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The possibility of integrating a slow pyrolysis process with activation of the char produced is investigated using an auger reactor. Production of activated carbon is usually done in a two-step process, by first carbonizing a carbon source (coal, coconut shell, other biomasses, etc.) and then subjecting the solid product, char, to an activation process. With this work, by simultaneously producing and activating the char, the cost of production of activated carbon could be decreased, and further positive points are the fact that the process is continuous and that the feedstock would be a biomass-based waste, wheat straw pellets. Activation will be carried out in two separate ways: chemical activation using KOH, and physical activation with a steam atmosphere. The properties of the solid products produced will be compared with the properties from the chars activated with the conventional two-step process, as well as from non-activated char. The properties to focus on are the product’s surface area, pore size distribution and presence of chemical functionalities, which are key factors for the application of activated carbon in adsorption., Proceedings of the 27th European Biomass Conference and Exhibition, 27-30 May 2019, Lisbon, Portugal, pp. 1076-1079

A comprehensive study of the energy yield from slow pyrolysis of the organic fraction of municipal solid waste (OFMSW) and energy recovery from the aqueous liquid product by anaerobic digestion has been carried out. In this paper, the results of the liquid pyrolysis product characterisation are presented, with toxicity and methane potential assessments of the aqueous liquid product. The OFMSW feedstock was obtained from a UK waste treatment plant. Shredded samples dried to different moisture contents (12.7–45.8%) were processed in a 300 g per hour auger screw pyrolysis reactor at temperatures from 450 to 850 °C. Sixteen pyrolysis runs were performed, with process mass balance closures above 90% obtained (wet feed basis). Pyrolysis liquids showed clear phase separation under gravity. With increasing processing temperature, the liquid yield (both organic and aqueous fraction) reduced but the gas yield increased. An investigation into the product energy distribution indicated that processing temperature had a strong effect on the product energy distribution, while the effect of feedstock moisture was relatively small. Batch anaerobic testing of the aqueous fraction showed that toxicity increased with pyrolysis processing temperature and decreased with feedstock moisture content. Statistical analysis confirmed that the pyrolysis processing temperature was the dominant factor affecting the toxicity of the aqueous product. Careful acclimatisation of the microbial consortium to the applied substrate and loading is likely to be necessary for improved digestion of the aqueous fraction.

The main driver for the investigation of fast pyrolysis oil marine fuel blends is EU directive 2012/33/EU which aims to cut the sulphur content of marine fuel and thereby reduce air pollution caused by marine vessels. The aim of this study was to investigate the miscibility of three- and four- component blends containing pyrolysis oil, 1-butanol, biodiesel (RME) and/or marine gas oil (MGO). The ideal blend would be a stable homogenous product with a minimum amount of butanol, whilst maximising the amount of pyrolysis oil. A successful blend would have properties suitable for use in marine engines. In order to successfully utilise a marine fuel blend in commercial vessels it should meet minimum specification requirements such as a flash point ≥60°C. Blends of pyrolysis oil, RME, MGO and 1-butanol were evaluated and characterised. The mixed blends were inspected after 48 hours for homogeneity and the results plotted on a tri-plot phase diagram. Homogenous samples were tested for water content, pH, acid number, viscosity and flash point as these indicate a blend's suitability for engine testing. The work forms part of the ReShip Project which is funded by Norwegian industry partners and the Research Council of Norway (The ENERGIX programme).

Combined heat and power from the intermediate pyrolysis of biomass materials offers flexible, on-demand renewable energy with some significant advantages over other renewable routes. To maximise the deployment of this technology an understanding of the dynamics and sensitivities of such a system is required. In the present work the system performance, economics and life-cycle environmental impact is analysed with the aid of the process simulation software Aspen Plus. Under the base conditions for the UK, such schemes are not currently economically competitive with energy and char products produced from conventional means. However, under certain scenarios as modelled using a sensitivity analysis this technology can compete and can therefore potentially contribute to the energy and resource sustainability of the economy, particularly in on-site applications with low-value waste feedstocks. The major areas for potential performance improvement are in reactor cost reductions, the reliable use of waste feedstocks and a high value end use for the char by-product from pyrolysis.

