Search

Pressure and temperature are the most important state variables for monitoring physicochemical processes to detect deviations that might lead to explosions and to verify levels, flow rate, and solids/gas hold-up. Pressure fluctuations in multi-phase systems identify regime changes and flow anomalies. Pressure signals are the first indicator of a process upset and are tied into distributed control systems (DCS) to sound alarms when they drift to high or low and activate safety interlocks in the case of high, high-high, low, and low-low conditions. To maximize the information, it requires that pressure gauges (transducers) are installed and calibrated precisely. Pressure measuring devices include manometers, aneroid devices like bellows and Bourdon gauges, and electronic instruments—piezoresistive, piezoelectric, and capacitive. The electronic elements have the advantage of higher precision and faster response times to measure fluctuations. The Bourdon gauges are standard equipment for pressure regulators and are mounted on the exterior of vessels and pipes to facilitate visual inspections. Over 2 million articles indexed by the Web of Science Core collection mention pressure, and in 2021, chemical engineering ranks had over 7000 articles—only multidisciplinary material sciences and energy and fuels had more. A bibliometric analysis identified five research clusters: temperature, combustion, and kinetics; separation, membranes, and energy efficiency; carbon dioxide (capture and storage), water, and thermodynamics; methane, adsorption, and transport phenomena (e.g., diffusion and permeability); and modelling, optimization, and computational fluid dynamics (CFD)., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., ChemE/Product and Process Engineering

Poly(methyl methacrylate) (PMMA) is a versatile polymer with a forecast market of 4 Mtons/y by 2025, and 6 USD billion by 2027. Each year, 10% of the produced cast sheets, extrusion sheets, or granules PMMA end up as post-production waste, accounting for approximately 30 000 tons/y in Europe only. To guide the future recycling efforts, we investigated the risks of depolymerization process economics for different PMMA scraps feedstock, capital expenditure (CAPEX), and regenerated MMA (r-MMA) prices via a Monte-Carlo simulation. An analysis of plastic recycling plants operating with similar technologies confirmed how a maximum 10 M USD plant (median cost) is what a company should aim for, based on our hypothesis. The capital investment and the r-MMA quality have the main impacts on the profitability. Depending on the pursued outcome, we identified three most suitable scenarios. Lower capital-intensive plants (Scenarios 4 and 8) provide the fastest payback time, but this generates a lower quality monomer, and therefore lower appeal on the long term. On 10 or 20 years of operation, companies should target the very best r-MMA quality, to achieve the highest net present value (Scenario 6). Product quality comes from the feedstock choice, depolymerization, and purification technologies. Counterintuitively, a plant processing low quality scraps available for free (Scenario 7), and therefore producing low purity r-MMA, has the highest probability of negative net present value after 10 years of operation, making it a high-risk scenario. Western countries (especially Europe), call for more and more pure r-MMA, hopefully comparable to the virgin material. With legislations on recycled products becoming more stringent, low quality product might not find a market in the future. To convince shareholders and government bodies, companies should demonstrate how funds and subsidies directly translate into higher quality products (more attractive to costumers), more economica