Carbon Dioxide Clean Technology: A Business Sustainability Strategy

In an environment of escalating manufacturing challenges—including intense global competitiveness, environmental regulation and energy supply issues—managers must have both lean and green manufacturing (a.k.a “clean manufacturing”) technology necessary to identify and eliminate multifaceted manufacturing wastes in their operations that stealthily steal away business profits. CO₂ CleanTech represents a significant business opportunity for those manufacturers that can adapt their production tools and operations to meet the new challenges ahead. Moreover, the merging of green practices into manufacturing promises to deliver additional value in the form of less chemical, energy, labor and water usage, as well as fewer pollutants.

Manufacturing waste is generally thought of as any resource used in a production process that does not go out as part of the product and/or costs money to get rid of it (Example: wastewater treatment operations for rinse water). However, manufacturing waste also exists in many other forms: for example, excessive factory space utilization for equipment (production and waste treatment equipment), inefficient material and process flows, inefficient use of facility labor and lost productivity of both labor and equipment. These types of wastes significantly impact a company’s bottom line, too, but are often obscured in overhead accounts or generally overlooked in the manufacturing operation. However, as exemplified in Figure 1, these wastes are real but addressable.

Leading companies in the high tech manufacturing industries are moving beyond just producing high capacity, low-power products.

For example: Seagate Technologies, a hard disk drive manufacturer, is implementing various environmentally protective manufacturing initiatives, summarized on their website. The supply chain in this industry is also implementing cleaner production techniques to reduce energy inputs and product defects. ¹ Introduction to CO2 CleanTech. Over the past 25 years, our CO₂ clean manufacturing technology (CO₂ CleanTech) has been used by many companies in high technology, high reliability, and high capacity manufacturing operations. Industries have included aerospace, hard disk drive, electronics, and optics, among many others. CO₂ CleanTech has been used primarily as a means for increasing the cleanliness of components, assemblies, tools and fixtures to increase both capacity and quality. However, arguably more significant, CO₂ CleanTech has proven itself to be a means for reducing the cost and improving the productivity of manufacturing high volume and high reliability products. CO₂ CleanTech is an effective business sustainability strategy.

CO₂ CleanTech offers manufacturers, component suppliers and assembly equipment OEMs new techniques to re-tool their factories and equipment for clean production. Assembly tool builders can develop and deliver clean-in-place assembly process-tool combinations to support sustainable manufacturing initiatives. Component suppliers can produce and supply better quality product at lower cost and device manufacturers can adapt dry clean-in-place capability throughout the factory. CO₂ CleanTech can uniquely address the composite opportunity to reduce both lean and green manufacturing waste throughout the production network; tool suppliers, components suppliers and manufacturer.

High tech, high reliability manufacturers require state-of-the-art clean manufacturing technology and implementation strategies for successful design and execution of product quality improvement and manufacturing waste reduction programs. Manufacturing waste reduction programs involving CO₂ CleanTech provide a combination of possibilities (and benefits), including:  

• CleanTech eliminates or reduces composite forms of manufacturing waste: time, labor,  space, transport, defect, inventory,  processing, equipment, raw materials, air pollution, water  pollution, wastewater, solid wastes, and energy wastes.
• CO₂ CleanTech improves quality and reliability requirements imposed by advanced materials, manufacturing methods and processes, and new performance standards.
• CO₂ CleanTech integrated into flexible automation, modular and clustered assembly operations (cells) eliminate repetitive operational task errors and reduce skilled labor wastes.
• CO₂ CleanTech integrated into tools and processes produces more adaptable and flexible production    tools and methodologies which improve efficiency and  productivity in high volume or high tech production operations.

CO₂ is a Unique Manufacturing Solution. CO₂ is a safe and abundant compound that plays a very important role in many commercial and industrial applications. As described in Figure 3, CO₂ can be used in cleaning, cooling and machining applications. Leading companies have implemented CO₂-based cleaning technology and have realized improved productivity and a lower cost-of-operation of their production operations. CO₂ CleanTech has also served as a strategy for complying with worker safety and environmental regulations. The CO₂ used in our cleaning, machining and thermal control products and processes is the same CO₂ used to charge fire extinguishers, carbonate beverages, weld steel, cast metals, and refrigerate products, among many other important industrial uses. In fact it’s the same CO₂ that you are exhaling while reading this article—approximately 1 kilogram of it every day!

CO₂ is an abundant (and recyclable) by-product of numerous industrial and natural processes. Recycled CO₂ is a valuable and renewable manufacturing resource that will never run out of supply. Unique benefits derived from using recycled CO₂ include the conservation of water, reduced energy consumption and a reduction in industrial CO₂ emissions. Moreover CO₂-based process technology is a positive contribution to Hazardous Air Pollutant (HAP), Volatile Organic Compound (VOC), and Greenhouse Gas (GHG) emissions reduction strategies.

