46 research outputs found
Effect of stage of maturity of orchardgrass hay on yield, chemical composition, and animal performance
Three stages of maturity of orchardgrass hay which were harvested at the boot stage, 14 days after the boot stage, and 26 days after the boot stage were studied in order to determine the effect of stage of maturity on its productive and nutritive values. Due to mold contamination in the boot-stage hay of the first cutting, the boot-stage hay of the second cutting was used in the feeding and digestion trials. Total dry matter yield which was estimated at each stage of maturity by weighing the forage from a known area and determining the percent dry matter increased with advancing stage of maturity. A decrease in percent crude protein and an increase in percent of acid-detergent fiber, acid-insoluble lignin, and cell-wall constituents were found with an increase in stage of maturity. Nutritive value was determined by a feeding trial with dairy heifers and effectively demonstrated that a decrease in body weight gain and voluntary feed intake occurred with increasing maturity of hay, A digestion trial conducted with sheep showed that the hay cut at the late stage of maturity had lower digestibility coefficients for every nutrient than those of hays cut at an early and the medium stage of maturity. With advancing stage of maturity, digestible dry matter (DDM) obtained by in vivo digestion trial and dry matter disappearance (DMD) obtained by in vitro fermentation technique and nylon bag technique decreased. It also appeared that dry matter disappearance (DMD) values by in vitro technique and nylon bag technique could produce reasonable estimates of the nutritive value of these forages
An analysis of the environmental pressure exerted by the eucalyptus-based Kraft pulp industry in Thailand
The study reported here focuses on the environmental pressure exerted by large-scale eucalyptus-based kraft pulp industry in Thailand. The objective of this study was to identify the most important sources of greenhouse gases, acidifying and eutrophying compounds and tropospheric ozone precursors, human toxicity compounds and solid waste associated with the kraft pulp industry. To this end, we performed an environmental systems analysis of the kraft pulp industry system in which we distinguished between two subsystems: the eucalyptus forestry subsystem and the kraft pulp production subsystem. The results indicate that the environmental pressure is caused by the kraft pulp production subsystem rather than by the eucalyptus forestry one. The chemical recovery unit was found to be the most important source of carbon dioxide (CO2) and sulfur dioxide (SO2) and responsible for more than one-half of the emissions of greenhouse gases and acidifying compounds from eucalyptus-based kraft pulp production in Thailand. Biomass combustion in the energy gene ration unit is an important source of nitrogen oxide (NOx) and carbon monoxide (CO) which in turn are responsible for over 50% of the emissions of tropospheric ozone precursors. About 73% of the eutrophication is caused by biological aerobic wastewater treatment emitting phosphorus (P). With respect to the eucalyptus forestry, only fertilizer use in eucalyptus plantations is a relevant source of pollution through the emission of nitrous oxide (N2O) and phosphate (PO4 3-)
Estudo computacional das emissões e dispersões atmosféricas do processo Kraft de produção de celulose: avaliação da qualidade do ar
Evaluating environmental performance of concentrated latex production in Thailand
Thailand is currently the world's largest natural rubber producer. To maintain a leadership position of natural rubber producer, it has been challenging for Thai rubber entrepreneurs to seek appropriate measures towards producing environmentally friendly rubber products. The objective of this study is to assess the potential environmental impact of concentrated latex production by partial Life Cycle Assessment (LCA), and to investigate the effects of the options to reduce the impact. The methodology is based on the ISO 14040 series, taking a "Gate-to-Gate" approach (Partial LCA). The activities taken into account include production of chemicals, production of diesel and electricity, diesel combustion, and wastewater treatment. The functional unit is 1 ton of concentrated latex, and the environmental impacts considered in this study include global warming, acidification, eutrophication, human toxicity, photochemical oxidation, and the total environmental impact. The results indicate that electricity use for centrifugation has the largest share, compared with other activities, in global warming (50%), acidification (58%), and photochemical oxidation (55%). Ammonia use for latex preservation accounts for 37% of human toxicity, whereas use of DAP (Diammonium phosphate) accounts for 46% of eutrophication. Based on these results, the following reduction options are therefore identified: 1) electricity efficiency improvement (by installation of inverters to centrifugal machines); 2) improvement of ammonia preparation and storage (by chilling systems); 3) minimizing the use of DAP (by extending coagulation time); and 4) substitution of diesel by LPG. These four options were technically and practically feasible for concentrated latex production, and result in reductions of the total environmental impact by 12%, 8%, 3%, and 5%, respectively
