Diesel regulations an opportunity for sulphur processing industry
As the trend to tighten air quality regulations puts pressure on US oil refiners to remove sulphur from gasoline and diesel, the market for equipment which can convert liquid sulphur into a stable and saleable commodity is growing.
This is a growth market for companies such as Devco of Oklahoma, one of two companies selling and operating plant designed to convert liquid sulphur from refineries into hard sulphur pellets for agribusiness or industry.
Devco’s president, Mike Martin, told edie that Devcos started operating sulphur conversion plant in California in the 1980s but that the main players in oil refining now buy the units to operate themselves. The company recently installed a new plant for Mobil in Sumatra.
According to the USEPA, its plans to reduce the sulphur content of diesel from 500 parts per million (ppm) to 15 ppm will bring about a reduction of more than 90% of NOx and particulates from the 30 million plus vehicles on the roads in the US (see related story in this section). However, removing the sulphur presents the refiners with increasing quantities of a potentially hazardous by-product to be dealt with.
Sulphur has long been the bane of oil refiners because of its existence in crude oil and oil products; sulphur emissions are implicated in causing asthma and acid rain. This volatile chemical is an essential raw material in the manufacture of sulphuric acid, one of the world’s most important and largest tonnage industrial chemicals. Almost two thirds of the world’s annual consumption of elemental sulphur is used to make fertilisers.
The sulphur conversion process takes sulphur from refineries in a liquid state at a temperature that is hotter than boiling water. Sulphur must be transported in a hot liquid form and made into pellets because when it is refined from petroleum it forms into a powder so volatile that it can be ignited by static electricity, similar to dust explosions in grain silos.
The capacity of the units range from six tons per hour to 100 tons per hour. The demand for sulphur is stable and growing slightly. However, the supply is increasing as new oil plant comes on stream.
The explosion in oil production and consumption in the second half of the twentieth century has brought about a complete reversal in elemental sulphur sourcing. Sulphur recovered from oil and gas processing has risen to 80% of the world’s supply (some 40 million tonnes per year), effectively replacing much of the world’s mined sulphur in the market place.