In this study, rice husk and corn stalk have been pyrolyzed in an auger pyrolysis reactor at pyrolysis temperatures of 350, 400, 450, 500, 550, and 600 °C in order to investigate the effect of the pyrolysis temperature on the pyrolysis performance of the reactor and physicochemical properties of pyrolysis products (this paper focuses on char and gas). The results have shown that the pyrolysis temperature significantly affects the mass yields and properties of the pyrolysis products. The mass yields of pyrolysis liquid and char are comparable to those reported for the same feedstocks processed in fluidized bed reactors. With the increase of the pyrolysis temperature, the pyrolysis liquid yield shows a peak at 500 °C, the char yield decreases, and the gas yield increases for both feedstocks. The higher heating value (HHV) and volatile matter content of char increase as the pyrolysis temperature increases from 350 to 600 °C. The gases obtained from the pyrolysis of rice husk and corn stalk mainly contain CO2, CO, CH4, H2, and other light hydrocarbons; the molar fractions of combustible gases increase and therefore their HHVs subsequently increase with the increase of the pyrolysis temperature.

The present paper offers a methodological approach towards the estimation and definition of enthalpies constituting an energy balance around a fast pyrolysis experiment conducted in a laboratory scale fluid bed with a capacity of 1 kg/ h. Pure N2 was used as fluidization medium at atmospheric pressure and the operating temperature (∼500°C) was adjusted with electrical resistors. The biomass feedstock type that was used was beech wood. An effort was made to achieve a satisfying 92.5% retrieval of products (dry basis mass balance) with the differences mainly attributed to loss of some bio-oil constituents into the quenching medium, ISOPAR™. The chemical enthalpy recovery for bio-oil, char and permanent gases is calculated 64.6%, 14.5% and 7.1%, respectively. All the energy losses from the experimental unit into the environment, namely the pyrolyser, cooling unit etc. are discussed and compared to the heat of fast pyrolysis that was calculated at 1123.5 kJ per kg of beech wood. This only represents 2.4% of the biomass total enthalpy or 6.5% its HHV basis. For the estimation of some important thermo-physical properties such as heat capacity and density, it was found that using data based on the identified compounds from the GC/MS analysis is very close to the reference values despite the small fraction of the bio-oil components detected. The methodology and results can help as a starting point for the proper design of fast pyrolysis experiments, pilot and/or industrial scale plants.

In Scandinavia, the wood processing industry leaves large amounts of forest residue that could be used for producing a renewable liquid fuel through fast pyrolysis. A bottleneck for pyrolysis liquids produced from ash¬containing feedstock is that the presence of solids (char, ash) in pyrolysis liquids makes the pyrolysis liquid unsuitable for direct combustion in conventional boilers and turbine operations due to problems with fouling, corrosion, erosion and plugging. The aim of this study is to explore whether "char/ash free" pyrolysis liquids can be produced from forestry residues by separating solids from freshly produced pyrolysis liquid by high speed centrifugation. Pyrolysis liquids were produced from various forest residue feedstocks in a 1 kg/h continuous fluid bed rig and the liquids were subjected to high speed centrifugation to separate solids. Effects of forestry residue feedstock composition and high speed centrifugation on product yields, solids separation efficiency and liquid phase separation have been explored., Proceedings of the 20th European Biomass Conference and Exhibition, 18-22 June 2012, Milan, Italy, pp. 1246-1248

Scandinavian paper mill industry leaves great amounts of forest residues in the countryside that could be used to produce a renewable and CO2 emission free liquid fuel, bio-oil, through fast pyrolysis. The aim of this work is to characterise products and measure yields of this process with Scandinavian forest residues to permit further designs and assessments of the process at an industrial scale. Because Scandinavian forest residues are a changing mixture of clean wood, bark and needles of spruce, it is necessary to understand how feedstock composition modifies yield and product characteristics. Several tests have been performed in a continuous 1 kg/h fast pyrolysis fluid bed rig using different feedstock compositions. Experimental results are reported in terms of product yields (gas, liquid and solid) and mass balances. CHN and ash content of char, the solid product, has been analysed for each run. The main characteristics of bio-oil, in terms of water content, CHN composition and pH are also reported. Finally, yields and product characteristics are studied as a function of feedstock composition., Proceedings of the 20th European Biomass Conference and Exhibition, 18-22 June 2012, Milan, Italy, pp. 1264-1269

