I. De Marco

Pilot scale micronization of amoxicillin by supercritical antisolvent precipitation

The supercritical antisolvent precipitation (SAS) process has been frequently applied to pharmaceutical compounds, due to its potential capacity to control particle size (PS) and distribution and the simple separation and recovery of the solvent and of the antisolvent. However until now, the SAS process has been performed prevalently in laboratory scale apparatus; therefore, process limitations that are significant on the large scale, have not been studied yet. These limitations may even lead to the failure of translating the process to commercial dimensions. Herein we report the results of SAS precipitation of Amoxicillin from N -methylpyrrolidone performed in a semi-continuous pilot plant equipped with a 5 dm 3 precipitator, operated at 40 8C and 150 bar. Non coalescing spherical microparticles were obtained with mode diameters ranging from 0.3 to 1.2 mm depending on the concentration of Amoxicillin in the liquid solution. The effect of the scale enlargement and of the kind of injection device on the powder size and morphology has been investigated and a comparison with laboratory scale results is also presented. The change of nozzle arrangement and diameter from the laboratory to the pilot scale does not affect significantly the PS and distribution of Amoxicillin. # 2002 Elsevier Science B.V. All rights reserved.

Pyrolysis of plastic packaging waste: A comparison of plastic residuals from material recovery facilities with simulated plastic waste.

Pyrolysis may be an alternative for the reclamation of rejected streams of waste from sorting plants where packing and packaging plastic waste is separated and classified. These rejected streams consist of many different materials (e.g., polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), aluminum, tetra-brik, and film) for which an attempt at complete separation is not technically possible or economically viable, and they are typically sent to landfills or incinerators. For this study, a simulated plastic mixture and a real waste sample from a sorting plant were pyrolyzed using a non-stirred semi-batch reactor. Red mud, a byproduct of the aluminum industry, was used as a catalyst. Despite the fact that the samples had a similar volume of material, there were noteworthy differences in the pyrolysis yields. The real waste sample resulted, after pyrolysis, in higher gas and solid yields and consequently produced less liquid. There were also significant differences noted in the compositions of the compared pyrolysis products.

Pyrolysis of municipal plastic wastes: Influence of raw material composition.

The objective of this work is the study of pyrolysis as a feedstock recycling process, for valorizing the rejected streams that come from industrial plants, where packing and packaging wastes are classified and separated for their subsequent mechanical recycling. Four real samples collected from an industrial plant at four different times of the year, have been pyrolysed under nitrogen in a 3.5dm(3) autoclave at 500 degrees C for 30min. Pyrolysis liquids are a complex mixture of organic compounds containing valuable chemicals as styrene, ethyl-benzene, toluene, etc. Pyrolysis solids are composed of the inorganic material contained in the raw materials, as well as of some char formed in the pyrolysis process, and pyrolysis gases are mainly composed of hydrocarbons together with some CO and CO(2), and have very high gross calorific values (GCV). It has been proved by the authors that the composition of the raw material (paper, film, and metals contents) plays a significant role in the characteristics of pyrolysis products. High paper content yields water in the pyrolysis liquids, and CO and CO(2) in the gases, high PE film content gives rise to high viscosity liquids, and high metals content yields more aromatics in the liquid products, which may be attributed to the metals catalytic effect.

Tailoring of nano- and micro-particles of some superconductor precursors by supercritical antisolvent precipitation

Semi-continuous supercritical antisolvent (SAS) precipitation has been used to produce europium (EuAc) and gadolinium (GdAc) acetate nano- and micro-particles with the aim of obtaining controlled size and particle size distributions of these superconductor precursors. For both the compounds tailored micro- and nano-particles have been produced from dimethyl sulfoxide (DMSO). Their particle size and particle size distribution were controlled by varying the concentration of the liquid solution injected into the precipitation vessel. Spherical particles with mean diameters ranging from about 0.2 to 10 μm were obtained. The mechanisms that control particle size and particle size distribution were explained in terms of the relative relevance of nucleation and growth processes.

Deactivation and regeneration of ZSM-5 zeolite in catalytic pyrolysis of plastic wastes

In this work, a study of the regeneration and reuse of ZSM-5 zeolite in the pyrolysis of a plastic mixture has been carried out in a semi-batch reactor at 440°C. The results have been compared with those obtained with fresh-catalyst and in non-catalytic experiments with the same conditions. The use of fresh catalyst produces a significant change in both the pyrolysis yields and the properties of the liquids and gases obtained. Gases more rich in C3-C4 and H(2) are produced, as well as lower quantities of aromatic liquids if compared with those obtained in thermal decomposition. The authors have proved that after one pyrolysis experiment the zeolite loses quite a lot of its activity, which is reflected in both the yields and the products quality; however, this deactivation was found to be reversible since after regeneration heating at 550°C in oxygen atmosphere, this catalyst recovered its initial activity, generating similar products and in equivalent proportions as those obtained with fresh catalyst.

Pyrolysis of municipal plastic wastes II: Influence of raw material composition under catalytic conditions.

