Interest in dimethyl carbonate (DMC), a saleable chemical destination of CO2, has grown significantly. DMC is an oxygenated octane-booster and a safer and nontoxic substitute of well-established methylating-carbonylating hazardous chemicals like dimethyl sulfate and phosgene. Considering the CO2 routes to DMC, the one commercially promising converts CO2 with ethylene oxide (EO) to ethylene carbonate (EC), which then reacts with excess methanol (MeOH) to DMC and ethylene glycol (EG). This indirect route (IR) apparently exhibits green chemistry attributes. It converts greenhouse gases (GHG) to valuables, such as EG, EC, and DMC. Apparently, it is not energy intensive; it has 100% atom economy without wastes. However, there is a massive energetic obstacle occluded in the separation of the azeotropic pair DMC–MeOH yet to be considered. This work assesses the technical, economical, and environmental IR flowsheet for CO2 conversion to DMC. Assessment of entrainers for extractive distillation of DMC–MeOH was accomplished for EG versus methyl–isobutyl–ketone. Process design, energy consumption, and GHG emissions were assessed and showed that both alternatives are profitable but gave negative chemical sequestration indexes. Their GHG emissions through energy consumption and purges overcome the chemical conversion of CO2 to DMC. The process alternative using EG as the entrainer exhibits higher profitability and better sustainability indexes.

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In petroleum refineries, water is used in desalting units to remove the salt contained in crude oil. Typically, 7 % of the volume of hot crude oil is water, forming a water-and-oil emulsion. The emulsion flows between two electrodes and is subjected to an electric field. The electrical forces promote the coalescence of small droplets of water dispersed in crude oil, and these form bigger droplets. This paper calculates the forces acting on the droplets, highlighting particularly the mechanisms proposed for droplet-droplet coalescence under the influence of an applied electric field. Moreover, a model is developed in order to calculate the displacement speed of the droplets and the time between droplet collisions. Thus, it is possible to simulate and optimize the process by changing the operational variables (temperature, electrical field, and water quantity). The main advantage of this study is to show that it is feasible to increase the volume of water recycled in desalting processes, thus reducing the use of freshwater and the generation of liquid effluents in refineries.

Glycerol from biodiesel is a potential raw material for synthesis of several products with high added value. The world demand and the market value of these products are important information for defining the best investment for the implantation of a biorefinery. The information is available on websites of social associations, production companies and market consulting companies and can be mined, free of charge. The International Trade Center (ITC), with information on world trade and websites linked to the foreign trade agencies of every country, such as Comex Stat, in Brazil, are relevant search sources. In this context, this work presents procedures and search techniques for prospecting such information. Such a procedure is illustrated through a case study for which a search of market parameters for glycerol and its derivatives was carried out for use in the process design and economic evaluation of an industrial plant. It was found that crude glycerol had a market price close to US$ 170/ton, in 2019. Among its derivatives, acrylic acid, acrylonitrile and 1,3-propanediol have great potential for the development of new processes, within the scope of a biorefinery. Industrially, acrylic acid (US$ 1100/ton) and acrylonitrile (US$ 1500/ton) are produced from propene (US$ 880/ ton) and 1,3-propanediol (US $ 2000/ton) comes from glucose (US$ 460/t) or ethylene oxide (US$ 1200/t), which encourages the development of new sustainable processes.