Gas 2025 Issue

Impact on olefins product yields

Ethane cracking: Yields ~80% ethylene, minimal propylene and heavier products Propane cracking: Yields ~40-45% ethylene, ~15% propylene Butane cracking: Yields ~35-40% ethylene, ~20-25% propylene Naphtha cracking: More balanced yields of ethylene (~30-35%), propylene (~15-20%), and aromatics

Table 1

LNG with plans to build 15 new LNG-fired power plants by 2035 with a combined capacity of more than 22 GW. According to Shell’s LNG Outlook 2024 , global demand is expected to increase by more than 50% by 2040. This will be driven largely by the move away from higher-emitting fossil fuels. In addition to heightened energy security, this leads to economic development. New facilities Two major LNG projects in the US, including Plaquemines LNG and Corpus Christi Stage III, hit major milestones in December, and feed (as deliveries) reached a new record high in January. Comments from the new US Administration seem to indicate a preference for LNG capacity. The first six blocks of Plaquemines LNG have Federal Energy Regulatory Commission (FERC) approval to introduce hazardous fluids, and feed gas deliveries have already surpassed 1.3 Bcf/d. Meanwhile, press releases indicate Corpus Christi Stage III achieved its first LNG on 30 December 2024, and Cheniere expects Train 1 of the project to reach ‘substan - tial completion’ at the end of 1Q25, with production antici - pated to ramp soon thereafter. Looking to the end of 2025, the 2.05 Bcf/d Golden Pass LNG project is expected to start up in December, according to the guidance given in Exxon’s 3Q24 earnings call. However, the company noted there is a risk that the project could slip into early 2026. Other gas-based resources In addition to LNG, both condensate (API gravity: 55-65°) and NGLs (C₂H₆, C₃H₈, and C₄H10) play a crucial role in the energy industry. Condensate production has increased sig - nificantly in recent years, driven by the growth of uncon - ventional gas production. It has become an important component of the global oil market, with its price often linked to benchmark crude oil prices. For example, in the US, wells operated by a half-dozen exploration and pro - duction companies (E&Ps) in eastern Ohio’s Utica Shale are now churning out more than 100 Mb/d of superlight crude oil (aka condensate), more than twice as much as three years ago, according to a report by H. Carr in 2025. NGLs, on the other hand, have a well-established market and are traded separately from crude oil. They are in high demand for various industrial and residential applications, making them an essential part of the energy supply chain, including steam cracking to olefins. Increasing the use of NGLs in steam cracking is a trend driven by the growing availability of NGLs from shale gas production. This shift impacts the production of ethylene, propylene, and other key petrochemicals.

As with LNG, the rapid expansion of shale gas resources has led to increased availability of NGLs (ethane, propane, and butane), often cheaper feedstocks than naphtha, leading to lower production costs. Ethane and propane cracking pro - duces a higher percentage of ethylene compared to naphtha (see Table 1 ). However, ethane cracking produces almost no propylene, requiring additional on-purpose propylene pro - duction (for example, propane dehydrogenation, PDH). However, as with LNG, there are challenges when shift - ing to NGL feedstocks in steam cracker operations, such as accurately estimating the investment needed in fractiona - tion, transportation, and storage to handle increased NGL use in mixed feed steam crackers. A detailed discussion on mass transfer and product separation concerns is beyond the scope of this discussion. Suffice it to say that process adjustments and steam cracker designs must be optimised for different feedstocks to balance heat integration and byproduct handling (see Figure 2 ). Many new plants, such as new and recent projects along the US Gulf Coast and the Middle East, are designed spe - cifically for ethane cracking, while other steam crackers are being modified for mixed feeds to balance ethylene and propylene production. Shifting to more NGLs in steam cracking requires adjustments in process design, reaction conditions, and downstream processing, including feed - stock handling and preheating, where the fractionation units in NGL service must be separated into pure ethane, propane, or butane before cracking. The fractionation units (cryogenic distillation) are critical for this, and the ethane and propane require preheating to vapourise fully before entering the cracking furnace. Special heat exchangers and vapourisers also must be used. Just as challenging is the cracking furnace design, which involves high-temperature pyrolysis. NGL cracking occurs at 750-900°C (1,380-1,650°F) in the presence of steam to prevent coking. To maximise ethylene yield and minimise coke formation, the gas stays in the reactor for a short res - idence time of only 0.1-0.5 seconds. Other complexities with the NGL involve radiant coil design, where ethane and propane require different coil designs from naphtha. For example, ethane cracking uses shorter, high-radiance coils to optimise heat transfer. Additional processing challenges Figure 2 World-scale steam crackers benefit from the abil - ity to process mixed feeds Courtesy of BASF SE

Gas 2025