In this work, the results obtained in catalytic pyrolysis of three plastic waste streams which are the rejects of an industrial packing wastes sorting plant are presented. The samples have been pyrolysed in a 3.5 dm(3) reactor under semi-batch conditions at 440 °C for 30 min in nitrogen atmosphere. Commercial ZSM-5 zeolite has been used as catalyst in liquid phase contact. In every case, high HHV gases and liquids which can be useful as fuels or source of chemicals are obtained. A solid fraction composed of the inorganic material contained in the raw materials and some char formed in the pyrolysis process is also obtained. The zeolite has shown to be very effective to produce liquids with great aromatics content and C3-C4 fraction rich gases, even though the raw material was mainly composed of polyolefins. The characteristics of the pyrolysis products as well as the effect of the catalyst vary depending on the composition of the raw material. When paper rich samples are pyrolysed, ZSM-5 zeolite increases water production and reduces CO and CO(2) generation. If stepwise pyrolysis is applied to such sample, the aqueous liquid phase can be separated from the organic liquid fraction in a first low temperature step.

Possibilities and limits of pyrolysis for recycling plastic rich waste streams rejected from phones recycling plants.

The possibilities and limits of pyrolysis as a means of recycling plastic rich fractions derived from discarded phones have been studied. Two plastic rich samples (⩾80wt% plastics) derived from landline and mobile phones provided by a Spanish recycling company, have been pyrolysed under N2 in a 3.5dm3 reactor at 500°C for 30min. The landline and mobile phones yielded 58 and 54.5wt% liquids, 16.7 and 12.6wt% gases and 28.3 and 32.4wt% solids respectively. The liquids were a complex mixture of organic products containing valuable chemicals (toluene, styrene, ethyl-benzene, etc.) and with high HHVs (34-38MJkg-1). The solids were composed of metals (mainly Cu, Zn, and Al) and char (≈50wt%). The gases consisted mainly of hydrocarbons and some CO, CO2 and H2. The halogens (Cl, Br) of the original samples were mainly distributed between the gases and solids. The metals and char can be easily separated and the formers may be recycled, but the uses of the char will be restricted due to its Cl/Br content. The gases may provide the energy requirements of the processing plant, but HBr and HCl must be firstly eliminated. The liquids could have a potential use as energy or chemicals source, but the practical implementation of these applications will be no exempt of great problems that may become insurmountable (difficulty of economically recovering pure chemicals, contamination by volatile metals, etc.).

Pyrolysis behavior of different type of materials contained in the rejects of packaging waste sorting plants

In this paper rejected streams coming from a waste packaging material recovery facility have been characterized and separated into families of products of similar nature in order to determine the influence of different types of ingredients in the products obtained in the pyrolysis process. The pyrolysis experiments have been carried out in a non-stirred batch 3.5 dm(3) reactor, swept with 1 L min(-1) N(2), at 500°C for 30 min. Pyrolysis liquids are composed of an organic phase and an aqueous phase. The aqueous phase is greater as higher is the cellulosic material content in the sample. The organic phase contains valuable chemicals as styrene, ethylbenzene and toluene, and has high heating value (HHV) (33-40 MJ kg(-1)). Therefore they could be used as alternative fuels for heat and power generation and as a source of valuable chemicals. Pyrolysis gases are mainly composed of hydrocarbons but contain high amounts of CO and CO(2); their HHV is in the range of 18-46 MJ kg(-1). The amount of COCO(2) increases, and consequently HHV decreases as higher is the cellulosic content of the waste. Pyrolysis solids are mainly composed of inorganics and char formed in the process. The cellulosic materials lower the quality of the pyrolysis liquids and gases, and increase the production of char.

Influence of the type of solvent on coal liquefaction with different catalysts

Abstract The liquefaction behaviour of a series of solvents in coal liquefaction both without catalyst and with two catalysts, red mud (an Fe 2 O 3 catalyst) and CZMFA2 (a CoZnMo/Al 2 O 3 ) catalyst), was evaluated. Three H-donor solvents (tetralin, 9,10-DHA and 1,2,3,4-THQ), three non-donor solvents (naphthalene, anthracene and phenantrene) and two industrial type solvents (anthracene oil and creosote oil) were tested. The experiments were conducted in a 250 ml autoclave, with 10 g of a subbituminous A coal, 30 g of solvent, 425 °C, 17 MPa operating pressure, 1 hour reaction time and 400 rpm stirring speed. The liquefaction products were fractionated into oils, asphaltenes and preasphaltenes using pentane, toluene and THF as extractive solvents. The behaviour of a solvent is greatly influenced by the type of catalyst used and viceversa, the catalyst effect depends on the solvent utilized. Industrial type solvents can give better coal conversions than strong H-donor solvents if appropriate catalysts are used

Life cycle assessment of ale and lager beers production

The food production industry requires great amounts of resources and energy, causing, during the productions, negative effects on environment. For these reasons, in the last years, different products of consumption were analysed from the environmental point of view, following Life Cycle Assessment (LCA) approaches. This work aimed at studying the environmental performance and the energy consumption of different beers produced in Italy by a small brewery. The study followed a life cycle approach and was focused on the industrial phases of the productions. A comparison among ale (high fermentation) and lager (low fermentation) beers’ productions was made with the aim of address the productions toward a higher sustainability. The system boundaries covered by our research are only the industrial steps of the entire products’ life cycle path: production in the brewery, bottling, packaging and waste disposal treatments (“gate to gate” and “gate to grave” approach). Raw materials, energy consumption and emissions to air, soil and water were normalized to the functional unit (beer in 33 cL glass bottle). In accordance with the reference standard for LCA (i.e., ISO 14040-14044), data were analysed using SimaPro 8.0.4 software and Life Cycle Inventory (LCI) was obtained using primary data and the Ecoinvent 3.1 database.