In 1999, a survey conducted by a leading publication in the chemical process industry found that reducing product development lifecycles was one of the greatest challenges in the industry.
This hurdle, as well as others, are part of the pressures found in a competitive specialty and commodity chemical industry that has seen a sizeable growth spurt from Asian markets - notably China - where a trade surplus of over $200 billion dollars exists. For most any chemical producer, every little bit counts. Any way that a chemical process can be made more efficient in time, labor, and material cost, may ultimately translate into a strategic advantage.
Each year, over $2 billion is invested in capital improvements for the chemical process industry. Filtration is one area in the capital equation often overlooked in helping to shave away the fat in the product development cycle.
The problem in specifying filtration for a chemical process is that many variables affect the proper filtration method and configuration. Each application needs to be considered and analyzed with the big production picture in mind. Here are five points to consider for the filtration in your operation:
1. Media Material
For chemical process applications, self-cleaning technology is ideal, as it requires less labor, product replacement and process interruption. However, one must consider the tradeoff between disposable filter media and the initial capital outlay of stainless steel, ceramics or other metal used in many self-cleaning filtration configurations - particularly in the biopharmaceutical market. Filtration media made of a porous ceramic material will often come out on top in a cost benefit analysis of disposable vs permanent filter media.
Media integrity is a key consideration. Any savings in labor time and quality may be trumped by poor integrity. Chemical leaching from the filtration media, tearing, breaking, and a breakdown in the integrity of the media for a certain fluid filtration application needs to be examined carefully before deciding on one filtration method over another.
2. Maintainability
The volume of the fluid throughput and the filtered particulate often dictate the frequency of cleaning and change out. Selecting a permanent filtration configuration versus a disposable one has its tradeoffs with regard to maintenance practices.
What are some important considerations in back flushing and cleaning? The selection of filtration media may greatly influence the lifecycle of a disposable filter and thus, the labor and materials to renew.
A properly designed filtration system allows for minimal interruption and process downtime. For example, back pulsing is very economical and allows minimal interruption of fluid flow. It may be remotely activated and is ideal to consider.
3. Utility Costs
Often, a chemical process requires water flows and wastewater flows. In light of utility cost and demand, a proper and effective filtration system allows more water reuse and a boosted water recycling effort. Nearly half of all water used in a chemical operation is non-process use and its reuse and recycling can add an extra effort in plant efficiency and overhead costs. A simple analysis with filtration recommendations can have a short payback and help the process greatly.
In addition, there are energy costs to factor in when considering the maintenance of a filtration system. When many plant and capital investments were made in the chemical process industry, benchmark crude was at prices less than half of what they are at today. Chemical producers need ways to cut costs to compensate for such an unforeseen economic condition. Efficiency in filtration design is one means of lowering energy consumption and, therefore, cost.
For example, the pump and motor that may move your fluid throughput across your filter may be selected to produce a minimum of energy consumption. The prime mover, such as the pump and motor that moves the fluid, is often overlooked in specifying a filtration configuration.
A more efficient motor alone, with a variable speed, may be specified and significantly reduce your electric bill and energy consumption. There are other small changes in the fluid movement to the filter that can make a big difference. The pump impeller may be trimmed or the pump discharge may be throttled or controlled through use of a valve or fitting.
A prudent approach in system design for the process engineer is to commission a pumping system survey. This may be done as an adjunct to filtration system design. A pumping system survey is a comprehensive survey of all pumps within a system or subsystem that gathers all pertinent information ranging from oversized pumps, noisy pumps, pump capacity, operating requirements, suitability, and impeller and casing wear and clearances. All of this data may be evaluated and analyzed relative to the nameplate data, design parameters and actual operating conditions.Such analysis may result in removal of unnecessary pumps, addition of adjustable speed drives or modifying the pump configuration by adding more pumps, pumps with more efficient motors, and many other modifications to bring about greater efficiencies.
According to research conducted by the U.S. Department of Energy, a reduction in kWh usage, depending on the billed kWh rate, may yield thousands of dollars in annual energy savings from a pumping system survey.
4. Hazardous Waste Considerations
Can the removal cost of waste fluid and hazardous particulate trapped in filter media be minimized with the proper selection?
Good filter integrity with a high particulate holding capacity can mean less contaminated fluid. This translates into fewer dollars for hazardous fluid removal and contaminated cartridge removal where applicable.
5. Consider Ceramic Filters
Yes, this category of media deserves its own bullet point. The advantages of ceramic filters for most chemical processing applications are too great to ignore. In fact, they meet most of the aforementioned considera