麻豆传媒

Aromatics are the building blocks of the petrochemical industry. When converted into the right intermediates or polymers, aromatics enable the production of everyday items such as computers, paints, packaging, adhesives and more.

Despite predicted growth, there are some concerns when it comes to feedstock availability. Aromatic molecules such as benzene, toluene and xylene are primarily produced from petroleum or as part of the petroleum refining process. Therefore, a shortage in their supply can be linked to reduced gasoline production. For instance, during the summer months, there is an expectation that aromatics production will decline with increasing petroleum prices. This situation will also create feedstock shortages.^[1]

Another significant development is the need to transition towards a more sustainable and circular plastics value chain, which provides a compelling opportunity for progressive petrochemical companies.

Fortunately, Shell Catalysts & Technologies can help customers to adapt to changing industry dynamics such as these. For example, it can offer insights into renewable feedstocks, and its aromatics portfolio can help customers to reduce both operating costs and the carbon footprint of their aromatics complex. During times when feedstock is not readily available, catalyst performance optimisation simulations can be used to determine output based on substitute feedstocks. Additionally, Shell Catalysts & Technologies provides catalyst application support in relation to temperature and pressure conditions, and hydrocarbon selection.

On Thursday, 8 December, Agnes Lim and Richard Mauer hosted a webinar and live Q&A to discuss the challenges facing aromatics customers, the role aromatics play in the energy transition and how the future of aromatics links to the . To follow up on what they discussed during the webinar, we asked them a few questions.

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Richard Mauer: The main challenge in making aromatics is feedstock availability and cost, which is about 80% of the total cost of making aromatics. So, the cheaper the feedstock, the lower the cost for the user.

The next challenge is to convert the expensive feed into the desired products as efficiently as possible. Catalyst selection plays an important role in securing smooth operation and efficient conversion of the feed to the desired product while limiting losses from the production of by-products. Regarding these, a distinction can be made between recoverable and unrecoverable by-products. An example of an unrecoverable by-product is the conversion of the feed (aromatic molecule) into gas, which results from undesired hydrogenation and/or ring opening reactions unintentionally promoted by the catalyst.

Agnes Lim: A number of external factors have also challenged aromatics producers. For example, the mega-scale assets recently built in China, and other parts of Asia, brought overcapacity and, consequently, low margins.

And COVID-19, of course, also had a major effect. I read recently that global GDP fell by over 3% in 2020 鈥� that鈥檚 over $2 trillion of lost economic output. That recovered in 2021, only for the global economy to stall in 2022 as a result of Russia鈥檚 war in Ukraine, COVID-19-induced lockdowns in mainland China, tightening financial conditions and rising inflation.

To improve margins in such a challenging environment, many aromatics producers have been looking to optimise their processes by improving yields and energy efficiency. Others have been seeking to diversify their product slates: for example, some have been seeking to revamp their xylene isomerisation unit from the reforming type to the dealkylation type in order to produce additional benzene.

However benzene鈥搉aphtha/mixed xylene margins have also been depressed, so this does not always guarantee margin improvement. What can really make a difference, I believe, is building flexibility into your aromatics process. The producers that have a more flexible process will be in a much stronger position to navigate the market鈥檚 volatility.

Agnes Lim: When I think of aromatics in the energy transition, I think about the circular economy. As mentioned earlier, aromatics are building blocks in plastics. The circular economy provides two ways in which aromatics can play a part in the energy transition. The first is through mechanical recycling. Think: reduce, reuse and recycle. Plastic wastes are milled, washed, and dried and then used to create new plastic products.

Alternatively, there is chemical recycling. In this process, plastic waste is broken down to its raw materials using heat, chemical reactions or both. The Shell Recovered Plastics Upgrader (SRPU) prepares raw plastic-derived oil that is fed to downstream refining or petrochemical units. This leads to the creation of aromatics, as well as fuel and other chemicals.

Richard Mauer: Completely agree, and I also see aromatics playing a role in the energy transition at the refinery level, as part of crude oil-to-chemicals technology. For those refineries looking to optimise low-value streams when there is a decrease in gasoline demand, aromatics provide a possible outlet. In this way, refineries can produce aromatics as a potential product. Our aromatics catalysts provide bespoke solutions throughout the aromatics complex, and particularly in trans-alkylation and xylene isomerisation. Combined with our hydrocracking catalyst portfolio, our latest ATA-41 and ZATARIS-21 catalysts can further improve product xylene yields while improving energy efficiency and carbon dioxide emissions.

