A large stainless steel and titanium pickling and finishing company had an issue with visible NOx fumes discharging out of one of their Midwest facilities. The plant had been tasked with the elimination of the fumes that were being generated from their various pickling baths they utilize. Visible threshold limits for NOx gas are generally 300-400 ppm depending on weather conditions. One of the facilities pickling baths is particularly aggressive and pickles a continuous titanium sheet on a coiler machine and has twice the residence time of other treatments in turn generating high levels of NOx. This can overwhelm the stack gas scrubber, causing NOx levels to rise well over 600 ppm with orange plumes emanating from the plant which are visible to the public.
The company’s environmental department reached out to USP Technologies (USP) for assistance. Initial discussions with USP confirmed successful implementation of their hydrogen peroxide (H2O2) technology to pickling baths can specifically inhibit NOx formation. USP had done prior work for stainless steel finishers and it was deemed the technology was transferrable to titanium processing.
On a mass basis, the H2O2 demand is a composite of that due to NO2 and NO, with the typical 50:50 ratio producing a theoretical demand of approximately 1.0 parts H2O2 per part NOx.
HNO2 + H2O2 → HNO3 + H2O Wt. ratio: 0.4
2NO + 3H2O2 → 2HNO3 + 2H2O Wt. ratio: 1.7
As shown in the reactions above, oxidation of NOx by H2O2 in-bath, produces nitric acid, thereby allowing recovery and reuse of a critical process reagent.
After initial testing, a full-scale demo was put in place for several months on the coiler bath at the plant. USP’s turn-key supply scope included 50 percent technical grade H2O2, a 3,000 gallon double walled bulk storage and an automated feed system. The turn-key system was solely maintained by USP. The program also included USP’s ChemWatch™ – advanced control system with remote telemetry, allowing tank monitoring for inventory and pump systems control and analysis.
The tank and pump system are located in the middle of the coil storage area. Since the delivery connection is outside of the building, the system employs a remote delivery alarm system. Results shown in Figure 1 demonstrates how after an initial high dose of H2O2 to treat the NOx that had already built up in the bath, the NOx emissions were effectively controlled with a steady feed rate of 5 gph.Read More Download Case Study_Pickling Bath-17-HR (pdf)
A gulf coast refinery was experiencing unacceptable hydrogen sulfide (H2S) releases into occupied work areas in the Coker unit during cutting & quenching operations. Refinery Coker units are used to process residual oil or ‘heavy ends’. A part of the coking process requires quenching the hot coke with water, resulting in latent hydrogen sulfide being transferred to the water stream and stripping into the vapor phase creating potential exposure risks to operations personnel. In order to protect worker s, hydrogen sulfides in the process water stream must be eliminated.
In late 2016, USP Technologies (USP), leaders in peroxygen-based technologies for industrial water and wastewater treatment applications, was contacted by the refinery in search of a viable solution for its H2S issues. USP recommended a full-service chemical treatment program which included 27% refinery grade hydrogen peroxide, chemical storage, a dosing equipment system, inventory analysis, logistics management, safety training and ongoing field and technical support.
Full-Service Hydrogen Peroxide Treatment Program
The refinery recycles coker quench water in a closed loop, where any chemical used for treatment cannot negatively impact the coking process. Under near neutral pH conditions, the theoretical weight ratio of H2O2:H2S is 1:1, and proceeds according to the following reaction:
H2O2 + H2S → S0 + 2 H2O
Since the products of the above reaction are water and inactive elemental sulfur, the chemistry does not negatively impact the batch coking process.Read More Download Case Study_Refinery Coker Quenchwater-18-HR (pdf)[/vc_column_text][/vc_column][/vc_row]
This paper describes the evolving odor control program of the City of Wichita, Kansas from 2008 to 2015. In 2010, the City reduced odor control technology expenditure due to a reduction of revenues. The odors increased resulting in an upswing in citizen complaints as well as more corrosion in existing plant and lift station equipment. In 2013, the City re-evaluated their existing technology approaches to odor control and implemented optimized chemical dosing strategies to maximize cost-effectiveness and provide wide-ranging benefits. USP Technologies (USP) partnered with the City to implement state of the art chemical dosing controls to efficiently target sulfides with their hydrogen peroxide (H2O2) and peroxide regenerated iron sulfide control (PRI-SC®) treatment programs. Implementing the proper treatment technology and chemical dosing controls resulted in dramatically reduced sulfide levels in both the liquid and gaseous phases while providing more cost-effective treatment.
Odor control, cost-conscious approach, Wichita, hydrogen sulfide, PRI-SC®, peroxide regenerated iron – sulfide control, hydrogen peroxide, ferrous chloride, RFQ process, odor complaints, corrosion controlRead More Download Wichita – OAP 2016 (pdf) Download Wichita Odor Control PPT – OAP 2016 (pdf)[/vc_column_text][/vc_column][/vc_row]
In 2015, a maintenance turnaround of the wastewater aeration tank was undertaken at United Refining Company in Warren, PA. During the planned 70 day turnaround, the refinery needed a temporary chemical oxidation program to maintain compliance with permitted effluent phenol levels. This paper will present data and key learnings from all phases of this successful project, including laboratory treatability testing, process design, full scale implementation and successful completion.
