FUMING ACIDS SPILL MITIGATION TRAINING

Transcription

1 AIChE Central Flrida Sectin 2017 Clearwater Cnference June 10, 2017 Mark Salzbrenner, P.E. Brad Van Scik Velia Nrth America Regeneratin Services FUMING ACIDS SPILL MITIGATION TRAINING

2 FUMING ACIDS SPILL MITIGATION TRAINING Sulfur based fuming acids such as leums, sulfur trixide and chlr-sulfnic acid are essential chemicals in tday s sciety. They are imprtant chemicals in the manufacture f pharmaceuticals, shamps, detergents, surfactants, flurchemicals, agricultural prducts, lubricants, in exchange resins, rubbers and plastics. In fact, it can be said, ne can tell the standard f living f a sciety by hw much fuming acids are cnsumed. The mre acids cnsumed, the higher the standard f living. Incidents invlving the fuming sulfuric acids are rare. Even s, Fuming acids can be a prblem if they are nt handled prperly. Relatively small leaks r spills can have a tremendus visual effect. The dense, whitish fumes can be easily seen and may travel lng distances depending n weather cnditins. The acid mist clud is visible dwn t abut 3 ppm in the air. This prduces terrific vide shts fr the lcal and smetimes natinal televisin news. Our jb is t first have the discipline t fllw gd prcess management prcedures s that we dn t have leaks r spills with these prducts. And, secndly, t have the prper trained persnnel and equipment in place t minimize the effects f any accidental release that may ccur. The purpse f the Fuming Acids Spill Mitigatin Training Wrkshp is t present the spill mitigatin techniques and prcedures that have prven effective fr the businesses that make, transprt and use fuming acids. Much f the practical knwledge has been cmpiled during the Fuming Acids Spill Mitigatin Wrkshps spnsred by Velia and its prir cmpanies. These wrkshps have been held at the United States Department f Energy s Hazmat Spill Center lcated in Mercury, Nevada. This facility has been designed by the U.S.D.O.E. t allw live spills f varius prducts with n detrimental effect n the surrunding envirnment. The bjectives f the wrkshp are: 1) Train in mitigatin technlgy and visually cmpare different mitigatin techniques; 2) Witness fume cluds which result frm the release f the fuming acids; 3) Reinfrce the imprtance f keeping the acids cntained in the prper tanks, piping and equipment, and: 4) Enhance emergency preparedness fr the fuming acids prducers, cnsumers and lcal cmmunity stakehlders. Fuming Acid Prperties: Fuming sulfuric acids are strng inrganic acids that are clear, t slightly straw clred. They have a sharp irritating dr, are nn-flammable and react vilently with water. SO3 and leums prduce vaprs f SO3, which react with misture in the air t prduce particles f sulfuric acid mist. CSA releases a mixture f HCl and SO3. Here are standard physical prperties: Prperties 65% Oleum SO3 CSA Mlecular Wt 178 (apprx) Melting Pt (C) Biling Pt (C) Vapr Pressure (mmhg) Density (g/cc) Viscsity (cp)

3 Fuming Acid Hazards: A spill r accidental release f fuming acids creates 2 types f ptential hazards, ne frm the liquid pl and ne frm the acid mist clud. Liquid The liquid pl is a strng mineral acid. It is a stable but dangerusly reactive liquid. It will react vilently with water, if the water is added imprperly. The reactins are highly exthermic. The acid is nn-cmbustible, but may react with rganics (paper, sawdust, il, etc.) and generate enugh heat t aut-cmbust. Will cause immediate skin r eye burns n cntact. Acid Mist Vaprs react instantly with atmspheric misture t create very fine sulfuric acid mist drplets r particles. Any spill/release will result in a dense white, highly visible acidic clud. Clud may g ff-site, depending n weather cnditins and size f release Inhalatin f mists may cause irritatin (r wrse) f the nse, thrat and/r lungs. Severe ver-expsure can be life threatening. Mitigatin Techniques General Inf: Water cnverts the fuming acids t a nn-fuming sulfuric acid slutin. H 2O + SO 3 H 2SO 4 plus heat (fr leums and Sulfur Trixide) H 2O + HSO 3 Cl H 2SO 4 + HCl plus heat (fr Chlrsulfnic acid) The water must be added in a cntrlled manner t avid undesired effects. Tw primary mitigatin techniques are taught at the wrkshps: water spray and mid-expansin fam additin. Other techniques have been tried n an experimental basis with varying success, such as the applicatin f dry chemicals, silica pwders, mineral il, flurchemical il and limestne rcks. N matter which mitigatin technique is used, when mitigatin is first started, the fume release will initially lk wrse. This is t be expected due t the heat f reactin f acids with water. The

