Tuesday, August 07, 2007

Activated Carbon Prices Going Up Again!

I just had a meeting with Calgon Carbon Corp. to discuss new pricing, again. The tariff decision here in the US and the Chinese VAT change conspired to increase the cost of activated carbon regardless of manufacturer. In addition to these changes, the worldwide demand for activated carbon has increased substantially, so "supply & demand" pressures can be added to the mix.

It's always hard to tell customers when prices go up, but it's not something we as an OEM can control. Res-Kem Corp. continues to get the best available pricing on Calgon Carbon, but we can't absorb the price increases. These need to be passed along to the end-user.

Before you buy your next load of activated carbon, you might want to re-evaluate your application, equipment operation, and activated carbon selection. Keep in mind the following:

  • Chlorine is easy to remove- To most efficiently remove chlorine, choose the carbon with the highest surface area, not the highest iodine number. Activated carbon with a high iodine number typically is a more expensive option.

  • Confirm whether you are removing chloramine or chlorine- Check with your water utility to determine whether they are chloraminating or chlorinating the water coming to your plant. There is a difference in capacity for chloramine vs chlorine. You will need to consider using a different activated carbon for more effective capacity. It may cost more but it will last longer and be more effective.

  • Organic removal- To most efficiently remove organics, look at the iodine number, BUT remember this is a good measure of how much iodine or similarly sized molecules the activated carbon is capable of removing. If you have the option, consider trialing different types of activated carbon to determine which works best for your application.

  • Review your operating procedures-
    Are you backwashing too much or too little? Activated carbon filters don't necessarily need to be backwashed every day. Res-Kem recommends backwashing based on pressure drop in most cases. Unlike steam activation, backwashing the activated carbon filter doesn't extend the life of the activated carbon.

    Unless you are using treated (carbon-filtered) water, activated carbon filters, used for the removal of contaminants such as VOC's (volatile organic contaminants), should not be backwashed at all. Any time you backwash an activated carbon filter with raw water you run the risk of contaminating the bottom portion of the bed.

    Bottom line - water costs money and you might be using too much if you are backwashing too frequently. Consult with the manufacturer or the activated carbon equipment manufacturer or Res-Kem if you have questions.

    Are you losing activated carbon every time you backwash? Be sure the backwash rate is set correctly. Activated carbon weighs anywhere between 16 and 31 pounds per cubic foot. If you change the type of carbon you are using, make sure the backwash rate is set properly. If you set the rate too high, you run the risk of floating the carbon out of the tank. Conversely, if the rate is set to low, the bed is not cleaned sufficiently for full effectiveness.

  • Are you able to monitor the contaminant levels? If you are running activated carbon filters in series, be sure to monitor the first bed of the series for contaminant breakthrough, IF you have the means of measuring for that contaminant. Change out or rebed the activated carbon filter only when it is fully exhausted, that is when the first undesirable contaminant shows up in the effluent water of the first tank. If possible, make that newly rebedded activated carbon tank the polishing tank and begin to monitor the older tank for breakthrough.

    If you have other ideas for more effective ways of saving money when operating activated carbon filters, let me know. I'll be happy to pass on the knowledge.
  • 1 comment:

    Anonymous said...

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