Potential Nontraditional Uses for Byproduct Sulfur in Kazakhstan
Authors: Denney Dennis 
Published: February 2015

This article, written by Technology Editor Dennis Denney, contains highlights of paper SPE 94177, “Potential Nontraditional Uses of Byproduct E&P Produced Sulfur in Kazakhstan,” by P.W. Beall and J.M. Neff, Battelle Memorial Inst., prepared for the 2005 SPE/EPA/DOE Exploration and Production Environmental Conference, Galveston, Texas, 7–9 March.

Kazakhstan oil and gas companies recover approximately 2000 to 3000 tonne/d of elemental sulfur from product streams. In Europe and the U.S., recovered elemental sulfur normally is sold into the chemical and manufacturing markets as a raw material for phosphate fertilizer, sulfuric acid, detergents, and other chemicals; metal and fiber industries; paint manufacture; rubber products; paper; and pharmaceuticals. Byproduct elemental sulfur also can be used as a binder replacement in petroleum asphalt and Portland concrete, yielding sulfur-modified asphalt and concrete that meets or exceeds American Soc. for Testing and Materials and/or American Concrete Inst. standards.

Potential Uses

Potential outlets for Kazakhstan produced sulfur include: sulfur/polymer concrete slabs and blocks for construction and sulfur/polymer stabilization solidification (SPSS) for radioactive- and mercury-contaminated materials. The developing Kashagan East prospect is presalt and involves drilling to a depth of approximately 5000 m. Any oil discovered in this area will likely be similar to Tengiz crude (i.e., exceptionally light with a high H2S content), requiring market outlets for recovered elemental sulfur. This field could more than double recovered elemental sulfur production in Kazakhstan. The Tengizchevroil and Kashagan East fields and treatment facilities are in a very sensitive environmental and geopolitical area with multiple important stakeholders, including consortium partners and Kazakhstan regulators.

The remoteness of these sulfur-recovery facilities, the difficulties of transport, and underdevelopment of the emerging markets for sulfur have made it difficult for Kazakhstan to tap into outlets for elemental sulfur. Hence, as Fig. 1 shows, the recovered sulfur typically is stored on the ground. Tengizchevroil has started an export pro-gram in which flaked sulfur is exported to eastern Europe, Africa, and China. There are three potential nontraditional market outlets for elemental sulfur in Kazakhstan: sulfur-extended asphaltic concrete, polymer-modified sulfur concrete, and SPSS.

Sulfur-Extended-Asphaltic Concrete

Kazakhstan has 189×103 km of roads, of which 109×103 km are paved. Kazakhstan has three major oil refineries supplying the northern region (at Pavlodar), western region (at Atyrau), and southern region (at Shymkent), with a total refining capacity of 57 600 tonne/d. Only the Pavlodar refinery produces asphalt/bitumen material and has a capacity of 5×105 tonne/a. The petroleum asphalt can be extended by 50 wt% using elemental sulfur.

The asphalt produced at the Pavlodar refinery provides Kazakhstan with enough binder material to pave or repave approximately 1000 km/a of roadway. Extending current petroleum-asphalt production capabilities with elemental sulfur would allow Kazakhstan to pave or repave an additional 250 km of roadway each year, equivalent to oil production of approximately 18 400 tonne/d.

Paving or repaving 1250 km/a of road-way means that Kazakhstan rebuilds its roads every 150 years, assuming that asphalt is always used. By increasing asphalt and asphaltic-concrete production capabilities, the turnaround ratio can be reduced dramatically, providing additional outlets for elemental sulfur. Use of elemental sulfur to extend asphalt-production capabilities does not threaten an existing industry in Kazakhstan.