4 temperature rise increases the vapr pressure f the slutin resulting in higher fume evlutin, and larger visible cluds. Very quickly after mitigatin is started, the fuming will cease, but yu have t g thrugh the reactin stage first, which fr mst spills shuld nly last fr a few secnds r minutes. This lack f understanding has been a prblem during actual release events in the past. Be sure that the lcal respnders knw this will ccur and are prepared fr it s they d nt shut dwn the mitigatin n the initial increase f fumes. When this happens, it simply makes the situatin wrse. Belw is a list f the cmmn fuming sulfuric acid grades and their equivalent sulfuric acid strength. 20% Oleum 104.5% H 2SO 4 25% Oleum 105.6% H 2SO 4 30% Oleum 106.8% H 2SO 4 65% Oleum 114.6% H 2SO 4 SO % H 2SO 4 Enugh water must be added t dilute these grades dwn t less than 100% H 2SO 4. If the water is nt artificially added, the fuming will cntinue until it absrbs enugh water frm the grund r air t dilute itself t the less than 100% H 2SO 4 strength[ms1][ms2]. Once the liquid pl is belw 100% H 2SO 4 strength, fuming will stp. Yu will still have a strng, ht, liquid acid t cntend with fr remediatin, but the fuming will have ceased, eliminating the vapr hazard frm the emergency respnse equatin. Water Spray: A fine mist water spray is the technique typically fund mst effective fr spills. The water fine mist (fg pattern) shuld be sprayed ver the entire surface frm the upwind side. The fg pattern shuld be verified befre spraying n the spill. Streams f water must be avided because f vilent interactin between the fuming acids and water. Steam generated by streams f water can cause acid t be ejected vilently frm the liquid spill pl. Water fg additin causes a rapid temperature increase, which results in a temprary fume evlutin increase. As mre water is added, the fuming acid will be cmpletely reacted with water and the fuming immediately stps. At that pint there are nly wisps f vapr, mstly steam, cming frm the slutin. Fr the 10 galln fuming acid spills tested at the Spill Mitigatin Training, the average time t mitigate the fuming was less than 2 minutes. Rule f Thumb fr Water Additin: 1 galln f water fr 12 gallns f 20% Oleum 1 galln f water fr 3 gallns f 65% Oleum 1 galln f water fr 2.5 gallns f SO 3 1 galln f water fr 4 gallns f CSA

5 Advantages: Usually quickest respnse technique Readily available equipment Fuming usually stps in under 5 minutes (depending n spill size) Disadvantages: Initial applicatin will cause fuming increase Initial rapid temperature increase Prduces crrsive weak sulfuric acid Fam Applicatin: Fam applicatin was als successfully tested fr the mitigatin f the fuming acids. Fam wrks in tw ways. The primary benefit is that the fam prvides a very cntrlled way t intrduce water int fuming acids and dilute the fuming acids t nn-fuming acids. In additin, if the fam layer cmpletely cvers the surface f the spill, it des prvide sme fume suppressin while mitigatin is taking place. Fam additin als causes a temperature increase, which results in a temprary increase in fume evlutin, until the surface f the spill can be cmpletely cvered. Apply, r re-apply fam as needed t cmplete the reactin and the fuming stps. As with water spray mitigatin, it is very imprtant t avid streams f water being added t the spill pl. Therefre, befre applying the fam nt the fuming acid, it is essential that the line be cmpletely full f fam and gd fam is prduced at the nzzle. This can be dne by pening the fam nzzle ff t the side f the spill. Once gd quality fam is established, it can be applied t the fuming acid. Fr the fam mitigatin spills at the wrkshps, a wden ramp is used t gently rll the fam int the spill pan t avid plunging fam int the acid. The fam is applied by sweeping back and frth t cver the entire spill pan surface. Mid-expansin fams, arund 50 t 1 rati, have been fund t prduce the ptimal fam blanket fr vapr mitigatin. The water drains frm the mid-expansin fam better than lw-expansin r high expansin fams t get the desired dilutin results. The fam blanket may eventually char and degrade making it necessary t reapply. In the fam mitigatin tests cnducted, the cntrl time averaged ne and a half minutes. A number f fams have been tested ver the years. Previus fams have all been the C-8 (perflurctanic acid, r PFOA) cntaining variety. As f June 2016, the C-8 frmulatins are n lnger available fr envirnmental reasns. As part f the 2016 Fuming Acids Spill Mitigatin Wrkshp, we tested the new C-6 frmulatins which perfrmed similarly t the C-8 versins. The Alchl Resistant-Aqueus Film Frming Fams (AR-AFFF) wrked the best verall fr mitigating fuming. The AFFF fams als gave adequate results. The Class A fire-fighting fam was nt as effective as the AR-

