what is the best replacement for TCE as a cleaning solvent?
373023
Ultrasonic cleaners might be the best solution.\n\nHere is an excerpt from the source listed below: \n\nAlthough a range of possible alternative products is available today, experience has shown that substitution of TRI is not easy and even not feasible for a number of specific cases, either for technical or economical reasons. For all cases, substitution of TRI needs a thorough evaluation of all process aspects. For this reason we intend to work with the authorities in order to prevent a blanket implementation of forced substitution, and allow sustainable and continued safe use of TRI. \n\nThe alternatives you will probably consider first are the chlorinated solvents perchloroethylene (PER) and methylene chloride (MC). They match closest the technical features of TRI, such as non-flammability, high solvency power, a wide range of material compatibility and excellent drying and recycling properties.\n\nBeside PER and MC, you have probably also heard about other alternatives such as aqueous (water-based) alkaline systems, flammable solvents (e.g. hydrocarbons or modified alcohol based formulations), supercritical CO2 or hydrofluorocarbons (HFCs), etc.\n\nIt is impossible to say definitively which technology is best. That depends on your specific application, on what you are cleaning, which materials you want to remove, the cleanliness required, the variability of the parts cleaned, the throughput to be achieved, the cycle times, etc. \n\nFor example, for the cleaning of parts between two water-based manufacturing steps (e.g. galvanising), aqueous systems may be better, since parts are put into water phase again later and no energy-intensive drying step to remove the water is required. \n\nIf you need to have very clean and dry surfaces (for coating or surface hardening, for example) and if you have a variety of different metals or blind holes, narrow distances and very fine orifices or a lot of residual oil to clean, hydrocarbons or aqueous systems may not clean and dry well enough. In these cases, chlorinated solvents will offer most often the best solution as they are compatible with most materials, have a high cleaning power, are easy to dry, don't leave residual films and are easy to recycle with high quality by distillation. In addition, chlorinated solvents are today best suited to be used in modern closed systems with minimal losses. Their ecological performance has very much increased and, when used in well-operated metal cleaning systems, they outperform aqueous cleaning as long as drying is required. This has been shown by a Life Cycle Analysis carried out by Ecobilan. \n\nPER comes closest to TRI in technical performance and is often the first choice candidate as an alternative to TRI. However, it shows clear inherent technical differences, which need to be taken into consideration. On one side, PER offers a lower volatility and therefore is advantageous to minimise emissions in closed equipment. On the other side, PER has a lower solvency power and is therefore normally used at a higher cleaning temperature to achieve similar performance. This may raise concerns regarding the compatibility with specific metal working fluids and temperature-sensitive parts. \n\nMethylene chloride (MC) shows excellent cleaning properties already at low temperatures, favouring the cleaning of temperature sensitive parts. However, its high volatility makes emission control more difficult and requires special equipment.\n\nHydrofluorocarbons (HFC) and hydrofluorocarbon ethers (HFCE) are very expensive and show very limited solvency power. A thorough evaluation of the global warming potential is also required to choose the adequate product.
458582
Nuetrogena.I used to use it all the time but i don't need to anymore.
42178
Spot Shot (tm)... \n\nIt also depends on what the stain is... \n\nFor me it's Carbona(tm) for food stuff and Spot Shot(tm) for pet stains
29189
WD-40, pal.  Works like a charm.  You may have to scrub it off with a wire brush, but the 40 works on everything.  Try to keep a couple cans around the house.
483391
I'd sure be cautious with any Methylene Chloride!  It is highly volatile and it is a carcinogen.  Nasty stuff!  I would first try a strong detergent and steam.  Steam will loosen a lot of compounds that you wouldn't expect to respond to heat and water alone.\n\nJohnny
74385
I also vote for Coke. We use it at home to remove rust from screws and bolts.
749652
try it out yourself, but kitty litter is the same stuff they use in machine shops to clean up oil spills.\nthere is your hint on which one is quickest.
666889
Part of pharmaceutical manufacture involves solvents such as isopropyl alcohol which are driven off during the process. Typically, the volatile solvents are incinerated because letting them just go to the atmosphere is considered pollution.  An attractive option to VOC incineration is solvent recovery. This is a process whereby the process hydrocarbon is sent not to an incinerator but to a bed of activated carbon or zeolite. This material has the unique property by which hydrocarbons are highly attracted and adsorb to it. This functionally filters the hydrocarbon from the process stream effectively removing the pollutant.  The hydrocarbon on the carbon may then be de-sorbed and processed such that the hydrocarbon is recovered. The recovered hydrocarbon may then be re-processed, saving the manufacturer the cost for more solvent. This amounts to a huge cost savings in manufacturing the product, as upwards of 95% or more of the solvent is driven off the product and upwards of 98% of the solvent is filtered from the stream. That means that more than 93% of the solvent may be recovered and reused. Solvent recovery systems, when properly applied will actually pay for themselfs in recovered solvent within 2 years.
