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Abstract This paper characterized the wood pellet and torrefied wood pellet fuel as compared to coal for 100 MW co-firing power generation plant. There were five experiments to characterise the chemical and physical properties of coal, wood pellet and torrefied wood pellet namely moisture analysis, Thermo gravimetric Analyser (TGA), Bomb Calorimeter, Organic Elemental Analyser and Scanning Electron Microscope (SEM). The moisture analysis result from moisture analyser and TGA shows that the moisture content of torrefied wood pellet is lower than wood pellet at 6.760% and 3.629%. Moreover, the volatile matter, hydrogen and nitrogen content of torrefied wood pellet is lower than wood pellet at 65.20%, 5.993% and 0.4078% correspondingly. The calorific value, fixed carbon content, ash and sulphur also increase in torrefied wood pellet at 20.68 MJ/kg, 28.85%, 2.321% and 0.1656% respectively. In general, torrefaction improve the fuel properties of wood pellet similar to coal. The 100 MW direct co-firing power plant provides less capital investment, operation and maintenance cost for low rate co-firing ratio. However, there is economic challenges for high rate co-firing substation of torrefied wood pellets.

AbstractEnergy is the biggest crisis to humanity in the future. Nowadays, most of the energy used on earth comes from oil, gas and coal. According to the recent exploring and consuming rates, the energy will be exhausted in 50-100 years. Whether we can solve the crisis is closely related to the survival of humanity on the earth. The irradiation from the sun is the biggest energy source. Building PV power plant to utilize the energy from sun will be an only way to sustain the life cycle on the earth. However, the development of PV power plants require the huge supply of PV cell and the fabrication process may bring a quantity of pollution and waste, which is harmful to the environment. On the other hand, super large PV power plant will occupy huge land. If the land cannot be explored and used reasonably, this will not benefit the human life either. In this article, we address the discussions about the above problems and propose the initial suggestions about development trend of PV industry and the safety operation mode of super PV power plant.

AbstractElectrochemical splitting of calcium carbonate (e.g., as contained in inexpensive and abund ant minerals such as limestone) is proposed as a novel method of forming hydroxide solutions that can absorb, neutralize, and store carbon dioxide from the air or from waste streams. CaCO3 is dissolved in the presence of the highly acidic anolyte of a saline water electrolysis cell, forming Ca(OH)2 and H2CO3 (or H2O and CO2). By maintaining a pH between 6 and 9 in the resulting solution, subsequent hydroxide reactions with CO2 primarily produce dissolved calcium bicarbonate, Ca(HCO3)2. Thus, for each mole of CaCO3 split, there can be a net capture of up to 1 mole of CO2. The resulting dissolved Ca(HCO3)2 can be diluted and stored in the ocean, or in reservoirs on land or underground. Net process cost is estimated to be <$100/tonne CO2 mitigated.Other potential co-benefits of the approach include: i) production of significantly carbon-negative H2 if renewable - or nuclear - derived electricity is used as the power source, ii) the option of locally producing electricity and freshwater via fuel cell oxidation of the H2, iii) direct neutralization of ongoing ocean acidification if the Ca(OH)2 generated is added to seawater, iv) preservation or enhancement of otherwise threatened marine shellfish and coral populations, via CO2 absorption and Ca(HCO3)2 formation in or addition to the marine environment, and v) safe ut ilization of the ocean’s vast carbon storage and energy production potentials for CO2 mitigation and “super green” hydrogen generation.

Abstract Recently, the amount of Yogyakarta province municipal solid waste (MSW) came into Piyungan landfill site stood at around 470 ton/day consisting of 77% organic and 23% inorganic fractions. Annually, there was an increase as many as 8% per annum for the amount of MSW. Reduction of the MSW can be "forced" in integrated waste management site (in Indonesia is called TPST) which was built in the municipal level. In each TPST, there are two main activities which are Recycling and Composting. Both scenarios assume that 23% of inorganic waste can be recycled so that the subsequent need is to manage organic waste. Based on these considerations, calculations performed with: 1). Scenario 1: The TPST has been operated but there is no waste reduction at the source; 2). Scenario 2: TPST is operated and followed by solid waste reduction at the source. If the second scenario is applied, the amount of waste that goes to landfill Piyungan can be reduced up to 200 ton/day. Actually, scenario 1 is the realistic one because of Indonesian’s culture. Unfortunately, as scenario 1 was highly dependent on the TPST, the number of TPST which must be built increase steadily that it can reach 60 units in 2030 which is impossible to find space in Yogyakarta province. If the second scenario is applied, the amount of waste that goes to Piyungan landfill site can be reduced gradually from 25% (1-3 years), 35% (4-7 years), and 50% (8-15 years) through composting activity. The challenge possessed by scenario 2 is how to force people reduce their own organic waste by composting activity.

