Novel waste printed circuit board recycling process with molten salt

The objective of the method was to prove the concept of a novel waste PCBs recycling process which uses inert, stable molten salts as the direct heat transfer fluid and, simultaneously, uses this molten salt to separate the metal products in either liquid (solder, zinc, tin, lead, etc.) or solid (copper, gold, steel, palladium, etc.) form at the operating temperatures of 450–470 °C. The PCB recovery reactor is essentially a U-shaped reactor with the molten salt providing a continuous fluid, allowing molten salt access from different depths for metal recovery. A laboratory scale batch reactor was constructed using 316L as suitable construction material. For safety reasons, the inert, stable LiCl–KCl molten salts were used as direct heat transfer fluid. Recovered materials were washed with hot water to remove residual salt before metal recovery assessment. The impact of this work was to show metal separation using molten salts in one single unit, by using this novel reactor methodology. The reactor is a U-shaped reactor filled with a continuous liquid with a sloped bottom representing a novel reactor concept. This method uses large PCB pieces instead of shredded PCBs as the reactor volume is 2.2 L. The treated PCBs can be removed via leg B while the process is on-going

Comparison of deterministic, stochastic and fuzzy logic uncertainty modelling for capacity extension projects of DI/WFI pharmaceutical plant utilities with variable/dynamic demand

The last 30 years have seen Fuzzy Logic (FL) emerging as a method either complementing or challenging stochastic methods as the traditional method of modelling uncertainty. But the circumstances under which FL or stochastic methods should be used are shrouded in disagreement, because the areas of application of statistical and FL methods are overlapping with differences in opinion as to when which method should be used. Lacking are practically relevant case studies comparing these two methods. This work compares stochastic and FL methods for the assessment of spare capacity on the example of pharmaceutical high purity water (HPW) utility systems. The goal of this study was to find the most appropriate method modelling uncertainty in industrial scale HPW systems. The results provide evidence which suggests that stochastic methods are superior to the methods of FL in simulating uncertainty in chemical plant utilities including HPW systems in typical cases whereby extreme events, for example peaks in demand, or day-to-day variation rather than average values are of interest. The average production output or other statistical measures may, for instance, be of interest in the assessment of workshops. Furthermore the results indicate that the stochastic model should be used only if found necessary by a deterministic simulation. Consequently, this thesis concludes that either deterministic or stochastic methods should be used to simulate uncertainty in chemical plant utility systems and by extension some process system because extreme events or the modelling of day-to-day variation are important in capacity extension projects. Other reasons supporting the suggestion that stochastic HPW models are preferred to FL HPW models include: 1. The computer code for stochastic models is typically less complex than a FL models, thus reducing code maintenance and validation issues. 2. In many respects FL models are similar to deterministic models. Thus the need for a FL model over a deterministic model is questionable in the case of industrial scale HPW systems as presented here (as well as other similar systems) since the latter requires simpler models. 3. A FL model may be difficult to "sell" to an end-user as its results represent "approximate reasoning" a definition of which is, however, lacking. 4. Stochastic models may be applied with some relatively minor modifications on other systems, whereas FL models may not. For instance, the stochastic HPW system could be used to model municipal drinking water systems, whereas the FL HPW model should or could not be used on such systems. This is because the FL and stochastic model philosophies of a HPW system are fundamentally different. The stochastic model sees schedule and volume uncertainties as random phenomena described by statistical distributions based on either estimated or historical data. The FL model, on the other hand, simulates schedule uncertainties based on estimated operator behaviour e.g. tiredness of the operators and their working schedule. But in a municipal drinking water distribution system the notion of "operator" breaks down. 5. Stochastic methods can account for uncertainties that are difficult to model with FL. The FL HPW system model does not account for dispensed volume uncertainty, as there appears to be no reasonable method to account for it with FL whereas the stochastic model includes volume uncertainty

Tyre recycling utilising molten metal – risk assessment of a laboratory scale investigation

This paper describes the process undertaken prior to the commencement of a proposed tyre laboratory scale experiment carried out in University College Cork, Ireland to identify the hazards, assess the risks, change the design and implement control measures to manage the hazards of the experiment

Scrap tyre recycling process with molten zinc as direct heat transfer and solids separation fluid: A new reactor concept

Every year about 1.5 billion tyres are discarded worldwide representing a large amount of solid waste, but also a largely untapped source of raw materials. The objective of the method was to prove the concept of a novel scrap tyre recycling process which uses molten zinc as the direct heat transfer fluid and, simultaneously, uses this media to separate the solids products (i.e. steel and rCB) in a sink-float separation at an operating temperature of 450–470 °C. This methodology involved: construction of the laboratory scale batch reactor, separation of floating rCB from the zinc, recovery of the steel from the bottom of the reactor following pyrolysis