Current technologies to make aromatics and/or the individual building blocks are fairly energy intensive as the various processes require relatively high operating temperatures. By developing high-activity catalysts such as zeolites, we can ensure that operating temperatures and thus recycling of unconverted material can be significantly reduced. In this way, Shell Catalysts & Technologies can help aromatics producers to use less energy. A catalyst with a high feed-to-product selectivity will help the aromatic producer reduce by-product formation, so greenhouse gas emissions will be reduced.

Richard Mauer: One change is that we鈥檙e seeing more renewable feedstocks. As an alternative to naphtha derived from crude oil, bionaphtha, which meets legacy naphtha specifications and is derived from non-edible vegetable oils and animal fats, is available today.

And this is anticipated to grow significantly in the next five years, as it is a by-product of second-generation biofuels, such as renewable diesel and sustainable aviation fuel. These fuels are increasingly incentivised by government legislation, such as the Inflation Reduction Act in the USA.

The impact for refiners and the plastics industry is significant. As a renewable feedstock, bionaphtha will help petrochemical producers to both reduce their Scope 3 emissions and bring circular products to the consumer market.

Agnes Lim: The aromatics industry will remain relevant in the future as aromatic chemicals are essential in many of the products we use in our daily lives. These chemicals will continue to be used to make plastic bottles, clothing and packaging with desirable properties that help improve the lives of many.

However, today鈥檚 aromatics producers will need to evolve and adapt in the next 5 to 10 years as the industry moves towards circularity. While we continue to improve feed and energy efficiency to lower our carbon footprint, innovations or disruptions in this space will be required for the future. To stay competitive, we will need to investigate alternative low-carbon technologies and feedstocks to enhance the existing aromatics value chain. In addition to mechanical and chemical recycling, developments in biomass to bionaphtha and bio-aromatics is also a critical enabler and a space to watch.

Some questions that we may need to consider as we decide on a future road map, are: What are the advantages of the available feedstocks? And how do these feedstocks affect efficiency?

Richard Mauer: There is also the rapid growth of world-scale crude-to-paraxylene complexes that has happened during the last decade. In the next five years, I expect that, given the growing oversupply, there will be no further announcement of large-scale aromatics investments, so the market might shift from greenfield developments to revamps and catalyst refills.

In the next 10 to 20 years, there will be continued development of new catalysts as alternative and/or difficult feedstocks become widespread. I believe there may be new technologies in the aromatics space. In just the last few years, there has been growing talk of creating aromatics from biomass such as yeast and even recovering aromatic compounds from industrial wastewater.^[2],[3] These technologies are in their infancy, but they give the sense that, even though the aromatics space is mature, there are innovations that will impact aromatics production and efficiency.

Agnes Lim: The aromatics industry has improved the lives of many people by enabling the manufacture of convenience products. Although there is a negative association of aromatics with fossil fuels, remember that plastics have reduced the overall carbon footprint of the end-to-end transport of goods and have improved hygiene in the food industry.

For example, aromatic molecules are found in carbon fibre resins, widely used in aircraft construction. Boeing reduced the fuel consumption of the 787 Dreamliner by up to 30% compared with the aircraft that it replaced. This was partly achieved by integrating new, lightweight composite plastic materials into the Dreamliner鈥檚 construction.

Often, the role of plastics in enhancing use efficiencies, for example, decreasing food spoilage and reducing greenhouse gas emissions, is overlooked. In applications for which non-plastic alternatives exist, plastic use can offer greenhouse gas savings of 10 to 90%, considering both the product life cycle and the impact of use.

The most compelling case is for specialist food packaging. A study by Denkstatt found that the carbon footprint of food waste is, on average, five times higher than that of the plastic packaging used to prevent that waste. Airtight and flexible plastic packaging can keep food safe from bacteria and other contaminants that lead to deterioration during transport. Just 1.5 g of plastic film wrap can extend a cucumber鈥檚 shelf life from 3 to 14 days. Plastics found in multi-layer smart food packaging offer an effective solution that significantly reduces food loss and waste, thus avoiding greenhouse gas emissions.

Plastics, as previously mentioned, may be a viable feedstock in the future, so we should embrace them while seeking opportunities to mitigate the downsides. To be involved in the development of technology that impacts so many excites me, and I look forward to our continuous effort in pushing boundaries and creating innovative, more sustainable, solutions.

Richard Mauer: In the future, a growing world population, coupled with socio-economic development, will mean that consumers will have an increased need for materials made from plastics. Aromatics will continue to have an important place.

Currently, the production of aromatics is based on the conversion of naphtha, derived from the refining of crude oil, by means of naphtha reforming and steam cracking technology. To meet future demand, we will need to consider new and sustainable technologies.

There are exciting developments in the field of aromatics from biomass, natural gas, and plastic and other wastes, so it may become possible to achieve a circular economy for plastics. There is no doubt that catalysts will continue to play a crucial role in the successful launch and commercialisation of these new technologies.