Step washing: A modified pretreatment approach for industrial applications to improve chemical composition of agricultural residues

Flue Gas-Enhanced Water Leaching: AAEM Removal from Agricultural Organic Solid Waste and Fouling and Slagging Suppression during Its Combustion

Alkali and alkaline earth metals (AAEMs) in agricultural organic solid waste (AOSW) contribute to the fouling and slagging during its combustion. In this study, a novel flue gas-enhanced water leaching (FG-WL) method using flue gas as the heat and CO₂ source was proposed for effective AAEM removal from AOSW before combustion. The removal rate of AAEMs by FG-WL was significantly superior to that by conventional water leaching (WL) under the same pretreatment conditions. Furthermore, FG-WL also obviously reduced the release of AAEMs, S, and Cl during AOSW combustion. The ash fusion temperatures of the FG-WL-treated AOSW was higher than that of WL. The fouling and slagging tendency of AOSW greatly decreased through FG-WL treatment. Thus, FG-WL is a simple and feasible method for AAEM removal from AOSW and suppressing fouling and slagging during its combustion. Besides, it also provides a new pathway for the resource utilization of power plant flue gas.

Bioresource technology for bioenergy, bioproducts & environmental sustainability

The 3rd International Conference for Bioresource Technology for Bioenergy, Bioproducts & Environmental Sustainability (BIORESTEC) was held online from 17 to 19 May 2021. More than 120 participants from all over the world participated in this conference. The conference was studded with nine plenary lectures, ten invited lectures as well as more than 50 oral presentations along with several poster presentations. The purpose of the conference was to foster the exchange of knowledge and ideas among researchers in academia and industry as well as policymakers working on various aspects of biorefinery to discuss the progress made during the intervening three years and the latest trends in biotechnology, bioenergy, and biobased products. Biorefinery is winning over petrol refinery due to its sustainable nature and is the major driving force to a positive push to World's bioeconomy. Biorefinery enables us to obtain cascades of products by using biomass; including bioenergy, platform chemicals and various other bioproducts. Most of the talks during the conference dealt with sustainable practices for producing or synthesizing biomolecules via microorganisms. Bacteria, fungi as well algae were presented as bio machinery to convert the waste residues into value-added products including bioenergy and other biomolecules. This virtual special issue includes a selection of papers presented at the BIORESTEC conference, which contribute to environmental sustainability and give a strong message on sustainable technologies through developing bioproducts in order to overcome environmental issues.

Parametric and kinetic study of washing pretreatment for K and Cl removal from rice husk

Rice husk is an abundant agricultural waste that can be used in combustion applications. The use of agricultural waste in combustion applications is hindered by slagging, fouling, and corrosion due to elements such as K, Cl, and Si. With the aim of removing those problematic elements using water washing, lab-scale experiments were conducted to study the effect of washing parameters; temperature, time, and liquid to solid ratio and to recommend suitable washing conditions. The washing temperature of 65 °C and liquid to solid ratio of 100 was selected as the best process conditions. Within 10 min of washing time, 75% of Cl and 50% of K can be removed. Pseudo-second-order kinetic model is suitable to describe the leaching behavior, and the kinetic parameters were obtained for the leaching of K and Cl. In industrial installations, hot condensate from process use of steam can be recommended as a good source of washing medium.