Realization of quasi-steady-state piled smouldering using sequential operation chambers for industrial treatment of biomass wastes.

Piled smouldering has great potential for treatment and utilization of biomass wastes. However, its unsteady-state nature limits its industrial utilization, as well as treatment of smoke. This article addresses this issue by proposing the sequential operation of numerous smouldering chambers to realize steady- or quasi-steady-state piled smouldering.

Absorbing oxygen carriers promotes phosphorus recovery from sludge via the microwave thermal conversion process.

This study aims to apply the Absorbing oxygen carriers (AOCs) to induce the migration and transformation of phosphorus compounds during the microwave thermal conversion of sludge so the hard-to-extract organic phosphorus (OP) can be converted to easy-to-extract inorganic phosphorus (IP) and be enriched onto the sludge char. The AOCs were recycled by screen separation from the IP-rich sludge char, with the latter being a renewable phosphorus source from sludge. The AOCs in this novel process enhanced the conversion efficiency of OP into non-apatite inorganic phosphorus (NAlP), which was further converted to apatite inorganic phosphorus (AP).

Insight into derivative Weibull mixture model in describing simulated distributed activation energy model and distillers dried grains with solubles pyrolysis processes.

The kinetics of biomass pyrolysis is fundamental for exploring its mechanisms and optimizing its processes, which is helpful for designing its systems. The derivative Weibull mixture model was proposed for kinetic description of the simulated distribution energy model (DAEM) processes and distillers dried grains with solubles (DDGS) pyrolysis processes. The conversion rate data of these processes at different heating rates could be accurately described by the derivative Weibull mixture model.

Stainless steel membranes for harvesting cyanobacteria: Performance, fouling and cleaning.

Stainless steel membranes with 0.45, 1 and 2 μm pore sizes were applied to harvest cyanobacteria. Their critical fluxes were determined and continuous filtration tests were conducted.

Sustainable and scalable in-situ synthesis of hydrochar-wrapped TiAlC-derived nanofibers as adsorbents to remove heavy metals.

To ensure a sustainable future, it is imperative to efficiently utilize abundant biomass to produce such as platform chemicals, transport fuels, and other raw materials; hydrochar is one of the promising candidates derived by hydrothermal carbonization of biomass in pressurized hot water. The synthesis of "hydrochar-wrapped TiAlC-derived nanofibers" was successfully achieved by a facile one-pot hydrothermal reaction using glucose as the hydrochar precursor. Meanwhile, cellulose and pinewood sawdust as raw materials were also investigated.

Synergetic effects during co-pyrolysis of biomass and waste tire: A study on product distribution and reaction kinetics.

The synergetic effects during co-pyrolysis of biomass and waste tire (WT) were investigated concerning the product distribution and reaction kinetics. Two biomass feedstocks were separately mixed with WT at different effective hydrogen/carbon ratio (H/C), and analytical co-pyrolysis of mixtures was conducted using pyrolysis gas chromatography/mass spectroscopy at 500 °C. Product distributions were similar between different biomass feedstocks but varied significantly at different H/C values.

Kinetic compensation effect in logistic distributed activation energy model for lignocellulosic biomass pyrolysis.

The kinetic compensation effect in the logistic distributed activation energy model (DAEM) for lignocellulosic biomass pyrolysis was investigated. The sum of square error (SSE) surface tool was used to analyze two theoretically simulated logistic DAEM processes for cellulose and xylan pyrolysis. The logistic DAEM coupled with the pattern search method for parameter estimation was used to analyze the experimental data of cellulose pyrolysis.

Sensitivity analysis of three-parallel-DAEM-reaction model for describing rice straw pyrolysis.

The three-parallel-DAEM-reaction model was used to study the slow pyrolysis kinetics of rice straw based on thermogravimetric analysis (TGA) data. The kinetic parameters of the model were calculated using the pattern search method. A comparison between the predicted DTG data and experimental values showed good agreement.

Iterative linear integral isoconversional method: theory and application.

In this work, the theory of the iterative linear integral isoconversional method was illustrated in detail. This method allows the dependence of the activation energy (Eα) on the conversion degree to be accurately determined in a short time. Moreover, the method can yield the term [Aαf(α)] (Aα: the frequency factor at conversion α, f(α): the reaction model).

A critical study of the Miura-Maki integral method for the estimation of the kinetic parameters of the distributed activation energy model.

Using some theoretically simulated data constructed from known sets of the activation energy distribution f(E) (assumed to follow the Gaussian distribution [Formula in text] where E is the activation energy, E(0) is the mean value of the activation energy distribution, and σ is the standard deviation of the activation energy distribution) and the frequency factor k(0), a critical study of the use of the Miura-Maki integral method for the estimation of the kinetic parameters of the distributed activation energy model has been performed from three cases. For all cases, the use of the Miura-Maki integral method leads to important errors in the estimation of k(0). There are some differences between the assumed and calculated activation energy distributions and the differences decrease with increasing the assumed k(0) values (for Case 1), with increasing the assumed σ values (for Case 2), and with decreasing the b values (for Case 3).

Logistic distributed activation energy model--part 2: application to cellulose pyrolysis.

The pyrolysis behavior of cellulose has been investigated by using thermogravimetric analysis (TGA). The non-isothermal TGA data obtained at different heating rates have been analyzed simultaneously. Pattern Search Method has been proposed for the estimation of the model parameter values.

Logistic distributed activation energy model--Part 1: Derivation and numerical parametric study.

A new distributed activation energy model is presented using the logistic distribution to mathematically represent the pyrolysis kinetics of complex solid fuels. A numerical parametric study of the logistic distributed activation energy model is conducted to evaluate the influences of the model parameters on the numerical results of the model. The parameters studied include the heating rate, reaction order, frequency factor, mean of the logistic activation energy distribution, standard deviation of the logistic activation energy distribution.

A new iterative linear integral isoconversional method for the determination of the activation energy varying with the conversion degree.

The conventional linear integral isoconversional methods may lead to important errors in the determination of the activation energy when the significant variation of the activation energy with the conversion degree occurs. Vyazovkin proposed an advanced nonlinear isoconversional method, which allows the activation energy to be accurately determined [Vyazovkin, J Comput Chem 2001, 22, 178]. However, the use of the Vyazovkin method raises the problem of the time-consuming minimization without derivatives.

Weibull mixture model for modeling nonisothermal kinetics of thermally stimulated solid-state reactions: application to simulated and real kinetic conversion data.

The possibility of applying Weibull mixture model for the fitting of the nonisothermal kinetic conversion data has been investigated. It has been found that the kinetic conversion data at different heating rates can be successfully described by one or the linear combination of few Weibull distribution functions. Several simulated and real kinetic conversion traces have been analyzed.

New distributed activation energy model: numerical solution and application to pyrolysis kinetics of some types of biomass.

In the present paper, a new distributed activation energy model has been developed, considering the reaction order and the dependence of frequency factor on temperature. The proposed DAEM cannot be solved directly in a closed from, thus a method was used to obtain the numerical solution of the new DAEM equation. Two numerical examples to illustrate the proposed method were presented.