refining india 2024
Role of spiral heat exchangers in refineries Nexson is a French company based in Garchizy in the Nièvre region. Aware of environmental issues, the company helps manufacturers optimise their manufactur- ing processes by saving energy. Every day, it does more to preserve natural resources, providing customers with concrete solu- tions to combat energy wastage and its impact on the environment. NEXSON
their durability and longevity, even in the harsh operating conditions typical of refin- eries. They are usually constructed from materials resistant to corrosion and thermal stress, such as stainless steel. This durability reduces the likelihood of equipment failure and ensures continuous operation, which is critical for maintaining the high productivity levels demanded in refinery environments. Cost-Effectiveness While the initial investment in SHEs might be higher compared to traditional shell-and- tube heat exchangers, the long-term cost benefits are substantial. The enhanced heat transfer efficiency leads to lower energy consumption, and the reduced fouling and maintenance needs decrease operational downtime and maintenance costs. Over time, these factors contribute to a lower total cost of ownership, making SHEs a financially sound choice for refineries. Conclusion SHEs offer a multitude of benefits that make them well-suited for use in refineries. Their exceptional heat transfer efficiency, compact design, reduced fouling, versatility, robust construction, and cost-effectiveness are key attributes that address the specific needs of refinery operations. As refineries continue to seek improvements in efficiency and reliability, the adoption of SHEs is likely to increase, solidifying their role as a critical component in the refining industry.
Heat exchangers are integral components in various industrial processes, playing a crucial role in transferring heat between fluids. Among the different types available, spiral heat exchangers (SHEs) have gained significant traction in refineries due to their unique design and efficiency. Exceptional Heat Transfer Efficiency SHEs are designed with two concentric spi- ral channels, allowing for counter-current flow of fluids. This configuration maximises the temperature gradient between the hot and cold streams, enhancing the overall heat transfer efficiency. In refineries, where pre- cise temperature control is essential for pro- cesses like distillation and catalytic cracking, the efficient heat transfer offered by SHEs is invaluable. The improved heat exchange capabilities lead to energy savings and opti- mised operational performance. Compact Design and Space Utilisation Refineries often face constraints regard- ing space, especially in areas with numer- ous processing units. The compact design of SHEs addresses this challenge effec- tively. They have a high surface area-to-
Figure 1 Nexson spiral plate heat exchangers installed in a refinery
between cleaning cycles, thus enhancing the overall reliability and uptime of the refin- ery processes. Versatility and Adaptability SHEs are highly versatile and can handle a wide range of fluids, including gases, liquids, and even slurries. This adaptability is crucial in refinery operations, which involve diverse processing streams with varying thermal properties. Additionally, SHEs can operate efficiently across a wide range of tempera- tures and pressures, making them suitable for different stages of refining processes. Whether preheating crude oil or cooling down final products, SHEs can be tailored to meet specific process requirements. Robust Construction and Durability The robust construction of SHEs ensures
volume ratio, meaning they can provide a large heat transfer area within a relatively small footprint. This compactness not only saves valuable space but also simplifies the installation process and reduces the structural support requirements. Reduced Fouling and Maintenance One of the most significant advantages of SHEs is their self-cleaning nature, which drastically reduces fouling. The spiral design induces a high level of turbulence within the channels, preventing the accu- mulation of deposits on the heat trans- fer surfaces. This is particularly beneficial in refineries, where the fluids being pro- cessed can often be laden with particulates and other contaminants. Reduced fouling translates to lower maintenance require- ments and extended operational periods
Contact: marketing@nexson-group.com
Additised solvent closed-loop cleaning package
Kandanelli Ramesh, K B Dhiravidaselvi AND K R Krishna HP Green R&D Centre, Hindustan Petroleum Corporation Limited
The additised solvent package was able to convert 95% of the sludge into process- able oil in one to two days of continuous operation. In comparison to non-additised solvent cleaning, the tank downtime also decreased from 45 days to just six to seven days. This closed-loop cleaning pro- cess benefitted from ease of operation, reduced manpower requirements, reduced hazardous waste generation, scalability of operation, and more. Thus, it is a compre- hensive solution for removing condensed asphaltenic foulants from the bitumen stor- age tank. Novel solution The newly developed additised solvent package is a novel solution for converting heavy asphaltenic streams into processa- ble oil within a closed loop without compro- mising safety and operational flexibility. It significantly enhances the asphaltene dis- solving capacity of the solvent, resulting in thorough defouling and reduced downtime of units and tanks.
tional cleaning procedure using aromatic- rich extract solvent was unsuccessful in meeting the specifications of the product. The additised cleaning package could defoul the extractors by dissolving the asphaltenic foulants and help meet the desired product specifications under opti- mum unit operating conditions. Compared to using a non-enhanced solvent, the amount of asphaltene removed increased by 70%. The unit downtime was also halved, providing operational flexibility. Case study 2: A bitumen storage tank was due an outage as part of a tank farm revamp- ing plan. The tank contained approximately 73.1 kl of condensed unpumpable bitumi- nous sludge. The usual process using a reg- ular light vacuum gas oil stream can only remove 10% of the hard bottom material, leaving the remaining 90% to be removed through mechanical and manual inter- vention. This is time-consuming, involves high-end mechanical equipment, and is labour-intensive. As a result, the regular pro- cess incurs significant costs and exposes workers to solvent-hydrocarbon mixtures.
eral cleaning cycles using aromatic solvents or manual intervention is required. However, the execution of these methods can lead to production loss, unit downtime, loss of business opportunities, and safety issues. This often results in timely main- tenance being postponed or taken up only upon complete breakdown of the process units or storage facility. The additised solvent package developed by HP Green R&D Centre is a closed-loop cleaning solution. It converts sludge and deposits into processable oil, reducing envi- ronmental impact and downtime of units and tanks. The process is also economically viable, can be used for high-temperature operation, and is easily scaled up. Case study 1: The propane deasphalting unit at HPC’s Mumbai refinery had issues meeting the quality requirements for the fin- ished product in terms of colour and viscos- ity. The presence of condensed asphaltenic deposits in the extractor was suspected to be leaching into the consequent product streams, leading to poorer product quality as crude processing limitations. The conven-
Defouling process units in the refining sec- tor can be tedious and time-consuming. Unit and storage cleaning is crucial to ensure better feed quality, but it can be costly and pose safety risks. This article focuses on the removal and recycling of hard hydrocar- bon deposits in refinery process and stor- age units. We introduce a novel and highly efficient additised solvent package that aids in dissolving tough condensed asphaltenic deposits. This methodology employs a chemical formulation that reduces facility downtime, minimises manual intervention, and ensures the recovery of 100% of the hydrocarbons. The recovered liquid is then processed further to extract valuable resid- ual oil for various applications. Process Processing heavy crudes can lead to prob- lematic asphaltene deposition in down- stream units and storage tanks. Over time, these deposits condense and become hard, causing issues such as poor product quality, suboptimal unit performance, and increased maintenance and downtime. Generally, to restore the performance of these units, sev-
Contact: ramesh.kandanelli@hpcl.in
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