Dan Freeman, Fenco

The production of sulphuric acid is generally a cost centre. The operation has no cash flow and must vie for maintenance resources in a crowded arena of other cost centers arguing strenuously for an equitable share to prevent “imminent failure”. Typically acid plants suffer a slow failure process, which permits timely intervention. Anyone can distinguish abject failure of a component and plan its rehabilitation. Within the sulphuric acid plant, it is the tracking of detailed history, non-destructive testing and on-line performance that allows for meaningful prediction and resource allocation. This presentation will highlight some of data collection and collation methods that can be used.

Terry Baker of PCS Phosphates & Bob Fell of MECS

The largest sulfuric acid plant in North America was recently placed into operation for PCS Phosphate Company, Inc. in Aurora, NC. This 4500 STPD sulfur burning plant was designed and built by MECS, Inc. of St Louis, MO. The plant includes MECS Heat Recovery System (HRS) which recovers waste heat from the sulfuric acid process. The new plant recovers 95% of the heat generated and supplies approximately 700,000 pounds per hour of steam to the turbogenerator and fertilizer complex. Utilizing the steam recovered from the sulfuric acid process saves approximately 800,000 tons of carbon dioxide per year that would otherwise be emitted by burning coal at the plant site to generate the same level of steam. In addition, the plant is also designed to high environmental standards and the emissions for this plant are half of the current US EPA standard for SO2 emissions. This paper will cover the performance and features of the new plant such as ZeCor acid towers, large single compressor, cylindrical superheater and novel expansion joints.

Thomas H. Kroeger, PE, Vice President, Kirk & Blum, a CECO Environmental Company

This paper will review and update traditional design parameters in industrial ventilation and process dust collection with integration of new NFPA regulations.
Points covered will be:

• Increased awareness of need for appropriate for in-plant hygiene
• Role played by dust collection systems
• Efficiency of traditional dust collection systems
• Benefits of considering process modifications to reduce dust collection requirements
• Impacts of NFPA regulations on system design
• Impacts of NFPA regulations on equipment selection
• Need for monitoring and maintenance
• Role of Makeup Air in complementing performance of dust collection system

Objective will be to raise awareness of participants of challenges, opportunities and options available to them in evaluating new and existing dust collection systems.

Rick Davis, P.E., Davis & Associates Consulting

This paper will examine how a sulphuric acid plant operator, implemented plant changes to react to changes in environmental regulation and the marketplace. The paper will examine how technical options were evaluated and a plan was developed to meet their corporate objectives and governmental requirements.

The plant was built as part of the World War II war effort to expand the country’s production capacity of ammonium nitrate. Over the years the site has been transformed to meet a changing marketplace. The sulphuric acid plant originally supported the production of concentrated nitric acid, which is not required now. Currently, the plant produces acid for the regional merchant acid market.

The plant owner was faced with increasing environmental concerns to reduce the sulphur dioxide and acid mist emissions from their sulphuric acid plant. Davis & Associates Consulting, Inc. (DAC) was retained to review the possible routes to reduce emissions. The paper will provide an overview of the abatement options considered.

After extensive review, it was decided that the conversion to double absorption was the best option. DAC offered various double absorption options and two cost estimates were developed. DAC was given the go ahead to finish the engineering on August 15, 2007 with a targeted start-up date of June 30, 2008.

DAC worked with Penn Pro of Mulberry, Florida to perform the detailed engineering. With the tight project schedule the procurement of major equipment quickly became critical. The paper will review the project execution of this fast track project and how the owner and DAC put together an effective project team for the design, procurement, construction, and the successful commissioning of the plant.

Dr. Juergen Weinerth, Friatec AG - Rheinhütte Pumps Division

Sulphuric acid is an important raw material in the chemical industry and represents a particularly aggressive medium for all materials. This is why some materials from the range of metallic alloys, plastics and ceramic materials are presented as materials for building pumps in the sulphuric acid medium (H2SO4). For this, attention should be directed particularly to the limits to use related to temperature and concentration. These limits to use are discussed here against the background of typical sulphuric acid media in the production of sulphuric acid and the application as desiccator acid. This is where the Friatec Rheinhütte Company’s experience in chemical plant construction from over 100 years of pump building comes into play.

Don Kelley, Ashland Composite Polymers

The composition or chemistry of fiberglass-reinforced plastic (FRP) resins can be quite diverse resulting in FRP that is suitable for a given chemical environment or FRP that is not suitable. The chemical resistance of FRP is mostly dependent on the composition of the resin that is used to encapsulate the glass fibers and lock them into the desired shape. The purpose of this paper is to give an overview of resin chemistries that are used with FRP in various chemical environments and how these chemistries affect its performance.

Dr. Girish Srinivias, TDA Research, Inc.

TDA is developing a Cs V2O5/SiO2 based catalyst for SO2 oxidation that contains a proprietary promoter that allows it to operate at temperatures as low as 340„aC when used in the 4th bed of the SO2 converter in a sulfuric acid plant. The presentation will illustrate the conversion possible with TDA¡¦s low temperature catalyst compared to a conventional SO2 oxidation catalyst. By using TDA¡¦s SO2 oxidation catalyst and operating at 340„aC, the maximum thermodynamic conversion limit is 99.89%. The study shows that we obtained 99.6% experimentally under 4th bed conditions, which is substantially higher than the 98.8% measured using a commercial catalyst at ~400„aC. No deactivation was observed over the course of 900 hours of laboratory testing (again 4th bed conditions) for two separate tests with the same catalyst.

With funding from the Department of Energy, TDA synthesized and tested a series of catalysts and compared their activities to several commercial catalysts. We are currently optimizing our catalyst formulation and making reaction rate and other kinetic measurements. We will scale up the catalyst and carry out bench scale demonstrations with the scaled up formulations.

Donal Tunks, Jacobs Engineering

No matter the industry, every company is looking for ways to reduce costs and increase profits. In the manufacture of diammonium phosphate fertilizer (DAP), there are many methods available to cut costs which are not being utilized as much as they should. This paper will focus on various design options that yield a high rate of return on investment. The design options that will be investigated are as follows:

* Granulator Pipe Reactor in conjunction with a Preneutralizer
* Dual Mole Scrubbing
* Recycling Dedust Gas to the Combustion Chamber
* Ammonia Vaporization using Tail Gas Scrubber Liquor
* Ammonia Air Chiller

These options result in a reduction of fuel consumption in the Dryer, a reduction of citrate insoluble P2O5, and reduction in the amount of strong phosphoric acid needed which increases the amount of power that can be generated from sulfuric acid production. Each one of these options will be compared against a base case that does not contain any of these options to determine the rate of return of investment for each. Then a final case including all of the design options will be compared against the base case.