Decarbonisation Technology - November 2021

How advanced process control can support decarbonisation Process analytical technology can help to overcome the challenges of converting refineries into renewable fuel facilities

Martin Gadsby Optimal Industrial Technologies

R efineries and crude oil processing plants are being upgraded to use more sustainable feedstocks to produce greener fuels and help create a circular economy for materials. Effective, data-driven control systems are needed to ensure highly efficient, responsive and flexible processing activities. These, in turn, enable facilities to maintain low carbon footprints while delivering high-quality products at competitive prices. Refineries and crude oil processing facilities can benefit from innovative technologies that can be applied to existing plants to help process resources with a reduced environmental impact. For example, a number of leading companies have already adapted their existing equipment to produce biofuels. An established process is the use of crops or lignocellulosic materials to obtain bioethanol. Generally, the raw materials first undergo a pre-treatment to separate hemicellulose and lignin from cellulose. Subsequently, cellulose is hydrolysed to obtain fermentable sugars and these are converted into ethanol. This stage is followed by distillation to purify the fuel. It is also possible to produce biodiesel from waste oils and fats, such as bleachable fancy tallow, vegetable oils, e.g. soybean and inedible corn oils, or algae. The feedstock is pre- processed to reduce the content of impurities, water, phospholipids and other plant matter. The glycerides undergo transesterification to obtain fatty acid methyl esters (FAME), which are consequently purified to obtain high- octane biodiesel. In addition to these established methods, new solutions are constantly being developed. In

particular, waste-to-fuel processing technologies offer a way to create a circular economy for currently unrecyclable materials, such as certain single-use plastics and municipal solid waste. At the same time, processes to reduce the emission of waste gases from industrial activities are also coming to the fore. These alternatives are often based on pyrolysis, a process that heats the waste without oxygen to decompose the polymers and gasify them into short hydrocarbon chains. Impurities, such as sulphur and chloride, are removed while the gaseous hydrocarbons are condensed and separated into relevant oil fractions. Identifying the optimum conditions for sustainable production These decarbonising strategies greatly differ in the feedstocks used as well as in the main processes that they apply; namely, fermentation, transesterification and pyrolysis. However, the novel methods they use share some common challenges. Businesses interested in adapting their crude oil facilities may not have the necessary in-depth process understanding to create highly effective setups. In fact, analysing processing data and leveraging comprehensive, actionable insight is key to maintaining ideal operating conditions. These conditions, in turn, lead to optimum energy efficiency and cycle times as well as high product quality while reducing off-specification materials and waste. One particularly common challenge that refineries and oil processing plants face is the implementation of highly effective separation processes. The raw materials used often