scholarly journals Thermal Biomass Conversion: A Review

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 516 ◽  
Author(s):  
Witold M. Lewandowski ◽  
Michał Ryms ◽  
Wojciech Kosakowski
Keyword(s):  
Biomass Conversion ◽  
Hydrothermal Carbonization ◽  
Thermal Conversion ◽  
Steam Gasification ◽  
Waste Biomass ◽  
Renewable Fuel ◽  
High Temperature Steam ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Environmentally Friendly Method

In this paper, the most important methods of thermal conversion of biomass, such as: hydrothermal carbonization (180–250 °C), torrefaction (200–300 °C), slow pyrolysis (carbonization) (300–450 °C), fast pyrolysis (500–800 °C), gasification (800–1000 °C), supercritical steam gasification, high temperature steam gasification (>1000 °C) and combustion, were gathered, compared and ranked according to increasing temperature. A comprehensive model of thermal conversion as a function of temperature, pressure and heating rate of biomass has been provided. For the most important, basic process, which is pyrolysis, five mechanisms of thermal decomposition kinetics of its components (lignin, cellulose, hemicellulose) were presented. The most important apparatuses and implementing devices have been provided for all biomass conversion methods excluding combustion. The process of combustion, which is energy recycling, was omitted in this review of biomass thermal conversion methods for two reasons. Firstly, the range of knowledge on combustion is too extensive and there is not enough space in this study to fully discuss it. Secondly, the authors believe that combustion is not an environmentally-friendly method of waste biomass utilization, and, in the case of valuable biomass, it is downright harmful. Chemical compounds contained in biomass, such as biochar, oils and gases, should be recovered and reused instead of being simply burnt—this way, non-renewable fuel consumption can be reduced.

scholarly journals Thermogravimetry of the Steam Gasification of Calluna vulgaris: Kinetic Study

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 657
Author(s):  
José María Encinar ◽  
Juan Félix González ◽  
Sergio Nogales-Delgado
Keyword(s):  
Kinetic Study ◽  
Raw Materials ◽  
Biomass Conversion ◽  
Calluna Vulgaris ◽  
Thermal Conversion ◽  
Positive Influence ◽  
Steam Gasification ◽  
Conversion Model ◽  
Oil Reserves ◽  
Shrinking Core

On account of the continuous decrease in oil reserves, as well as the promotion of sustainable policies, there is an increasing interest in biomass conversion processes, which imply the search for new raw materials as energy sources, like forestry and agricultural wastes. On the other hand, gasification seems to be a suitable thermal conversion process for this purpose. This work studied the thermogravimetry of the steam gasification of charcoal from heather (Calluna vulgaris) in order to determine the kinetics of the process under controlled reaction conditions. The variables studied were temperature (from 750 to 900 °C), steam partial pressure (from 0.26 to 0.82 atm), initial charcoal mass (from 50 to 106 mg), particle size (from 0.4 to 2.0 mm), N2 and steam volumetric flows (from 142 to 446 mL·min−1) and catalyst (K2CO3) concentration (from 0 to 10% w/w). The use of the shrinking core model and uniform conversion model allowed us to determine the kinetic parameters of the process. As a result, a positive influence of catalyst concentration was found up to 7.5% w/w. The kinetic study of the catalytic steam gasification showed activation energies of 99.5 and 114.8 kJ·mol−1 and order of reactions (for steam) of 1/2 and 2/3.

Complete Parametric Study of Bagasse Pellets During High-Temperature Steam Gasification

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Hong Nam Nguyen ◽  
Toshiki Tsubota
Keyword(s):  
Weight Loss ◽  
High Temperature ◽  
Parametric Study ◽  
Maximum Rate ◽  
Pyrolysis Temperature ◽  
Steam Gasification ◽  
Operating Conditions ◽  
Energy Yield ◽  
High Temperature Steam ◽  
Kinetics Of

