Feedstock Environmental Impact

The environmental impact can also be calculated for the feedstock of the process (PEIin), allowing us to assess the hazards and the costs associated with the use of the starting materials of a particular process. This should always be carried out to make sure that a decrease of the environmental impact of waste is not made at the expense of using more hazardous or (environmentally) expensive starting materials. 

For the feedstock environmental impact evaluation, EATOS considers risk-phrases and the cost associated with each substance. (For a discussion of the cost as a metrics for starting material environmental impact, see Reference [11].) These data were obtained for all substances, of both routes, from the 2007 Sigma-Aldrich catalogue. 

The results are summarized in Table 16.1. Route B achieves a decrease over route A, in the environmental impact of the waste produced (EI out —42%), and this is not done at the expense of more hazardous starting materials. In fact, the environmental impact of starting material is also decreased in route B (EI in —34%). Erom Table 16.1, it is also possible to see the largest relative reduction that route B brought 

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Bioethanol from different feedstocks environmental impact assessment... 

Methods for the large-scale production of hydrogen must be evaluated in the context of environmental impact and cost. Synthesis gas generation is the principal area requiring environmental controls common to all syngas-based processes. The nature of the controls depends on the feedstock and method of processing. 

Coal used in power stations has the potential to be partly replaced by fuels derived from pre-treated plastics and paper waste, reducing both dependency on fossil fuels and reliance on landfill. APME reports on a project in the Netherlands which it co-sponsored to develop a substitute fuel from plastics. The environmental assessment of the project compared the environmental impacts of coal substitution with other plastics recovery methods, including gasification in feedstock recycling and energy recovery from plastics waste in cement kilns. The study also compared coal substitution with the generation of power from burning biomass. 

This article presents details of the gloomy picture of the environmental impacts associated with PVC waste which has been painted by four PVC waste management studies carried out for the European Commission. The studies cover mechanical recycling, feedstock recycling, behaviour in landfill, and the influence of PVC on incinerator flue gas cleaning residues. 

There is a real opportunity to reduce biodiesel production costs and environmental impact by applying modem catalyst technology, which will allow increased process flexibility to incorporate the use of low-cost high-FFA feedstock, and reduce water and energy requirement. Solid catalysts such as synthetic polymeric catalysts, zeolites and superacids like sulfated zirconia and niobic acid have the strong potential to replace liquid acids, eliminating separation, corrosion and environmental problems. Lotero et al. recently published a review that elaborates the importance of solid acids for biodiesel production. ... 

Although in principle stationary and transport-specific energy chains can be analysed, here the assessment of the latter is explained in more detail, and is then referred to as well-to-wheel (WTW) analysis. The primary focus of WTW analysis in Europe is on global environmental impact, i.e., greenhouse-gas emissions expressed as C02-equivalents. Other issues of interest are (a) primary energy demand (which equals resource utilisation), (b) local pollutant emissions and (c) full energy or fuel supply costs. Well-to-wheel analysis covers the entire fuel supply chain from feedstock extraction, feedstock transportation, fuel manufacturing and fuel distribution to fuel use in a vehicle. 

Lignocellulosic perennial crops (e.g., short-rotation coppices and grasses) are a promising feedstock becanse of high yields, low costs, good snitability for low-quality land (which is more easily available for energy crops), and the low environmental impacts. 

Feedstocks For either gaseous (ethane/propane) or liquid (C4/naphtha/ gasoil) feeds, this technology is based on Technip s proprietary Pyrolysis Furnaces and progressive separation. This method allows producing olefins at low energy consumption with particularly low environmental impact. 

The second phase is the feasibility study. This stage may require the expenditure of 1 to 2% of the total project cost. Thus for a 1,000 million project about 20 million will be required. This will define the location, feedstock and product market and the technology to be used. It will also typically encompass outline regulatory approval and assessment of environmental impacts. The error in the estimate is typically not less than about +/-10%. Financiers (bankers and corporate boards) like the error to be +1-5%. This level of estimate can usually only be achieved by a FEED study. 

In goal definition, the scope and purpose of the LCA is defined. The functional unit and system boundaries are also established. The functional unit is the reference point to which environmental impacts are attributed. The choice of functional unit depends on the application of the LCA. For a process it could be a tonne of product or feedstock, or a tonne of impurity removed. For a commodity product the functional unit could be a tonne of product, but for specialty chemicals and most consumer products performance properties are more important and the choice can become complex. For example, performance of a paint would be related to its surface coverage and durability hence a possible functional unit for the paint might be the quantity required to cover a square meter of surface over a time span of 20 years. 

A study by the Association of Plastics Manufacturers in Europe (APME) assessed the environmental impacts of mechanical and feedstock recycling and energy recovery of waste plastics. It was compared in terms of consumption of resomces and environmental emission pollution potential. The criteria of consumption of energetically exploitable resources and contribution to the greenhouse effect lead to the following order of preference for feedstock recycling and energy recovery processes ... 

A second example concerns the use of alkanes instead of alkenes to both use alternative feedstocks and reduce the environmental impact. An interesting example is the oxidation of isobutane to methacrylic acid [331]. 

In 2002, Eissen and Metzger proposed EATOS (an environmental assessment tool for organic syntheses), an environmental performance metrics for daily use in synthetic chemistry [11]. This tool allows rapid quantitative assessment of both the E-factor and the potential environmental impact (PEI, Sheldon s Q) of a process. They also provided a PC software application to perform this calculation, which is available from them [12]. With this tool, Sheldon s Q can be quantitatively assessed for both the feedstock and the output (product and wastes) of a multistep synthesis. The assessment is made on the basis of the available substance s ecotoxicological and human toxicological data. 

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