This paper presents the main results of the French project PRECOND which aimed at evaluating the technical & economical viability of fast pyrolysis as biomass preconditioning route for the following utilizations: gasification and FT-synthesis into synthetic transport bio-fuels; petroleum co-refining into transport bio-fuels; combustion for CHP. First, the expected bio-oil specifications have been assessed according to the utilization. A bench scale fluidized bed, identified as the reference technology, was constructed and operated on different biomasses. The methods for physico-chemical characterization of bio-oils were characterized were evaluated, as well as their stability and rheological behaviour. Besides, a new model of the reactor was set-up, resulting in good predictions of the experimental mass balances. Finally, a techno-economical assessment of the whole pre­conditioning route has led to evaluation of bio-oil production costs and the consequence on the utilizations considered., Proceedings of the 18th European Biomass Conference and Exhibition, 3-7 May 2010, Lyon, France, pp. 14-19

The use of biomass-derived liquids (in short: bioliquids) instead of solid biomass can help overcome some of the barriers hindering a wider use of biomass in smaller-scale CHP systems. Relevant bioliquids included biodiesel, vegetable oils as well straight and upgraded pyrolysis oil. In this joint EU-Russian research project Bioliquids-CHP prime movers (engines and turbines) will be developed and modified so that these can run efficiently on bioliquids. At the same time, bioliquids will be upgraded and blended in order to facilitate their use in prime movers. Preliminary results with regard to bioliquid selection, production, and characterisation; the selection and modification of a micro gas turbine; and the development of engines and components are discussed. The research also covers NOx emission reduction and control and an assessment of the benefits and economics of bioliquids-based CHP systems in EU and Russian markets., Proceedings of the 18th European Biomass Conference and Exhibition, 3-7 May 2010, Lyon, France, pp. 1921-1925

Pyrolysis is one of the three main thermo-chemical routes to convert biomass into useful primary energy products. Fast pyrolysis has benefited from active research programmes since the 1980's in order to obtain bio-oils, which can be used in engines for the generation of electricity or after refining in transport. Today, several demonstration plants are operating in Europe and North America where significant quantities of bio-oils are produced for research and development purposes and several commercial plants are at an advanced stage of planning. Thus, for a commercial development the question of safety procedures for human health and environment preservation is raised. The aim of this ongoing European Project (Biotox) is to comprehensively assess toxicity and eco-toxicity of a representative bio-oil after preliminary screening of a wide range of bio-oils from different processes and temperatures in order to: - identify the best operating conditions avoiding or minimising the formation of toxic products from the composition of the bio-oils, - produce a comprehensive and definitive MSDS with the proper preventive and remedial procedures to adopt during production, transport and use of bio-oils, - produce fast pyrolysis bio-oils with low impact on human health and environment by avoiding bio-oils production presenting potential toxic characteristics. In the project, the relation between process parameters on one hand and chemical composition and toxicity for human health and environment on the other hand will be investigated so as to recommend the operating conditions to produce bio-oils with the lowest impacts. Then, the optimised compositions of bio-oils will be submitted to the mandatory tests required by the EU legal authority, the objective being the definition of secure handling and storage procedures, in order to control the risks related to the product for the population and the environment. The effects of different types of exposure (inhalation, ingestion or skin contact) will be quantified, as well as the effects of long-term exposures. The impacts on the environment will also be evaluated for biodegradability and effects on bio-organisms. A MSDS safety procedure and guidelines for bio-oils use and transport will be published in order to allow oil producers to legally market and transport on the European market. Bio-oils have been produced from different reactors (fluid bed, rotating cone, circulating fluid bed, ablative pyrolysis, vacuum pyrolysis), under different temperature conditions (450 to 600°C), and from different biomass (forest residue, wood chips, beech...) in order to relate these parameters to oil composition, toxicological characteristics and biodegradability. (Texte intégral)

To use the product gas of a biomass gasification unit in, for instance, gas engines, its tar content must be reduced to less then 100 mg/Nm3 [1]. A novel technology has been tested which is characterised by periodic reversal of the gas flow through a packed-bed tar removal reactor. Because the entrance and outlet sections of the reactor act as efficient heat exchangers, the producer gas leaves the reactor at relatively low temperatures. A small fraction of the producer gas is burned in situ to supply the energy required for the tar conversion reactions. This way of operation provides a high degree of heat integration. The main parts of the pilot plant installation are a 100 kWth wood gasifier and a packed bed tar converter, with a diameter of 0.22 m and is filled with approximately 50 kg of dolomite catalyst. Depending on the operating conditions the direction of the flow is reversed every 10 to 60 min. Tar conversions above 98% were achieved, without any notable on the caloric value of the treated gas. Optimization of the system should focus on improvement of the switching valves and application of a more active catalyst.