AbstractThe International Energy Agency Energy Technologies Perspectives (ETP) model is used for the assessment of the prospects for carbon abatement options, including carbon capture and storage, up to 2050. Three main scenarios are considered: a baseline scenario with current energy policies, an accelerated technology scenario (ACT) with an associated CO2 reduction incentive development, and a scenario in which global greenhouse gas emissions are reduced by 50% compared to current levels in 2050 (BLUE). The analysis suggests that CCS can account for up to 19% of all CO2 reduction in 2050, which would equal 10.4 Gt CO2 capture and storage. The power sector would account for 54% of all CCS, the remainder is in manufacturing industry and the fuel transformation sector.CCS is a critical option. Without CCS, the cost to meet the same target would rise by 71%. The potential rate at which CCS can be introduced exceeds the rate at which regular capital stock is typically replaced, if plants are retrofitted or closed down before the end of their technical life span. Retrofitting of coal plants with CCS plays a very significant role in the ACT Map scenario. But at the price of USD 200/t CO2 envisaged in the BLUE scenario, there is sufficient economic incentive to accelerate the replacement of inefficient power plants with new plants equipped with CCS before the existing plants reach the end of their life span. In the BLUE scenario, 350 GW of coal-fired power-plant capacity is closed down early. The remaining 700 GW consists of 80% new capacity that is equipped with CCS, and 20% retrofits with CCS.Following IEA recommendations, the G8 countries have announced that they will commit 20 demonstration plants for CCS by 2010. Also the G8, China India and Korea have asked the IEA to continue its work on roadmaps and transition paths for CCS in power generation and in industry, in cooperation with other bodies such as CSLF. This work has started and final results will be reported in 2010.

AbstractThe hydrothermal treatment (HT) has demonstrated the ability to improve fuel characteristics of biomass. On the other hand, the liquid by-product, which potentially contains solubilized nutrient, is being poorly utilized. This paper presents an investigation on HT of empty fruit bunch (EFB) on both solid and liquid product characteristics. In this work, the effects of HT on EFB were investigated at the HT temperatures of 100, 150, 180 and 220°C with the holding time of 30minutes. The results showed that HT can increase the carbon content, remove up to 55% of ash content from EFB, lowering the potassium and chlorine contents down to 0.84% and 0.18%, respectively. Moreover, maximum of 37% of nitrogen, 65% of potassium and less than 10% of phosphorus in EFB were dissolved into the liquid product which positively correlated with the HT temperature. These results demonstrate the possibility of employing HT for producing solid fuel as well as nutrient recovery from EFB.

Abstract As a representation of smart and green city development, bike-sharing system is one of the hottest topic in the fields of transportation, public health, urban planning, and so on. With the development of Mobility as a Service (MaaS), emerging technologies such as mobile data mining give some new solutions for optimizing bike-sharing system and predicting the emission reduction. Here, we propose a bike-sharing layout optimization and emission reduction potential analysis structure under the concept of MaaS. A human travel mode detection method and a geometry-based probability model are proposed to support the particle swarm optimization process. We implement a comparison study to analyze the computational efficiency. Taking Setagaya ward, Tokyo as the study case with about 3 million GPS trajectories, the result shows that with the increase of station number from 30 to 90, the adoption of bike-sharing system can reduce about 3.1-3.8 thousand tonnes of CO2 emission.

Abstract The urgent need for alternative energy, climate change mitigation and environmental protection in the world today cannot be over-emphasized. Researchers are at top gear in search of non-edible energy crops. The huge environmental benefits of renewable energy notwithstanding, new discoveries in this area arise every day. The potentials of selected tropical seed-oils for biodiesel production and utilization as fuels were therefore explored and subsequently produced. The seed-oils studied include: sand box tree, fluted pumpkin seed and wild melon seeds. Oils of these seeds were extracted, optimized, synthesized and characterized as biodiesel fuels by transesterification process using different alcohol/oil ratios of (4:1 and 6:1) and catalysts types (NaOH and KOH) at optimization temperatures of 38oC and 55oC and reaction time of 5 mins and 30 mins respectively. Optimized biodiesel produced were investigated for their chemo-physical properties in conformity with ASTM standards of biodiesel. Results showed that sandbox tree seeds, wild melon seeds and pumpkin seeds have high percentage oil content (69.32%; 70.24% and 46.88%) respectively. They also hold great potentials as feedstocks in biodiesel production. Chemo-physical properties of the biodiesel produced as well as their blends with automotive gas oil (AGO) fell within specification. Pumpkin seed oil however showed highest average percentage optimized yield of biodiesel (97%) in (1 wt of oil), NaOH catalyst, and alcohol to oil ratio of 6:1 at a reaction temperature of 55°C. Under the given conditions, different biodiesel fuels and blends were successfully produced from the selected feedstock with properties very close to that of conventional AGO. They can therefore be commercialized for large scale utilization as biodiesel fuels or as blends with existing AGO which would be more environmentally friendly.