A Review of Biochemical Process of Anaerobic Digestion

The search for alternative energy and fuels has motivated researchers to focus on renewable and sustainable means of getting them instead of relying on the conventional way of energy and fuel production. Anaerobic digestion is a biochemical process during which complex organic matter is decomposed in absence of oxygen, by various types of anaerobic microorganisms. The process of Anaerobic digestion is appropriate for all waste water treatment systems given that the solid can be introduced to the system at an acceptable concentration. Biogas, the product of anaerobic digestion process is a clean and renewable form of energy which can be a substitute for conventional sources of energy which are causing ecological-environmental problems and at the same time depleting at a faster rate. This paper reviews the anaerobic digestion process and its complexities;it covers different stages involved in the process, the substrate used in the process, the relationship between the substrate and microorganisms and important operating parameters such as pH, temperature and loading rate.

Processing of Lyocell Fiber Mat: An Alternative Renewable Reinforcement in Composite Manufacturing

The carding of the Lyocell cellulose fiber was done with a cylindrical cross lap machine supplied by Cormatex Prato, Italy. Several mats were made by carding and needle punching in order to have a compact and well entangled mat suitable for reinforcement. The speed of the cross lap machine, the frequency of needle punching, the number of times the mat goes through needle punching, the feeding rate of the carded fiber and the depth of needle penetration determined the level of entanglement of the Lyocell fiber which ultimately increased the mechanical properties of the fiber. The good mechanical properties of the carded Lyocell fiber made it a renewable and environmentally friendly alternative as reinforcement in composite manufacturing. Compared with other jute fiber reinforced composites, the mechanical properties of the resulting Lyocell composites were found to be better. Regenerated cellulose fiber (Lyocell) composites were environmentally friendly and the mechanical properties were comparable to those of natural fibers.

Surface Treatments of Natural Fibres—A Review: Part 1

This review is based on the surface treatment of natural fibres which can be used in technical applications. Natural fibres on their own have some draw backs regarding moisture uptake, quality variations, low thermal stability, and poor wettability. Insufficient adhesion between polymer matrix and fibre leads in time to debonding. Overcoming the weaknesses of these natural fibres gave the motivation for this study where physical and chemical methods of modification were considered. Physical methods such as electric discharge and mercerization were reported as well as the chemical methods such as graft copolymerization and treatment with isocyanates, and the results due to these modifications were discussed. This study reveals that natural fibres are good candidates for reinforcement but they have to be suitably treated to improve their properties if they are to be used in technical applications. The various fibre surface treatments actually improve the interfacial adhesion between the fibre surface and the matrix, thereby giving good mechanical properties to the resulted polymer composites.

Bio-Based Polymers for Technical Applications: A Review — Part 2

Triglyceride oil of plant seed cannot be used on its own without further modification. The fatty acids must be suitably functionalized in order to add polymerisable functionalities which will help in the curing process. The purpose of these modifications is to reach a higher level of molecular weight and cross-link density, and also to incorporate chemical functionalities known to impart stiffness in a polymer network. The modification can go through various path ways which were described in this study.