Aboveground Woody Biomass, Carbon Stocks Potential in Selected Tropical Forest Patches of Tripura, Northeast India

To estimate woody plant biomass stocks in different patches of forest ecosystems, total 20, 500 × 10 m (0.5 ha) sized line transects were laid in a protected area of Tripura, Northeast India. Overall, 9160 individuals were measured at ≥10 cm diameter at breast height (dbh) in 10 ha sampled area. Estimation of biomass suggested that highest coefficient for allometric relationships between density and biomass in 10 dbh classes was observed in bamboo brakes (R2 = 0.90) than lowest for semi evergreen patch (R2 = 0.48). The stock of carbon (C) was differ significantly along the forest patches (F = 7.01, df = 3.19;p < 0.01). Most of biomass stock (69.38%) was accumulated in lower dbh class (<30 cm) and only 23% of biomass was estimated at higher dbh classes (> 70 cm). Range of biomass stock (37.85 - 85.58 Mg ha-1) was low, compared to other tropical forest ecosystems in India, which implies that the proper management is required to monitor regional ecosystem C pool.

Recent advances in thermochemical conversion of woody biomass for production of green hydrogen and CO_(2)capture:A review

Hydrogen as a clean energy carrier has attracted great interests world-wide for substitution of fossil fuels and for abatement of the climate change concerns.However,green hydrogen from renewable resources is less than 0.1%at present in the world hydrogen production and this is largely from water electrolysis which is beneficial only when renewable electricity is used.Hydrogen production from diverse renewable resources is desirable.This review presents recent advances in hydrogen production from woody biomass through biomass steam gasification,producer gas processing and H_(2)/CO_(2)separation.The producer gas processing includes steam-methane reforming(SMR)and water-gas shift(WGS)reactions to convert CH_(4)and CO in the producer gas to H_(2)and CO_(2).The H_(2)storage discussed using liquid carrier through hydrogenation is also discussed.The CO_(2)capture prior to the SMR is investigated to enhance H_(2)yield in the SMR and the WGS reactions.

Estimating potential harvestable biomass for bioenergy from sustainably managed private native forests in Southeast Queensland, Australia

Background： Australia＇s energy future is at the crossroads and the role of renewable sources is in focus. Biomass from sustainably managed forests provide a significant opportunity for electricity and heat generation and production of liquid fuels. Australia has extensive native forests of which a significant proportion are on private land. However, there is limited knowledge on the potential capacity of this resource to contribute to the expansion of a biomass for bioenergy industry. In addition, there are concerns on how to reconcile biomass harvesting with environmental protection. Methods： We used regional ecosystem vegetation mapping for Queensland to stratify harvestable forests within the 1.8 m hectares of private native forests present in the Southeast Queensland bioregion in 2014. We used a dataset of 52,620 individual tree measurements from 541 forest inventory plots collected over the last 10 years. Tree biomass was estimated using current biomass allometric equations for Australia. Biomass potentially available from selective sawlog harvesting and silvicultural treatment across the bioregion was calculated and mapped. Results： Current sawlog harvesting extracts 41.4% of the standing tree biomass and a biomass for bioenergy harvest would retain on average 36% of felled tree biomass on site for the protection of environmental and fauna habitat values. The estimated area extent of harvestable private native forests in the bioregion in 2013 was 888,000 ha and estimated available biomass for bioenergy in living trees was 13.6 million tonnes （t）. The spotted gum （Corymbio citriodora subsp, variegata） forests were the most extensive, covering an area of 379,823 ha and with a biomass for bioenergy yield of 14.2 t-ha-1 （with approximately 11.2 t.ha-1 of the biomass harvested from silvicultural thinning and 3 t.ha-1 recovered from sawlog harvest residual）. Conclusions： Silvicultural treatment of private native forests in the Southeast Queensland bioregion, has the capacity to supply a large quantity of biomass for bioenergy. The availability of a biomass for bioenergy market, and integration of sawlog harvesting and silvicultural treatment operations, could provide land owners with additional commercial incentive to improve the management of private native forests. This could potentially promote restoration of degraded forests, ecological sustainability and continued provision of wood products.

