Time for a Change in Pharmaceutical Process Cooling?New Technology Can Greatly Reduce Water, Energy Use

Tue, 11/10/2009 - 5:51am
Recent regulatory rumblings suggest it may be time for pharmaceutical processors to take a closer look at their use of water resources.

Two federal studies released in 2009 reflect increasing scrutiny of the impact manufacturers including drug companies have on the water supply. The tests showed higher levels of a variety of medicines in the water handled by treatment plants directly downstream from major pharmaceutical facilities. EPA officials have signaled that the results of these tests may necessitate new regulations to keep toxic chemicals out of America's drinking water.

Add this new concern to the constant cost pressures faced by pharmaceutical processors in a fiercely competitive climate, and it's clear that using, and reusing, water wisely should be a top priority.

One place to start: process cooling equipment. Poorly designed and inefficient cooling systems rank high on the list of water related problems cited by the FDA and other regulatory inspections. Most processors are still using outdated methods such as traditional cooling towers for their process cooling needs, consuming and dispensing of 1 to 1.5 million gallons of often contaminated water per year. But there's a better way that many processors may not be aware of.

Uses of Process Cooling Water in Pharmaceuticals
Cooling water often is a key component of pharmaceutical processing, so it makes sense to examine how effectively and efficiently this resource is being used. It is used in R&D, bulk manufacturing and packaging. Examples include:
n Batch processing in multipurpose reactors, which requires water for chemical reactions at high temperatures and crystallization of final products at low temperatures.
n Cooling ointments before rolling and packaging.
n Controlling the temperature of the molding process that forms gelatin for capsules.
n Heating and subsequent cooling of components of creams before they're mixed together.
n Heating and cooling during sterilization of liquid pharmaceuticals.
n Water used in the wet granulation process for tablet forming.
Other applications include cooling needed for condensers, plasma-etch equipment, vacuum systems and chambers, calorimeters, power supplies, heat exchangers, jacketed vessels, plastic molding and extrusion equipment.

The Drawbacks of Cooling Towers
Traditional process cooling systems dependent on continuous water use and disposal remain the standard in the pharmaceutical processing industry. These systems come with significant costs because they require maintenance and consume a lot of energy, water and chemicals.

With the typical open-loop, cooling-tower systems, process water is far from ideal. It's not uncommon for water to be filled with dust and other airborne contaminants. Cooling towers also suffer from solid deposits, gases, algae, bacteria/legionella, microbiological growth, scale accumulation and oxidation. And all of these issues must be fixed with chemicals.

Some of those chemicals then evaporate into the atmosphere, and the remaining water is subject to extensive treatment or specialized hazardous handling for disposal. High disposal costs for concentrated and contaminated fluids are being imposed by many local governments. These practices are picking up momentum and will begin to play a bigger role in purchasing decisions made by business owners.

Meanwhile, excessive consumption of process water occurs as it either evaporates or is dumped down a drain-two events that are inevitable with traditional cooling tower systems. This continuous water consumption is a costly issue for many pharmaceutical processors.

These problems are not new, and the search for a solution is a common challenge for pharmaceutical companies. One example is the “zero discharge” efforts pharmaceutical giant, Pfizer, put in place, citing scarce water resources and high operating and wastewater disposal costs. Initiatives like this to eliminate continuous water use and discharge hassles at pharmaceutical processing plants are not as wide spread as they should be unfortunately.

The problem is bigger than any one company can fix. Clean water resources are an increasingly global concern, and industry uses 22 percent of the earth's available clean water. The issue is only becoming more critical as global economic development continues. The current energy and water strain, combined with processors' need to operate faster, in more places and more cost effectively than ever before, poses a great challenge for the pharmaceutical industry. The time is now to change things.

The Closed-Loop Alternative
There's a water-saving alternative to cooling tower systems for pharmaceutical processors. An eco-friendly, closed-loop, dry-cooling system known as the Ecodry System by Frigel has been used in Europe for years and is becoming more common in the United States.

Dry-cooling systems can provide economic and environmental advantages that are particularly important to the drug industry today. This closed-loop system was designed to dramatically reduce water use, keeping cooling water clean without costly chemical treatment. It reduces water used for process cooling by 98 percent, using only 20,000 to 40,000 gal/yr compared to hundreds of thousands (and sometimes millions). In addition, the system saves up to 95 percent of the energy typically associated with cooling tower systems.

Water-friendly highlights of the Ecodry include:
n A closed-loop design ensuring water is never exposed to outside elements and never disposed of into groundwater
n Water returning from the process pumped into heat exchangers and cooled with ambient air flow, providing clean water at the right temperature year round
n Intelligent controls to maintain the most efficient use of water, even during extreme hot and cold weather conditions
n Absence of chemicals makes the system ideal for clean room or other sterile environments
To maintain water below setpoint in hot weather (85°F or above), outside air passes through an “adiabatic chamber” before reaching the heat exchanger. A fine mist of water is pulsed into the incoming air stream inside the chamber. The mist evaporates instantly, cooling the air before it impinges on the cooling coils that carry the process water, hence the term “dry-cooling”. This drops the temperature at or below setpoint.

To ensure consistent cooling, the control panel continuously adjusts the amount of water sprayed. During colder months, the Ecodry has a fully-automatic, self-draining system that protects it from freezing and also provides “free” cooling when ambient air temperatures permit.

Evolutionary Improvements in the Technology
A variety of improvements over the years have made the technology more efficient.
For example, intelligent controls have optimized equipment operation, conserving resources and maximizing the life of the equipment. The Ecodry now operates using an advanced microprocessor featuring an easy-to-use, remote interface for monitoring temperature, operating parameters and alarms. These sophisticated controls adjust fan speed, initiate adiabatic functions, control the free-cooling valve and maintain pumping stations. The system takes into account real-time ambient temperature and adjusts operation accordingly to keep it running using the most efficient method possible, all without any input needed from an operator.

New models of the system also improve heat rejection through a redesign of the air flow and an increased efficiency of the system's adiabatic chamber. The latest iteration features an enhanced, V-shaped adiabatic chamber that allows for greater, unrestricted airflow into the unit. The result is greater overall cooling capacity, better humidification of the air in the adiabatic chamber and reduced air pressure within the cooling chamber.

Produced by Frigel, a global manufacturer of process cooling and temperature control equipment, the closed-loop system minimizes environmental impact by using less water and avoiding disposal of chemicals into the ground, lakes and streams. With evaporation virtually eliminated, the closed-circuit technology poses the lowest risk of refrigerant gas emissions into the atmosphere.

Traditional cooling tower problems have long been accepted by pharmaceutical processors as a necessary evil, but new technology is changing all of that. As the pharmaceutical industry faces increasing economic and environmental challenges, closed-loop, dry-cooling systems are worth careful consideration and should be part of a pure water, sustainability plan.

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