585025
I don't know that you can, different solvents react differently to pressure, so I don't think it's a one eqaution fits all kind of process.  That's why they all have different graphs for phase vs temperature/pressure.  I'm sorry.\nSounds like you have a pretty high boiling point though, the things I've taken off that had to be real high temp were water, toluene, and pyridine.  Could it be one of them?  They smell pretty different, so you'd know which.  \nThat's an interesting question though, I've never stripped a solvent that I didn't know what it was.
22413
I would recommend looking into a study of a cleaning(cleanability vs surface finish) for processing equipment in the pharmaceutical industries. This has not been performed to my knowledge(I have thought about performing and writing a paper but haven't had the time), should be reasonably simple to to perform, and would open oppertunities into a growth industry.
480971
acetates are ionic, and will more easily dissolve in water than an oil. thats your best bet.
583395
hmmm! go to this site>>>\n Candidate Reagents for Dissolution of Hanford Site Tank Sludges ...File Format: PDF/Adobe Acrobat - View as HTML\nIn none of the 5 runs with these compounds was the complete dissolution of ... acidic or moderately alkaline media without perturbing the oxidation state of ...\n \n  >>>> www.pnl.gov/main/publications/ external/technical_reports/PNNL-14378.pdf
610973
hi, \n\nacetone will do the job nicely.\n\nbe careful, though, it essentially is making napalm.\n\nhere is a list of the effects of variuos solvents, though i think it's on bulk polyurethane, not the foam:\nhttp://www.rimnetics.com/rimsolventsheet.htm\n\nanything there that says breaking, collapse or degradation would probably eat the foam up.\n\ncheers!
677148
I used to buy a product from Exxon called Varsol.  You can use gasoline also.
1035975
Small area:  Use paint remover (paint stripper for furniture).\nPaint remover (the original kind) uses methylene chloride to soften the paint so it can be removed easily.  Problem:  methylene chloride evaporates very quickly.  Possible solution:  after applying the stripper, put a plastic polyethlyene sheet over the paint to keep the methylene chloride from evaporating so quick (work on cool days/evenings too).  Methylene chloride works on epoxy based paints which are normally chemically resistant.  Methylene chloride is becoming harder to get because of VOC requirements and CFC considerations.\n\nLarge area:  use sodium hydroxide (lye) or Drano crystals or similar caustic.  **Concentrated** (saturated solution) lye will soften the paint so it can be brushed away.  Its less expensive than paint stripper.\n\nPLEASE READ CAREFULLY:  \n\nYou are going to have a disposal problem - don't wash it down the drain or you may be fined.  The EPA monitors the drains for polluters.  \n\nThese are very hazardous chemicals that require respirators, adequate air, protective chemical equipment (rubber gloves, face shields), the area needs to be isolated so a pet or kids don't come in contact with the chemicals.  If you won't take these precautions or don't know what you're doing, call a professional.  Truly.\n\nFor the methylene chloride residue: pickup the old paint residue and let it dry out.  Then you can dispose of the residue in plastic bags in the garbage (dry paint is considered non-hazardous in most areas, but not all - contact your waste management service).\n\nThe lye will soften the paint and can be dried out, but even the dried crystals can be hazardous if water is re-introduced - you may be able to neutralize the waste with a weak acid like vinegar to neutral pH, and then dry it out and dispose of it.  You'll need some pH strips to test for neutral pH.  Dried, neutral pH paint can be disposed the same way as regular dried paint - the exact method depends on where you live and your waste disposal service.  Most areas have free disposal days for hazardous waste if you are otherwise required to pay.\n\nBE CAREFUL with powerful chemicals and USE PRECAUTIONS so you don't hurt yourself, or others.\n\nAnother method: Sandblast.  Look up a sandblast service in the Yellow pages and they'll come out with their portable blasting unit.  Paint removal is their job.  I can't advise further because I don't know the constraints, paint type, substrate, enclosed area, etc.  \n\nMost paints are acid-resistant to some degree, so muratic isn't effective; most paints ARE vulnerable to alkaline solutions (but not all).  Concrete is an alkaline material, so won't be attacked to the same degree as with nuratic acid.  Muratic acid will attack and eat up the concrete (maybe that's what you want, but probably not).
410501
i really like loreal kids chlorine and dirt remover. it's works great, smells good, and it's inexpensive!
41206
I used to use some stuff called "CLR" that used to work fairly well.  I've been told coke will work, vinegar, basically anything acidic will "eat" the gunk off.