(262a) Proposal for a New Evaluation Method for Green & Sustainable Chemistry

INTRODUCTION Various groups have proposed many metrics and evaluation methods for Green & Sustainable Chemistry (GSC) and some of them are actually utilized in some area. However, most of them require a lot of basic data and rather complicated procedures to evaluate the improvement by a GSC technology. This paper shows a new simple and easy method, which compares the current technology with the improved technology about products or processes by a GSC technology, and which shows the improved effects overall. This method is useful in R&D, business activity and policy making as well as for enlightenment and education. In a chemical production process, for instance, a GSC technology might be defined to innovative effects as follows, To reduce the number of process to a large degree To improve process yields without production of by-product To moderate process condition such as temperature, pressure To change reaction solvents from organic compounds to water If these effects are evaluated with ease and shown in a simple way, everyone would understand the effects at a glance. One of our aims in this paper is to propose a new method that evaluates the effect of the improved technology from the stand point of GSC easily. The other aim is to propose a new method that shows pertinent details of the GSC effect clearly.

OUTLINE As well known, sustainability is generally described as three aspects, Environmental, Economical and Social aspects. However, after careful study, we arrived at the trial conclusion that the illustration of three viewpoints as follows, 1) Environmental aspect 2) Human health and product/production Safety and Security 3) Economical and Social aspects These viewpoints indicate the improved effect by a GSC technology very clearly and simply. ?Human health and the product/production Safety? is an important viewpoint to express the effect by a GSC technology. We might say that people may have a deep interest in health and safety. Non-specialists in this field are eager for the viewpoint of health and safety of products and processes by a GSC technology. This viewpoint is easy for them to understand the GSC effect. Of course, the Economical aspect and the Social aspect are also important, but they could be depicted in one viewpoint.

METHODOLOGY LCA is a useful tool for assessing the environmental aspects and potential impacts with regard to a product or a system. It considers the entire life cycle of a product from resource extraction to waste disposal. On the other hand, our approach is to provide a tool for assessing these aspects of a product or a process only in the specific area related to the distinctly improved technology by GSC, not the entire life cycle. Limitation of the assess area helps to save the labor and time for the assessment. In addition, by the limitation the assessment could focus easily on the specific point of the improved technology.

We designed three-aspects method, which expresses triple bottom line of sustainability Environmental, Economical and Social aspects, and four categories of each line to share the common understanding among different sectors. This method can be objectively and universally suitable for GSC metrics. Four items evaluate environmental aspect as follows, 1-1) Energy consumption 1-2) Emission to the environment 1-3) Material consumption 1-4) Waste volume

Four items evaluate the aspect of the Human health and product/production Safety & Security as follows, 2-1) Health safety of the raw material 2-2) Disaster safety of the raw material 2-3) Health safety in production, usage and disposal 2-4) Disaster safety in production, usage and disposal We tried to classify hazard variety and degree of products with regard to health and safe. Consequently we conclude that Risk phrases (R-phrases) defined by European Union are proposed for the classification at this moment. These phrases or combination of phrases describe the hazards associated with chemical products. R-phrases of a product is easily obtainable, because they may appear, for example, on each label and material safety data sheet for chemical compounds.

Economical and Social aspects are evaluated by four loss of benefits as follows, 3-1) Loss of global benefit 3-2) Loss of social benefit 3-3) Loss of user benefit 3-4) Loss of producer benefit In general there are several kinds of the methods to evaluate these benefits. For example, panel method by multiple people including the third person, and the questionnaire method typified by CVM and conjoint method. This proposal selected the panel method by specifying evaluation person names.

CASE STUDY As a case study of this evaluation method, we applied this method for the evaluation of Electrolytic soda processes with the objective of GSC. Electrolytic soda processes are the main technologies for the production of chlorine and caustic soda by the electrolysis of brine solution. Three commercial processes, Mercury Cell Process, Diaphragm Cell Process and Membrane Cell Process, are in use around the world, however the processes consume large quantity of electric power and have high potential for hazard. We evaluated these processes by using our new metrics.

CONCLUSION As a result, we present you how handy to explain the improvement about these processes, how easy to comprehend the difference and how readily to promote GSC technology. As a result, Membrane Cell Process is most preferable in the meaning of GSC among other existing processes. We do expect this evaluation method will be a strong help for GSC.