Waste and Biomass Valorization 

About: Waste and Biomass Valorization is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Chemistry & Biology. It has an ISSN identifier of 1877-2641. Over the lifetime, 3145 publications have been published receiving 44495 citations.

A Review of Biogas Utilisation, Purification and Upgrading Technologies

Abstract: Biogas is a valuable renewable energy and also a secondary energy carrier produced from biodegradable organic materials via anaerobic digestion. It can be used as a fuel or as starting material for the production of chemicals, hydrogen and/or synthesis gas etc. The main constituents of biogas are methane (CH4) and carbon dioxide (CO2), with various quantities of contaminants, such as ammonia (NH3), water vapour (H2O), hydrogen sulfide (H2S), methyl siloxanes, nitrogen (N2), oxygen (O2), halogenated volatile organic compounds (VOCs), carbon monoxide (CO) and hydrocarbons. These contaminants presence and quantities depend largely on the biogas source, which could be anaerobic digestion of many substrates and landfill decompositions. The removal of these contaminants especially H2S and CO2 will significantly improve the quality of the biogas for its further uses. In parallel, biogas upgrading market is facing challenges in term of operating costs and energy consumption. The selection of appropriate technology depends on the specific biogas requirements, site specific, local circumstances and is case sensitive. This paper reviews the present state-of-the-art of biogas cleaning and upgrading technologies, including its composition, upgrading efficiency, methane recovery and loss. In addition, biogas production, utilization and the corresponding requirements on gas quality for grid injection and vehicle usage are investigated. Based on the results of comparisons of various technologies, recommendations are made on further research on the appropriate low cost technologies, especially using solid waste as low cost materials for biogas purification and upgrading.

Chemical Research and Climate Change as Drivers in the Commercial Adoption of Alkali Activated Materials

Abstract: Portland cement production has been identified as a primary contributor to the world’s Greenhouse gas emissions, calculated at around 5–8% of all manmade emissions worldwide The majority of these emissions are inherent to the chemistry of cement and the high-temperature processing required for its synthesis, and so can only be avoided by radical changes in construction materials chemistry and synthesis pathways Inorganic polymer (including “geopolymer”) binders provide an alternative to traditional cements with approximately 80% less CO2 emissions, and are derived from industrial waste materials such as fly ash and metallurgical slags, which additionally provide a means of valorizing these wastes This paper reviews the technical and commercial factors driving the growing commercial adoption of geopolymer technology, and explains that an understanding of the chemistry and mechanisms of geopolymer synthesis is pivotal for the optimal mix design of “green” concretes in industry Demand pull by a carbon conscious market at a time of growing public awareness of climate change continues to be the key driver for the short term adoption of geopolymer concrete A detailed chemical understanding of the properties of geopolymers, such as setting time, workability and durability, plays an enabling role in the commercialization process

Biological Pretreatment of Lignocellulosic Biomass for Biofuels and Bioproducts: An Overview

Abstract: Increasing energy demands are not only exploiting the fossil resources but, also depleting natural environment. Biofuels from lignocellulosic biomass is a renewable, ecofriendly, sustainable and could be a promising alternative to fossil fuels. However, pretreatment is an essential step to disarray the layers of lignocellulose prior to enzymatic hydrolysis. Among various pretreatments of lignocellulose, the biological pretreatment using microorganisms such as bacteria and fungi are gaining popularity due to its financial and environmental benefits. Careful selection of the suitable microbial consortium for efficient pretreatment of biomass is a critical step. The co-culture of bacteria and/or fungi in consolidated bioprocessing (CBP) is highly beneficial in the breakdown of complex biopolymers due to their high enzyme activity. Our selection of highly promising bacterial and/or fungal consortium has the ability to produce various extracellular enzymes including cellulase, hemicellulase, and lignases. It can be used in CBP for efficient biological pretreatment of lignocellulosic biomass following production of biofuels and bioproducts.

Biological Treatment of Municipal Organic Waste using Black Soldier Fly Larvae

Abstract: Valorisation of municipal organic waste through larval feeding activity of the black soldier fly, Hermetia illucens, constitutes a potential benefit, especially for low and middle-income countries. Besides waste reduction and stabilisation, the product in form of the last larval stage, the so-called prepupae, offers a valuable additive in animal feed, opening new economic niches for small entrepreneurs in developing countries. We have therefore evaluated the feasibility of the black soldier fly larvae to digest and degrade mixed municipal organic waste in a medium-scale field experiment in Costa Rica, and explored the benefits and limitations of this technology. We achieved an average prepupae production of 252 g/m2/day (wet weight) under favourable conditions. Waste reduction ranged from 65.5 to 78.9% depending on the daily amount of waste added to the experimental unit and presence/absence of a drainage system. Three factors strongly influenced larval yield and waste reduction capacity: (1) high larval mortality due to elevated zinc concentrations in the waste material and anaerobic conditions in the experimental trays; (2) lack of fertile eggs due to zinc poisoning, and (3) limited access to food from stagnating liquid in the experimental trays. This study confirmed the great potential of this fly as a waste manager in low and middle-income countries, but also identified knowledge gaps pertaining to biological larvae requirements (egg hatching rate, moisture tolerance, …) and process design (drainage, rearing facilities, …) to be tackled in future research.

Biohydrogen Production from Biomass and Wastes via Dark Fermentation: A Review

Abstract: The present review article aims to summarize the microbiological and technological background of the dark fermentation processes for hydrogen generation, emphasising on the exploitation of biomass and wastes as potential feedstocks. The basic principles, the microbiology and the current technology of the processes are outlined. Subsequently, the use of different types of biomass and wastes that have so far been tested as feedstocks is analysed focusing on the advantages, possible limitations and future prospects of their exploitation. Moreover, different types of so far suggested pretreatment methods for better utilisation of the feedstocks are presented, pointing out the advantages and disadvantages of each method. Finally, methods for possible further utilisation of the generated by-products are laid out as well as the present status of the real scale applications.