ARKHANGELSK, January 25. /TASS/. Experts of the Russian Arctic scientific-educational center developed a new efficient technology to make building materials with sulfur for Arctic conditions. According to Yuri Ryabkov, Deputy Director for Scientific Work of the Chemistry Institute at the Komi Research Center (the Urals Branch of the Russian Academy of Sciences (Syktyvkar, Komi)), the new composite materials are made of waste from oil and gas and deep wood processing enterprises.
One of the priorities the scientific center focuses on is to develop materials and technologies using man-made waste in the Arctic region, where the waste, accumulated in large quantities, threatens human life in the North.
"Our participation in one of the center's technological projects is aimed at developing new structural composite materials for the Arctic," he told TASS. "The new technology to make sulfur composites is based on the use of man-made waste in the oil and gas industry and waste from deep processing of wood."
Sulfur is one of the most common impurities in hydrocarbons. It is separated during the primary processing of oil and natural gas. The concentration of this chemical element and its derivatives, for example, in crude oil ranges from hundredths of a percent (such is, for example, oil from the Baku fields) to 6-10% (in oil from most other fields, including fields in the Russian Arctic).
The removal of sulfur is of great importance, since sulfur-containing compounds adversely affect the quality of petroleum products. They cause corrosion and damage equipment. Sulfur in natural gas affects the transportation, storage, processing and its use as fuel, leading to corrosion of pipelines, storage tanks, internal combustion engines and exhaust systems.
The researchers have proposed to make a sulfur composite material from technical sulfur, which gets accumulated in huge quantities at deposits in the Russian Arctic regions.
Large-tonnage sulfur waste is stored and is not transported away, as the regions are remote and hard-to-reach. "For the studies we have used sulfur from the Usinsk gas field, where it is currently accumulated in large amounts, while a demand for it is very small - only for the production of sulfuric acid, sulfate fertilizers and feed additives," the expert said.
Sulfur concrete and sulfur asphalt
Sulfur, the scientist continued, is an excellent raw material for making composites. It melts well when heated. Other technological waste in the mining industry can be added to molten sulfur: fine fractions of sand, crushed stone, ash, that is, the substances that normally are thrown away. The result is sulfur concrete. When asphalt components are added, the final product is sulfur asphalt. After solidification, it is a sufficiently durable material. However, sulfur itself is quite fragile. In order to make the structures durable, materials require additives, known as modifiers.
The researchers have proposed an effective sulfur modifier - turpentine mixtures containing aromatic compounds. They are used to obtain a stable sulfur polymer matrix. "When we use turpentine-containing waste from wood processing as a new sulfur modifier, we get a new material. The combination: a technological waste - sulfur - plus another technological waste from wood processing, and here is the novelty that we offer. It's a useful technical product," Ryabkov said.
Use in the Arctic
Sulfur-based materials have a few important features that make them very promising for use in the Arctic. Currently, concrete is produced from Portland cement. This is a type of cement most widely used in all countries. Cement powder is mixed with water, after which it hardens and gains strength for about 28 days.
"There are two disadvantages here: water and 28 days. Sulfur does not have these fundamental drawbacks. Sulfur is a thermoplastic material. We heat it up, add a modifier, and the fillers - the same as in cement: sand, crushed stone, though not into a water mixture, but into sulfur melt," the scientist said, adding that all these processes can be carried out at freezing temperatures, which are typical for the Arctic regions.
The material does not require 28 days to obtain strength. Besides, sulfur composite structures can be made under water, even in a swamp or on the seabed.
Sulfur composites in the Arctic will also solve the environmental problems caused by the accumulation of large amounts of technical sulfur at enterprises in the Arctic zone.
Sulfur concrete products can be made at regular asphalt concrete plants. "With a small upgrade of existing standard enterprises - asphalt concrete plants - this technology can be introduced, distributed and used," the expert said.
The Russian Arctic Center
In December 2020, the Russian government supported the organization of the Russian Arctic Scientific-Educational Center. The Arkhangelsk, Murmansk, Nenets and other regions participate in its work. The center is aimed at implementing new technological projects, introducing new materials and technologies, as well as at research that ensures competitiveness and world-class studies and development. The center also trains personnel to solve major scientific and technological problems in the region in the interests of the Russian Arctic's industries and economy.