Novel waste printed circuit board recycling process with molten salt

The objective of the method was to prove the concept of a novel waste PCBs recycling process which uses inert, stable molten salts as the direct heat transfer fluid and, simultaneously, uses this molten salt to separate the metal products in either liquid (solder, zinc, tin, lead, etc.) or solid (copper, gold, steel, palladium, etc.) form at the operating temperatures of 450–470 °C. The PCB recovery reactor is essentially a U-shaped reactor with the molten salt providing a continuous fluid, allowing molten salt access from different depths for metal recovery. A laboratory scale batch reactor was constructed using 316L as suitable construction material. For safety reasons, the inert, stable LiCl–KCl molten salts were used as direct heat transfer fluid. Recovered materials were washed with hot water to remove residual salt before metal recovery assessment. The impact of this work was to show metal separation using molten salts in one single unit, by using this novel reactor methodology. The reactor is a U-shaped reactor filled with a continuous liquid with a sloped bottom representing a novel reactor concept. This method uses large PCB pieces instead of shredded PCBs as the reactor volume is 2.2 L. The treated PCBs can be removed via leg B while the process is on-going

Tyre recycling utilising molten metal – risk assessment of a laboratory scale investigation

This paper describes the process undertaken prior to the commencement of a proposed tyre laboratory scale experiment carried out in University College Cork, Ireland to identify the hazards, assess the risks, change the design and implement control measures to manage the hazards of the experiment

Scrap tyre recycling process with molten zinc as direct heat transfer and solids separation fluid: A new reactor concept

Every year about 1.5 billion tyres are discarded worldwide representing a large amount of solid waste, but also a largely untapped source of raw materials. The objective of the method was to prove the concept of a novel scrap tyre recycling process which uses molten zinc as the direct heat transfer fluid and, simultaneously, uses this media to separate the solids products (i.e. steel and rCB) in a sink-float separation at an operating temperature of 450–470 °C. This methodology involved: construction of the laboratory scale batch reactor, separation of floating rCB from the zinc, recovery of the steel from the bottom of the reactor following pyrolysis

Economic assessment of a 40,000 t/y mixed plastic waste pyrolysis plant using direct heat treatment with molten metal: A case study of a plant located in Belgium

Pyrolysis has been identified as an ideal process to recycle mixed plastic waste (MPW). This study investigates the economics of a 40,000 t/y MPW pyrolysis process, called PlastPyro, located in Belgium, to an accuracy of +/- 15% i.e. "Definite Estimate". The process uses molten metal in a direct heat treatment process to pyrolyse the waste. An internal rate of return (IRR) of 20% strongly indicates that a 40,000 t/y PlastPyro plant is financially attractive for private investors. The capital expenditure (CAPEX) is estimated to be (sic)20.1 m or (sic)26.1 m if the cost of capital is included. The operating expenditures (OPEX) of the plant are estimated (sic)3.4 m per year. The sensitivity analysis shows six main variables having major impacts on the financial returns of a PlastPyro plant: (1) the addressable volume and quality of plastic waste, (2) the feedstock costs, (3) the capital and operating expenditures, (4) the revenues from the sale of the produced pyrolysis oil (P-oil), (5) the tipping fees and (6) the potential to co-locate a PlastPyro plant with a waste plastic sorting facility. For example, the 15-year low P-oil revenue price of (sic)210/t results in an IRR of 20%; but on the 6th of March 2020 the P-oil price may have achieved (sic)227/t, resulting in an IRR of 37%. The paper also shows that a reliable supply of MPW is available, and that reliable, accessible markets for the P-oil are available. Finally, cost estimates should state their accuracy and usually factorial cost estimates are not accurate enough to state the IRR

Recycling of aluminium laminated pouches and Tetra Pak cartons by molten metal pyrolysis - Pilot-scale experiments and economic analysis

Aluminium laminated (AL) pouch packages and aluminium laminated Tetra-Pak cartons are considered unrecyclable, reducing their otherwise excellent lifecycle performance. This paper describes experimental results on pilot plant trials to recycle AL packages with a molten metal pyrolysis reactor. The experimental evidence shows that both package formats can be recycled and that clean aluminium can be recovered. However, the recovered aluminium from Al pouches may require mechanical cleaning as the consumer's information is printed onto the aluminium, leaving a carbon residue on the recovered aluminium. On the other hand, over 90% of the polypropylene plastic layer on the AL packaging pyrolysed into waxes, pointing to excellent kinetics. Moreover, an economic analysis of a 4,000 t/y commercial-scale plant demonstrates that a molten metal AL recycling plant is economically viable, achieving an internal rate of return (IRR) of over 20%