Abstract A complete parametric study of bagasse pellets under high-temperature steam gasification in relevant industrial operating conditions was investigated. Regarding thermal behaviors, the maximum rate of weight loss (Rmax = 0.55%/°C) occurred at the temperature Tmax = 305 °C. The final pyrolysis temperature and heating rate were proportional to the mechanical strength, the bulk density, as well as the char yield and energy yield. However, the changes were not significant after 600 °C. Regarding steam gasification kinetics, an increase from 850 to 1000 °C and from 0.1 to 0.4 atm accelerated 10 times and two times the conversion rate of bagasse pellet char, respectively. Gasification kinetics of a pellet char produced at 2000 °Cmin−1 was 1.4 higher compared with a pellet char produced at 5 °C min−1. An empirical model that takes into account all the changes in the reactive surface could successfully predict the conversion of the bagasse pellet char during high-temperature steam gasification. Experimental results and the kinetic model proposed could be useful for the calculation of industrial or academic codes, necessary for the conception of new efficient gasifiers.

scholarly journals Upgrading fuel potentials of waste biomass via hydrothermal carbonization

2021 ◽  
pp. 25-25
Author(s):  
Jelena Petrovic ◽  
Marija Simic ◽  
Marija Mihajlovic ◽  
Marija Koprivica ◽  
Marija Kojic ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Hydrothermal Carbonization ◽  
Volatile Matter ◽  
Waste Biomass ◽  
Corn Cob ◽  
Heating Value ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Biomass Transformation ◽  
Van Krevelen Diagram

In recent decades, massive exploitation of fossil fuels caused a growing demand for the production of energies from renewable sources. Hydrochar obtained from waste biomass via hydrothermal carbonization (HTC) possesses good potentials as a biofuel. Therefore, we performed HTC of corn cob, paulownia leaves, and olive pomace at different temperatures (180, 220, and 260 oC). The main goal of this study was to comparatively evaluate the influence of HTC conditions on the structure and fuel characteristics of the obtained solids. The results showed that the yields of hydrochar decrease significantly with increasing temperature in all samples. The carbon content and higher heating value increased and reached the highest values in hydrochars obtained at 260 oC, while the content of volatile matter decreased. Furthermore, the Van Krevelen diagram reveals that the transformation of feedstock to lignite-like products upon HTC was achieved. In this study, the results showed that processes of dehydration and decarboxylation during HTC provoke intensive biomass transformation and that hydrochars obtained at higher temperatures have significantly enhanced fuel properties and fewer volatiles compared to the feedstock.

scholarly journals Sewage Sludge Treatment by Hydrothermal Carbonization: Feasibility Study for Sustainable Nutrient Recovery and Fuel Production

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2697
Author(s):  
Gabriel Gerner ◽  
Luca Meyer ◽  
Rahel Wanner ◽  
Thomas Keller ◽  
Rolf Krebs
Keyword(s):  
Liquid Phase ◽  
Sewage Sludge ◽  
Hydrothermal Carbonization ◽  
Economic Feasibility ◽  
Phosphorus Recovery ◽  
High Yield ◽  
Nutrient Recovery ◽  
Waste Biomass ◽  
Sludge Treatment ◽  
Sewage Sludge Treatment

Phosphorus recovery from waste biomass is becoming increasingly important, given that phosphorus is an exhaustible non-renewable resource. For the recovery of plant nutrients and production of climate-neutral fuel from wet waste streams, hydrothermal carbonization (HTC) has been suggested as a promising technology. In this study, digested sewage sludge (DSS) was used as waste material for phosphorus and nitrogen recovery. HTC was conducted at 200 °C for 4 h, followed by phosphorus stripping (PS) or leaching (PL) at room temperature. The results showed that for PS and PL around 84% and 71% of phosphorus, as well as 53% and 54% of nitrogen, respectively, could be recovered in the liquid phase (process water and/or extract). Heavy metals were mainly transferred to the hydrochar and only <1 ppm of Cd and 21–43 ppm of Zn were found to be in the liquid phase of the acid treatments. According to the economic feasibility calculation, the HTC-treatment per dry ton DSS with an industrial-scale plant would cost around 608 USD. Between 349–406 kg of sulfuric acid are required per dry ton DSS to achieve a high yield in phosphorus recovery, which causes additional costs of 96–118 USD. Compared to current sewage sludge treatment costs in Switzerland, which range between 669 USD and 1173 USD, HTC can be an economically feasible process for DSS treatment and nutrient recovery.

