Processing

All of the oil and gas produced by wells in Turner Valley required some sort of processing. This might consist of simple separation of liquids and gases or more complex chemical manipulation to remove impurities. Over time, as the processes became more complicated and efficient, the quality of resulting products improved, and waste decreased.

The Turner Valley gas plant had its beginnings in 1914 with Calgary Petroleum Products. It all began with a small compressor and a low-pressure absorption plant. The compressor forced the gas through a vessel where it came into contact with lean oil, which absorbed the liquids suspended in the gas, producing rich oil. Then the rich oil was distilled, freeing the gasoline that had been suspended in the natural gas.

A 1959 article in the Imperial Oil Review noted that gasoline was the marketable product of the Dingman No. 1 and No. 2 wells:

The gasoline could power the cars of that period just the way it came out of the ground; [it was sold] to drivers who needed fuel for the return trip to

Calgary. “The gasoline worked all right,” one old-timer remembers, “but it was full of sulphur and the smell from the exhaust was enough to sicken you. You had to stay a mile or two behind the car ahead of you.”

Some of the natural gas produced was used locally, but most was simply burned off, or flared. The plant represented new technology; it was based on a design first used at a plant in the United States. In 1920 a fire destroyed the uninsured plant, and Calgary Petroleum Products was forced to sell because it did not have the resources to rebuild.

In 1921 the ruined plant was purchased by Royalite, a newly-formed subsidiary of Imperial Oil. The wells were renamed Royalite No. 1 and No. 2, and a new plant was built under the supervision of Samuel G. Coultis. In principle, the Royalite plant was very similar to the one it replaced, but it was larger and operated at a higher pressure. Critically, the natural gas it produced could be marketed outside Turner Valley, since Royalite also built a pipeline to Okotoks that connected with an existing line to Calgary.

The sour gas from the Royalite No. 4 well, which started producing in 1924, posed a number of processing challenges. Its vast output—close to 595,000 cubic metres (21,000,000 cu. ft.) of gas per day—emerged from the ground at -6°C (22°F) and was mixed with slush ice and gasoline. In addition, it was tainted by the presence of large amounts of hydrogen sulfide (H₂S), which not only gave the gas a rotten egg smell, but made it extremely poisonous and corrosive.

In order to be useable, the gas needed to have the water, gasoline and hydrogen sulfide removed. S. C. Coultis, who oversaw the construction and expansion of the scrubbing plant erected to achieve these goals, claimed in 1928 that it was the largest of its kind in the world. The plant used a method of purifying gas at high pressure:

The gas is first stripped of the gasoline, then heated to remove ice and water, after which it enters a battery of 12 absorbers 36” by 60’ where it flows counter current to a solution of Na₂CO₃ [sodium carbonate—a common household chemical also known as baking soda] under 300 lb. pressure over 1,800 sq. ft. of baffling in each unit. The H₂S in the gas is absorbed by the Na₂CO₃…

Further processing separated the hydrogen sulfide from the products of

this reaction and left Na₂CO₃ (sodium carbonate) and Na₂ S₂O₃ (sodium thiosulfate).

This reaction is brought about by heating the solution to 70° F., discharging it into the top of a battery of 4 actifiers. The actifiers are steel shells 15’ by 54’ filled with 4,500 sq. ft. of baffling, over which the solution flows against a current of air 2½ times the volume of the gas being treated. Five Buffalo Forge Stoker Fans are used for this purpose…The liberated H₂S is blown from the top of two 54” x 126’ heavy steel stacks.

The Na₂CO₃ was reused in the scrubbing process, and the cleaned gas was piped to Calgary. Known as the Seaboard Process, this method removed 97% of the sulfur from 1,271,000 cubic metres (45 million cubic feet) of gas per day.

The scrubbing equipment at the Turner Valley gas plant changed over time. In 1935 a new scrubbing plant was built, and in 1941 a Girbotol scrubber was added. This new process was similar to that of the older scrubbing plant but used a solution of monoethanolamine (MEA), rather than sodium carbonate, to scrub the gas. With this addition, the capacity of the plant rose to 2,825,000 cubic metres (100 million cubic feet) daily. The scrubbing plant was a state-of-the-art facility for the time and continued in use, with alterations, until 1952.

Gasoline continued to be produced at the Turner Valley gas plant. In 1933, the plant was substantially enlarged with the addition of Canada’s first high pressure natural gasoline plant. The equipment could extract the gasoline from approximately 2,119,000 cubic metres (75 million cubic feet) of wet gas per day. It was, essentially, an absorption plant with four large towers. This facility was expanded in 1942 and made more efficient by the addition of a reabsorber tower, through which vapours already processed by the absorption towers were passed to extract all possible gasoline.

World War II resulted in further technological development at the Turner Valley gas plant. In 1941 the Allied War Supplies Corporation—a crown corporation of the Government of Canada—established two factories outside Calgary. One required isobutane in order to produce alkylate, a blending agent used in the production of

high-octane aviation fuel. The other needed large volumes of natural gas to produce ammonia, an essential ingredient in the manufacture of explosives. New facilities were built at the Turner Valley gas plant so that it could fulfill both these requirements.

A minimum of 329 barrels of isobutane were required daily from the plant. This volatile compound was best stored under pressure as a liquid, so two 5,000 barrel tanks known as Horton spheres were imported from the United States and erected on the site. The shape of these vessels is ideal for this purpose, as all points on the surface of the tank are equally resistant to the outward pressure of its contents. Initially, the Turner Valley gas plant was able to supply 113,000 cubic metres (4 million cubic feet) per day of natural gas to the ammonia plant, but by 1943, production had increased to 254,000 cubic metres (9 million cubic feet) daily.

After the war, production slumped. In an effort to bring new life to the facility, a sulfur plant and a propane plant were built. It was not until 1952 that the practice of venting the poisonous hydrogen sulfide produced by the scrubbing of sour gas was stopped. At that time, equipment was added that removed elemental sulfur using a two-step process. First, hydrogen sulfide and oxygen were burned in a reactor furnace at a temperature in excess of 871°C (1,600°F) to produce sulfur dioxide. Then, at a lower temperature of 289°C to 343°C (550°F to 650°F), a catalyst (bauxite) was used to break down the sulfur dioxide into sulfur and water. The resulting molten sulfur flowed by gravity to a location below the plant, where it cooled and solidified.

The final innovation was the installation of a propane plant, purchased used from

a nearby facility. It was disassembled and re-erected adjacent to the gasoline plant, with production beginning in October 1952. Since propane is a lighter fraction, it can be separated from gasoline by precise heating in a controlled environment. Propane gas can be converted into a liquid under relatively low pressure and is 270 times more compact as a liquid than as a gas and is, therefore, more easily stored and transported. It is used in both industrial processes and in homes and commercial establishments for heating and cooking.

For more than thirty more years, the Turner Valley gas plant continued to process natural gas, using equipment dating as early as 1925 and as late as 1981. Finally, in 1985, the plant was decommissioned, and some of the buildings and machinery were removed.