Enzymatic hydrolysis of fish frames using pilot plant scale systems

Papain was used to hydrolyse fish frames under controlled conditions at a batch-pilot plant scale-process, for the pro-duction of fish protein hydrolysates (FPH). Mass balance calculations were carried out so that the rate of hydrolysis, rate of protein solubilisation and yields could be estimated. Almost complete hydrolysis could be achieved in 1 hour, at 40°C, with no pH adjustment, at 0.5% (5 g·kg−1) enzyme to substrate ratio (E/S, were S is Kjeldahl protein) using whole fish frames (including heads and flaps). This was achieved both with the addition of water (1/1 to 2/1 frames/water) but more importantly from commercial considerations without the initial addition of water (after mincing of the fish mate-rial). The degree of protein solubilisation ranged between 71% - 86% w/w. Four different processes are described, namely: 1) a soluble spray-dried FPH powder; 2) a liquid FPH; 3) a partly soluble, spray dried FPH powder and; 4) a crude, drum-dried protein for animal consumption. The amino acid profile of the FPH was identical to that of the par-ent substrate (fish frames)

Comprehensive Utilization of Iron-Bearing Converter Wastes

Basic oxygen furnace (BOF) sludge is composed of not only valuable iron but also impurities like Zn, Pb, and some alkaline oxides. It is collected from wet cleaning system in steelmaking plants. How to deal with these double identity wastes? Will the traditional landfill treatments result in environmental pollution? What technologies have been developed recently, and is it actually useful? In this chapter, physical-chemical properties and mineralogical phases of converter sludge were characterized, and different recycling technologies were introduced. The proven metalized pellet-producing process would be highlighted that green pellets made from iron-bearing sludge are dried and preheated in a traveling grate firstly, and then reduced at high temperature in a rotary kiln or a rotary hearth furnace (RHF) to get direct reduced iron (DRI), served as a good iron source for blast furnace

Organic Waste Torrefaction – A Review: Reactor Systems, and the Biochar Properties

Torrefaction is a thermochemical process in a narrow temperature ranging from 200 to 300°C, where primarily hemicellulose fibers are depolymerized. This process is carried out under atmospheric pressure and in anaerobic conditions; heating ratio is low (<50°C/min) and the residence time is relatively long, up to 1 h. During the process, a biomass is partially decomposed and forms different condensing and noncondensing gases. The final product is a constant substance rich in carbon, which is called a torrefied biomass—biochar and biocarbon. Currently an increase in energy demand is impacting the environment considerably. For this reason, in this chapter the organic waste torrefaction technology will be presented, including the reactor systems review. Torrefaction process may be conducted in different types of reactors, with diverse technologies. From this variety, two main groups of reactors can be distinguished, with direct and indirect heating. Direct heating group consists of reactors with multiple design, such as Multiple Hearth Furnace, microwave reactor, moving bed, vibrating belt, the reactor belt, and auger. Indirect heating reactors are less common and this group consists of rotating drum and auger reactor. All mentioned reactor types will be presented and discussed

Pyrolysis of Sawdust

Lakeland Steel Limited developed a pilot plant for biomass pyrolysis based on sawdust. The pilot plant was based on an auger screw design which was indirectly heated using a double pipe heat exchange configuration to prevent oxidation (combustion) of the feedstock. This thesis covers the preliminary assessment of sawdust pyrolysis for R.H Tregoweth sawmills on behalf of Lakeland Steel Limited. Proximate and ultimate analyses were deployed on the sawdust to determine its composition. Proximate analysis results gave a moisture content of 60%. The dry solids had an organic matter content of 99.22% with ash making the balance. Ultimate analysis was used to determine content levels of elemental carbon, hydrogen, nitrogen sulphur and oxygen. The results on a dry basis were 47.2%, 6.5%, 0.3%, 0.3%, and 44.9 % respectively. Drying models were also used to analyse the sawdust drying characteristics. Drying curves were obtained experimentally and four models: Newton; Page; Henderson and Pabis; and Simpson and Tschernitz, were fitted to the data and their accuracy of fit was determined using residual squared sum of errors. Page’s model was used to describe the sawdust behaviour in the dryer design as it had the highest accuracy. The sawdust reaction kinetics were determined using data from thermogravimetric analysis (TGA) and analysed using distributed action energy model. The kinetics were observed at three heating rates of 10, 20 and 30 °C/min with a maximum temperature of 900°C under an argon atmosphere. Sawdust was modelled as a mixture of water, hemicellulose, cellulose and lignin. Good agreement between Gaussian distribution functions for each component and experimental data were observed. Pilot plant trials were performed using a three factor-three level design of experiment. The factors under investigation were; feedstock moisture content with levels at 15, 30 and 60; reaction temperature with levels at 400, 450 and 500°C; and reactor auger speed with levels at 15, 20 and 25 rpm. Experiments at 60% moisture could not be performed to completion as the auger blocked repeatedly. The other two moisture contents showed that moisture content enhanced heat exchange properties of the feedstock and this generally increased the amount of volatile organic matter released. It was observed that for 15% moisture sawdust increase of temperature did not consistently exhibit an increase in degree of devolatilisation of organic matter. However, the 30% moisture sawdust showed an increase in devolatilisation with increase in temperature. The effects of increasing reactor auger speed had the most consistent trend with which an increase in speed showed a decrease in degree of devolatilisation thus increasing char yield. The empirical data collected from lab scale and pilot plant experiments were used to create mass and energy balances. These were the basis of the large scale mobile pyrolysis plant which was designed to process 3.45 tonnes per hour. Due to size restrictions the large scale dryer was not fitted in the container. It was then determined that the feedstock would either be dried using an onsite kiln or the reactor would process green sawdust. A preliminary economic feasibility assessment was performed for the base case scenario which processed pre-dried sawdust of 15% moisture content at 400°C and a retention time of 45 minutes. A sensitivity analysis based on predicted optimistic and pessimistic conditions showed that automation of the plant had the potential to increase the economic viability of the large scale process

