Sustainable process alternatives

Jensen, N., CoU, N., and Gani, R. (2003) An integrated computer-aided system for generation and evaluation of sustainable process alternatives. Clean Technology Environment Policy, 5, 209-225. 

For abiotic stock resources, the resource value is set as equal to the production and environmental cost for a sustainable alternative. For fossil oil, gas and coal, these alternatives are rapeseed oil, biogas and charcoal, respectively. For metal (metal ores), the production and environmental costs to upgrade low-quality ores (sustainable supplies), such as silicate minerals, to a quality similar to present day ores, using a bioenergy-driven process (near-sustainable process), is used as the resource value. 

A similar method proposed by Hoffmann [26] involves analyzing process alternatives based on two indices. The total armuabzed profit per service unit (TAPPS) and material intensity per service unit (MIPS) are calculated as economic and environmental factors, respectively. TAPPS is used to calculate the maximum profit per unit of product produced. MIPS is used to calculate the number of input and output streams in a process. MIPS was used based on the knowledge that a global reduction in material streams (solvents, reactants,) is necessary to lead toward sustainable development. TAPPS and MIPS are determined for several process alternatives, which are analyzed using a Pareto Chart for their feasibihty within a plant. However, MIPS does not account for the release of toxic solvents and reagents into the environment. Therefore it has been noted that it should be used in conjunction with LCA and other methods to avoid the use of highly toxic solvents and other raw materials [26]. 

Polymers which arc not cross-linked to form infinite networks can behave elastically under transient stressing conditions. They cannot sustain prolonged loads, however, because the molecules can flow past each other to relieve the stress, and the shape of the article will be deformed by this creep process. [Alternatives to cross-linking are mentioned on pages 20 and. 315.]... 

Although providing only comparative and not absolute values, the methodology of eco-efficiency is very useful for an evaluation of process alternatives. In Chapter 1 (Section 1.6.1), Table 1.10 summarizes the results of a study by EuropaBio to evaluate the contribution of biotechnologies to sustainability. One of the dted examples is the synthesis of vitamin B2, an essential nutrient found in meat, dairy foods, plant foods and corn products and which is required by the body to break down food components, maintain tissue and absorb other nutrients. Using the eco-efficiency and, particularly, the portfolio plot it is possible to further demonstrate the benefits... 

With increasing environmental standards and a new law that forced Hoechst in Frankfurt to pay additional taxes on wastes to be incinerated, the chemical process came under more and more economic pressure. The challenge was to develop a sustainable process or to shut down the 7-ACA production plant in Frankfurt. Hoechst decided to search for alternative processes, in particular for biocatalytic... 

On the other hand, fluorinated olefins are used as intermediates for fluorinated polymers. A growing effort is currently being performed to set out cleaner processes for these latter compounds. To achieve an environmentally sustainable process, a possible alternative for fluorinated alkenes synthesis is the reaction of olefins with fluorinated solids. 

This new method is named SEEBALANCE. SEEBALANCE targets the adoption of life-cycle social data to the results of eco-efficiency analysis for a complete sustainability assessment methodology. It is a helpful tool in different fields for the evaluation of product or process alternatives. " ... 

Carvalho A, Matos HA, Gani R. SustainPro—a tool for systematic process analysis, generation and evaluation of sustainable design alternatives. Comput Chem Eng 2013 50 8-27. 

Carvalho A. Design of sustainable processes systematic generation evalnation of alternatives [Ph.D. thesis]. Portugal Instituto Superior Tecnico 2009. 

First of all, the electric vehicle as an approach for alternative propulsion, but also interesting works for enhancing sustainability with alternative manufacturing processes, materials as well as drive systems have been addressed. 

The mass- and energy-based indicators help to identify process alternatives for which sustainability metrics, environmental impact factors, as well as inherent safety indices can be estimated. The goal here is to optimize the process so that there is improvement in all these metrics with respect to the base case design. The application of the methodology requires a combination of tools ranging from databases to process simulation software (such as Aspen , Hypro , Sim Sci , etc.), to computational routines for various types of indicators and process synthesis/design tools. 

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