New directions in VOC/HAP destruction.

Editor's Note: This article is the result of the Forest, Wood and Paper Industry's Agenda 2020 program, which is focused on providing the industry with technology for a robust and sustainable future. Summarized here is one of the key areas of Technology Summit II, held in May 2004.

More than US$800 million: using current technology, that is the wood products industry's projected cost for control of volatile organic chemical (VOC) and hazardous air pollutant (HAP) emissions over the next few years (see Table 1). Agenda 2020--a special project committee of AF & PA that continues to improve forest products economics and improve value to society through leveraged technology deployment--has funded research resulting in several technologies to address this issue. Process modifications promise the greatest near term benefits. Non-thermal plasma technology promises longer-term benefits to the total industry, but at a higher cost.

The following analysis includes capital benefits to oriented strand board (OSB) manufacturers only; therefore, total benefit to industry will be even greater than described here.

MACT TO THE FUTURE

In 2004, the U.S. Environmental Protection Agency (EPA) issued two Maximum Achievable Control Technology (MACT) regulations that will have a dramatic impact on the wood and paper products industry. Estimates show that in the next several years these rules will cost the forest products industry several hundred million dollars. All major sources in the paper, oriented strand board (OSB), medium density fiberboard (MDF), particleboard, hardboard, fiberboard, softwood plywood and engineered lumber businesses will be affected.

The final Wood MACT rule requires mills to reduce six HAPs from dryers and presses by 90%--essentially mandating incinerator controls unless the mill can show that emissions are safe. The most likely control device is the RTO (Regenerative Thermal Oxidation) unit, which is energy-intensive (using natural gas) and has high operational and maintenance costs.

An innovative approach advocated by industry and included in the final rule allows a mill to avoid or reduce control obligations on its dryers and presses by showing that risks to the public are minimal. Some mills may even put on partial controls or undertake other emission reduction strategies to avoid controls on all equipment. Emissions of acrolein and acetaldehyde will be the main drivers of risk. Mills that qualify as low risk are exempt from all future EPA air toxic regulations, including upcoming residual risk requirements.

Mills will have two years to show they are low risk or meet the 90% emission reduction obligation in three years. EPA estimates that 150 of the 200 wood product mills subject to the MACT will ultimately qualify as low risk and avoid the capital and operating expenses of using incinerator controls.

EPA has limited the risk assessment to only equipment covered by the rule, rather than the whole facility. Another positive component of the risk provision is that mills will not be penalized for emissions from other sources that might pose a greater risk. As a result, many more facilities will qualify as low risk, and all facilities will avoid the additional expense of conducting much more complicated risk assessments. These improvements are also applicable to the Boiler MACT risk provisions.

For sources that are above designated risk levels, the rule includes two provisions to help further offset compliance costs and minimize additional controls such as scrubbers and electrostatic precipitators. Under Wood MACT, a facility can use a pollution prevention approach or it can get emission reduction credits from unregulated sources (for instance, lumber kilns and board coolers) to offset reductions needed on presses or dryers. These additional compliance alternatives could reduce costs another 15% to 20%, or tens of millions of dollars.

As expected, three environmental groups challenged the final Plywood and Composite Panel (Wood) MACT, focusing on the provision to exclude low risk mills from expensive incinerator controls. In addition, they submitted an administrative petition to EPA for reconsideration of the rule, asking the Agency to stay the rule and make changes that would significantly reduce compliance flexibility. In December 2004, EPA granted the petition but denied the stay request, leading to another round of public comments on this controversial provision this spring.

Industry continues to work with EPA on a supplemental rule, also expected in the spring, to use emission estimates instead of emission tests for several low risk and hard-to-test process units in order to reduce compliance costs and speed regulatory determinations. This reconsideration by EPA and the litigation could alter the final compliance dates, but for now the deadlines remain the same.

VOC/HAP RESEARCH

To address the MACT issue, Agenda 2020 began funding research in 2001 on VOC/HAP destruction. Several projects are testing process modifications to reduce emissions, while a second technology uses non-thermal plasma destruction techniques.

Process modifications for OSB facilities are at the demonstration stage and can meet MACT timelines. A set of recommendations developed from research into the release mechanism of VOC/HAP emissions from wood has been developed. Most can be implemented with low capital outlay; e.g., reducing fines either through better flaking or screening and use of residuals such as ash or fines to trap and burn methanol and formaldehyde. Another possibility is reducing press emissions by minimizing exposure of pine to high platen temperature via surface layering with hardwood. Where control devices will still be required, they will be smaller and more efficient. The end result is expected to be a substantial decrease in both natural gas use and capital costs.

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Non-thermal plasma technology is ready for proof of process as a possible low-cost alternative across the industry. In this process, exhaust gas is passed through an electric grid that injects electrons into the gas stream. The VOCs/HAPs capture electrons and are oxidized. The advantage over conventional thermal oxidation is that the exhaust gas is not heated.

THE VALUE TO SOCIETY

When both technologies are fully deployed, benefits to society will include reduced air pollution and decreased use of fossil fuels. Lowering the costs of meeting government regulations should also improve profitability and increase jobs.