A semi-industrial investigation of the factors controlling the bioconversion of biodegradable waste to a consistent solid recovered fuel (SRF) for utilization by the cement industry

Imperial Users onl

Sustainable energy from paper industry wastes

Secondary fibre paper mills are significant users of both heat and electricity which is mainly derived from the combustion of fossil fuels. The cost of producing this energy is increasing year upon year. These mills are also significant producers of fibrous sludge and reject waste material which can contain high amounts of useful energy. Currently the majority of these waste fractions are disposed of by landfill, land-spread or incineration using natural gas. These disposal methods not only present environmental problems but are also very costly. The focus of this work was to utilise the waste fractions produced at secondary fibre paper mills for the on-site production of combined heat and power (CHP) using advanced thermal conversion methods (gasification and pyrolysis), well suited to relatively small scales of throughput. The heat and power can either be used on-site or exported. The first stage of the work was the development of methods to condition selected paper industry wastes to enable thermal conversion. This stage required detailed characterisation of the waste streams in terms of proximate and ultimate analysis and heat content. Suitable methods to dry and condition the wastes in preparation for thermal conversion were also explored. Through trials at pilot scale with both fixed bed downdraft gasification and intermediate pyrolysis systems, the energy recovered from selected wastes and waste blends in the form of product gas and pyrolysis products was quantified. The optimal process routes were selected based on the experimental results, and implementation studies were carried out at the selected candidate mills. The studies consider the pre-processing of the wastes, thermal conversion, and full integration of the energy products. The final stage of work was an economic analysis to quantify economic gain, return on investment and environmental benefits from the proposed processes

Issues related to waste sewage sludge drying under superheated steam

Sewage sludge was dried in a rotary drum dryer under superheated steam. Particle size and moisture content were shown to have significant influences on sticking and agglomeration of the materials. Pouring partially dried sludge (70–80% moisture content, wet basis) directly into the screw feeder of the drum dryer resulted in a significant sticking to the surface of the drum and the final particle size of the product was greater than 100 mm in diameter. The moisture content of this product was slightly less than its initial value. To overcome this issue, the sludge was mixed with lignite at variety ratios and then chopped before being introduced to the feeding screw. It was found that mixing the sludge with lignite and then sieving the chopped materials through a four millimetre mesh sieve was the key to solve this issue. This technique significantly reduced both stickiness and agglomeration of the material. Also, this enabled for a significant reduction in moisture content of the final product

Advance Drying Technology for Heat Sensitive Products

This book presents the advance drying technology for heat sensitive products cited from international journals, handbooks, and current research of authors. In the first edition, the printing and publication was funded Diponegoro University. In this second edition, the publication was supported from Directory of Higher Education under competitive research grant. The topic discusses the current drying technology for heat sensitive product, challenges, development and application in accordance with high quality product as well as efficient energy usage. Unlike first edition, this book observes and evaluates several food products drying under air dehumidification. The conceptual process has been also submitted to Indonesian Patent 2014. In the first edition, the book consisted of 7 chapters. Whereas, in this second edition, the book was extended up to 10 chapters completed with application of air dehumidification for food drying. Chapter 1 discusses about the challenge and progress on drying technology development. Chapter 2 describes the application and research of vacuum and freezes dryer. It is followed by the concept of air dehumidified by zeolite for efficient drying, depicted in Chapter 3. Chapter 4 evaluates the conventional condenser and adsorption dryer for low temperature drying. Chapter 5 is an overview of microwave and radio frequency dryer. After that, Chapter 6 presents the types of dryers applied in industries involving tray, spray, fluidized, moving bed, and drum dryer. Chapter 7 evaluates the future possible development for innovative dryer namely adsorption dryer with zeolite for industry. Chapters 8, 9 and 10 present the application of air dehumidification for agriculture and food drying. These chapters are results of the research conducted during 2012 – 2014