KEYWORDS: Phenol, Aeration Basin, Oxidation, Permanganate, Dissolved Air Flotation (DAF), Total Suspended Solids (TSS)
Read MoreDownload United Refining Company – IWC 2016 (pdf)[/vc_column_text][/vc_column][/vc_row]
ABSTRACTThis paper presents a systematic, step-by-step approach to assist utilities in developing an effective, priority-driven, sulfide and corrosion management plan for their collection systems. Along with aging infrastructure, utilities are faced with problems with high hydrogen sulfide and corrosion in their collection systems. One of the main challenges in addressing these concerns is developing a method to prioritize critical areas of concern for rehabilitation/replacement and/or corrosion treatment. The systematic approach presented herein provides a comprehensive means which includes six key steps as listed below:
- Identification of potential Critical Areas of Concern (CAC) for corrosion
- Review of current schedule for Capital Improvements Projects (CIPs)
- Risk assessment of interceptor condition and risk rating of CAC
- Evaluation of odor control and corrosion treatment methods
- Rating of interceptor repair and replacement techniques
- Development of corrosion management program (CMP)
The City of Tolleson, Arizona operates a 44.7 cubic meter per hour (m3/hr) [17 million gallon per day (mgd)] capacity, wastewater treatment plant (WWTP). Several residential and commercial developments have been built within ó kilometer of the Plant and odor complaints have increased. The Plant-wide odor control study was initiated in 2006 to determine the best long-term odor control approach. The initial results of the odor study, plus the urgency of the situation with adjacent neighborhoods, required immediate odor mitigation efforts – specifically by implementing an aggressive chemical addition program utilizing ferric chloride plus hydrogen peroxide. This chemical combination had been tried elsewhere, and had shown considerable success in reducing odors at trickling filters preceded by primary clarifiers. The test work demonstrated that the majority of sulfide reduction and odor control is accomplished with just ferric chloride. The addition of hydrogen peroxide produced approximately 30 percent reduction in sulfide and hydrogen sulfide emissions from the trickling filters.
KEYWORDS: Sulfide, ferric chloride, hydrogen peroxide, trickling filters, odor controlRead More Download Tolleson – WEFTEC 2009 (pdf)[/vc_column_text][/vc_column][/vc_row]
Shell Puget Sound Refinery (PSR) is a fully-integrated production facility that first went on stream in September 1958, initially processing up to 45,000 barrels of crude oil per day. Currently, the plant processes up to145,000 barrels (6.1 million gallons) of crude oil per day producing many useful products — including several grades of gasoline, fuel oil, diesel fuel, propane, butane, petroleum coke.
The Effluent Plant’s Bioreactor at Shell PSR is a three channel oxidation “ditch” style biotreater (a.k.a. Racetrack) built in the early 1990’s. The Bioreactor is a concrete basin with three 14’ deep channels. While the Bioreactor has gone through several upgrades over the years, including the addition of boat-type aerators and the recent addition of steel brush-type aerators, it was limited in aeration capacity to treat peak load, non-routine wastewater while maintaining target dissolved oxygen. Bioreactor aeration capacity required processing peak load wastewater at reduced rates and led to storage issues. The lack of dissolved oxygen in the first stage of the Bioreactor led to odors and subsequent complaints from neighboring communities. In an effort to process wastewater without odors, Shell would store (divert) the peak load material and process it back to the Bioreactor slowly.Read More Download Shell PSR Paper – WEFTEC 2013 (pdf)[/vc_column_text][/vc_column][/vc_row]
The paper will present results of a trial initiated in February 2004 by the San Antonio Water System (SAWS) to quantify the impacts of hydrogen peroxide injection prior to dissolved air flotation thickening of wastewater sludges. Since February 2000, the San Antonio Water System has successfully used iron salts (FeSO4) for odor and corrosion control in the Dos Rios Water Recycling Center (WRC) collection system. In May of 2003, the Dos Rios WRC began receiving about 300,000 gallons per day of a mixture of primary and waste activated sludges from SAWS’ Leon Creek WRC. When the Dos Rios WRC facility started receiving sludge from Leon Creek, several negative impacts were observed. Operators immediately noticed a significant increase in sulfide odors from the DAF units treating the Leon Creek sludge. In addition, a 2-3% decrease in percent solids of combined Leon Creek/Dos Rios belt filter press dewatered sludge was observed. In addition, volatile solids reduction through the anaerobic digestion process decreased dramatically. Finally, an expected increase in methane production due to increased sludge volume was not realized.Read More Download SAWS – WEFTEC 2006 (pdf)[/vc_column_text][/vc_column][/vc_row]