6 AFFF r AFFF fams fr leums, and was significantly wrse at fume suppressin. Class A fam was nt effective fr CSA. Fams frm tw different fam manufacturers were tested and gave similar results. The effectiveness f the fams was mre dependent n fam type and amunt f expansin/quality versus differences in fam manufacturer. Fam Summary (average time t mitigate fuming fr 10 galln release): AR-AFFF 1-1/2 minutes AFFF 2 minutes Class A 4 minutes Advantages: Mre cntrlled way t slwly add water fr dilutin Fam blanket prvided sme fume suppressin Fuming usually stps in under 4 minutes (depending n spill size) Mst lcal fire departments carry either the AR-AFFF, AFFF r Class A fams Disadvantages: Requires specialized equipment t make adequate fam (high pressure water surce) Requires fam equipment and supplies readily available Takes lnger t set up than water spray Initial applicatin will cause fuming increase Prduces crrsive weak sulfuric acid Spill Mitigatin Summary and Recmmendatins: Fuming Acids can create large billwing white clud if released frm cntainment. The clud itself is nt amenable t Knck Dwn with a water spray/cannn. Train yur emplyees n the prper techniques t mitigate a fuming acid release and practice regularly. Train yur lcal cmmunity HazMat respnders n what t expect if a release ccurs, and the apprpriate mitigatin techniques t use. SDS s and the 2016 Emergency Respnse Guidebk DO NOT cnvey all the nuances invlved in a fuming acid release and mitigatin.

7 N matter what mitigatin technique used, the fuming will initially lk wrse, but will be cntrlled. Once yu start the mitigatin technique, KEEP GOING until the fuming stps. The fuming cannt be cmpletely mitigated until the surce f the release is stpped. Be prepared t cntrl the liquid prtin f the spill during/after mitigatin. In general, Shelter-in-Place is better than Evacuatin thrugh an acid mist clud. The Presenters: Mark J. Salzbrenner (Velia NA Regeneratin Services Acid Technlgy Center) has wrked in the chemical/refining industry since 1975, and is currently the Chairman f the Velia Fuming Acids Safety Guardian Cmmittee. He has wrked with DuPnt/Chemurs/Velia sulfuric acid prducts since Prir Experience includes Engineering, Technical, Prductin, Maintenance, Quality and Technical Services with several HTM s (fuming sulfuric acids, anhydrus ammnia, chlrine and fuming nitric acid) in varius chemical prcesses. In all he has 39 years experience wrking in High Hazard Prcesses and Emergency Respnse. He currently has a Prfessinal Engineering (PE) license frm the State f Delaware. He has been invlved with the Fuming Acids Spill Mitigatin Training sessins since the inceptin in Brad A. Van Scik (Velia NA Regeneratin Services Acid Technlgy Center) has wrked in High Hazard Chemical prcesses since 1990 invlving multiple Highly Txic Materials, and explsive and/r crrsive materials. He has been part f the DuPnt/Chemurs/Velia Acid Technlgy Center since 2007 and is the Technical Guardian fr 3 fuming acid prducts (CSA/specialized Oleum/anhydrus HCl). Previus experience acrss multiple business units includes wrk as Operatins Supervisr, 6 Sigma Black Belt, Quality Cntrl Labratry Area Manager, and SAP implementatin team leader. Brad lives in the Richmnd, VA area and is the Principal Engineer fr tw manufacturing lcatins. He has been an instructr at previus spill schls and was peratins directr fr the 2016 Fuming Acids Spill Mitigatin Wrkshp.