Using recycled CO₂ to reduce pollution, conserve energy and eliminate wastes (both environmental and manufacturing) produces numerous tangible and measurable benefits. Major industrial sources of CO₂ emissions include:  

1. Electrical power generation and usage
2. Chemical generation and usage
3. Transportation

The use of recycled CO₂ technology as a chemical/process substitute lowers electrical power usage, reduces manufacturing wastes, increases manufacturing productivity, and decreases the need for chemicals such as lubricants and solvents, among many other positive socioeconomic and environmental benefits. A reduction of manufacturing wastes or elimination of production chemical inputs of any kind decreases industrial CO₂ (carbon) footprint. Following are examples of how this works:

• Less CO₂ is produced if less electricity is consumed for processing.
• Less CO₂ is produced if less oil is refined, transported and consumed.
• Less CO₂ is produced if less cleaning solvents are produced, transported and consumed.
• Less CO₂ is produced if more products can be manufactured for the same energy, labor and space inputs.
• Less CO₂ is produced if products don’t have to be cleaned using hot deionized water or dried using solvents or other drying agents.

Thus, from a GHG emissions perspective, using recycled CO₂ significantly offsets new CO₂ gas production and emission from both the industrial supply and consumption sides of the equation. Pending USEPA CO₂ emissions reporting legislation is intended to impact the “generators” of CO₂. A user of recycled CO₂ is not considered a generator of CO₂. Note: The CO₂ used in commercial and industrial processes is already accounted for in the GHG emissions inventory.

With regards to smog generation, CO₂ is not a VOC and is not regulated as such. From a worker health and safety perspective, CO₂ is non-toxic. From a building safety and equipment protection perspective, CO₂ is non-flammable and non-corrosive. CO₂ is a perfect solution for protecting the environment and improving the health and safety of both workers and communities, while improving the performance and cost-of-operation of supplier and manufacturing operations.

CO₂ is Many Manufacturing Agents in One. CO₂ is a very versatile manufacturing agent—actually four manufacturing agents in 1. It can be used as a spray, immersion solvent, extraction solvent, and plasma in the form of composite sprays, hybrid solid-plasma sprays, centrifugal liquid carbon dioxide cleaning systems, and supercritical fluid extraction systems. In addition, CO₂ fluids purification and management systems have been developed to support these various capabilities. CO₂-based manufacturing and industrial applications are as diverse. Applications for CO₂ CleanTech include precision degreasing, departiculation, outgassing, drying, disinfection, surface modification and functionalization, cooling and lubrication, among many others.

CO₂ physical and chemical properties are similar to HFE and CFC solvents such as Freon^® 113 and HFE-7100. CO₂ possesses a Hildebrand solubility parameter in the adjustable range between 14 MPa1/2 to 22 MPa1/2 depending upon phase, temperature and pressure. CO₂ can be compressed to a range of liquid-like densities, yet it will retain the diffusivity of a gas with extremely low viscosity. Supercritical and liquid CO₂cleaning agent densities may be adjusted between 0.5 g/cm3 and 0.9 g/cm3. Solid phase CO₂ has a density of 1.6 g/cm3, identical to Freon 113. Surface tensions range from 0 dynes/cm (supercritical) to 5 dynes/cm (liquid). Practical benefits derived from these unique properties include rapid penetration and wetting, oil solubility and, cooling and dry lubrication effects. CO₂ Technology Reduces or Eliminates Manufacturing Waste. CO₂ CleanTech eliminates or significantly reduces waste generation at the production operation level (i.e., at the source) by modifying manufacturing processes, and in particular precision cleaning, assembly processes requiring critical cleaning, and precision machining operations. CO₂ modifies conventional manufacturing processes and tools in several dimensions, described as follows;  

1. Physically; shape, size, space, application and configuration;
2. Chemically; solvency, toxicity, and dryness;
3. Quality; defects, rework, scrap; and
4. Time; productivity.

CO₂ CleanTech may be implemented in a variety of production equipment and process configurations to meet the needs of lean production schemes and product flow constraints, including both existing and new production line and tool implementations.

Examples of manufacturing activities that produce manufacturing waste include:  

• Moving products off-line or out of cells to clean them and then returning them back to the line or cell
• Filtering and treating spent alkaline cleaning chemistries
• Monitoring cleaning and machining fluid chemistries
• Rinsing parts with deionized water
• Drying parts with compressed air or alcohol
• Treatment and disposal of spent dicing, cleaning and machining agents
• Completing waste hauling manifests
• Preparing environmental reports
• Deionized water treatment
• Rinse water treatment and disposal
• Disposal of spent filters and sludge

Consider how CO₂ CleanTech can eliminate many different forms of manufacturing wastes:  

• Space and process step reduction: CO₂-enabled cleaning processes can reduce multiple processing steps to a single step and perform in less space, sometimes no extra space is needed if the CO₂ process is integrated directly into/onto a new or existing manufacturing tool such as a bonder, dispenser, or machining tool.
• Materials selection and productivity: Recycled CO₂ itself  does not generate waste, does not require environmenta management, and eliminates equipment cleaning and maintenance.
• Energy conservation: Using recycled CO₂ eliminates the need for additional energy to heat cleaning baths, dry parts, or evaporate and concentrate wastes.
• Waste reduction and elimination: CO₂ does not itself become a waste by-product. CO₂ eliminates the wasteful consumption, treatment and disposal of water,wastewater and associated solid wastes.
• Air pollution reduction: CO₂ is not considered an air pollutant, is non-toxic and is odorless within the factory atmosphere.

