Co-combustion, co-densification, and pollutant emission characteristics of charcoal-based briquettes prepared using bio-tar as a binder

Densification of agro-residues for sustainable energy generation: an overview

“…Investigation was conducted utilizing feedstock from different origin such as Poland (Berdychowski et al 2021 ), Colombia (Juan and Gonz 2020 ), India (Dhote et al 2020 ; Rajput et al 2020 ), Mississippi (Thapa and Engelken 2019 ), Korea (Park et al 2020 ), Philippines (Navalta et al 2020 ), Nigeria (Ajimotokan et al 2019b ), China (Xia et al 2019 ) South Africa (Shuma and Madyira 2019 ), and Poland (Czeka et al 2018 ) among other origins. Some of feedstock reported recently include cashew nutshell (Ifa et al 2020 ; Chungcharoen and Srisang 2020 ), sugar cane bagasse (John et al 2020 ; Setter et al 2020 ), sawdust (Ajimotokan et al 2019b ; Yang et al 2021 ; Afsal et al 2020 ; Wang et al 2020 ), rice husk and rice brain (John et al 2020 ; Faverzani et al 2020 ), palm kernel shell and oil palm fruit bunch (Cabrales et al 2020 ; Osei et al 2020 ), citrus peel (Faverzani et al 2020 ), Sitka Spruce and olive pit (Trubetskaya et al 2019 ), miscanthus, wheat, barley (Mitchell et al 2020 ), areca nut (Chungcharoen and Srisang 2020 ), mushroom(Rafael et al 2020 ) and biomass charcoal-based product (Ajimotokan et al 2019b ; Lubwama et al 2020 ; Jelonek et al 2020 ; Cong et al 2020 ). Generally, government policy regarding renewable energy, greenhouse emission, and energy demand greatly determines the growth of solid biomass fuels in any region (Bajwa et al 2018 ).…”

“…Different binders and a blend of binders have been reported in the literature to influence fuel properties (Zhai et al 2018 ; Shuma and Madyira 2019 ). Examples of binders popularly utilized in the manufacture of biomass solid fuel are starch (Ajimotokan et al 2019c ; Navalta et al 2020 ; Merry et al 2018 ; Hu et al 2019 ), molasses (Zhai et al 2018 ; Wang et al 2019 ; Barriocanal 2020 ), bio-tar (Cong et al 2021 ), coal tar (Barriocanal 2020 ), xanthan and guar gums (Espuelas et al 2020 ) thermoplastics (Song et al 2021 ), pyrolysis oil (Riva et al 2019 ), calcium carbonate (Matkowski et al 2020b ), glycerol contents (Martín et al 2020 ; Juan and Gonz 2020 ; Xia et al 2019 ; Azargohar et al 2019 ), recovered polyvinyl alcohol (Rajput et al 2020 ; Hu et al 2019 ), waste cooking oil and waste lubricating oil (Rajput et al 2020 ), paraffin (Xia et al 2019 ; Barriocanal 2020 ), red clay and sodium humate (Song et al 2019 ), cassava peel (Ajimotokan et al 2019b ), alkali lignin and L-proline (Azargohar et al 2019 ), cow dung and cactus (Shuma and Madyira 2019 ) and calcium hydroxide (Merry et al 2018 ). A comprehensive review of densification binders and densification mechanisms can be found in Zhang et al ( 2018 ).…”

“…For enhanced mechanical properties, l -proline and polyvinyl alcohol binder is highly recommended (Hu et al 2019 ; Azargohar et al 2019 ). Also, utilization of bio-tar, thermoplastic substantially enhance fuel physical and mechanical stability (Song et al 2021 ; Cong et al 2021 ). Addition of plastic up to 10% at 300 kN compacting force will produce fuel with optimum properties comparable to coal (Song et al 2021 ).…”

“…For example, the addition of a binder such as bio-tar was reported to increase greenhouse gas emissions during fuel combustion. However, the addition of 3 wt% of hydrated lime eliminates or weakens the greenhouse gas effects (Cong et al 2021 ). In addition, acidified calcium oxide has been utilized as desulphurized, while the blend of molybdenum and calmogastrin has been reportedly used as a smoke suppressor (Song et al 2019 ).…”

“…However, preheating feedstock before densification enhances physico-mechanical properties (Ajimotokan et al 2019a ; Ojolo et al 2016 ). Thermal pretreatment was reported to improve fuel thermal and combustion properties (Xia et al 2019 ; Cong et al 2021 ; Sharma and Dubey 2020 ). Cong et al reported that increasing densification temperature beyond 20 °C would negatively affect the mechanical fuel property (Cong et al 2021 ).…”