| Distillation is the simple process of heating a mixture | | | | environment of the facility is unusually hot. The water |
| of ingredients until a solvent or other selected | | | | cooled condenser will then be more efficient. |
| material evaporates-then cooling and condensing that | | | | Solvent recyclers are fairly unique among tools in |
| vapor into a pure liquid. Alcohol has been produced | | | | industry in that they do almost all the work on their |
| this way since time immemorial and today the | | | | own. About the only thing you need to do is fill the |
| process is being used by large and small companies | | | | tank (either manually for small machines or |
| to reduce their waste streams and recover reusable | | | | automatically for large), turn on the machine and |
| products, thus saving significant cost. | | | | remove the solid material that is left after the |
| The ability to easily recycle solvents in-house has | | | | process. In the case of large automated machines, |
| developed over the past 20 odd years with the | | | | even the waste is removed without manual |
| advent of batch stills. These solvent recycling units | | | | intervention. |
| ranging in size from 2 gallons per batch up to | | | | Any organization using solvents on a continual basis is |
| equipment handling one hundred gallons per batch | | | | a potential candidate for a solvent recycler. In |
| have made it cost effective for companies to | | | | addition, any organization using a waste hauling |
| consider replacing expensive service companies. In | | | | service would be well advised to do a payback |
| recent times even larger units have been developed | | | | analysis on the purchase of a solvent recycler. Here is |
| which can work either stand alone or built into a | | | | the way to determine the degree to which you will |
| process system to reduce or eliminate the needs for | | | | benefit from owning a solvent recycler: |
| full time personnel to over see the operation. | | | | First, figure what you are paying per year to have |
| These solvent recyclers save money in two ways: | | | | your dirty solvent or waste hauled off (generally |
| by recycling used solvents for reuse and eliminating | | | | from $100 to $400 per drum, depending upon the |
| most (and sometimes all) of the expense of | | | | content and where you reside). Add this number to |
| disposing of the hazardous waste. Although even the | | | | the cost of purchasing replacement solvent for about |
| smallest solvent recyclers cost several thousand | | | | 80% of the volume of the sludge-or 95% of the |
| dollars, they can easily pay for themselves in a year | | | | volume of the solvent waste you are recycling with a |
| or two. In the case of large scale continuous | | | | service company. The exact percentages will vary |
| operation equipment, it may be surprising to learn | | | | depending on how much of the material is solid |
| that the payback can easily be justified in less than | | | | waste). Then, weigh this figure against the price of a |
| one year. In fact in certain process industries the | | | | solvent recycler and determine how long it will take |
| equipment vendors recommend the purchase of a | | | | for your savings to pay for it. |
| solvent recycler to defray the cost of the | | | | As an example, let us say you generate one drum of |
| exceedingly expensive solvents required in their | | | | waste every month; let us say that it costs $300 to |
| equipment. | | | | have the drum hauled away and that you pay $800 |
| When one examines the amount of waste generated | | | | once a month for two new drums of solvent. Let us |
| in industry, and the costs associated with its handling, | | | | also estimate that you only have 50% of the solvent |
| it becomes evident that waste has a major economic | | | | to recover after use before recycling. |
| impact on the performance of most businesses. If | | | | The following calculation indicates your potential |
| you consider all the waste as product, then what | | | | yearly savings: Add $3,600 (the cost of having |
| value would that waste have to the average | | | | twelve drums of waste solvent hauled off) to $3,840 |
| business. Clearly, the best solution to hazardous | | | | (80% of $4,800, which represents the cost of |
| waste is to NOT make as much of it! Given that a | | | | replacing the half of the solvent that remains after |
| business is a successful entity, that success will | | | | use). That works out to a savings of $7,440 in one |
| create more hazardous waste problems. Just as the | | | | year, which comes close to the cost of a small |
| quality of your work and throughput affect your | | | | recycler. Multiply this by the large volumes generated |
| businesss' competitive edge, so too can hazardous | | | | by industry in manufacturing, painting, printing, etc. |
| waste and its disposition. Thus, in-house solvent | | | | The potential for savings is enormous. |
