The use of large volumes of corrosive and possibly toxic chemicals to remove fouling deposits from industrial size equipment, as well as pipelines, is an inherently hazardous process. In addition to the chemicals themselves, the fluids must be pumped and circulated at high pressures and frequently high temperatures to achieve the cleaning goal. At the end of a job thousands (possibly hundreds of thousands) of gallons of toxic waste must be disposed of in some manner.
Almost since its formation as an offshoot of the oilfield acidizing business, an emphasis on improving the triple goals of the health of employees and the public, chemical and mechanical safety of operations and protection of the environment (HSE), has been an integral part of the development process.
This paper will review the development of healthier, safer and more environmentally acceptable chemicals, equipment and process. The time frame reviewed is the 1950s to the present time, and the innovations have been revolutionary 8S well as evolutionary. These have been driven both by economic (business) factors as well as governmental regulations.
The author will describe the changes from the use of toxic and hazardous chemicals such as HCI with thiourea for cleaning boilers to much less hazardous (and environmentally improved) organic acids and chelating agents. Initially, necessary corrosion inhibitors for Hel contained very hazardous chemicals including arsenic compounds and polyaromatic hydrocarbons. Over the years, these were replaced with ever improving less toxic molecules. Many other improvements in chemistries will be described that have affected HSE issues.
Mechanical cleaning of refinery equipment (especially heat exchangers) initially required the use of very high pressure water lances, which required people to physically place them into the equipment being cleaned. These "hand lances" have mostly been replaced with many types of automated equipment to protect the workers (and to improve productivity).
New chemicals coupled with improved processes have enabled the industry to more safely dispose or recycle some of the waste products in an environmentally acceptable manner. This is an area where environmental regulations worldwide have partially driven developments, but have produced business advantages based on new processes. One revolutionary process uses a steam boiler's in house systems to completely destroy the wastes.
The improvements on multiple levels usually resulted in more efficient as well as less wasteful process that benefited people, the environment as well as the companies' bottom line.