Examples of unique CO₂-enabled production configurations and manufacturing waste reduction benefits are summarized in Table 1. CO₂ Technology Implementation in the Production Network. CO₂ CleanTech can be implemented throughout the production network. Following are some examples and benefits:  

• Tool Builders – Production of new, hybrid clean-, cool-, or lubricate-in-place manufacturing tools (Clean-Assembly Tools).
• Component Manufacturers – More profitable operations and cleaner products produced.
• Automation and Robot Suppliers – Integrate robots with CO₂ Processor Unit (CPUTM) and assembly technology to provide drop-in-place reconfigurable automated clean assembly solutions.
• Production Line Builders –  Integrate CO₂ technology into new factories to decrease space, improve product flow and process efficiency.
• Contract Cleaning Service Providers – Utilize CO₂ cleaning rather than aqueous or solvent technology for more profitable operations and cleaner products.
• Device Manufacturers – Adapt existing production lines, tools, and processes with CO₂ technology to enable cellularity, lean operation and green production.

CO₂ CleanTech can be integrated into virtually any machine, equipment platform, and process to provide in-situ dry, clean surface treatment, process thermal control and cooling-lubrication. CO₂ CleanTech performs these functions without producing air pollution, wastewater or solid wastes, and enhances product yield, tool productivity and increases energy savings.

Following are examples of implementation:  

• Mobile tools, including mobile robotic tools
• Production line integrated tools
• Manufacturing tools (Clean-Assembly tools)
• Cellular or island cleaning tools
• Robot-enabled tools, including tenders
• Work bench tools

CO₂-enabled cellularity is very productive because two or more value-add manufacturing operations can be performed along with non-value-add dry cleaning, cooling and lubricating within the same work space. Products don’t have to be removed, transported, cleaned and returned, resulting in reduced movement, smaller footprints, less human interaction, higher throughput, and decreased cost-of-assembly. Products stay cleaner with less movement as well.

CO₂ CleanTech Transforms Manufacturing. It has been 250 years since carbon dioxide (CO₂) was discovered by Joseph Black, about 150 years since the first understanding of CO2’s remarkable chemical properties, and 25 years since our first CO₂ precision cleaning applications were developed. Today CO₂ CleanTech is being used commercially in many forms throughout industry to address a variety of manufacturing challenges. CO₂ CleanTech serves as an alternative to many conventional surface immersion, extraction, spray and plasma cleaning and treatment processes.

Our pioneering work over the past three decades has demonstrated that CO₂ CleanTech is uniquely versatile and adaptable to the production of a diverse array of manufactured products ranging from radial tire molds to guidance gyros, automobile fuel injectors to spacecraft materials, and aircraft engines to disk drive components. More recently, CO₂ CleanTech has found its way into machining operations as a replacement for flooded coolants, and more specifically to address the higher cutting heat demands of advanced materials such as ceramics, superalloys and composites. CO₂ CleanTech transforms manufacturing operations in a variety of ways to provide better, faster, cleaner and cost-effective solutions for many different manufacturing applications.

CO₂ CleanTech has been applied in ways not possible using conventional technologies such as aqueous and solvent cleaning technology, and more recently machining coolant technology. This is a quality that portends a transformational technology. A transformational technology changes the “value networks” for the manufacturing industry. Value networks comprise sales and distribution channels, performance standards, suppliers and product and services forms, among other elements. New value networks – the creation of new contexts of consumption and competition – are currently being developed for CO₂ CleanTech to realize its full potential throughout the manufacturing industry.

REFERENCES

1. Chompu-inwai et al, “Application of Cleaner Technology Concepts in the Arm Coil Assembly Process of Hard Disk Drive Manufacturing”, Proceedings of the International Conference of Engineers and Computer Scientists, 2010, Volume III.

BIO David Jackson (a.k.a The CO₂ Guy) is president of CleanLogix LLC and CleanLogix Asia Pte. Ltd. based in California and Singapore, respectively. CleanLogix offers manufacturers, tool builders, and component suppliers a variety of CO₂ -based clean manufacturing integration products, CO₂ supply and purification equipment, and installation and equipment commissioning services. Over the past 27 years, Jackson has spearheaded the development and commercialization of more than a dozen products utilizing recycled CO₂ for cleaning, machining and thermal control applications. He holds a Bachelor’s degree in Chemistry and has been issued more than 30 patents worldwide.