| recycling must be considered as a relevant solution to | | | | If a solvent recycler is of interest to your |
| the hazardous waste problem. | | | | organization, the next step in the process is finding |
| It also must be said that solvent recyclers are good | | | | one that suits your needs. Here are some questions |
| for the environment: They make it possible to use | | | | to consider: |
| the same material over and over radically reducing | | | | 1. Is the capacity of the solvent recycler adequate to |
| disposal and saving money by eliminating or reducing | | | | handle the volume produced? 2. Is the tank heated |
| purchase of new material. | | | | by steam, hot oil or by a direct electric element? |
| What are the considerations? Do you take on liability | | | | (Hot surround oil is widely regarded as the best |
| with EPA if you recycle? The answer is: yes, but it is | | | | option). 3. Is the solvent vapor cooled and condensed |
| the same liability you have with a service company. | | | | by coolant, water or fan? (A fan is generally |
| When a company buys potentially hazardous | | | | adequate for small units and is considerably cheaper. |
| materials, they acquire cradle to grave liability. This is | | | | For large units the conditions must be considered to |
| also acquired when using a service company. That | | | | determine which solution is sufficient.) 4. Is the |
| being the case, there is no reason not to look at | | | | supplier capable of supporting maintenance issues if |
| in-house recycling as an alternative to service | | | | they occur? Are parts readily available? 5. Check |
| company costs. | | | | references for reliability of the equipment in general |
| There are two types of solvent recyclers: continuous | | | | and in your industry in specific. What is the vendor's |
| and batch. | | | | track record? |
| Continuous solvent recyclers use in-line or auto-fill | | | | Once you determine the features of the equipment |
| technology-that is, dirty solvent flows into one end | | | | that will do the job for your organization, go out and |
| and clean solvent comes out the other. This solution, | | | | solicit quotations from several venders as with any |
| available in varying volume capabilities, is used in | | | | capital purchase. At this point it will take some |
| industrial applications by large generators of solvent. | | | | intuitive judgement to determine which vender can |
| By contrast, batch solvent recyclers distill one load of | | | | provide the right solution. More times than not, price |
| solvent at a time over a period of several hours. | | | | should not be the determining factor in the acquisition. |
| The principal components in any solvent recycler are | | | | Do the homework and you will make the correct |
| a tank in which the waste is deposited, a heating | | | | choice. Remember, as with all capital purchases, once |
| system for turning the liquid part of the waste into | | | | you purchase a solution you will have to live with it |
| vapor and a condenser to cool the vapor back into a | | | | for a long time. |
| liquid. | | | | On the good side, the organization who chooses to |
| The size of the tank determines the size of the | | | | recycle gains several benefits. The reduction of the |
| solvent recycler. Methods of heating include steam, | | | | waste stream is obvious as is the cost savings. The |
| direct heat (using an electric heating element or heat | | | | green image that accrues to the company is valuable |
| plate) and indirect heat (where an oil bath surrounding | | | | to its position as a good neighbor in the community. |
| the tank is heated by direct electric heat). Indirect | | | | It is hard to put a value on this aspect, yet its |
| heat is usually the preferred approach because the | | | | benefit is great. |
| heating is more uniform. | | | | With society's increasing concern for protecting the |
| The condenser is most often a series of looped | | | | environment, it only makes sense (both for the sake |
| copper or stainless steel coils (resembling a car | | | | of the environment and for the cost savings) to |
| radiator) that are cooled by a built-in fan or | | | | recycle your used solvents. Regardless of the size of |
| surrounded by water or coolant to chill the vapor | | | | the equipment needed, the decision to recycle |
| back into a liquid. Cooling by air is less expensive than | | | | in-house almost always shows a positive return on |
| cooling by water or coolant and is adequate for small, | | | | investment. With ever more difficult conditions to |
| batch type solvent recyclers. Water cooled | | | | earn a profit, more and more organizations are |
| condensers may be necessary for applications where | | | | turning to solvent recycling units to reduce cost and |
| the condensing temperature is particularly low or the | | | | save money. |