Pva Pva

Weight Fraction Molecular Weight

FIGURE 5.16 Time profiles of mineralization of PVA samples having different degree of hydrolysis in an aqueous medium in the presence of acclimated PVA-degrading microorganisms. No detectable amount of PVA was released from montmorillonite samples when suspended in water, suggesting that the adsorption process is almost irreversible.101 The influence of the adsorption by montmorillonite on the biodegradation of PVA was investigated in the presence of an acclimated microbial inoculum90 in liquid...

Analysis And Comparison Of Lifecycle Assessment Studies

In our assessment, we analyze 11 LCA studies for biobased energy, fuels, and materials 3, 5, 9-17 . These studies compare biobased energy, fuels, or materials with their conventional counterparts made from fossil resources. The criteria that led to the selection of these LCA publications were that (a) the studies should compare environmental impacts of biobased products with fossil-based product alternatives on a cradle-to-grave basis, i.e., including the entire process chain from the...

Introduction

Bipolar Plate

A large amount of primary energy stored in hydrocarbon-based solid, liquid, and gaseous fuels is consumed for electricity and heat generation in residential and industrial sectors and for internal-combustion-engine-based transportation. Worldwide, 7235 million t of oil equivalent MTOE , or 75 of energy use, in 1997 was based on fossil fuels. Per capita CO2 emissions in that year amounted to 1.13 t of carbon 1 . In the 20 th century, the human population has quadrupled, while the FIGURE 8.1...

Info

Note Energy content is based on dry material. the disposal of postconsumer items.1213 Plastic articles that are used once and then disposed of are targeted as the primary market areas, such as food-packaging films, foams, bags, food-service items containers of milk, water, soft-drinks , mulching films, and transplanting .14 It is, however, taken for granted that infrastructures have to be available to allow for their biorecycling as a final stage of their recovery. Biopolymers can, in contrast...

Carlos R Apesteguia

15.1 Introduction 15.2 Green Catalytic Processes in the Synthesis of Fine 15.2.1 Introduction 15.2.2 Sample Preparation and Characterization 15.2.3 Catalytic Results 15.3 Sustainable Catalytic Processes in the Synthesis of Fine 15.3.1 Introduction 15.3.2 Sample Preparation and Characterization 15.3.3 Catalytic Results 15.4 Biodiesel from Low-Value Raw Materials 15.4.1 Introduction 15.4.2 Materials and Methods 15.4.3 Catalytic Results

Conclusions

The accumulation of plastic waste and problems connected with waste collection and eventual recycling are promoting interest in the use of plastic materials suitable for biorecycling, particularly in compost plants. The worldwide available biomass could largely supply low-cost polymeric matrices and fillers for bioplastics produc tion without competing with food production. Thus the use of by-products and waste from agricultural, ethanol, dairy, and pharmaceutical industries, among others, is...

Palm Oil As Diesel Substitute

Many researchers have investigated the possibility of using vegetable oils straight or blended as a diesel substitute. A good account of their attempts was reported in the 1983 JAOCS Symposium on Vegetable Oils as Diesel Fuels Klopfenstein and Walker, 1983 Pryde 1983 Strayer et al., 1983 . The symposium revealed that vegetable oils have good potential as alternative fuels if some problems could be overcome satisfactorily. These include high viscosity, low volatility, and the reactivity...

Technical Realizations

A single fuel cell, as depicted in Figure 12.1, is capable of delivering a voltage of about 0.7 to 0.9 V under operating conditions. According to today's standards, a typical current density of an MCFC is at about 150 mA cm2, so a cell of 1 m2 size delivers approximately 1 kW electric power. To obtain systems with higher power, several cells are combined in a cell stack Figure 12.2 . From the chemical engineering point of view, these are parallel reactors from the electric point of view, this...

Hydrogen Production Methods Hydrogen Production by Reforming

Reforming Hydrogen

Figure 11.2 outlines the main options available for production of H2 for use as an energy source. It should be noted that the hydrogen economy envisages combined FIGURE 11.2 Scheme of the main options for the production of hydrogen. FIGURE 11.2 Scheme of the main options for the production of hydrogen. H2 and electricity generation. Electricity generation from nuclear energy could also be included in the scheme, but this is not an option available everywhere. Clearly, the choice is quite...

Enhancements In The Profitability Of Pha Production

Bioreactors Lactase Production

6.2.1 Factors Influencing the Profitability of Bioplastic Production Conventional plastics like polyethylene PE and polypropylene PP are produced at a price of less than US 1 kg. In 1995, the Monsanto Company sold PHA products at about 17 times the price of petrol-based plastics. It is clear that to achieve a truly cost-effective process, all production steps must be taken into account 15 . Hanggi pointed out that the raw materials constitute the major part of the production cost for...