Life cycle environmental impact assessment of biochar-based bioenergy production and utilization in Northwestern Ontario,Canada

Biochar-based bioenergy production and sub- sequent land application of biochar can reduce greenhouse gas emissions by fixing atmospheric carbon into the soil for a long period of time. A thorough life cycle assessment of biochar-based bioenergy production and biochar land application in Northwestern Ontario is conducted using SimaPro Ver. 8.1. The results of energy consumption and potential environmental impact of biochar-based bioenergy production system are compared with those of conventional coal-based system. Results show that biocbar land application consumes 4847.61 MJ per tonne dry feedstock more energy than conventional system, but reduces the GHG emissions by 68.19 kg CO2e per tonne of dry feed- stock in its life cycle. Biochar land application improves ecosystem quality by 18 %, reduces climate change by 15 %, and resource use by 13 % but may adversely impact on human health by increasing disability adjusted life years by 1.7 % if biomass availability is low to medium. Replacing fossil fuel with woody biomass has a positiveimpact on the environment, as one tonne of dry biomass feedstock when converted to biochar reduces up to 38 kg CO2e with biochar land application despite using more energy. These results will help understand a comprehensive picture of the new interventions in forestry businesses, which are promoting biochar-based bioenergy production.

Effect of pellet die diameter on density and durability of pellets made from high moisture woody and herbaceous biomass

Densified products produced from pellet mill are commercially used as a commodity type product for energy applications that are transported nationally and internationally.The quality of the pelletized biomass produced depends on the process variables such as die diameter,length to diameter(L/D)ratio,die speed,preheating,and steam conditioning;and feedstock variables such as feedstock type,moisture content,and particle size and shape.In the present study,pelleting tests were conducted with both woody(i.e.,lodgepole pine and pinyon-juniper)and herbaceous(i.e.,corn stover,wheat straw,and energy sorghum)biomass.A high level of feedstock moisture content of 33%(w.b.)was selected,while the die speed and preheating temperature process variables were kept at 60 Hz(380 rpm)and 70
C.Results indicated that during the pelleting and cooling process,an approximate 10–13%(w.b.)moisture loss in both the woody and herbaceous biomass was observed.The high moisture pellets produced were further dried in a laboratory oven at 70
C for three hours to reduce the moisture content of the pellets to<10%(w.b).The dried pellets were then evaluated further for other quality attributes including unit,bulk,and tapped density;and durability.The pellets that resulted in the highest unit,bulk,and tapped densities following this process were the herbaceous biomass corn stover(e.g.,>1133,>580,>620 kg/m3)and the woody biomass lodgepole pine(e.g.,>1037,>568,>641 kg/m3),respectively.In the case of durability for the 8 mm diameter pellets,wheat straw and corn stover recorded a maximum of about 96%,respectively,while the lodgepole pine and pinion juniper recorded a maximum of>96%,respectively.

Woody biochar potential for abandoned mine land restoration in the U.S.:a review

There are thousands of abandoned mine land(AML)sites in the U.S.that need to be restored to reduce wind and water erosion,provide wildlife forage,shade streams,and improve productivity.Biochar created from woody biomass that would normally be burned in slash piles can be applied to soil to improve soil properties and is one method to restore AML soil productive capacity.Using this‘waste’biomass for biochar and reclamation activities will reduce wildfire risk,air pollution from burning,and particulates released from burning wood.Biochar has the potential to improve water quality,bind heavy metals,or decrease toxic chemical concentrations,while improving soil health to establish sustainable plant cover,thereby preventing soil erosion,leaching,or other unintended,negative environmental consequences.Using forest residues to create biochar also helps reduce woody biomass and improves forest health and resilience.We address concerns surrounding organic and inorganic contaminants on the biochar and how this might affect its’efficacy and provide valuable information to increase restoration activities on AMLs using biochar alone or in combination with other organic amendments.Several examples of AML biochar restoration sites initiated to evaluate short-and long-term above-and belowground ecosystem responses are presented.