, coconut shell based activated carbons have the highest microporousity and surface area.  Carbon tetrachloride values up to 95% and iodine numbers up to 1300 mg/g are possible.

Therefore, coconut shell activated carbon is superior in adsorbing volatile organic chemicals (VOC) from water and air.  Volatile organic chemicals typically are less than 200 molecular weight.  Coconut based activated carbon is preferred to remove trihalomethanes (THM) and methyl tertiary-butyl ether (MTBE) from water because of its higher adsorption capacity.  The activated carbon adsorption isotherm below compares coconut and bituminous based activated carbons to adsorb chloroform from water.  Chloroform is the most prevalent THM present in municipal treated surface water.

The isotherm indicates coconut based activated carbon has a capacity advantage of approximately 30% compared to bituminous activated carbon.  This means coconut based activated carbon would last 30% longer before changing-out with new activated carbon would be required. 

The higher microporousity where most of the high-energy pores are gives the coconut based activated carbon higher retentivity.  The ability of the activated carbon to hold onto a contaminate once it has been adsorbed.  Desorption is an undesirable effect, and it occurs less with coconut based activated carbon.  Therefore, coconut based activated carbons have traditionally been preferred in respirator applications and trace removal of VOC from water.

Bituminous coal based carbons have higher molasses numbers compared to coconut shell based activated carbons.  Molasses number measures the amount of decolorization of a molasses solution.  Because the color bodies present in a molasses solution are large, molasses number is an indicator of macropores or larger size pores.  Therefore, bituminous coal based “B” series or other activated carbons with more macropores like “A” series are preferred when decolorizing solutions.  

Coconut shell based activated carbons have the highest purity levels.  Total ash is less than 4%.  Bituminous coal based activated carbons have total ash values from 8 – 15 %.  Traditionally bituminous coal based activated carbons need to be acid washed with hydrochloric acid to reduce ash levels to 5 – 10% and reduce leachable heavy metals.  Even then non-acid washed coconut activated carbon has lower ash levels.  For some sensitive medical applications, acid-washed coconut based activated carbon is available.

Carbon Resources “C” series is available in many mesh sizes, 4 X 8, 4 X 10, 6 X 12, 8 X 16, 12 X 30, 12 X 40, 20 X 50 and powder form.  Other mesh sizing is available upon request.  Please contact us if you need assistance to determine if our “C” series is an alternative for you.

By Kimberly Walsh

It certainly has been an interesting year for Carbon Resources! Highlights of the year, completion of our 10th year in business; the tumultuous activated carbon market conditions (new high tariffs on Chinese activated carbon, repeal of the China VAT rebate and associated carbon shortage); sales gains of our MaxAmine® amine service carbon and Spartan series® enhanced surface area carbon line and the upcoming grand opening of our joint-venture coconut shell activated carbon plant in Mexico. 

We are experiencing a 30% sales increase year to date over last year’s volume mainly due to business generated by supplying new customers that lost their carbon providers due to the Asian supply situation.  We also continue to increase our sales with the “A” series carbon which is a high activity, low density non-Chinese coal base carbon.

Carbon Resources developed a new product called MaxAmine® for the amine purification market.  It has several advantages over the existing carbon product being used in this market.  Not only does it have a higher activity (roughly 20%), but it also has a lower density and is macroporous.  All of these parameters make it very attractive for this marketplace.

We recently performed on-site isotherm testing at one of our potential customers to determine if coconut shell carbon would work as well, if not better, than their existing coal base carbon.  Robert Potwora performed this test at the customer’s request so that they could potentially reduce costs and have a reliable alternative supplier to their current coal carbon company.

We would also like to welcome three new members to our Carbon Resources team:  Keri Homer, Kevin Wright and Katie Jenkins -(yes we only hire people whose first name starts with a “K”!!) Keri will focus on Customer Service/Marketing Department tasks while our newest technician, Kevin, will be assembling our Guardian® adsorption systems for liquid and vapor applications and performing warehouse duties.  Katie is responsible for handling our AP/AR work.

We will be exhibiting for the first time at the Pacific Water Quality Association (PWQA) annual convention October 23-26, 2007 at Pechanga Resort in Temecula, CA.  Ken Schaeffer is a member of the PWQA Board of Directors and is active in their Educational/Technical Committee.  Ken will be giving a presentation on Oct. 25th entitled “GAC: Right Product - Right Job”.

Next month on October 18th, Ken Schaeffer and Robert Potwora will be presenting papers at the annual IACC (International Activated Carbon Conference) in Pittsburgh, PA sponsored by PACS.  Ken’s presentation will be focused on events in the Activated Carbon industry while Robert’s presentation will be on surface enhanced carbons for special applications.

The grand opening of our new joint venture plant in Mexico is scheduled for November 2007.   Carbon Resources will have exclusive marketing rights for all the carbon products produced at this facility.  The plant has a unique kiln for converting coconut shells into char.  This charring alternative will produce better and more consistent char feed material and helps reduce energy costs in the activation phase.  It also is environmentally “green” and greatly reduces the carbon dioxide emissions that occur with common pit charring method.  In our April newsletter, we will show pictures of the grand opening so stayed tuned!