Potential value of pyrolysis oil derived from shellfish processing by-product

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Biochar: Product development in remote regions from mixed residues

Biochar is a particularly interesting pyrolysis product in regions where there is an abundance of waste biomass to convert but limited ability to effectively turn the waste into a product due to distance to market, lack of infrastructure (e.g. pipelines for gas), and the heterogeneous nature of the biomass (e.g. forestry residues, fishery by-product etc.). Biochar is a more homogeneous material (compared to waste biomass) expanding possible applications, is a less dense solid (making transport less costly), and could be used to sustainably develop an industry/product in these regions. Please click on the file below for full content of the abstract

Crab body pyrolysis: Characterization and applications of crab biochar: A crabby solution

Nova Scotia crab harvesters sell over 5 million lbs of Snow Crab (Chionoecetes opilio) annually. The commercially desired product are the legs and shoulders generating resultant waste streams from bodies of the snow crabs (approximately 1/3 of the crab). Currently this waste is landfilled which is costly and fossil fuel intensive. There is a desire to find a more environmentally sustainable practice to divert this organic animal waste from NS landfills. In a landfill, snow crab residues will decompose and generate some small amount of fixed carbon, however much of the carbon is released into the environment as CO2 during decomposition and aside from some microbial benefits none of the remaining interesting chemicals are utilized during landfill decomposition. The chemical composition of the snow crab includes a high content of protein (34.2% dw) and essential amino acids; they also have fat (17.1% dw), with a high proportion of ω3 polyunsaturated fatty acids and approximately 28.5% dw minerals (calcium, phosphorous, and magnesium) making this waste stream very intriguing as a starting biomass for the generation of biochar. In this paper we have determined the optimal pyrolysis conditions and highest yield for the char generated from the crab body waste stream. The chars have been fully characterized and we have investigated several applications ranging from neutralization material for acidic waters to concrete additives and catalysis. Please click Additional Files below to see the full abstract

Pyrolysis of waste plastic fish bags (polyethylene and polypropylene) to useable fuel oil

The objective of this study is to determine the feasibility of pyrolysis of waste plastic fish feed bags to heating oil. Pyrolysis is a thermal treatment without oxygen and produces three products (gas, oil, and solid), the yields depend on the feedstock and operating conditions. The fish feed bags are polyethylene (PE) or polypropylene (PP) and are typically contaminated with a small amount of residual fish feed. This limits the treatment and disposal options. Thermal decomposition of the bags to their original oil base could potentially produce a fuel for use in heating and possibly power for the plant. Unused and used bags were pyrolyzed and compared to determine the impact of the fish feed on the oil and the residual solids and gas evolved during the process. The temperature for the pyrolysis temperature is a function of the feed material. For waste plastic the temperature can range between 400−550°C depending on the type of plastic. In this work a series of pyrolysis experiments were performed where key factors that would impact the oil quality produced, were varied including; temperature of pyrolysis 400−550°C) type of bag (PE, PP, and mixtures of the two), mass of residual fish feed retained in bag (0-40% by mass of feedstock) and gas residence time. Based on these experiments the optimum operating conditions were obtained. A temperature of 500°C produced the maximum wax/oil yields, 69-75wt% of feedstock with a solids (residue) between 6-7wt%, and gas between 23-25wt%, depending on the feedstock. The melting point of wax/oil samples varied between 53-62°C. The melting point of the wax/oil samples decreased slightly with increasing amounts of fish feed. The increase in wax/oil yield is likely a result that the FF pyrolysis products are predominantly lipids, this would both add to the overall oil content and possibly decrease the uncondensable gas content through co-pyrolysis. The heating values of the wax/oil samples varied from 42.8- 45.7 MJ/kg. The pure fish feed heating value was 25.47 MJ/kg. The heating values of all waxes are comparable to standard fuels, 44-46 MJ/kg petrol/gasoline, 43 MJ/kg for diesel, and from 43-44 MJ/kg for fuel oil. Although, the wax/oil samples are solid (wax) at temperatures below 50oC, heating to above 60oC produces a liquid oil with a high heating value. The gas produced in 2 the pyrolysis, largely methane and ethane, could be used as a fuel gas. Based on 100 metric tonnes of waste bags per year this translates to 2.8 MJ/yr from the oil and 1.38 MJ/yr from the gas

Parametric analysis of pyrolysis process on the product yields in a bubbling fluidized bed reactor