Biocatalysis and biomass conversion: enabling a circular economy

2020 ◽  
Vol 378 (2176) ◽  
pp. 20190274 ◽  
Author(s):  
Roger A. Sheldon
Keyword(s):  
Circular Economy ◽  
Biomass Conversion ◽  
Raw Material ◽  
Liquid Fuels ◽  
Waste Biomass ◽  
Renewable Biomass ◽  
Precious Metal Catalysts ◽  
Mitigate Climate Change ◽  
Forestry Residues ◽  
The Right

This paper is based on a lecture presented to the Royal Society in London on 24 June 2019. Two of the grand societal and technological challenges of the twenty-first century are the ‘greening' of chemicals manufacture and the ongoing transition to a sustainable, carbon neutral economy based on renewable biomass as the raw material, a so-called bio-based economy. These challenges are motivated by the need to eliminate environmental degradation and mitigate climate change. In a bio-based economy, ideally waste biomass, particularly agricultural and forestry residues and food supply chain waste, are converted to liquid fuels, commodity chemicals and biopolymers using clean, catalytic processes. Biocatalysis has the right credentials to achieve this goal. Enzymes are biocompatible, biodegradable and essentially non-hazardous. Additionally, they are derived from inexpensive renewable resources which are readily available and not subject to the large price fluctuations which undermine the long-term commercial viability of scarce precious metal catalysts. Thanks to spectacular advances in molecular biology the landscape of biocatalysis has dramatically changed in the last two decades. Developments in (meta)genomics in combination with ‘big data’ analysis have revolutionized new enzyme discovery and developments in protein engineering by directed evolution have enabled dramatic improvements in their performance. These developments have their confluence in the bio-based circular economy. This article is part of a discussion meeting issue ‘Science to enable the circular economy'.

scholarly journals Kinetics of drying of basil leaves (Ocimum basilicum L.) in the infrared

2012 ◽  
Vol 16 (12) ◽  
pp. 1346-1352 ◽  
Author(s):  
Renata C. dos Reis ◽  
Ivano A. Devilla ◽  
Diego P. R. Ascheri ◽  
Ana C. O. Servulo ◽  
Athina B. M. Souza
Keyword(s):  
Experimental Data ◽  
Ocimum Basilicum ◽  
Coefficient Of Determination ◽  
Chisquare Test ◽  
The Mean ◽  
Drying Curves ◽  
The One ◽  
Increasing Temperature ◽  
Air Circulation ◽  
Kinetics Of

The objective of this paper was to model the drying curves of the leaves of basil (Ocimum basilicum L.) in the infrared at temperatures of 50, 60, 70 and 80 ºC and to evaluate the influence of drying temperature on the color of dried leaves. Drying was conducted in infrared dryer with temperature and greenhouse air circulation. Experimental data were fitted to eight mathematical models. The magnitude of the coefficient of determination (R²), the mean relative error (P), the estimated mean error (SE) and chisquare test (χ2) were used to verify the degree of fitness of the models. From the study it was concluded that: a) the behavior of the drying curves of basil leaves was similar to most agricultural products, the drying times in the infrared were less than the drying times in an oven with air circulation, b) the mathematical drying model proposed by Midilli et al. (2002) was the one which best adjusted to the experimental data, c) the diffusion coefficient ranged from 9.10 x 10-12 to 2.92 x 10-11 m² s-1 and d) the color of the samples was highly influenced by drying, becoming darker due to loss of chlorophyll with increasing temperature.

scholarly journals Potential for Production of Biochar-Based Fertilizers from Olive Mill Waste in Mediterranean Basin Countries: An Initial Assessment for Spain, Tunisia, and Greece

2020 ◽  
Vol 12 (15) ◽  
pp. 6081 ◽  
Author(s):  
Evan A.N. Marks ◽  
Vasiliki Kinigopoulou ◽  
Hanene Akrout ◽  
Ahmed Amine Azzaz ◽  
Charalampos Doulgeris ◽  
...  
Keyword(s):  
Total Mass ◽  
Hydrothermal Carbonization ◽  
Thermal Conversion ◽  
Application Rate ◽  
Solid Wastes ◽  
Initial Assessment ◽  
Olive Mill Waste ◽  
Olive Mill Wastes ◽  
Mill Waste ◽  
Olive Mill

