Search results for "Raw material"
showing 10 items of 204 documents
Recovery of polyhydroxyalkanoates (PHAs) from wastewater : a review
2020
Abstract Polyhydroxyalkanoates (PHAs) are biopolyesters accumulated as carbon and energy storage materials under unbalanced growth conditions by various microorganisms. They are one of the most promising potential substitutes for conventional non-biodegradable plastics due to their similar physicochemical properties, but most important, its biodegradability. Production cost of PHAs is still a great barrier to extend its application at industrial scale. In order to reduce that cost, research is focusing on the use of several wastes as feedstock (such as agro-industrial and municipal organic waste and wastewater) in a platform based on mixed microbial cultures. This review provides a critical…
MAB2.0 project: Integrating algae production into wastewater treatment
2018
Abstract Different species of microalgae are highly efficient in removing nutrients from wastewater streams and are able to grow using flue gas as a CO2 source. These features indicate that application of microalgae has a promising outlook in wastewater treatment. However, practical aspects and process of integration of algae cultivation into an existing wastewater treatment line have not been investigated. The Climate-KIC co-funded Microalgae Biorefinery 2.0 project developed and demonstrated this integration process through a case study. The purpose of this paper is to introduce this process by phases and protocols, as well as report on the challenges and bottlenecks identified in the cas…
Combustion Properties of Birch (Betula pendula) Black Liquors From Sulfur-Free Pulping
2016
Sulfur-free pulping has an environmental advantage over the traditional kraft process. This article describes the combustion properties of the black liquors produced from silver birch (Betula pendula) sawdust using three different cooking processes: two sulfur-free cooks (soda-anthraquinone and oxygen-alkali), and one reference kraft cook. It also considers the corresponding black liquors from an integrated forest biorefinery, in which a hot-water pretreatment of feedstock was performed prior to pulping. With the same cooking time, the total burning times for the sulfur-free black liquors were higher (15–55%) than those for the conventional kraft black liquors. However, no significant diffe…
Fast pyrolysis of hot-water-extracted and soda-AQ-delignified okra (Abelmoschus esculentus) and miscanthus (miscanthus x giganteus) stalks by Py-GC/MS
2018
Abstract The thermochemical behavior of various samples of okra ( Abelmoschus esculentus ) and miscanthus ( Miscanthus x giganteus ) stalks (initial, hot-water-extracted, and those from sulfur-free delignification) were studied by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). In all cases, major GC-amenable condensable products were measured semi-quantitatively and classified into several product groups. The formation of these product groups from different feedstock samples with varying mass portions of their structural constituents (carbohydrates and lignin) was investigated at 500 °C and 700 °C with a residence time of 5 s and 20 s. The main product groups were aliphatic comp…
Effect of Seasonal Storage on Single-Stem Bark Extractives of Norway Spruce (Picea abies)
2021
Increasing the net value of forestry side-streams has both ecological as well as economic benefits for emerging biorefining industries. Spruce bark represents one of the nature’s abundant sources of valuable extractives. In this study, the impact of storage on the quality and quantity of Norway spruce (Picea abies) extractives was examined as a function of storage time, environmental conditions and season (i.e., winter or summer). The bark from stored spruce saw logs was extracted with an accelerated solvent extractor (ASE) at 120 °C with hexane and water. The produced extracts were analysed qualitatively and quantitatively by gas chromatography with a flame ionisation detector (GC-FID) and…
Life Cycle Energy Consumption and Carbon Dioxide Emissions of Agricultural Residue Feedstock for Bioenergy
2021
The depletion of fossil fuels and climate change concerns are drivers for the development and expansion of bioenergy. Promoting biomass is vital to move civilization toward a low-carbon economy. To meet European Union targets, it is required to increase the use of agricultural residues (including straw) for power generation. Using agricultural residues without accounting for their energy consumed and carbon dioxide emissions distorts the energy and environmental balance, and their analysis is the purpose of this study. In this paper, a life cycle analysis method is applied. The allocation of carbon dioxide emissions and energy inputs in the crop production by allocating between a product (g…
Sewage sludge as cheap alternative to microalgae as feedstock of catalytic hydrothermal liquefaction processes
2019
Abstract Production of biocrude through hydrothermal liquefaction (HTL) of sewage sludge (SS) and Chlorella vulgaris was investigated. NiMo/Al2O3 (KF 851), CoMo/Al2O3 (KF 1022) and activated carbon felt, tested as catalysts at 598 K for 30 min, did not change the biocrude yield but significantly improved its quality. Quantitative sulfur removal and lower oxygen content were found in biocrude when KF 851 and KF 1022 were used with C. vulgaris. The same catalysts decreased O/C and S/C ratio of the biocrude from SS. The highest HHV (38.19 MJ/kg) and H/C ratio (1.65) and the lowest O/C (0.11) of the biocrude from SS were obtained with the cheaper activated carbon felt. A new product phase, prob…
From lab to industry: Scaling up green geopolymeric mortars manufacturing towards circular economy
2021
Abstract Construction is nowadays considered an extremely energy intensive industry and one of the main sources of environmental pollution in the world. Therefore, the research and the development of novel energy-saving manufacturing processes and sustainable construction materials is more than ever urgent and challenging. This paper aims at identifying the industrial process for the production of novel geopolymers to be used as a greener substitute for cement, especially the Portland one, widely used for structural applications to significantly reduce the environmental impact of the construction industry. Here, the materials sustainability and the manufacturing process are improved by valo…
Fast pyrolysis of hot-water-extracted and delignified silver birch (Betula pendula) sawdust by Py-GC/MS
2017
The thermochemical behavior of birch (Betula pendula) sawdust both untreated and after various chemical treatments (hot-water extraction, delignification, and hot-water extraction followed by delignification) was investigated by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). In each case, major GC-amenable condensable products were classified into several compound groups, and the formation of these monomer-related fragments from feedstock samples with varying mass portions of the structural constituents (cellulose, hemicelluloses, and lignin) were determined at 500 °C and 700 °C at hold times of 5 s and 20 s. The formation of pyrolysis products was shown to be characteristically…
Regarding the influence of the particle size of crumb rubber from waste rubber on the physical and mechanical characteristics of reclaimed rubber
2017
Thus, at present, a large amount of rubber waste cannot be higher harnessed due to recovery technologies used. Also, the requirements for new products of rubber worldwide are greater than the production capacity and the availability of raw materials. To offset this balance is necessary to improve technologies for recycling waste rubber so to can get regenerated rubber with the best mechanical physical characteristics. The main technology for obtaining the regenerated rubber is based on the rubber waste shredding and making the powder, so that it can be carried out de-vulcanization in autoclave. All the time it was monitored as the de-vulcanization process to be as economical and less pollut…