General Pathways For Hydrogen Production

A simple general scheme for hydrogen production is given in Figure 8.7, while Table 8.4 lists the major hydrogen production processes from various feedstocks, convenient energy sources to drive these processes, and the emissions that each process produces 11 . It can be quickly realized that the only feedstock from which hydrogen can be produced without emissions is water. However, one has quite a number of possible processes to produce hydrogen from water. Further on, we shall focus on the...

Acknowledgments

This work was funded by the Hungarian National Scientific Research Fund T047207 . High-pressure NMR tubes were donated by Exxon-Mobil Research and Engineering Company. We are grateful to the Department of Chemistry at Princeton University for donating a Bruker AC 250 NMR spectrometer and to the American Chemical Society for covering the shipping cost from Princeton to Budapest. 1. Aleklett, K., Campell, C.J., The Peak and Decline of World Oil and Gas Production, Minerals amp Energy 18, 5, 2003....

Inulin And Fructose

Inulin Lauryl Carbamate

A relative newcomer in the carbohydrate field is inulin, a fructan Figure 2.9 consisting of p-linked 2 1 fructofuranose units with an a-glucopyranose unit at the reducing end. Inulin GFn is obtained in Belgium and The Netherlands from the roots of chicory. The average degree of polymerization is relatively low, n 12 45 . Small amounts of purefructan Fm, are also present in unulin. Another interesting inulin-containing crop is the Jerusalem artichoke 46 . Inulin is applied as a health additive...

Palm Oil Methyl Esters As Diesel Substitute

Biodiesel has gained much attention in recent years due to increasing environmental awareness. Biodiesel is produced from renewable plant resources and thus does not contribute to the net increase of carbon dioxide. From 1996 to 2004, the biodiesel production capacity in the European Union EU has increased by a factor of four from 591,000 t to a total of 2.355 million t Bockey, 2002 Bockey, 2004 . Further utilization of biodiesel is anticipated due to the initiative of the respective...

Technologies for Application and Utilization

Of Renewable Resources 1 Chapter 1 Rationale, Drivers, Standards, and Technology for Biobased Chapter 2 Biobased Key Molecules as Chemical Chapter 3 Industrial Chemistry with Nature-Based Bioprocesses 35 Chapter 4 Catalytic Conversion of Carbohydrates to Oxygenates 55 Hasan Mehdi, Robert Tuba, Laszlo T. Mika, Andrea Bodor, Kornel Torkos, and Istvan T. Horvath PART II Plastics and Materials from Renewable Chapter 5 Developments and Future Trends for Environmentally Degradable Emo Chiellini,...

Hydrogen Distribution And Onboard Storage

Rehydrogenation Borohydrides

11.3.1 Hydrogen Distribution Systems It is arguable that in no other area is the scale of the challenge faced by a transition to a hydrogen economy greater than in the transport sector. This is because the FIGURE 11.4 Scheme of an integrated model of a hydrogen distribution system. FIGURE 11.4 Scheme of an integrated model of a hydrogen distribution system. difficulties posed are not only the technical problems of production, common to all sectors, but there is the added complication of...

Eddy Kool Van Langenberghe

I have enjoyed working with a large number of collaborators, each of whom has contributed to the concepts and data discussed in this chapter. I would like to particularly mention Marie-Jose de Smet, Roland Lageveen, Jaap Kingma, Eddy Kool van Langenberghe, Olivier Favre-Bulle, Hans Preusting, Marcel Wubbolts, Andrew Schmid, Renata Mathys, Sven Panke, Bruno Buhler, Jin Byung Park, and Andreas Schmid for their work and very enjoyable discussions regarding two-liquid-phase bioreaction systems. I...

By Pseudomonas

Renewable Resources Collage

PHAs are biocompatible and biodegradable thermoplastic polyesters that are made by many bacteria when these are grown on ample supplies of carbon sources and FIGURE 3.5 Freeze fracture electron micrograph of P. oleovorans cells growing in a two-liquid-phase medium containing 85 aqueous phase and 15 octane. EM photo by Jaap Kingma and Hans Preusting, University of Groningen, The Netherlands, 1990. FIGURE 3.5 Freeze fracture electron micrograph of P. oleovorans cells growing in a two-liquid-phase...

Influence of the Oxygen Storage Capacity

Ceria Oxygen Storage

The cerium oxide catalysts are known for their high oxygen storage capacity, and it is clear that the cerium oxide has a direct role in the catalytic activity. However, the function of ceria and how the metal component promotes the WGS reaction is not clear. Some research groups 26, 27, 32 have claimed that the redox mechanism and oxygen storage capacity have a direct role in the WGS reaction. The other mechanism was proposed 28, 43 to proceed through the formation of surface-formate...

Methanation Reactions

Methanation Equilibrium

When carrying out the WGS reaction, methane can be formed in the reactor through the methanation reaction, which is the reverse methane steam reforming reaction and is highly exothermal CO 3H2 lt - gt CH4 H2O AH -205.8 kJ mol 8.21 Methane is an undesired product in the WGS reaction, and for every CH4 molecule formed, two H2 molecules are taken away from the product stream. Figure 8.14 shows two WGS equilibrium curves for the hydrogen-containing conditions. The upper dashed line is the WGS...

