Refinery amine systems must remove H2S to a required specification in order to comply with environmental regulations. These systems can be complex with multiple gas and liquid contactors on the same regeneration train. Experts in the GAS/SPEC Technology Group have helped refineries adapt to changing environmental regulations and feedstock conditions while minimizing operating costs for over three decades. 

GAS/SPEC SS Solvents are designed to selectively remove H2S while slipping CO2. As CO2 removal is not typically required in refineries, minimizing CO2 pick-up reduces the circulation rate requirements and energy consumption of the refinery amine system. Increased selectivity also reduces the load on the Sulfur Recovery Unit (SRU) by improving the H2S content of the acid gas feeding the unit. This is particularly important to refiners who face increasingly stringent sulfur specifications on gasoline and diesel fuels products. For refinery liquid treater applications, INEOS has developed GAS/SPEC TRS-2B Solvent which has shown to greatly reduce the overall cost of refinery liquid treating.

A European refinery faced increasing H2S processing demand in two amine systems with the addition of a diesel Hydrotreating unit. The existing amine solutions could not handle the increased processing requirements, and both systems were converted to GAS/SPEC SS Solvent. One amine system with ten absorbers was converted from 15 weight % Monoethanolamine (MEA), and another regeneration system with seven absorbers was converted from 25 weight % Diethanolamine (DEA). After both units were converted to GAS/SPEC SS, the overall amine complex was processing 46% more H2S the overall unit cost reduced by 48%.  

In refinery Tail Gas Units, achieving H2S specification while minimizing CO2 pick-up is critical. Failure to remove H2S to the required specification can result in emissions violations, and excessive CO2 pickup can overload the Sulfur Recovery Unit (SRU). GAS/SPEC TG-10 Solvent was developed specifically in response to tighter emissions requirements for refineries and is the first gas treating solvent capable of meeting a < 10 ppmv H2S tail gas specification. GAS/SPEC TG-10 Solvent helps ensure the most stringent H2S specification can be met, while also minimizing CO2 removal to provide a high H2S content feed gas for the SRU’s. As countries around the world have enacted tighter emissions limits, GAS/SPEC TG-10 Solvent has allowed refineries to comply with more stringent regulations without modifying existing equipment. The state of California in the United States has enacted some of the most stringent emissions regulations in the world and the majority of refinery tail gas units in that state are operating with GAS/SPEC TG-10 Solvent.

Cryogenic processing to make Liquefied Natural Gas (LNG) requires CO2 and H2S removal to very low levels in order to prevent freezing at low temperatures. GAS/SPEC CS-1000 and CS-2000 Solvent Series provide the maximum level of CO2 and H2S removal in these applications while also minimizing costs with low energy consumption and solvent usage.

Often we think of these applications in terms of the world-scale plants in Trinidad or Australia. However, LNG is also produced in smaller scale plants, sometimes as intermittent operations called “peak shaving”. The oldest facility of this type started operation in Alabama in 1965, before expanding and converting to a GAS/SPEC solvent in 2001 in order to increase capacity. Many of the new plants built for export of LNG are based on modular system design. The GAS/SPEC Technology Group has been providing process design support to the modular amine system suppliers for decades.

Synthesis Gas is a fuel gas mixture consisting primarily of hydrogen (H2) and carbon monoxide (CO). The process usually involves steam reforming of natural gas and the product is used in applications such as ammonia production or the source of hydrogen in a refinery. These applications typically contain high levels of CO2 (>20 mol-%) which must be removed to extremely low ppm levels. GAS/SPEC CS-1000 and CS-2000 Solvent Series have been utilized to help customers achieve greater capacity with lower energy usage in these applications.

Some of these plants have operated on older amine blends or potassium carbonate (K2CO3) technology which requires heavy metal based corrosion inhibitors. In addition to the corrosion risks posed by these older solvents, the heavy metals often have associated environmental considerations. GAS/SPEC Solvents provide reduced corrosion rates in these applications and do not require heavy metal corrosion inhibitors.

Coal has been gasified into “town gas” since the 1800’s. The modern technology for gasifying coal, or other biomasses, is another type of Synthesis Gas production which has taken shape since the early 1980’s.  Most recently companies have contemplated underground gasification. This gasified mixture contains not just CO, H₂, CO₂, and water vapor, but also contains H₂S. In some cases, CO₂ and H₂S must be completely removed and in others, the H₂S is selectively targeted. GAS/SPEC products have been used for both applications. The CO component tends to degrade amine systems. The GAS/SPEC group has worked with a large number of applications containing high CO content and has developed methods to accurately predict the rate of degradation as well as recommended process steps to most cost-effectively manage degradation products in the amine system.

While much attention in the general media is about CO₂ capture from power generating plants, the GAS/SPEC Technology Group has been supporting CO₂ capture for practical industrial use since its inception. One of the first flue gas CO₂ capture amine systems for full-scale operation began operating in 1983 using a GAS/SPEC Solvent. Since then, GAS/SPEC solvents have evolved to provide even better performance capabilities for removing CO₂ from flue gas streams. The large scale of carbon capture amine systems increases the importance of optimizing the circulation rate and energy requirements, an area where GAS/SPEC products excel. 

Enhanced Oil Recovery (EOR) is currently the largest industrial use for CO₂ capture. With EOR, CO₂ is injected into a reservoir for increased oil production. As the reservoir is depleted, the carbon dioxide level increases in the associated gas. GAS/SPEC specialty amines are utilized in these applications to meet the changing and challenging requirements or increasing CO₂. The Permian Basin is a region where EOR has been used extensively for over 30 years to recover difficult to extract oil reserves. GAS/SPEC Solvents have been used for a number of years in this field. As the CO₂ has increased, the removal requirements on the amine have increased as well. In recent years, GAS/SPEC CS-1160 Solvent has been employed to maximize throughput in these applications.