This paper presents a numerical study of operating factors on the product yields of a fast pyrolysis process in a 2-D standard lab-scale bubbling fluidized bed reactor. In a fast pyrolysis process, oxygen-free thermal decomposition of biomass occurs to produce solid biochar, condensable vapours and non-condensable gases. This process also involves complex transport phenomena and therefore the Euler-Euler approach with a multi-fluid model is applied. The eleven species taking part in the process are grouped into a solid reacting phase, condensable/non-condensable phase, and non-reacting solid phase (the heat carrier). The biomass decomposition is simplified to ten reaction mechanisms based on the thermal decomposition of lignocellulosic biomass. For coupling of multi-fluid model and reaction rates, the time-splitting method is used. The developed model is validated first using available experimental data and is then employed to conduct the parametric study. Based on the simulation results, the impact of different operating factors on the product yields are presented. The results for operating temperature (both sidewall and carrier gas temperature) show that the optimum temperature for the production of bio-oil is in the range of 500–525 °C. The higher the nitrogen velocity, the lower the residence time and less chance for the secondary crack of condensable vapours to non-condensable gases and consequently higher bio-oil yield. Similarly, when the height of the biomass injector was raised, the yields of condensable increased and non-condensable decreased due to the lower residence time of biomass. Biomass flow rate of 1.3 kg/h can produce favourable results. When larger biomass particle sizes are used, the intraparticle temperature gradient increases and leads to more accumulated unreacted biomass inside the reactor and the products’ yield decreases accordingly. The simulation indicated that the larger sand particles accompanied by higher carrier gas velocity are favourable for bio-oil production. Providing a net heat equivalent of 6.52 W to the virgin biomass prior to entering the reactor bed leads to 7.5% higher bio-oil yields whereas other products’ yields stay steady. Results from different feedstock material show that the sum of cellulose and hemicellulose content is favourable for the production of bio-oil whereas the biochar yield is directly related to the lignin content

Organic Waste in Newfoundland and Labrador: A Review of Available Agriculture, Fishery, Forestry and Municipal Waste Literature

Re-utilisation of organic waste is globally widely employed to maximise both economic and environmental sustainability of human activities. Re-utilisation of organic waste nutrients of biochars produced from such wastes do offer a critical element for enhancing soil fertility and thus supporting sustainable agriculture. Newfoundland and Labrador produces a variety of organic waste streams ranging from municipal to farm, fishery and timber production. We carried out a best estimate of the amount of these waste streams with a goal to understand the potential utility of each as a source of nutrients or biochar for sustaining agricultural activities in the province. Municipal sources, i.e. municipal organic waste streams and wastewaters, and fishery waste were estimated to offer the largest potential for nutrient recovery. Dairy industry is the largest producer of nutrient rich organic waste among agricultural activities. The dairy industry might possibly produce most of the nutrients required to fertilise their own land base; note that the dairies in the province still import a significant portion of their feed and that is reflected in the waste stream. Nutrients currently available in the estimated waste streams are likely sufficient to support most fertilisation needs of the current land-base, or nearly double the current land base in the case of phosphorus. Given the estimated balance of waste nutrients in the province any expansion in agricultural land base would require supplementary imports of fertilizers or, preferably, an integrated livestock and crop agriculture expansion. A secondary estimation was carried out to assess the value of the same organic waste streams for biochar production. This offered an alternative to nutrient reutilisation, an alternative that is also in support of soil fertility. Sawmill waste, that carried little nitrogen and phosphorus value, was also included in biochar estimates. The assessment has shown a significant potential for biochar production mainly for fishery and municipal organic waste. However, pursuing a biochar agenda for these materials would require a trade-off with the nutrients lost during pyrolysis. The assessment presented here confirms that organic wastes are a valuable resource for agricultural production and sustainability. However specific decisions would require a more detailed analysis of the geographic integration of waste streams and agricultural production

Risk-based Evaluation of Landfill Gas Flare Efficiency Using Computational Fluid Dynamics (CFD)

Methane is produced in landfills through the anaerobic digestion of organic material. Methane is a greenhouse gas with 24.5 times the global warming potential when compared to carbon dioxide (CO2). Landfill gas also contains hydrogen sulfide which may account for up to 1 percent by volume of landfill gas emissions and impacts human health even in low concentrations. As a result, landfill gas is typically collected and either flared (to convert methane and hydrogen sulphide to carbon dioxide and sulfur dioxide respectively) or used for power on site. Flaring is typically an incomplete combustion process, producing many other pollutants that may result in environmental and human health impacts. Quantifying these emissions would result in better flare designs and plume dispersion estimates. However, the efficiency of flare combustion is site and flare design specific, making predictions difficult. In this work a Computational Fluid Dynamics (CFDs) model (using Fluent as a tool) was developed to simulate the flow and combustion mechanisms of the flare. The model can be used as a tool in flare design and as a method to ensure an operating flare is working properly. It can also be used to predict dispersed gases concentrations, allowing operators to optimize environmental monitoring stations and flare operations. The model is a function of the input data and therefore critical parameters such as exit gas velocities, stack height and diameter among other parameters must be specified. The model was validated using lab data from published work. A risk assessment model is proposed as part of this work which integrates the CFD model with a risk model

Kinetic modelling of key reactions in the modified claus plant front end furnace

Bibliography: p. 163-169

Quantification of contact inhibition in ADC microcarrier cultures

Bibliography: p. 95-101