The current energy crisis, depletion of fossil fuels, and global climate change have made it imperative to find alternative sources of energy that are both economically sustainable and environmentally friendly. Here we review various pathways for converting biomass into bioenergy and biochar and their applications in producing electricity, biodiesel, and biohydrogen. Biomass can be converted into biofuels using different methods, including biochemical and thermochemical conversion methods. Determining which approach is best relies on the type of biomass involved, the desired final product, and whether or not it is economically sustainable. Biochemical conversion methods are currently the most widely used for producing biofuels from biomass, accounting for approximately 80% of all biofuels produced worldwide. Ethanol and biodiesel are the most prevalent biofuels produced via biochemical conversion processes. Thermochemical conversion is less used than biochemical conversion, accounting for approximately 20% of biofuels produced worldwide. Bio-oil and syngas, commonly manufactured from wood chips, agricultural waste, and municipal solid waste, are the major biofuels produced by thermochemical conversion. Biofuels produced from biomass have the potential to displace up to 27% of the world's transportation fuel by 2050, which could result in a reduction in greenhouse gas emissions by up to 3.7 billion metric tons per year. Biochar from biomass can yield high biodiesel, ranging from 32.8% to 97.75%, and can also serve as an anode, cathode, and catalyst in microbial fuel cells with a maximum power density of 4346 mW/m2. Biochar also plays a role in catalytic methane decomposition and dry methane reforming, with hydrogen conversion rates ranging from 13.4% to 95.7%. Biochar can also increase hydrogen yield by up to 220.3%.
The concentrations of 56 hydrocarbons from C2 to C12 were measured simultaneously in the southbound bore, the northbound bore
and the exhaust air shafts of the Hsuehshan tunnel near Yilan, Taiwan for 12 days during 2007 and 2008. A total of 60 integrated
air samples were collected using stainless steel canisters and analyzed using GC/FID and GC/MS. The five most abundant species in
all samples were ethylene, acetylene, isopentane, propylene and toluene. The exit/entrance ratios of total non-methane hydrocarbons
(NMHC) concentration were 7.8 and 4.8 for the southbound and northbound bores, respectively. Furthermore, the exhaust from the
vertical shafts affects air quality in the neighborhood. The most abundant species of emission rate (ER) was toluene (21.93–42.89
mg/sec), followed by isopentane, ethylene, propylene and 1-butene, with ER ranging from 2.50 to 9.31 mg/sec. The species in the
three exhaust air shafts showed that the reactivities of these emissions are similar to those of vehicle emissions. Notably, the control of
emissions in the vertical shafts of the vehicle tunnel will be important in the future. 相似文献
Journal of Polymers and the Environment - Outdoor building materials made of wood require preservatives containing chromated copper arsenate and other carcinogenic substances but still are subject... 相似文献
Reducing greenhouse gas emissions without hampering economic growth is a significant issue for China. Taking into account environmental sustainability principles, this study analysed the energy efficiency of 30 regions of China for the period 2002–2007. By employing a data envelopment analysis (DEA) approach, this study included undesirable CO2 and SO2 outputs and the desirable GDP output in the model. Empirical outcomes demonstrated that the overall average technical efficiency (TE) of China is 0.843, indicating a 15.70% input inefficiency. Among three geographic areas, the east has the highest technical efficiency, with the highest ability to set up clean-burning power plants based on best technology available. Performance in the west is less good because of much inefficient technology. Finally, the study demonstrates detailed management implications of the BCG matrix. The most important contribution of this paper is a detailed demonstration of an energy performance evaluation mechanism for China. The valuable results and insights gained can be equally effectively applied to studies in other developing countries facing the same gaseous emissions. 相似文献