Olive mill wastes continue to be a management challenge due to the large volumes produced, particularly due to their toxicity and impacts on the environment. Thermal conversion through pyrolysis or hydrothermal carbonization techniques can detoxify wastes while conserving nutrient contents. In this work, we produced up-to-date data on olive mill waste flows in Spain, Tunisia, and Greece and characterized representative samples in the laboratory. Assays of thermal conversion of olive mill wastewaters and solid wastes were also performed to understand biochar yields and final properties, and the total quantities of nutrients contained were estimated. Of particular note were the quantities of potassium in Tunisian wastewaters, representing 0.6% of the total mass and an annual flow of approximately 5000 t, and in the Spanish solid wastes, an average of 1.7% of the total mass is potassium, representing an annual flow of approximately 23,000 t. Concerning phosphorus, Spanish solid wastes had the highest contents (0.1%), double that of other countries’ wastes. Annually, olive mill wastes from the three countries are estimated to contain approximately 35 × 103 tons of potassium and 2.6 × 103 tons of phosphorus. With this resource converted to biochar, each year more than 700 km2 of soils could be enriched in 0.2% carbon with biochar at an application rate of 7 t ha−1.

scholarly journals A Review of Intermediate Pyrolysis as a Technology of Biomass Conversion for Coproduction of Biooil and Adsorption Biochar

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Deodatus Kazawadi ◽  
Justin Ntalikwa ◽  
Godlisten Kombe
Keyword(s):  
Fossil Fuel ◽  
Biomass Conversion ◽  
Environmental Problems ◽  
Review Article ◽  
Soil Treatment ◽  
Waste Biomass ◽  
High Quality ◽  
Good For ◽  
Intermediate Pyrolysis ◽  
Microbial Attack

The agenda to utilize and efficiently convert biomass has been raised to alleviate environmental problems and pressure on the reliance on fossil fuel. Intermediate pyrolysis has the ability to treat different biomasses and coproduction of biooil and adsorption biochar. This review article aims to evaluate the appropriateness of intermediate pyrolysis for the coproduction of biooil and adsorption biochar. It was observed that coproduced biooil is of high quality, stable, and miscible that can be used directly to existing engines or be easily blended. The biochar coproduced is good for adsorption but is not stable for microbial attack and hence unsuitable in soil treatment but for hydrometallurgy. Since the process is capable of treating waste biomass, it is an opportunity for further investigations in areas where wastes are plenty and less utilized. To increase the effectiveness of this technology for coproduction, optimizing parameters, design of efficient reactors, and use of catalyst must be worked upon.

scholarly journals Mathematical modeling of pequi pulp drying and effective diffusivity determination

2017 ◽  
Vol 21 (7) ◽  
pp. 493-498 ◽  
Author(s):  
Elisabete P. de Sousa ◽  
Rossana M. F. de Figueirêdo ◽  
Josivanda P. Gomes ◽  
Alexandre J. de M. Queiroz ◽  
Deise S. de Castro ◽  
...  
Keyword(s):  
Experimental Data ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Time ◽  
Air Speed ◽  
Drying Curves ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Best Fit

ABSTRACT The aim of this work was to study the drying kinetics of pequi pulp by convective drying at different conditions of temperature (50, 60, 70 and 80 °C) and thickness (0.5, 1.0 and 1.5 cm) at the air speed of 1.0 m s-1, with no addition of adjuvant. The experimental data of pequi pulp drying kinetics were used to plot drying curves and fitted to the models: Midilli, Page, Henderson & Pabis and Newton. Effective diffusivity was calculated using the Fick’s diffusion model for a flat plate. It was found that, with increasing thickness, the drying time increased and, with increasing temperature, the drying time was reduced. The Midilli model showed the best fit to the experimental data of pequi pulp drying at all temperatures and thicknesses, presenting higher coefficients of determination (R2), indicating that this model satisfactorily represents the pequi pulp drying phenomenon. There was a trend of increase in the effective diffusivity with the increase in pulp layer thickness and temperature.

Sign in / Sign up

Export Citation Format

Share Document