The velocity of nearly spherical mono-sized PVC powder in a cold-flow rotating cone reactor (top angle π/3 rad, height 0.43 m) was measured under variation of the particle diameter (140 –780 μm) and the cone rotational speed (up to 1800 rpm). Derived residence times for these particles vary from 0.05 to 0.3 second. The gas velocity distribution near the cone wall appeared to have a considerable influence on the velocity of particles smaller than 200 μm. Next to the experimental work a mathematical model is presented, using a single-particle description and a gas-flow description near the wall according to the universal velocity profile [1]. The conversion of biomass can be calculated by combining the hydrodynamic model together with a proper heat transfer and pyrolysis model. Particles smaller than 200 μm may pyrolyse completely in the present rotating cone flash pyrolysis reactor.

The velocity of nearly spherical monosized PVC powder in a coldflow rotating cone reactor (top angle π/2 and π/3 rad, width 0.5 m) was measured under variation of the particle diameter (140 780 μπι) and the cone rotational speed (up to 1800 rpm). Derived residence times for these particles vary from 0.05 to 0.3 second. A new particle temperature measurement technique is described together with temperature measurements used to calibrate the method. This temperature measurement technique will be used to investigate the heat transfer to particles in the rotating cone reactor. The first pyrolysis experiments will be described which showed that rice husks flow freely in the rotating cone flash pyrolysis reactor at 600 °C and 900 rpm. At these conditions a feed of 0.8 kg rice husks was converted to 0.2 kg ash and 0.6 kg pyrolysis vapours.

Analysis and characterisation of liquids from fast pyrolysis processes is an important area of research. Data on the physical and chemical properties of the liquids may give important indications about process parameters, quality, toxicity and stability of the pyrolysis liquids. Based on the growing interest in the utilisation of pyrolysis liquids as fuel for heat and power production as well as a source for chemicals, several analytical methods have been applied and modified to meet the special requirements of pyrolysis liquids. This paper will describe new achievements and developments in the physical and chemical characterisation of pyrolysis liquids. Two international working groups, Pyrolysis Network for Europe (PyNE) and the IEA activity on pyrolysis (PyRA) are currently active in reviewing, assessing, harmonising and developing standard procedures for pyrolysis liquids analysis. These activities will be presented and discussed.

Liquid-phase thermochemical processing of tall oil soap has been experimentally investigated. The organic matter of tall oil soap, which is a by-product of kraft pulping, originates mainly from wood extractives. Conventional processing of tall oil soap involves acidulation to yield crude tall oil and subsequent distillation of the oil at centralised refineries. Because tall oil originating from birch wood is far less valuable than that from pine, there is an economic incentive in the Nordic countries to develop alternative conversion processes for the tall oil soap produced at pulp mills where birch is widely used as feedstock.

The drying and the pyrolysis section of an updraft biomass gasifier is considered by using a numerical model. The drying and the pyrolysis usually occur simultaneously inside wood particles, since the particle size used in gasifiers is quite large. The effect of different parameters such as wood moisture content, particle size, gas flow velocity and gas and wood mass flow rates on the dimensions of the drying and pyrolysis section and on the gas outlet temperature is examined by model calculations.

This paper reports the further development of a Guideline (formerly Protocol) for sampling and analysis of "tars" from biomass producer gases. This Guideline is being developed in a project in the European Fifth Framework Programme with additional partn rs from Switzerland and North-America. This paper gives the outline and principle of the Guideline. The Guideline is based on isokinetic sampling of particles and tar from the main producer gas duct, particle filtration at high temperature, gas cooling in a liquid quench, tar absorption in a solvent at low temperatures, an optional backup adsorber, and flow measurement and control. The Guideline gives a definition for "Gravimetric tar" which is the "tar" number to be determined by the Guideline. Besides, the Guideline gives procedures for c mpound analysis by GC-MS or GC-FID. Moreover, in this paper the major choices that were made to come to the draft Guideline are explained. Finally, at the end of the paper it is described how and on what time scale the development of the Guideline will be completed. This paper does not contain the full text of the Guideline. This full text is available on the Internet at www.tarweb.net