Estimates maintain that 13 thousand megawatt hours (MWH) of power will be saved per facility annually. Further, the following annual reductions are anticipated per plant:

* 26,000 tons of carbon dioxide (C[O.sub.2])

* 300 tons of sulfur dioxide (S[O.sub.2])

* 200 tons of VOCs

* 90 tons of nitrous oxide (NOx)

* 60 tons of HAPs

PROCESS MODIFICATION TECHNOLOGY

By replacing RTOs with process modification processes, an avoided capital cost is estimated at US$ 7.7 million per facility. The costs of implementing the technology are estimated at 5% of the conventional process, for a total capital outlay of US$ 0.4 million per mill. Operating costs are expected to be minimal.

Capital costs are expected to be US$ 400,000, so the potential return to the host is estimated at US$ 7.3 million of avoided capital. Replacing RTOs also translates to US$ 2.0 million avoided total annual operating expense per plant. Other potential returns to research partners include new or modified equipment manufacturing.

The timeline for implementation is one to two years. During this time, process and emission evaluations, process modification and implementation, and emission verification will take place. Key assets needed at each facility include: scientific expertise (24 man/months), facility/process expertise in the host company of 12 man/months, and control and monitoring equipment. This is expected to cost US$ 250,000/yr for a total of US$ 500,000 to implement.

THERMAL PLASMA TECHNOLOGY

As with process modification technology, an avoided capital cost is estimated at US$ 7.7 million per mill by replacing RTOs. The costs of putting plasma technology into practice are estimated at 50% or more of a conventional process, which translates to total capital of US$ 3.85 million per plant. It is anticipated that annual operating costs will be approximately US$ 750 thousand per facility.

Potential return to the host is US$ 3.85 million of avoided capital and US$ 750,000 avoided annual operating expense per facility. Other potential returns include operational flexibility. Equipment manufacturers will also benefit from implementation. The timeline for implementation of thermal plasma technology is three to five years. During this time, proof of process, economic analysis, commercial size scale-up, deployment, and verification must occur.

Key assets required include: scientific expertise (36-48 man/months), process expertise in the host company of 24 man/months, and control and monitoring equipment. This is estimated to cost an average of US$ 1.5 million/yr for three years.

Table 1 provides a comparison of implementing process modification versus thermal plasma technology in wood product manufacturing facilities affected by MACT rules.

LOWER TOTAL COSTS?

Control of VOC/HAP emissions with current technology could cost the wood products industry more than US$ 800 million between now and 2009. Process modifications promise the greatest near-term benefits at a lower total cost. Non-thermal plasma technology promises longer-term benefits to the industry, but at a higher cost. With MACT rules still being challenged by environmental groups, the number of affected mills remains to be seen; however, additional research being funded by Agenda 2020 will continue to provide tools for industry compliance.

Technology    Avoided  New         Net      RTO     New
              Capital  Technology  Capital  Total   Technology
              Cost     Capital     Savings  Annual  Operating
              (RTO)    Cost                 Cost    Cost

Process       $7.70    $0.39       $7.32    $2.00   $0.10
Modification
Thermal       $7.70    $3.85       $3.85    $2.00   $0.75
Plasma

Technology    Potential  Implementation  Asset  Industry
              Annual                     Costs  Savings
              Return                            by 2009 (2)

Process       $1.90      1-2 years       $0.25  $816
Modification                             X 2 =
                                         $0.50
Thermal       $1.25      3-5 years       $1.50  $280
Plasma                                   X 3 =
                                         $4.50

(1) Costs and returns shown on an annual per facility basis.
(2) Industry savings estimated based on 50 OSB facilities X [Net capital
savings + potential annual return X (5 yrs) - asset costs]. Special
thanks to David Word of NCASI for RTO cost estimates.

Table 1. Comparison of implementing process modification versus thermal
plasma technology in oriented strand board manufacturing facilities
affected by MACT rules (US$ millions). (1)

WHAT YOU WILL LEARN:

* Details about the MACT regulations that require VOC-HAP compliance.

* The two technologies recommended by Agenda 2020-funded research.

* The costs and benefits associated with each compliance method.

ADDITIONAL RESOURCES:

* "Agenda 2020: Delivering value, improving industry economics," by Del Raymond and Ben Thorp, Solutions! February 2004, Product Code: 04FEBSO06. (Enter product code in search field on www.tappi.org).

* "The technology platforms of Agenda 2020," by Del Raymond and Ben Thorp, Solutions! July 2004, Product Code: 04JULSO45.

ABOUT THE AUTHORS:

Timothy G. Hunt is the senior director of air quality programs at the American Forest & Paper Association, Washington, D.C., USA. Prior to joining AF & PA in 2000, Hunt worked for the American Petroleum Institute (API) where he was manager of environmental issues for four years. He received his Master's degree in City and Regional Planning from Harvard's Kennedy School of Government.

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Eddie W. Price, Ph.D. is director technical services building products. Since 1988 he has been manager of Georgia-Pacific's Wood Products Service Group at the Research and Development Lab in Decatur, Georgia. He earned his Ph.D. in Materials Engineering from the University of Illinois, and has written more than 50 technical papers.

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John "Buddy" Showalter, P.E., joined the American Forest & Paper Association staff in 1992, and serves as director of technical media for the American Wood Council (AWC). He coordinates the efforts of AF & PA's Agenda 2020 Wood and Wood Composites Task Group, which is responsible for development of industry research RFPs and review of research conducted by government agencies like the USDA Forest Service and Department of Energy.

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