Renewable materials definition

Since the TSA conducts the security threat assessment for drivers seeking to obtain, renew, or transfer a hazardous materials endorsement (HME) on a state-issued commercial drivers license (CDL), the hazardous material definition is the same as used by PHMSA. 

Recall from Chapter 2 the definition of atom economy, the ratio of the mass of the species in the desired product relative to the mass of all of the reactants. In all of these reactions the atoms present in the reactants are also present in the products. In this case it is implied that these reactions are 100% atom economical. Remember from Chapter 2 that atom economy is a mass utilization number only it does not take into account the energy usage, the toxicity of the products, or whether the feedstocks are derived from renewable materials. 

Chemurgy is defined as that branch of appHed chemistry devoted to industrial utilization of organic raw materials, especially from farm products. A more modem and general definition for chemurgy is the use of renewable resources particularly biomass, usually plant or microbial material, for materials and energy (see Fuels frombiomass Fuels fromwaste). 

Furthermore, as will be apparent from the following sections, all properties of biological products that lead to their industrial utilization are, by definition, functional ones. The expected enhanced reliance on biological "renewable resources" due to the exhaustion of the fossil materials will necessitate increased emphasis on the clarification, evaluation, and modification of their functional properties as a prerequisite to their efficient utilization. 

The PED has definitely the merit that it supersedes, from a legal perspective, the very many old local codes in all European member states, codes such as BS (UK), ISPESL (Italy), TUV (Germany), Stoomwezen (the Netherlands), and UDT (Poland). Compliance with PED allows the manufacturer to CE mark their product as required by the European Union (EU) and is an assurance for the end-users that the selected material to protect their systems is in accordance to the law. Manufacturers approvals, however, are limited in time and need to be renewed regularly, which is an additional guarantee. Therefore, even with the most reputable manufacturers, it is always wise to check the status of the approvals to make sure they have not expired. 

Figure 13.4b emphasizes the finite nature and strong irreversibility of an economic system. The stock of energy and resources will eventually run out and so will the absorptive capacity of the environment for waste. An obvious extension of Figure 13.4b, therefore, is the one represented by Figure 13.4c. Just like in nature, waste has to be recycled. In nature, there is no real waste. Every form of waste is a resource for a living system. This living system is very small and called a microbe. Microbes make sure that all matter recycles in nature. Man needs to assume this humble but valuable and important role of microbes in the economic system and make sure that the material cycles get closed. Therefore, energy (or rather work) is required. But obviously this work should not be supplied from a nonrenewable source, like fossil fuels, but rather from a renewable source like the sun. Figure 13.4c therefore seems to be characteristic for a sustainable economic system and agrees remarkably with the definition of sustainability from biological systems A...

Accordingly, biomass has become increasingly popular again. The reasons are simple. Biomass is, per definition, renewable and sustainable if the amount utilized equals the amount that is naturally replenished, for instance, by replanting in the case of wood utilization (Figure 16.1). Broadly speaking, biomass can be utilized as (1) a source of renewable chemicals and materials and (2) an energy source. 

In its simplest terms, biomass is all the plant matter found on our planet. Biomass is produced directly by photosynthesis, the fundamental engine of life on earth. Plant photosynthesis uses energy from the sun to combine carbon dioxide from the atmosphere with water to produce organic plant matter. More inclusive definitions are possible. For example, animal products and waste can be included in the definition of biomass. Animals, like plants, are renewable but animals clearly are one step removed from the direct use of sunlight. Using animal rather than plant material thus leads to substantially less efficient use of our planet s ultimate renewable resource, the sun. So, we emphasize plant matter in our definition of biomass. It is the photosynthetic capability of plants to utlize carbon dioxide from... 

A reasonable working definition of green chemistry can be formulated as follows [10] Green chemistry efficiently utilizes (preferably renewable) raw materials, eliminates waste and avoids the use of toxic and/or hazardous reagents and solvents in the manufacture and application of chemical products. 

The diversification of energy sources tailored to the requirements and resources of each country using nature s renewable resources such as the sun (photovoltaics), wind power, geothermal energy and biomass is a definite requirement. If solar cells are chosen to provide an alternative to fossil fuels, significant research work is needed (i) to develop new routes for the production of crystalline silicon, (ii) in the development of amorphous silicon hybrid materials that could result in enhanced efficiencies, (iii) for further development of thin-layer technology, (iv) in concerted efforts for cheaper and more stable dyes, (v) in improving the efficiency of the dye-sensitized cells and (vi) in process development to deliver enhanced device performances, ensure sustainability and reduce production costs on an industrial scale. 

The language used to describe these new (or sometimes old ) materials can be confusing, and too often is misused. One particularly problematic term is bioplastics. One common definition for bioplastics is plastics that are either biodegradable or made from renewable sources a clear recipe for confusion. We will not use this term. Rather, we will use the term biobased plastics to refer to plastics made from biological sources (typically plants). The plastics may be made directly by biological organisms (e.g., polyhydroxyalkanoates) or by chemical polymerization of monomers made from such sources (e.g., polylactide). Plastics may also be partially biobased (such as the CocaCola PlantBottle made from PET that is partially biobased). 

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