Journal•ISSN: 1435-2974
Clean Products and Processes
Springer Nature
About: Clean Products and Processes is an academic journal. The journal publishes majorly in the area(s): Sustainable development & Heuristics. It has an ISSN identifier of 1435-2974. Over the lifetime, 64 publications have been published receiving 1468 citations.
Papers
More filters
TL;DR: In this article, a life cycle assessment was conducted on a coal-fired power system that co-fires wood residue, and it was found that cofiring significantly reduced the environmental footprint of the average coal fired power plant.
Abstract: The generation of electricity, and the consumption of energy in general, often result in adverse effects on the environment. Coal-fired power plants generate over half of the electricity used in the U.S., and therefore play a significant role in any discussion of energy and the environment. By cofiring biomass, currently operating coal plants have an opportunity to reduce the impact they have, but to what degree, and with what trade-offs? A life cycle assessment has been conducted on a coal-fired power system that cofires wood residue. The assessment was conducted in a cradle-to-grave manner to cover all processes necessary for the operation of the power plant, including raw material extraction, feed preparation, transportation, and waste disposal and recycling. Cofiring was found to significantly reduce the environmental footprint of the average coal-fired power plant. At rates of 5% and 15% by heat input, cofiring reduces greenhouse gas emissions on a CO2-equivalent basis by 5.4% and 18.2%, respectively. Emissions of SO2, NOx, non-methane hydrocarbons, particulates, and carbon monoxide are also reduced with cofiring. Additionally, total system energy consumption is lowered by 3.5% and 12.4% for the 5% and 15% cofiring cases, respectively. Finally, resource consumption and solid waste generation were found to be much less for systems that cofire.
182 citations
TL;DR: The Solvent Selection Guide as discussed by the authors provides a concise source of selected information and guidance to assist chemists and engineers to assist with their selection of solvents, and provides a relative ranking, and is limited by design to the inherent environmental, health and safety issues, in combination with general and specific process and facility issues associated with each solvent.
Abstract: A practical, easy to use Solvent Selection Guide has been developed to provide a concise source of selected information and guidance to chemists and engi- neers to assist with their selection of solvents. It provides a relative ranking, and is limited by design to the inherent environmental, health and safety issues, in combination with general and specific process and facility issues associated with each solvent. These represent areas that are not always considered by R&D chemists and engineers during normal product or process develop- ment. The guide is intended to augment existing proc- esses that mostly consider only technical, cost and regul- atory aspects so that chemists and engineers may make more broadly considered solvent selections early in the chemical development process. The Guide currently includes a total of 35 solvents which were most commonly used in SmithKline Beecham (SB) Research and Development and manufacturing activities over the past three years, although the methodology used to develop the guide is readily applicable to other solvents. Detailed guidance is provided in a manual, and is summarized within charts which relatively rank and iden- tify solvents and key issue areas, provide information on the new International Conference on Harmonization (ICH) guidelines for residual solvents in final pharmaceu- tical products, and supply data for co-solvent selection. The latter chart enables a chemist or engineer to choose solvents based on the ease of separation, which maxim- izes solvent utilization, recovery, and re-use. There is also a summary sheet for each solvent which reviews the scores and major issues for all the key categories used to develop the Environment & Safety Guide and provides essential solvent property data. 1 Introduction play an extremely important role in the chemical and allied industries, and millions of tons are used and disposed of each year. Over the past decade, there have been a variety of government and industry efforts to
147 citations
TL;DR: In this paper, a small amount of liquid nitrogen was injected to the chip-tool interface, but not to the workpiece, which yielded a 67% tool-life improvement at 3.82 m/s and a 43% improvement at the medium speed of 3.40m/s when compared with conventional emulsion cooling.
Abstract: While it is a clean alternative to conventional machining using environmentally polluting cutting oils and emulsions, cryogenic machining using liquid nitrogen has been reported to increase cutting forces and shorten tool life when cutting AISI 304 austenitic stainless steel. This paper presents improved results by using an economical cryogenic cooling approach designed after studying the cryogenic properties of the stainless steel material. By injecting a small amount of liquid nitrogen to the chip–tool interface, but not to the workpiece, this approach yielded a 67% tool-life improvement at 3.82 m/s and a 43% improvement at the medium speed of 3.40 m/s when compared with conventional emulsion cooling. It improved machining productivity and reduced production cost. In this study, different cryogenic machining approaches were compared in the machining test using commercial carbide inserts. The results show the cooling approach is crucial in attaining the benefits of cryogenic machining in cutting stainless steel.
118 citations
TL;DR: In this paper, the authors investigate the effect of heat generated in metal cutting in terms of its effects on chip formation, tool wear, and functional integrity of the machined component, and discuss the cooling strategies for cryogenic machining each material based on the thermal effects and material properties.
Abstract: Conventional machining prolongs tool life by using cutting oils to cool the metal cutting process. Unfortunately, the cutting fluid contaminates the environment, and endangers the health of humans. Cryogenic machining offers an environmentally safe alternative to conventional machining by using liquid nitrogen, which can be naturally recycled. However, for the cryogenic machining process to be effective and economical, manufacturers must select the correct cooling approach. This paper describes our experimental study to investigate the cryogenic properties of some common cutting tool materials and five workpiece materials of industrial interest: low carbon steel, AISI 1010, high carbon steel AISI 1070, bearing steel AISI 52100, titanium alloy Ti-6Al-4V, and cast aluminum alloy A390. The paper addresses the major aspects of heat generated in metal cutting in terms of its effects on chip formation, tool wear, and on the functional integrity of the machined component. The paper then discusses the cooling strategies for cryogenic machining each material based on the thermal effects and material properties. The investigators conclude that the cooling approach must be finely adjusted for different materials to obtain the optimum effectiveness in cryogenic machining. The goal of our study is to provide a basis for designing the cryogenic machining system.
104 citations
TL;DR: In this article, a new class of organic nanoporous polymers using cyclodextrins as basic building blocks were synthesized, called nanosponges, which have nanometer-size pores and exhibit superior ability to absorb organic molecules in water.
Abstract: We synthesized a new class of organic nanoporous polymers using cyclodextrins as basic building blocks. These processible nanoporous polymers were named 'nanosponges' because they have nanometer-size pores (distribution 0.7–1.2 nm) and exhibit superior ability to absorb organic molecules in water. Cyclodextrin cavities provide a hydrophobic environment and hence generate a strong affinity to organic molecules at water-solid interfaces. Indeed, the formation constant (K) of polymeric cyclodextrins and organic guest molecules is more than eight orders of magnitude larger than molecular cyclodextrin systems in water, and yet the process is completely reversible in organic solvents such as ethanol. The significant potential of these results is that hazardous organic contaminants may be reduced to parts-per-trillion levels in water by these polymers, as measured by ion-trap mass spectroscopy and UV-visible spectroscopy.
73 citations