We are delighted to present our Technical Programme to you.
Please note this is subject to change. Information is being added regularly so do come back!
18 November 2021
09:30 - 11:30 GMT
09:40 - 10:10
Carbon Dioxide Capture Options For Steam Methane Reforming Based Hydrogen Manufacturing Units
Speaker: Gary Bowerbank, Shell Global Solutions
Does Your Refinery Or Chemical Plant Have A Steam Methane Reforming (SMR) Based Hydrogen Manufacturing Unit (HMU)? Are you under pressure to meet your carbon dioxide (CO2) emissions mandate?
Growing numbers of national governments and energy companies, including Shell, are announcing net-zero-emission ambitions. To help fulfil their responsibilities under the 2015 Paris Agreement on climate change, governments around the world are increasingly likely to penalise CO2 emissions.
Consequently, refiners and chemical plants have mandates to reduce their CO2 emissions substantially. For this, carbon capture, utilisation and storage is widely regarded as one of the most effective decarbonisation solutions.
An SMR-based HMU provides a major opportunity because it creates significant CO2 emissions that can be captured in two main ways:
- from the high-pressure, pre-combustion stream after the shift reactor before pressure swing adsorption line-up. This recovers less CO2 but has a lower capture cost per tonne of CO2.
- from the low-pressure, post-combustion flue gas. This maximises the amount of CO2 captured but requires a more expensive unit needing more space.
This paper/presentation will:
- examine the key elements of a typical HMU and explain the options for CO2 capture;
- conduct a cost–benefit comparison of installing pre- and post-combustion technologies at a typical HMU; and
- provide a real-world example from the Athabasca oil sands project in Canada, where Shell is capturing more than 1 Mt/y of CO2 from SMR streams and generating valuable lessons for future projects.
10:10 - 10:40
Natural Gas fuels the Energy Transition
Speaker: Dr. Paul Hudson, Johnson Matthey
Climate change, the COVID-19 pandemic, and the global drive to be greener have accelerated the move away from using fossil fuels to fulfil energy demands. Achieving this transition as a step change to net zero poses huge difficulties, however, transitioning from coal and oil to natural gas is widely seen as a logical step on the path to lower carbon energy. Increased utilisation of natural gas over coal and oil will reduce CO2 emissions but must be done safely and without increases of other pollutants including H2S and mercury. Fixed bed gas purification has been enhanced and developed over many years but what is achievable with the next generation of fixed bed absorbents? Can existing plants be upgraded without CAPEX? Can new plants be designed for increased efficiency of mercury and sulphur removal with lower CAPEX and OPEX? And can waste be reduced and handled in an environmentally conscientious manner?
10:40 - 11:10
How the unique characteristics and application of brazed aluminium heat exchangers are driving us towards a lower carbon energy future
Speaker: Oliver Knight, Chart Industries
Brazed aluminium heat exchangers (BAHX) were adapted for industrial use from the aerospace industry shortly after WW2. Today tens of thousands are at the heart of the cryogenic processes separating air, liquefying and processing natural gas and in propane dehydrogenation and ethylene cracking. They are highly prized as they represent the most compact and efficient heat transfer solution for gas/gas and gas/liquid duties.
As the world moves rapidly towards a lower carbon energy future, BAHX are already taking centre stage in many of the processes driving this change. They are fundamental to many of the liquefaction processes enabling small- and mid-scale LNG, including bio-gas liquefaction, and they’re proven offshore in FLNG and on-board boil-off gas recovery systems. BAHX have been used in hydrogen liquefaction for years and are a crucial part in the development of larger capacity liquefaction plants. Liquid air storage utilises air separation technology so it’s natural that BAHX are central to LAES plants and Cryogenic Carbon Capture™ is an extremely exciting process that captures and liquefies carbon dioxide for use from industrial exhaust gases.
11:10 - 11:40
Understanding And Identifying Reflux In Ng Dehydrators Through Cfd
Speakers: François-Xavier Chiron, Axens and Alessandro Checchi, Resolvent
Drying natural gas is a mandatory step in a natural gas process unit, aiming at producing LNG. Strict specifications on water prior entering the cold box (typically 0.5 to 0.1 ppm vol.) impose the use of a dual bed composed by optimized alumina followed by molecular sieves. The desiccant is loaded in fixed beds that alternate between adsorption (drying downflow) and regeneration (heating upflow). That process is known as Temperature Swing Adsorption or TSA.
Drying is conveniently carried out at ambient temperature where water molecules are physisorbed (Van der Waals bonds) onto the molecular sieve. After a pre-determined duration, the water-saturated dryer is put into regeneration mode where the aim is to remove water from the desiccant by elevating the temperature with a hot gas stream. When the adsorbent temperature reaches some 110 – 130 °C, water desorbs from the desiccant and is entrained along the vessel together with the regeneration gas flow. The regeneration conditions have to
be carefully looked at since this transient operation brings the adsorbent material from ambient temperature to 280-290°C within a few hours. A well-known operational issue linked to the regeneration, is the condensation of water during the first moments of regeneration, on colder parts of the vessel. This phenomenon is known as reflux or retro-condensation. Liquid water can run along the vessel walls, fall onto the molesieve bed and destructure the binder that holds the zeolite crystals together, resulting in lump formation, pressure drop and premature molecular sieve change-out.
In that frame, Axens and Resolvent worked together on setting-up a CFD model that predicts the risks of condensation during the regeneration of such dehydrators. The model is developed using COMSOL™ and it is based on both industrial data and laboratory kinetic studies related to desorption of water on Axens’ 4A molecular sieve. The model solves heat and mass transport coupled to the desorption reaction across the whole geometry and detects the risk of condensation. The whole regeneration cycle has been simulated where the hot gas is entering the system and heat-up gradually the bed. In the first moment of the regeneration, the bottom is hot while the top of the bed is still cold. The risk of condensation is therefore greater at the top of the vessel and depends on the vessel insulation as well as on the distribution of the water along the bed during the adsorption phase. Several cases were investigated with a focus on the impact of the bed ageing on the risk of reflux.