Most industries benefit from the energy efficiency and compact strength of air compression technology, whether their ventures take place on land or underwater.
Though harnessing the power of compressed air in marine environments presents distinct challenges, maritime endeavors and aquafarms alike apply compressed air to better their businesses. Compressed air optimizes operations — making them safer, cheaper, or greener — in these five critical areas of marine enterprise:
When it comes to the often grueling conditions of drilling work at sea, pneumatic hoists provide a smart alternative to electric-powered machinery. Offshore rigs find themselves far removed from aid at the coastline when parts break or machinery malfunctions, and compressed air-powered systems fare better than their electrical counterparts in fluctuating weather conditions while still managing intense loads, according to Hydraulics & Pneumatics.
The magazine highlights one such example of durable and dependable air-operated hoists found aboard a Maersk offshore rig. Part of a blowout preventer handling unit, each hoist can support a load of 50 metric tons, lift 20 meters, and remain operational in temperatures as low as -20 degree Celsius.
Of course, pressurized air is crucial to diving operations. Whether individuals scuba dive in a recreational or professional capacity, they need a steady stream of purified compressed breathing air for as long as they remain underwater.
Scuba compressors either fill scuba tanks or float in a ring at the surface and provide air to divers via hose. The compressors that fill scuba tanks can compress air to about 3,000 psi, giving divers an incredibly compact and long-lasting supply. Crucially, scuba compressors filter out contaminants and particulates and neutralize carbon monoxide and other gases dangerous to inhale.
Compressed air not only facilitates seafaring activities like drilling and diving but is integral to the construction, maintenance, and operations of the vessels themselves. Builders use pneumatic tools, such as air-powered drills and air cylinders, to carry out a variety of construction tasks, while compressed air can also dust machinery, sandblast surfaces, and paint dilapidated exteriors.
Additionally, many ships quite literally would not move without compressed air, as it helps start their main and auxiliary engines and can also power emergency devices like back-up generators and fire pumps.
Aquaculturists use compressed air to power filtration technologies and aerate their fish and marine life farms. Aquatic air compressors can oxygenate water without disrupting its temperature stratifications. In this way, aeration protects the balance in delicate ecosystems, oxygenating ponds that have suffered from algae blooms or chemical treatments that cull plant overgrowth. In these scenarios, aquatic air compressors serves two main purposes: keeping marine species alive and supporting water circulation, which prevents the debris accumulation and mosquito populations that accompany stagnation.
Lastly, compressed air promises gains in the renewable energy sector. Compressed air energy storage (CAES) systems convert excess electricity to compressed air, which is held in storage units underwater. Later, the compressed air is released when the energy grid it supplements requires extra power to meet peak demand.
CAES systems face a long road before they see mainstream commercialization, given the model’s challenges — energy loss in the conversion process, the pragmatic difficulties of servicing system components offshore and underwater, and the limited applicability to coastal areas.
Still, CAES technology has advanced significantly in recent years: “Cleantech” company Hydrostor Inc. and Toronto Hydro partnered for the world’s first CAES deployment off the shore of Toronto Island in 2015. Hydrostar’s CEO pointed out that “it’s less than half the cost of the best batteries available for the grid and lasts twice as long,” demarcating a “step-change improvement in storage economics.” This cost-effective longevity, coupled with the fact that the system does not produce emissions and is ready to scale, offers hope for a green future.
From building ships and facilitating safe scuba diving to meeting the world’s appetite for seafood and revolutionizing renewable energy, compressed air is a foundational component of economizing, improving, and powering the marine industry.