Despite being a limited and scarce resource, the necessity and exploitation of fossil fuels are unstoppable in serving human demands. In order to supply energy demand without causing environmental damage, it is crucial to utilize a variety of renewable feedstock resources. Biochar, made up mostly of carbon, oxygen, and hydrogen, is the product of the thermochemical processes of pyrolysis, hydrothermal carbonization, torrefaction, and hydrothermal liquefaction. Biochar, once activated, has the potential to act as a catalyst in a variety of energy generation processes, including transesterification and fermentation. Transesterification is the process that is used to produce biodiesel from a variety of oils, both edible and non-edible, as well as animal fats in the presence of either a homogeneous or a heterogeneous catalyst. When selecting a catalyst, the amount of free fatty acid (FFA) content in the oil is considered. Homogeneous catalysts are superior to heterogeneous catalysts because they are unaffected by the concentration of free fatty acids in the oil. Homogeneous catalysts are extremely hazardous, as they are poisonous, combustible, and corrosive. In addition, the production of soaps as a byproduct and a large volume of wastewater from the use of homogeneous catalysts necessitates additional pretreatment procedures and costs for adequate disposal. This article examines the biochar-based fuel-generation catalyst in detail. At first, a wide variety of thermochemical methods were provided for manufacturing biochar and its production. Biochar’s chemical nature was analyzed, and the case for using it as a catalyst in the production of biofuels was also scrutinized. An explanation of how the biochar catalyst can improve fuel synthesis is provided for readers. Biodiesel’s transesterification and esterification processes, biomass hydrolysis, and biohydrogen generation with the help of a biochar catalyst are all reviewed in detail.

Pakistan is very rich in coal reserves specifically after exploration of Thar coal reserves. At the same time country is facing energy crises due to shortage or unavailability of sustainable fuel supply at a cheaper rate. One potential solution is coal gasification which gives clean synthetic gas usually called syngas for use as an alternative fuel source for electricity production at a cheaper rate as well as a source of recovering different chemicals used as basic raw materials in other industries. Numerical simulations have been performed in this work for the gasification process of indigenous coal on a 2D computational fluid dynamic (CFD) model of downdraft entrained-flow gasifier using commercial CFD software FLUENT®6.3.26. Navier-stokes equations along with transport equations for species have been solved using eddy-dissipation combustion model. The compositions of indigenous coals (Thar, Lakhra, and Sonda) were used in simulations as gasification feedstock. Rich oxidant conditions 95 % O₂ and 5 % N₂ were set for gasification. The gasification performance was studied by comparing efficiencies of gasification and quality of syngas produced for three types of coal feedings. The temperature and pressure profiles inside the gasifier were also studied. From simulation results, the great influence of coal composition was observed in the performance of gasification. Lakhra coal produced syngas with a maximum heating value of 20.55 MJ/kg whereas sonda coal produced syngas with a minimum heating value of 17.96 MJ/kg.