Assessing environmental performance by combining life cycle assessment, multi-criteria analysis and environmental performance indicators
We present a new analytical tool, called COMPLIMENT, which can be used to provide detailed information on the overall environmental impact of a business. COMPLIMENT integrates parts of tools such as life cycle assessment, multi-criteria analysis and environmental performance indicators. It avoids disadvantages and combines complementary aspects of these three tools. The methodology is based on environmental performance indicators, expanding the scope of data collection towards a life cycle approach and including a weighting and aggregation step. A case study on the Thai pulp industry illustrates the usefulness of COMPLIMENT
Greenhouse Gas Emissions from Rubber Industry in Thailand
Rubber production has been taking place in Thailand for many decades. Thailand is currently the world's largest natural rubber producer. We present emissions of greenhouse gases associated with the production of fresh latex, and three primary rubber products, including concentrated latex, block rubber (STR 20), and ribbed smoked sheet (RSS) in Thailand. Besides industrial activities in the rubber mills, the agricultural activities in rubber tree plantation are taken into account. The overall emissions from the production of concentrated latex, STR 20, and RSS amount to 0.54, 0.70, and 0.64 ton CO2-eq/ton product, respectively. This is for the case that rubber plantations have been located on cultivated lands for more than 60 years, which is current practice in most of Thailand. Emissions are largely associated with energy use and the use of synthetic fertilizers. We also quantify emissions for the case that tropical forests have been converted to rubber plantations relatively recently, which is a recent trend in Thailand. In this case the emissions are much higher because of carbon loss from land conversion: 13, 13, and 21 ton CO2-eq/ton product for concentrated latex, STR 20, and RSS, respectively. We discuss the implications of our results for strategies to reduce greenhouse gas emissions from rubber productio
Future trends in environmental impact of eucalyptus-based Kraft pulp industry in Thailand: A scenario analysis
This study explores possible future trends in the environmental impact of the Kraft pulp industry in Thailand between 2000 and 2020. Scenarios were developed to analyze the effect of different options to reduce the future environmental impact, and the costs associated with the implementation of these options. The analysis indicates that without currently applied reduction options the environmental impact would be twice as high as it currently is. For a Business-as-Usual scenario, in which no additional pollution reduction options are assumed to be implemented, the overall environmental impact is calculated to increase between 2000 and 2020 by a factor of two. Next, five Environmental Policy scenarios reflecting different strategies were defined to reduce the environmental impact. The results indicate that it is theoretically possible to reduce the overall environmental impact by almost 50% relative to the BAU 2020 levels. This scenario, however, may not be feasible because of the high costs involved. Four other Environmental Policy scenarios result in a reduction of the impact by 24-37% relative to the BAU scenario. Based on these results, it can be concluded that there are different ways to reduce the overall environmental impact by about one-third relative to BAU trends. Relatively large differences in the costs of the options included in the scenarios were also observed. We conclude that combining the most cost-effective options may be the most interesting strategy for reducing the overall environmental impact of Kraft pulp industry in Thailand
Options to reduce the environmental impact by eucalyptus-based Kraft pulp industry in Thailand: model description
Kraft pulp industry contributes to several environmental problems, including global warming, acidification, eutrophication, smog, toxicity and the production of solid waste. The objective of this study is to identify options to reduce the environmental pressure caused by Kraft pulp industry in Thailand, and to describe a model that quantifies the environmental impact. The model can be used to evaluate the effects of the options on the environmental impact, and the associated costs. The model includes 14 groups of options to reduce emissions and the production of waste