Polyvinylics Biodegradation

Endoenzymes

Of the current worldwide production of synthetic polymers, nearly 90 is represented by full-carbon-backbone macromolecular systems polyvinylics and polyvi-nylidenics ,49 and 35 to 45 of production is for one-time-use items disposables and packaging . Therefore, it is reasonable to envisage a dramatic environmental impact attributable to the accumulation of plastic litter and waste constituted by full-carbon-backbone polymers, which are recalcitrant to physical, chemical, and biological...

Olivia L Castillo Contents

13.3 Main 13.4 Renewable Energy 13.5 Asian Development Bank's PREGA 13.7 Status of Renewable Resources in Developed 13.8 Status of Renewable Resources in Less-Developed Countries 296 13.8.3 Sri 13.8.8 People's Republic of China 13.9 Conclusions and The Asia Pacific region holds about one-third of the world's population. Poverty alleviation or eradication should be the centerpiece and platform of governments in the region. The majority of the donor organizations, like the World Bank, the Asian...

Hasan Mehdi Robert Tuba Lszl T Mika Andrea Bodor Kornel Torkos and Istvn T Horvth

The sustainability of human civilization primarily depends on whether the energy requirements of its increasing population can be satisfied in the future. While the establishment of the exact date of the depletion of fossil fuels seems difficult, skyrocketing oil and gas prices could come much earlier than 2050, as predicted by several studies.1 Efficient conversion of solar energy to electricity could open the way to the production of increasing amounts of hydrogen and finally to the...

Green Catalytic Processes In The Synthesis Of Fine Chemicals

Sio2 Al2o3

Aromatic ketones are valuable intermediate compounds in the synthesis of important fragrances and pharmaceuticals. In many cases, these compounds are currently obtained in homogeneous processes via Friedel-Crafts acylations. However, Friedel-Crafts acylations are real and alarming examples of very widely used acid-catalyzed reactions that are based on 100-year-old chemistry and are extremely wasteful. Replacement of AlCl3 Friedel-Crafts catalysts by solid acids for acylation reactions would...

Conclusions And Perspectives

It is clear that many of the technologies necessary for the transition to the hydrogen economy are technically possible. The main problem is their high cost. Indeed, the possibility must be accepted that equivalent or lower costs than the current situation may never be achieved. However, cost is not the only issue, and the need to replace fossil fuels as well as environmental benefits must also be considered. Furthermore, as there now appears to be a firm commitment to research and development...

Rationale And Drivers For Biobased Products

Manufacturers traditionally have not concerned themselves with the impact on the environment of using various feedstocks. They have also not worried about the FIGURE 1.2 Biomass resources production and utilization. ultimate disposability of their products. The products of the future must be designed from conception to reincarnation or cradle to cradle using holistic life-cycle concepts. The use of annually renewable biomass corn, cellulosics, soy, or other vegetable oils, as opposed to...

Future Challenges And Developments

The current developments in the field of MCFC aim at adapting it to new applications and lowering its production costs. Investment costs per installed nominal power are expected to remain slightly higher than those of classical units, but the higher system efficiency, in the form of lower fuel consumption, should overcompensate that. Especially with fuel prices expected to rise in the future, fuel efficiency and fuel costs will become increasingly important. To further increase the area of...

Wholecell Bioconversions Of Organic Compounds In Twoliquidphase Media With Solventresistant Organisms

Preusting Continual Fermentation

3.2.1 Microbial Growth in Solvents and Emulsions It has been known for at least a century that some microorganisms are capable of growing in the presence of organic solvents, and in some cases they can metabolize solvents as sources of energy and carbon Fairhall 1920 Hopkins and Chibnall 1932 . In nature, such organisms play a role in the biodegradation of aliphatic and aromatic components in oil. They have been isolated from natural oil deposits or soil, from human-made oil wells, from oil...

Biobased Feedstocks

Biobased Feedstocks

Cellulose Derivatives CA, CAB Starch graft copolymers amp reactive blends Plasticizers Process aids FIGURE 1.6 Direct extraction of biomass to provide biopolymers for use in manufacture of biobased products. FIGURE 1.7 Conversion to biomonomers and other chemicals and polymers. FIGURE 1.7 Conversion to biomonomers and other chemicals and polymers. short-life, single-use, disposable packaging materials and consumer products can and should be engineered to retain inherent biodegradability...

Biogas From Pome

Besides the solid residues, palm oil mills also generate large quantities of liquid waste in the form of palm oil mill effluent POME , which, due to its high biochemical oxygen demand BOD , is required by law to be treated to acceptable levels before it can be discharged into watercourses or onto land. In a conventional palm oil mill, about 0.7 m3 of POME is generated for every tonne of FFB processed. Hence in 2004, about 49 million m3 of POME was generated in this country. The palm oil mills...